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heart

Stem cells can cure severe heart disease? Study suggests early reports may be oversold

The experimental treatment of injecting stem cells into the hearts of patients with severe heart disease or who are recovering from heart attacks has been under investigation in clinical trials for a few years. In a study published in The Lancet in 2011 scientists grew stem cells from patients’ own hearts after the patients had suffered serious heart attacks. These were patients who had serious, irreversible heart damage. Fourteen of the 16 patients had improved heart function after four months, and the results were even better after one year. The stems cells grew into new, functioning heart cells.

Just last week, the Cochrane Collaboration published a review of 23 trials, all of them attempting stem cell therapy for heart disease. The trials looked at the use of bone marrow stem cells in patients whose hearts were failing. Unlike the 2011 study, which looked at heart attack patients, these studies looked at patients with advanced heart disease who had not suffered a heart attack. The results: overall, stem cell treatments reduced the risk of death and improved heart function, though the benefits were not as dramatic as in the patients with heart attacks.

Overall, the therapy has been promising enough that more than 100 preliminary studies have been done, and some companies are already offering the treatment for profit.

But a review of the evidence on the stem cell treatment in the British Medical Journal (BMJ) identified some large errors in a majority of the studies. And, the studies that they reviewed without errors showed the treatment had no effect. A summary of the methodological errors from Scientist magazine:

Examining 133 different reports from 49 clinical trials for the use of autologous bone marrow transplants to treat heart disease, a team of researchers in the U.K. has revealed hundreds of discrepancies in the data: numbers that don’t add up, misclassification of a trial as prospective randomized rather than retrospective/observational, patients whose sex was misreported or who were listed as both dead and alive. In addition to calling into question the validity of this well-researched therapy, some errors are raising concerns of scientific misconduct.

The original mechanism of effect proposed by researchers–that the stem cells replaced damaged cells– has also recently been disputed. New evidence point towards enhanced healing of cardiac tissue. From Alison Abbott at Nature:

Therapies that use adult stem cells typically involve collecting mesenchymal stem cells from bone marrow taken from the patient’s hip bone. The cells are then injected back into the patient, to help repair damaged tissue. Original claims that they differentiated into replacement cells have been rejected, and many clinicians now believe that the cells act by releasing molecules that cause inflammation, with an attendant growth of oxygen-delivering small blood vessels, in the damaged tissue.

The editorial staff at Nature commented that, at the very least, evidence of error and the lack of effect in the error-free studies should be cause for pause before starting hugely expensive phase III trials (currently recruiting subjects). It might be more beneficial to take a step back and fund studies to examine the basic science behind the stem cell treatments, the editorial argues. But, now that treatments are becoming commercialized, that seems unlikely to happen:

When it comes to stem-cell therapies, the stakes are high — but not as high as the hopes of people who are severely ill. Over the past few years, dozens of small, early-phase clinical trials have tested the value of adult stem cells in treating debilitating or life-threatening heart disease. Results have been mixed, but most peer-reviewed academic reports have hinted that patients may be helped. This has, understandably, encouraged clinicians to move potential therapies into large and expensive phase III trials to establish whether the treatments can fulfil their promise.

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Genetically modified pig lungs or lab-grown lungs: Which is the future of our organ supply?

Your loved one might be saved by a lung transplant grown inside a genetically engineered pig.

This is the future promised by efforts to genetically modify pigs to grow “humanized” organs. Already a close match for humans in many aspects of their biology, it should take relatively little modification to make pig organs viable substitutes for human.

The idea has been around since at least 2006, but biotech pioneer J. Craig Venter has brought it back into the headlines by making a deal between his private company Synthetic Genomics and United Therapeutics’ Lung Biotechnology with the explicit goal of making genetically engineered pig organs for human use a reality.

Despite the close similarity of pig and human organs in terms of size and functionality, the genetic differences between human host and donor animal leads the immune system to attack the donor organ as a foreign object. Hence the need to create organs which will not set of the immune system’s hair trigger.

“We’re going to start with generating a brand new super-accurate sequence of the pig genome, and then go through in detail and compare it to the human genome,” Venter told Reuters reporter Julie Steenhuysen.

“The goal is to go in and edit, and where necessary, rewrite using our synthetic genomic tools, the pig genes that seem to be associated with immune responses,” he said. “We want to get it so there is no acute or chronic rejection.”

Steenhuysen summarizes Venter’s plans:

Venter’s team is tasked with editing and rewriting the pig genome and providing the United Therapeutics group with a series of altered cells. United Therapeutics will take those cells and transplant them into pig eggs, generating embryos that develop and are born with humanized lungs.

If all goes well, Venter thinks his team will be able to deliver the cells in a few years. Testing the humanized organs in clinical trials to ensure they are safe in people will take many more years.

So this future of pig-grown organs is still far off at best. And in the meantime efforts are are moving forward to grow human organs de novo in a lab. In February of this year a team at University of Texas announced their success at growing the first human lung in a lab using stem cells.

According to David McNamee at Medical News Daily:

Taking lungs from two children who had died from trauma (most likely a car accident), the researchers stripped one of the lungs down to a bare “skeleton” of just collagen and elastin – the main proteins in connective tissue.

Using this stripped-down lung as a “scaffold,” they then harvested cells from the other lung, which were applied to the scaffolding.

This lung structure was then placed in a chamber filled with a nutritious liquid […]

After 4 weeks of immersion, the team extracted a complete human lung from the liquid.

Unfortunately, according to the McNamee “the reality of lab-engineered lungs being used in transplants could be at least 12 years away”

With both methods of creating donor organs still far from clinical use, there doesn’t seem to be much ethical buzz around either approach yet. I can’t help but expect that pig-grown organs would see push-back, not least of all because creating a supply of genetically modified pigs would raise all the same ethical concerns as raising the animals for meat in addition to pushing the “unnatural” button common in opponents of biotech.

Regardless, pig-grown organs do seem to be coming. Venter’s team isn’t the only one trying to perfect the process of genetically modifying pigs to act as organ donors. Steenhuysen reports that “researchers at the National Heart, Lung, and Blood Institute […] grafted a genetically altered pig heart into the abdomen of a baboon and kept it functioning, aided by the baboon’s natural heart, for more than a year.”

Kenrick Vezina is Gene-ius Editor for the Genetic Literacy Project and a freelance science writer, educator, and naturalist based in the Greater Boston area.

