In what seems to be another piece of evidence in favor of genes being impacted in differential ways over time due to the environment, a certain type of genetic association with obesity seems to only show a significant effect for those children born after the early 1940s.
Dr. James Rosenquist in the Department of Psychiatry at Massachusetts General Hospital in Boston, and his colleagues have looked at the association between the FTO gene – individuals’ so-called ‘FTO-genotype’ and body mass index (BMI) in a way that incorporates the factor of the passage of time.
Studies conducted in what’s called a ‘longitudinal’ way – that is, those studies where measurements are taken of the subjects at different time periods, could potentially show if differences appear over time in relative risks of health problems. In this way, the factor itself of interest isn’t actually time, but instead how lifestyle and environmental effects have contributed, or differed, over time that could be related to observed effects.
Dr. Lu Qi of Harvard School of Public Health and Boston-area collaborators have found in separate research that certain genotypes are influenced differently by certain foods (sugary and fried foods); Their research concluded that “The association between consumption of fried foods and adiposity is strengthened by genetic predisposition.” In other words, fried foods don’t impact everyone equally and their interaction is associated with genetics.
Dr. Nicholas Christakis of Yale University, who also contributed to the study, suggested that certain genes and variants have had different influence on health risks over time based on their interaction with environmental factors.
This research is part of a profound mindset shift currently facing medicine and healthcare: How can we best provide treatment for those who may or may not be at risk for particular conditions based on their individual genetics? For example, two different patients with some of the same gene variants may be at different risks for diseases based on innumerable factors: diet, activity level, sunlight exposure, smoking status, sleep, stress, etc.
We each face different risk levels – even engaging in similar lifestyles and environmental exposures – because of differences in genotypes.
Ben Locwin, PhD, MSc, MBA is a contributor to the Genetic Literacy Project and is an author of a wide variety of scientific articles for books and magazines. He is also a researcher and consultant for a variety of industries including behavioral and psychological, aerospace, food and nutrition, pharmaceutical, petrochemical, and academic. Follow him at @BenLocwin.