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Mass General pediatrics chief says glyphosate, used with some GM crops, no danger in breast milk

A recent online article jointly written by two anti-GMO activist groups and posted on the Moms Across America website claimed that a “study”  that it financed found traces of glyphosate, the active ingredient in the herbicide Roundup in human breast milk. Specifically, the activist authors—Zen Honeycutt of Moms Across American and Henry Rowlands of Sustainable Pulse—claimed that three of 10 breast milk samples they sent for analysis tested positive for glyphosate, a product widely used for weed control for over 30 years with a well documented safety record for humans of all ages as well as the environment. As a result of this finding the authors hypothesized that glyphosate accumulates in the body, raising concerns about the safety of glyphosate and therefore indirectly the safety of breast milk.

In the following analysis I address the safety of glyphosate and the conclusions of this particular report from my perspective as a pediatrician and nutrition scientist.

Summary about glyphosate:

  • Glyphosate controls weed growth by interfering with the metabolism of plants; it has no effect on the metabolism of humans and animals and therefore has a very strong safety profile, documented over the past 40 years and confirmed by multiple independent international agencies.
  • Human exposure to glyphosate most often occurs from the very minute amounts that remain on food that is consumed. Because it is among the safest agents used to control weed growth the US Environmental Protection Agency has set an Allowable Daily Intake (ADI) of 1750 micrograms (ug) of glyphosate for every kilogram (kg) of body weight.
  • The current daily intake of glyphosate by individuals in the US is estimated, based on food intake data and assuming all foods carry maximal allowable residues, at about 13% of the ADI (or 230 ug per kg of body weight) from residues in or on foods. This is a maximum-case estimate. Tests for glyphosate in samples of urine suggest the typical dietary intake is well below 1% of the ADI or less than 17.5 ug per kg of body weight.
  • Glyphosate that is ingested is mostly passed unchanged in the stool. About one third is absorbed into the body and is promptly removed into the urine.
  • Glyphosate does not accumulate in the body or in breast milk based on its chemical properties.
  • No harm has been associated with the typical amount of glyphosate that passes into the body and then out in the urine.
  • In the recent report from Moms Across America, the levels of glyphosate detected in 3 of 10 samples of breast milk, if accurate (they still must be confirmed by using an assay validated for breast milk), suggest that a breastfeeding infant might be exposed to about 1/50th of the Allowable Daily Intake and do not support any risk, either to the mother or infant.

Conclusion: Mothers should be encouraged to breastfeed their infants. Even if the results of the recent report are backed up by future research, there is no significant risk to infant health, and the benefits of breastfeeding far outweigh any theoretical risks.

Background:

Is glyphosate toxic to humans?

Glyphosate acts on a specific pathway in the metabolism plants. This pathway does not occur in animals (including humans), and thus glyphosate itself has very limited toxicity for humans or animals. While there are many allegations about glyphosate safety to be found on the Internet, including allegations about cancer, endocrine disruption, and birth defects, these allegations largely emerge from misinterpretation of limited scientific studies, often times performed under test conditions that have no relevance to human exposure.

Glyphosate now has a 30+ year history of safe use and has been the subject of repeated independent regulatory assessments. It should be reassuring that glyphosate is now undergoing re-evaluation in the European Union and that the German Agency for Risk Assessment (Bundesinstitut fur Risikobewertung, or BfR) has now issued its draft assessment of glyphosate safety following a thorough review of publications, which include many of these allegations. BfR concludes, “the available data do not show carcinogenic or mutagenic properties of glyphosate nor that glyphosate is toxic to fertility, reproduction or embryonal/fetal development in laboratory animals.” References regarding glyphosate safety are provided at the end of this discussion.

What does it mean when a chemical is found in body fluids?

The US Centers for Disease Control and Prevention monitors a variety of chemicals in the blood and urine of Americans (it does not currently measure breast milk). Whether natural or synthetic, every chemical can be toxic at a sufficiently high dose. As the CDC states: “The measurement of an environmental chemical in a person’s blood or urine is an indication of exposure; it does not by itself mean that the chemical causes disease or an adverse effect. Research studies, separate from these data, are required to determine which blood or urine levels are safe and which are associated with disease or an adverse effect.”

There is an extensive body of knowledge about glyphosate that helps us to understand the meaning of recent reports of glyphosate in breast milk. Here are background reports from the CDC, the National Institutes of Health, the World Health Organization and the American Academy of Pediatrics.

 

How are safe levels of intake for glyphosate determined?

The US EPA looks at all available long-term animal studies for herbicides (and other pesticides) to determine an Allowable Daily Intake (ADI). In the case of glyphosate, because there are multiple manufacturers, there are now six independent sets of animal studies. The agency takes the highest dose tested in the various animal species, which produces no effect (the highest tested non-toxic dose) and uses this to set an ADI by applying a 100 fold safety factor. This means that the allowable daily intake is set at 100 times less than a dose which produces no effect, in the most sensitive animal species tested. The US ADI is 1750 micrograms (ug) of glyphosate for every kilogram (kg = 2.2 pounds) of body weight.

Do these intake limits apply to infants and children?

Yes. The limit is intended to apply to males and females at all ages. The large body of data on this issue includes reproductive and multi-generational studies in animals.

How close to the ADI limit is the typical US intake of glyphosate?

If we assume that all of the foods we consume contains the maximum allowable amount of glyphosate for that particular crop or food, and calculate a maximum estimate of glyphosate intake, the highest level of intake (adjusted for weight) occurs in young children (children eat a lot per pound of body weight to support growth and energy needs). The current maximum intake of glyphosate by individuals in the US is estimated to be about 13% of the ADI, about seven-and-a-half times less than the ADI. This is an over-estimate of exposure. More refined estimates can be developed based on actual residue levels, but this is not usually performed when conservative estimates provide good assurance that excessive intake is not occurring.

Another approach to determining glyphosate intake takes advantage of the fact that glyphosate is not broken down or metabolized in the body. Absorbed glyphosate is promptly eliminated in the urine and thus the absorbed glyphosate dose can be measured directly by looking at glyphosate in urine. Based on animal data, about 1/3 of ingested glyphosate is absorbed (the rest comes out in the stool). Therefore a 15 kg (35 lb) toddler taking in 13% of the ADI would have a urine value of 1000 micrograms per liter or greater (this calculation assumes 1 liter of urine per day, about 3 times the minimal urine output expected). Urine levels of glyphosate have been measured in several studies, including studies supported by industry (Farm Family Exposure Study) and studies by non-governmental independent organizations. Many individuals have no detectable glyphosate in urine at a detection limit of 1 microgram per liter, and if found, levels in non-farmers are typically in the 1-3 microgram per liter range.

 

The available data from Moms Across America indicates the highest level in the urine from the mothers that were tested as 7.5 micrograms per liter (as of April 17, 2014)- so it seems that these individuals have urine values in the range of 1 (or less) to 10 micrograms per liter. This is 100 to 1000 times LESS than you would expect based on current intake estimates. While the estimates of urine value at 13% of ADI are only approximate, these urine data suggest that intakes of glyphosate are far below the ADI.

How can glyphosate get into blood, urine, and breast milk?

For most people on any given day, glyphosate exposure is primarily in the form of food residues following use to control weeds on or around crops. Although we wash fruits and vegetables before cooking or eating them, a small amount of glyphosate may remain as a residue in foods, including seeds and grains (wheat, soybean). The residual glyphosate can be absorbed from the diet, circulate briefly in the blood, and is rapidly eliminated by the kidney like many other waste products- natural or otherwise, without causing any known ill effects. Glyphosate readily dissolves in water (and not in fat) and is a small molecule, so it can enter into breast milk and other body fluids.

Individuals using glyphosate products during planting or farming, or using consumer glyphosate products on the lawn or in the garden can also get exposed during the application process and may have additional exposure to glyphosate via skin or incidental ingestion (touching the face and mouth while using the product). The levels in the blood and urine of these individuals may be higher than seen in the general population with exclusively dietary intake. But, urine samples from adult and teen farmers involved in glyphosate application, (Farm Family Study) indicate that even these users have exposures within the Allowable Daily Intake.

Does glyphosate bio-accumulate in humans?

No. The Moms Across America website suggests that their data support bioaccumulation of glyphosate. Bioaccumulation is a phenomenon in which chemicals that dissolve in fat build up in the body over an extended period of time.

We know from extensive studies that glyphosate is water soluble, not fat soluble, does not accumulate and is not stored in body fat, and is readily excreted in urine. The Moms Across America data indicate the presence of glyphosate in urine samples and in some breast milk samples, but do not demonstrate that glyphosate accumulates in the body over time.

Is glyphosate concentrated in breast milk?

This issue has not been studied in detail for glyphosate in human milk. We do know that glyphosate does not concentrate in cow’s milk and that glyphosate does not have the characteristics of substances that accumulate in milk. Materials that concentrate in breast milk (have higher milk concentrations than blood concentrations) are generally fat soluble and accumulate in milk-fat within breast milk.

The Moms Across America data may have demonstrated glyphosate in breast milk (see discussion below), but very importantly there was no comparison of breast milk and blood concentrations of glyphosate in the same individual. Thus, no statement can be made from these data about glyphosate concentrating or accumulating in breast milk.

What else is in breast milk?

There are many natural and synthetic chemicals present in body fluids (blood, urine), and a number of these are measured and followed over time by the US Centers for Disease Control.1 The CDC has not routinely studied breast milk, but there is no fundamental barrier between blood and breast milk and most of the chemicals found in body fluids will exist in breast milk at some concentration as well. The most focus for breastfeeding moms, for obvious reasons, has been on those chemicals which are persistent, fat soluble and thus tend to concentrate in breast milk or body fat relative to other body tissues and fluids. These substances remain in the body, gradually declining over time if there is no further exposure.2

Are the reported levels in urine and breast milk correct?

The Moms Across America data report breast milk levels using an assay designed for water. However, no data standardizing this assay for breast milk have been published. In the assay used to generate the MAA data, milk is diluted down by 100-fold and measured using the assumption that it is essentially water. Urine levels are obtained using a 10-fold dilution and using the water assay. The accuracy of the test in breast milk remains unclear and, because of the dilution, levels of glyphosate below 75 ug/L cannot be detected by this assay method.

Given what we know about usual urine levels in individuals in the US, which are between 1 and 10 ug/L if detected at all, the reported breast milk values do not make sense. Glyphosate is eliminated in urine and, like most wastes, is concentrated in the urine. Blood levels and breast milk levels should therefore be less than urine levels on average. As discussed above, glyphosate should not concentrate in breast milk. This means that typical breast milk levels should be close to blood levels and less than urine levels- but this is not what Moms Across America found- three of ten samples had levels above the detection limit of 75 ug/L, with the highest value of 165 ug/l and all three levels were above those levels reported in the mothers’ urine samples.

Something seems to be wrong with the data. There are two possibilities. This assay has not been used for breast milk in the past and therefore the analytical method may be in error, either because it is not properly calibrated or because of some interfering factors, as there are many things present in breast milk (chemicals, vitamins, medications, etc.). Another possibility is that the breast milk samples with detectable glyphosate (over 75 ug/L) reflect exposures much larger than the typical exposure to glyphosate in the general population. Without any knowledge of how the samples were obtained and under what circumstances, we cannot speculate on the analytical accuracy. However, the mere fact that the breast milk levels seem highly irregular in comparison to existing urine data should have prompted the laboratory to confirm analytical results using a better, validated method.

Are breast milk levels of glyphosate “high”?

The Moms Across America information suggests that glyphosate levels are “high—but it defines “high” as anything above the limit of detection. Stated another way: anything they can measure is “high”. This is faulty reasoning of course; the limit of detection is determined by how samples are processed and what type of analysis is performed and is determined by laboratory procedures, not by safety considerations. Twenty years ago, we would not have been able to detect glyphosate levels in anyone, but laboratory methods have improved tremendously. Continued improvements will result in assays that are capable of detecting even lower levels of glyphosate.

The proper question is whether breast milk levels result in glyphosate intake above the ADI in the nursing infant. Even the highest value reported by Moms Across America results in infant exposure well below the ADI and also does not suggest that the mother is above the ADI.

The Moms Across America document also compares breast milk levels to the European drinking water standard “for glyphosate”—put in quotes because there is no standard for glyphosate in particular. Rather, the EU set a non-risk-based limit of 0.1 ug/L for all herbicides (and pesticides) in drinking water. Again, this level is independent of any risk assessment concerns and therefore this level is not useful in assessing whether intakes are safe or unsafe.

The World Health Organization (2005) concluded that because of low toxicity, a health based drinking water limit for glyphosate is not warranted and that the presence of glyphosate in drinking-water under usual conditions does not represent a hazard to human health.3

How do the reported levels compare to levels expected at safe levels of intake?

A mother consuming glyphosate in the diet at 100% of the ADI (assuming 50 kg weight and 1/3 of glyphosate absorbed) should be excreting almost 30 milligrams- or 30,000 micrograms of glyphosate in urine per day—about 15,000 ug/L, assuming normal urine output. As noted, most people have no detectable glyphosate in urine. For those with detectable levels in the range of 1-10 ug/L, this is 1500 to 15,000 times LESS than expected from intake at the ADI. Urinary levels suggest maternal intakes well within acceptable limits.

If one assumes that the breast milk values are correct, even the highest value (165 ug/L) would not raise concerns regarding maternal exposure given that breast milk concentrations should be similar to blood concentrations. Even if urine levels are 10-times more concentrated than breast milk or blood, maternal intake is still estimated to be well below the ADI.

What does this mean for the health of an infant?

The highest reported concentration of glyphosate in the 3 breast milk samples (165 ug/L) does not appear to be representative of what may actually be found in breast milk and may be incorrect for analytical reasons. However, even if taken at face value, this would still result in infant intakes well below the ADI. (A 5 Kg or 11-pound infant will take in roughly one liter per day of breast milk, or 165 ug per day. This would be 33 ug per kilogram of body weight per day versus an ADI of 1750 ug per kilogram per day. The intake of glyphosate, even at the highest reported breast milk level, is well below levels that would raise health concerns.

Should mothers stop breastfeeding?

No- based on the low level of exposure relative to the ADI, there is no significant risk to infant health as a result of glyphosate in breast milk. The American Academy of Pediatrics4 and the Centers for Disease Control5 agree that breastfeeding is the optimal way of feeding infants and that the benefits of breastfeeding clearly outweigh the risks of environmental chemicals found to date in breast milk, except in highly unusual exposure circumstances.

What can mothers do to minimize exposure? / Should they alter their diet or other practices?

There does not appear to be any need to reduce dietary exposure to glyphosate based on existing data. If you wish to reduce residue intake for glyphosate and other pesticides, choosing to eat an organic diet may help to reduce glyphosate intake and reduce breast milk levels. The health benefits/risk reduction resulting from this would appear to be minimal.

For users of the product containing glyphosate, follow all label directions. While all users in the Farm Family Exposure Study had acceptable levels of exposure, the use of rubber gloves is an effective means to limit exposure to the product (glyphosate is not volatile, so most applicator exposure comes from skin and incidental hand-to mouth contact).

If mothers are breastfeeding, should they have their breast milk tested for glyphosate?

Pending validation of the breast milk assay, and given that current reported levels do not raise a health concern, there is no need to test breast milk.

Should children be tested for glyphosate?

By all exposure estimates, children are well below the ADI for glyphosate intake. Actual urine values are limited- but in the farm family exposure study, urine glyphosate was undetectable in farm children (exception- teenagers who assisted in application), i.e. below 1 ug/L. Urine testing of children for glyphosate would seem highly unlikely to document any exposure of possible concern and thus is not recommended.

Reviews on the safety of glyphosate:

  1. BfR press release (current re-assessment): http://www.bfr.bund.de/en/the_bfr_has_finalised_its_draft_report_for_the_re_evaluation_of_glyphosate-188632.html
  2. Most recently completed review by the European Commission (Compounds are reviewed every 10 years and a review is in progress now.)

http://ec.europa.eu/food/plant/protection/evaluation/existactive/list1_glyphosate_en.pdf.

  1. Safety Evaluation and Risk Assessment of the Herbicide Roundup and Its Active Ingredient, Glyphosate, for Humans” (Williams et al., 2000): http://dx.doi.org/10.1006/rtph.1999.1371
  2.  Epidemiologic studies of glyphosate and cancer: A review. http://www.sciencedirect.com/science/article/pii/S0273230012000943
  3. Epidemiologic Studies of Glyphosate and Non-Cancer Health Outcomes: A Review. http://www.sciencedirect.com/science/article/pii/S0273230011001516
  4. Developmental and Reproductive Outcomes in Humans and Animals after Glyphosate Exposure: A Critical Analysis. http://www.tandfonline.com/doi/abs/10.1080/10937404.2012.632361

 

Dr. Ron Kleinman is the physician in chief, MassGeneral Hospital for Children, Chair of the Department of Pediatrics at the Massachusetts General Hospital and the Charles Wilder Professor Pediatrics at Harvard Medical School.

Black Swan author’s paper on precautionary GM food risks indulges in “fear mongering”

Recently, a paper on the precautionary principle in relation to genetically modified foods has been making rounds in the anti-GMO social media circles. One of the authors is statistician Nassim Nicholas Taleb, who has previously written books such as The Black Swan on the impact of low-probability events. The other two authors are physicist Yaneer Bar-Yam, and politician-philosopher Rupert Read. They attempt to develop an improved version of the precautionary principle in an effort to undermine the usage of GM crops.

What can a thinly veiled anti-GM paper written by a physicist, a politician and a statistician teach us about the risks of genetically modified foods? Unfortunately, it is just more of the same illusionary sophistry common among anti-GM activists.

Predictably, the authors quickly descent into anti-Monsanto fearmongering, apparently oblivious to the fact that counterparts exists in the traditional plant breeding industry. The authors claim that they do not want to pay for the “errors by executives of Monsanto”. What about the errors caused by the executives of multi-national corporations that deal in seeds from traditional plant breeding?

GM technology causes smaller, more precise and more well-known changes than traditional plant breeding, and they are much more stringently regulated. Thus, GM crops are safer than conventionally bred crops. If you accept conventional crops, then you must also accept GM crops.

Read the full, original article: Choking the Black Swan: GM Crops and Flawed Safety Concerns

Monsanto using biotech methods to speed up traditional breeding

Say the term “genetically modified organism,” or GMO, and you’re bound to get some strong opinions. But what is it? And should we be afraid?

Like it or not, humans have been in the business of genetically changing organisms since we first started domesticating them around 12,000 BC. Simply put, favorable traits were identified in one generation of plants or animals—higher fertility, bigger size, faster maturity—and those individuals were selectively bred to produce the next generation.

Today, we don’t have to breed for desired traits over many generations, we can directly insert genes to change genomes in only one generation. The Monsanto corporation has long been at the forefront of genetic engineering when it comes to the plants we eat. They’ve been both praised and bashed for this.

I wasn’t quite sure what to expect when I headed to the Monsanto laboratories. As an ecologist, I’ve been concerned about the ecological impacts of genetically engineered organisms, much of which we don’t know. I was surprised about what I found. Monsanto is using its biotech muscle to not only genetically engineer crops, but also to beef up its traditional cross-breeding activities.

So what to make of this? Maybe this modernized cross-breeding technique will be more palatable for many people who are concerned about the health impacts of genetically engineered foods. As for me, I’ll be sure to keep a close eye on Monsanto’s turbo-charged cross breeding efforts. They may very well be part of the solution for feeding an ever-expanding global population.

Read the full, original article: Inside Monsanto

No right to deprive someone of safety tested, life-saving, vitamin-enhanced Golden Rice

The blind girl lurched toward me across the parking lot at Tirta Empul temple, mewling. A whitish haze coated her eyes, each looking upward in a different direction. She moved herky-jerky due to poorly formed bones. I did not speak Indonesian; she did not speak English, yet there was no doubt what she wanted. Money.

I gave her what I had in my pocket: a 5000 Rupiah note, about 42 cents. She would buy rice with the little money I gave her. The food would fill her belly, but not her body’s needs.

Her condition is common for the poorest children in Asia; it is caused by a lack of Retinol (vitamin A). Chronic Vitamin A deficiency (VAD) causes irreversible blindness and poorly formed bones. Half of the afflicted will die within one year.

If only there were a way that the rice could help prevent vitamin A deficiency. There is: Golden Rice, a genetically modified food. You may not like the idea of genetically modified food, but you probably do not have to watch your child die due to a lack of vitamins. Neither you nor I have the right to deprive someone of food that can literally save his or her life.

Read the full, original article: Golden Rice, Golden Opportunity

Ancient, inert parts of our genomes may be protective

At hundreds of spots in our DNA, there are ancient swaths that have remained puzzlingly unchanged over hundreds of millions of years of evolution. No one knows exactly what to make of these regions of DNA, called ultraconserved elements — they don’t appear to serve essential functions, so why are they preserved?

“They are considered one of the most mysterious aspects of the genome,” Ting Wu, a Harvard Medical School geneticist, said at a talk at a genomics conference Wednesday in Cambridge.

But Wu has a provocative idea about these ultraconserved elements: Perhaps they are a natural defense system against harmful changes to our DNA. And perhaps there could be a way to harness this mechanism as a therapy, triggering it to cull cells that carry harmful genome rearrangements, before there is enough of a problem that a disease is even diagnosed.

Read the full, original story: Ancient swaths of DNA are a genomic puzzle that could lead to new therapies

Genetics make some people more vulnerable to repetitive brain injury

Scientists studying head injuries have found something surprising: Genes may make some people more susceptible to concussion and trauma than others. A person’s genetic makeup, in fact, may play a more important role in the extent of injury than the number of blows a person sustains.

While this research is still in its infancy, these scientists are working toward developing a blood test that may one day help a person decide — based on his her or her genetic predisposition — whether to try out for the football team, or perhaps take up swimming or chess instead.

“Until now, all the attention has been paid to how hard and how often you get hit,” said Thomas McAllister, a professor of clinical psychiatry at the Indiana University School of Medicine. “No doubt that’s important. But it’s also becoming clear that’s it’s probably an interaction between the injury and the genetics of the person being injured.”

Read the full, original story: Finding a link between genes and brain injury: Are some people predisposed to trauma?

Genes of benefit for athletic training response identified

There has long been a debate among doctors, scientists and psy­chologists about whether nature or nurture is more important in our development as humans. But when it comes to sports and fitness, do genes count more than constant practice?

Malcolm Gladwell made famous the dictum that to achieve expert status at anything, from playing a violin to kicking a football, you need at least 10,000 hours of practice. But it turns out there are genetic markers that can help determine what kind of sports you would be good at.

“The theme that’s coming out of exercise genetics is that they are finding trainability genes,” says David Epstein, a former athlete and author of The Sports Gene . Genes have an effect on anyone’s level of improvement from training, he says. “For muscle growth and endurance, some of those genes have been located.”

Read the full, original story: Our genes are an integral part of a training regime

eBook Lowdown on GMOs: What it’s like not to know anything about GMOs

This article is adapted from the chapter “On What It’s Like Not To Know Squat about GMOs” from the ebook “The Lowdown on GMOs: According to Science,” compiled by Fourat Janabi for smashwords.com:

Recently, a “ground-breaking” study by Gilles-Éric Séralini used by anti-GMO activists as “convincing evidence” of harm caused by genetically-engineered corn, was deep-sixed by the very journal that published it, Food and Chemical Toxicology.

I raised a glass of home-brewed hard cider and said “Salut!” to self-correcting science.

Changing my mind about GMOs has been easy. All it took was learning that the Humulin my Type-1 diabetic spouse takes every day to keep himself alive is a GMO.

When most people think of GMOs, they think of food. A freshman seminar I once taught at University of Southern Maine concerns how we laypeople should view claims about food we see in the media. I introduce the subject of genetically modified organisms by typing “GMO images” into a search engine. The results are hilarious.

I ask the students which images they see most represented on the screen. Immediately they say, “Hypodermic needles.”

There they are, sticking out of tomatoes like porcupine quills. I ask them how the hypodermic needle is employed in the creation of genetically modified organisms. Silence.

“It isn’t,” I tell them.

The Séralini fiasco tells us that when someone performs a bad “study,” smart people will sometimes be bamboozled by it – including the good folks at the journal Food and Chemical Toxicology.

And if they could be fooled, what about the rest of us?

I hope my students go out into the world with the awareness that we humans are built to believe, not to disbelieve; that it’s our life’s work to decide which beliefs to accept, which to discard; and that it won’t be easy.

Bad beliefs are like fishhooks: easy to swallow, difficult to cough up. It can be done, though.

Read the full, original article: Mike Bendzela is skeptical about the GMO skeptics

Sperm from skin cells have potential for male infertility treatment

Around 7.5 percent of men in the U.S. visit a fertility doctor at some point in their life, according to the CDC. Around 18 percent of those men go on to be diagnosed with infertility. As the Guardian reports, across the world, around one percent of men cannot produce any sperm at all. Researchers are hoping to give those men a chance at fathering their own children, however, with a new method that manufactures sperm cells from skin cells.

Although scientists haven’t proved the method is totally viable, the results of a recent study look promising. As the Guardian describes, researchers recruited three infertile men and collected skin cell samples from them. They manipulated those skin cells to become stem cells—generic cells that can grow into any other type of specialized cell in the body. Then, they inserted those human stem cells into the testes of live mice. There, the stem cells formed into immature sperm cells.

Read the full, original story: Scientists Transformed Men’s Skin Cells Into Immature Sperm Cells

Los Angeles Times editorial: California GMO labeling bill promotes “scare campaign”

The scientific evidence on genetically engineered food, which has been around for two decades, indicates that it is as safe for human consumption as any other food. A California bill that would require the labeling of bioengineered food — whose DNA has been modified in the laboratory to introduce certain traits — caters to a scare campaign that is not based on solid evidence.

State Sen. Noreen Evans (D-Santa Rosa) has said that her bill doesn’t make judgments about whether genetically engineered food is inherently good or bad but merely informs consumers. Yet the wording says otherwise. It’s full of negative declarations about such food, with no mention of the positives.

There are more worrisome agricultural practices that do affect human health, especially the overuse of antibiotics in livestock. “There is strong evidence that some antibiotic resistance in bacteria is caused by antibiotic use in food animals,” the U.S. Centers for Disease Control and Prevention reports. Yet no one has been campaigning for labels on meat that comes from antibiotic-treated livestock. As with bioengineered food, this is best dealt with by appropriate safety regulations, not labels.

Read the full, original article: Base food labeling on fact, not fear

Milestone reached: 4 billionth acre of biotech crops planted globally

It’s no small number – four billion acres of biotech crops have now been planted globally.  The impressive mark was met and passed Saturday, May 3, 2014, according to the Biotech Counter at Truth About Trade & Technology’s website.

The Biotech Counters, found in the upper right area of the website, track the number of biotech acres planted around the world, and the number of biotech acres harvested around the world (the harvested number is also approaching four billion acres).

Whoever the farmer was and where exactly he or she was at when that number was hit will never be known.  But what is known is biotech crops have been rapidly adopted and grown by farmers around the world, and safely consumed by billions of consumers over and over again.

Read the full, original article: Major Milestone: 4 billion acres of biotech crops now planted globally

New virus emerges, genetically related to small pox

Two herdsmen in the country of Georgia have been infected with a brand-new virus, scientists from the Centers for Disease Control and Prevention said.

The newly identified virus is a second cousin to smallpox. And, like smallpox, it causes painful blisters on the hands and arms‎. Other symptoms include a fever, swollen lymph nodes and overall weakness, CDC scientists at a meeting in Atlanta.

“We consider this family of viruses very important because smallpox could be used as a bioterrorism agent,” says disease detective Neil Vora, who led the team that made the discovery.

The virus doesn’t yet have a name, Vora says, because so little is known about it.

Read the full, original story: New Virus Related To Smallpox Is Found In Republic Of Georgia

Insects pass infections to their progency through sperm and eggs

The green rice leafhopper is never alone. When a female’s egg and a male’s sperm fuse into a new cell, that cell is already infected with bacteria. As the newly conceived leafhopper grows from one cell into millions, its internal bacteria—its endosymbionts—go along for the ride. Right from the start, the leafhopper isn’t an individual in its own right, but a collection of animal and microbes that live together.

Many insects and other animals inherit endosymbionts from their parents, but almost all of them do so from their mothers. There’s good reason for this. An egg cell is big. [A sperm’s] streamlined shape is good for swimming, but it’s terrible for packaging bacterial heirlooms. That’s why males almost never pass on endosymbionts to their kids, while females often do. Sperm just isn’t very good packing material.

But try telling that to the green rice leafhopper. This small green bug is a serious pests of rice plants in East Asia, and its cells are filled with at least three species of bacteria. And one of them—Rickettsia—can infect the insect’s sperm.

Read the full, original story: Bug Inherits Microbes From Dad’s Sperm

horseweeds

Union of Concerned Scientists blames GMOs for ‘superweeds’ but issue more complex

One of the biggest challenges facing farmers today are so-called “superweeds” — the popular term for weeds that have developed resistance to herbicides and are difficult to control. They were first observed decades ago as weeds adapted to survive the chemical herbicides that farmers used to boost yields.

More recently, anti-GMO activists have tried to blame the problem specifically on glyphosate, the active ingredient in Monsanto’s Roundup herbicide, which is used in conjunction with many herbicide resistant GMOs. Here is a recent post by GMO Inside, a group that supports labeling and a “right to know” but is also campaigning to get GMOs banned:

The strategy of combating weeds by engineering crops that can withstand herbicides and then blasting fields with those chemicals is no match for evolutionary adaptation, as demonstrated by the rapid growth of superweeds across the country. … There is no question that GE technology will continue to drive up the costs of food production, increase the use of harmful chemicals and undermine efforts for a sustainable food system.

This cause has been adopted by the Union of Concerned Scientists, which blames Monsanto and glyphosate for perpetuating what mainstream agricultural experts calls the Green Revolution, which has increased yields multi-fold in 60 years saving hundreds of millions of lives, but which the advocacy group derisively calls “industrial agriculture“–chemically intensive food production developed in the decades after World War II, featuring enormous single-crop farms and animal production facilities.

Last week, the UCS released a video that presents its view as to how Monsanto “supersized” farmers’ weeds problem with its Roundup Ready system. The UCS produced the video to promote a policy brief by Doug Gurian-Sherman and Margaret Mellon, UCS senior scientists in the Food and Agriculture program, and established GMO skeptics. It first paints weeds as “super villains,” stealing water, light and nutrients from crops, and Monsanto’s Roundup seeds and herbicide as “superheroes” fighting off weeds, but then the story turns darker:

The video is uncompromising in its critique of Monsanto and what it believes is the agribusiness takeover over global farming:

Roundup Ready seemed like a superhero. But this superhero had a fatal weakness: resistance. Some weeds have genes that protect them from Roundup’s effects, and the more Roundup farmers used, the quicker the resistance genes spread over time. Encouraged by Monsanto’s marketing campaigns, farmers used so much Roundup that resistance soon accelerated into a superweed crisis. Millions of US farm acres are now infested with superweeds. Instead of solving the farmers’ problems, Monsanto has supersized it.

“It sounds like a bad sci-fi movie or something out of The Twilight Zone. But ‘superweeds’ are real and they’re infesting America’s croplands,” said Gurian-Sherman in the press release that accompanied the release of the video. “Overuse of Monsanto’s ‘Roundup Ready’ seeds and herbicides in our industrial farming system is largely to blame. And if we’re not careful, the industry’s proposed ‘solutions’ could make this epidemic much worse.”

The UCS casts agricultural biotechnology and industrial farming as the culprit for creating the superweed problem. The core of industrial farming, they claim, is monoculture farming, the practice of growing only one crop intensively on a very large scale every year. In the United States, corn, soy, cotton and wheat are often grown this way, although that system has begun to change in recent years in part because of the development of hardier weeds.

Pests like weeds and insects affect crops selectively, so when farmers grow different crops each year, a practice called crop rotation, they disrupt the pests’ sources of food and nutrients, and prevent them from adapting.

In monoculture, the pests are only controlled by chemical means, and since the same crops are planted year after year, the pests are able to quickly adapt and evolve to survive. Herbicide-resistant weeds have become a major challenge, appearing in an estimated 60 million acres of farmland. The map below illustrates the area affected by glyphosate-resistant weeds in the United States:

Image via Farmland Network

Are Roundup Ready crops to blame for “superweeds”, as UCS and anti-GMO activists contend? Herbicide resistance in weeds developed long before the adoption of herbicide-resistant GM crops. Andrew Kniss, professor of weed biology and ecology at the University of Wyoming observed that the first glyphosate-resistant weeds “evolved in Australia, where no GM crops were grown” back in 1996. GM crops played no role in their development.

Weed resistance developed because of the way glyphosate was used in tandem with monoculture farming by some farmers looking for shortcuts. “Glyphosate-resistant weeds evolved due to glyphosate use, not directly due to GM crops,” wrote Kniss. Some farmers found it easier to simply plant the same crops and control weeds with a single herbicide, glyphosate, year after year.

The UCS has criticized Monsanto for what the advocacy group says is the company’s aggressive marketing campaigns that encourages farmers to become over-reliant on Roundup and neglect other weed-controlling techniques. Food writer Nathanael Johnson came to a similar conclusion in his series on GMOs for Grist:

Spraying glyphosate in conjunction with GM herbicide-tolerant crops was so easy and effective that agronomists started referring to it as “agricultural heroin.” It worked so much better than anything else that farmers became addicted.

To address what they believe is the real issues behind superweeds, Gurian-Sherman and Mellon’s policy brief hones in on three factors:

Monoculture. Growing the same crop on the same land year after year helps weeds to flourish.

Over reliance on a single herbicide. When farmers use Roundup exclusively, resistance develops more quickly.

Neglect of other weed control measures. The convenience of the Roundup Ready system encouraged farmers to abandon a range of practices that had been part of their weed control strategy.

Gurian-Sherman and Mellon recommend a shift away from herbicides and GM crops towards practices like crop rotation, which in fact is now more widely used by conventional farmers, and cover crops. They reject the new generation of herbicide-resistant crops awaiting approval from the USDA and EPA, contending that more herbicide-resistant weeds will eventually appear and some might even become resistant to multiple herbicides.

“Fighting fire with fire will only result in a conflagration – farmers deserve solutions that will not fail in a few years, and land them in an even deeper hole,” said Gurian-Sherman. “Instead of favoring the same industrial methods and genetically engineered products that got farmers into this mess, public policies should promote healthy farming practices that can produce long-term benefits for American farmers, consumers, and the natural resources we all depend upon.”

As an alternative to “industrial agriculture”, Gurian-Sherman and Mellon advocate for “agroecological” practices that look a lot like organic agriculture, using only “crop rotation, cover crops, judicious tillage, the use of manure and compost instead of synthetic fertilizers, and taking advantage of the weed-suppressing chemicals that some crops produce,” according to the policy brief.

Adding practices like crop rotation to address the problems of monoculture is not new; more and more conventional farmers are adopting a combination of ecological techniques called integrated pest management (IPM) to prevent superweeds and other excesses linked to conventional methods. But most ecologists and farming experts contend that removing chemical weed-control options from farmers, including limiting biotechnology, and returning to organic agriculture is too simplistic; multiple tools are needed to control weeds effectively without burdening farmers. Anthony Shelton, Cornell University professor with the department of entomology, wrote:

Even more than organic production, IPM strives to use the best scientific practices to ensure safe and sustainable agricultural systems. To do this, IPM incorporates practices from conventional and organic production methods, and even biotechnology, a method that has been turned into a bogeyman, but in reality is safer for humans and the environment. IPM has been a national policy for the United States since 1993 and its implementation has resulted in dramatic decreases in the use of harmful pesticides.

Additional Resources:

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Procrastination? Impulsivity? Either way, is it in your genes?

OK, I’ve got to stop putting off writing this piece about the genetics of procrastination.  I’ll just check my mail first. Oh, here’s an update on the genetics of autism. This huge Swedish study, which was just published in the Journal of the American Medical Association (so it must be true), is showing that the heritability of autism is 50 percent.

Now that’s interesting, because the procrastination study that I’m supposed to be writing about, a big twin study from the University of Colorado published in Psychological Science last month, showed that the heritability of procrastination was 46 percent.

And that rings a bell because of something I just read by psychologist Timothy A. Pychyl, of the Procrastination Research Group at Carleton University in Ottawa. Blogging about the procrastination paper at Psychology Today, Pychyl points out that study after study of personality traits show that each of them is . . . about 50 percent heritable.

On heritability

I don’t know that anybody understands why behavioral genetics research consistently shows that wildly disparate aspects of personality so often have a heritability of about 50 percent–although I’ll bet there’s a message there waiting to be figured out.

But I do know that “heritability” doesn’t mean what you might assume it means: that half of autism or procrastination or other personality traits are caused by genes.

Heritability is a technical term, a mathematical formula that does not apply to individuals. It applies only to populations—and only to populations that vary. It’s a measure of how much of the population variance of a trait is genetic.

Hair color is a fine example, frequently cited. In China, hair color varies hardly at all. Thus the heritability of hair color there is low—even though natural hair color in China, as elsewhere, is due entirely to genes. In the U.S., the heritability of hair color is high not because it’s somehow more genetic here, but because there’s an enormous variety of natural hair color in our heterogeneous population—and nearly all of it is genetic. (We’re talking natural hair color here, so I’m saying “nearly all” only to leave room for the lightening effects of the sun. This excludes henna, platinum blondes, toupees, blue streaks, and the many other calculated commercial transmogrifications of hair color.)

The problem with the term “heritability” is that it often leaves people, even some knowledgeable people, with completely wrong impressions. Heritability, remember, has nothing to do with individuals. It does not mean that 46 percent of my procrastination is because of my genes and the rest is a product of environmental factors. Also, to say that a trait is 46 percent heritable (or 5 percent or 95 percent) does not mean that a single gene causes it, or even a small group of genes.

But it’s soooo easy to slide into that sort of misunderstanding. For one thing, journalists like me hardly ever take the trouble to explain that heritability is not about genes in individual people. It’s a difficult concept to get one’s head around and a difficult concept to explain, and we are terrified of boring the audience and driving readers away.

On behavioral genetics

And it’s soooo appealing to believe in genetic causes for behavior, especially bad behavior. It takes us off the hook, relieves us of responsibility for making defective decisions. My genes made me do it.

Some of that is understandable, I guess. Non-genetic influences on behavior are complicated and very, very messy. They potentially include pretty much everything that happens, from the circumstances of your birth to air pollution to the people you went to high school with to what you ate this morning, not to mention what you ate ten years ago or what your grandfather ate at puberty. No hope whatever of sorting that all out and identifying the (ten or a hundred or a thousand) things that make me drag my metaphorical feet when faced with, say, writing an article about procrastination.

If something is partly genetic, that means it is shaped by the presence (or absence) of proteins that are the products of genes. That process is deeply messy too, and the more we learn about it, the messier it gets. But genes and their proteins have the aura of being more manageable. Proteins are tangible physical entities, and in theory they can be prevented from doing something (or encouraged to do something), for example by chemicals produced by the pharmaceutical industry. Someday, perhaps, I will take a pill and be able to get right to work.

Except that for some tasks, getting right to them may be a mistake. If I hadn’t delayed writing to check my mail, I wouldn’t have known about the autism paper. And if I hadn’t read the autism paper, it wouldn’t suddenly have hit me that aspects of personality routinely turn out to be about 50 percent heritable, and to wonder why. A question I hope someone will answer some day.

I’ll have more to say about the virtues of procrastination in a minute, but I’m putting it off for now.

The procrastination paper

I don’t want you to think I’m sneering at the procrastination paper. It has much interesting to say other than providing a heritability estimate that is all-too-typical of behavioral genetics studies—and, therefore, not terribly illuminating.

The procrastination research used classic twin-study methodology, comparing identical with fraternal twins. The theory is based on the idea that identical twins share 100 percent of their genes. (We now know that isn’t quite true, but never mind.) Fraternal twins are genetically no more alike than any other pair of sibs, on average sharing 50 percent of their genes. Thus, if identical twins are more similar to each other than fraternal twins are for a given trait, the trait must have a genetic component. That’s because these twin pairs were raised together, which in theory wipes out environmental differences between them. (We now know that isn’t quite true either, but never mind.) Twin studies have long been a mainstay of genetics research, especially behavioral genetics research. For a critique of the twin-study methodology see this recent post of Greg Laden’s.

Among the paper’s points of interest is that it builds on previous studies linking procrastination—the authors define it as “the voluntary but irrational delay of an intended course of action”— to the well-studied personality trait of impulsivity. There’s a lot of professional disagreement about how exactly to define impulsivity.  But for now let’s say impulsivity is acting on whim, the tendency to rash action without forethought. It’s a component of several psychiatric disorders. The Colorado authors put the heritability of impulsivity at 49 percent.

They argue that procrastination is a byproduct of impulsivity. This even though the two may seem contradictory, since procrastination is about delaying action and impulsivity is about plunging heedlessly into action.

But you can see that they are related, too, because I impulsively checked my mail at least partly to postpone writing about procrastination. Discussing this paper at the PBS Newshour, Rebecca Jacobson confessed to having “checked Facebook more than 35 times, watched 10 totally unrelated YouTube clips and browsed BuzzFeed. And I can’t even count the number of times I opened my email.” At least I am innocent of Facebook, YouTube, and BuzzFeed. This time.

The Colorado researchers’ more basic point is to relate these two, procrastination and impulsivity, to our ability to manage goals.  They say, “From this goal-management perspective, procrastination is about irrationally delaying actions that help accomplish one’s important goals, whereas impulsivity is about giving in to temptations, often at the expense of making progress on important long-term goals.”

Pychyl thinks they have put their collective finger on the real issue in understanding procrastination and its relation to impulsivity. These two are failures of self-regulation, the inability to manage goals.

This seems like a plausible scenario to me, the idea that what is going on here is, ultimately, allowing distractions to get in the way of getting on with it. On the other hand, it doesn’t allow for the differing reasons for delay, for giving in to impulse. There’s a big difference, for instance, between delay due to sloth and delay born of anxiety.

For example, last night I delayed going to bed in order to watch part of a favorite movie, “Adaptation.” “ Adaptation” is a very funny but very un-Hollywood account of a Hollywood screenwriter’s panicky procrastination when faced with the near-impossible task of (as he puts it) writing a movie about flowers. (Spoiler: He figures it out, and cleverly too.) For a writer–I speak from experience–procrastination can be a tool, a way of giving the brain, its unconscious processes mostly, time and space to work on solutions. I expect that’s true of endeavors other than writing, too.

I’m aware that may sound only like an alibi.

Managing procrastination, impulsivity, and goals

Note that the Colorado researchers’ analysis of what procrastination is about–a failure to manage goals effectively–is stated in psychological terms. In fact, it’s stated not only in psychological terms, but in moral terms. There’s no mention of genes at all.

This is not to argue against genes playing a role in these behaviors. How could they not? But no genes involved in procrastination or impulsivity or goal-managing have been identified. Maybe some will be eventually. But for the moment this is not really a biological analysis. It must be couched in the language of psychology—and the language of virtue.

Note too that 46 percent heritability means that this behavioral genetic study shows that 54 percent of the population variance in procrastination is attributable to non-genetic factors. We don’t know what those are either. But at least it’s clear that “procrastination” is not hard-wired.

Which we know by observation and experience anyway. Some people procrastinate more than others, and a few are dangerously irresponsible and feckless, but nobody procrastinates all the time. Most of us procrastinate some of the time but still are able to restrain the worst of our impulses, meet most of our deadlines, and manage our goals adequately. Nor, as I argue above, need these behaviors always be bad. Sometimes procrastination is a tool for managing goals successfully. Truly.

Also, we can modify a tendency to procrastinate. The self-help literature is stuffed with tricks for doing this. We can remove tempting distractions, keep color-coded calendars and todo lists, check off completed tasks, reward ourselves when we meet a deadline. Etc.

It cannot be said too often: Genes are not destiny.

Tabitha M. Powledge is a long-time science journalist and a contributing columnist for the Genetic Literacy Project. She writes On Science Blogs  for the PLOS Blogs Network. New posts on Fridays.