As with most things in science, health and nature, it's not one or the other that's the right answer. It's not vitamin A or vitamin C. It's not folic acid or pantothenic acid. In many cases with nutrition, it's a complex interplay of nonessential, conditionally-essential, and essential nutrients.
What ends up happening is that people either opt to not take a vitamin, citing lack of rigorous evidence that multivitamins have an unequivocal beneficial effect, or they take a multivitamin because it's an inexpensive way 'to just be sure' and bolster their diet with nutrients they may need. For those that tend to take vitamins, they'll often also be more likely to take a preferred letter vitamin (A, C, D, E, etc.); For some, it's to overcome a legitimate metabolic concern or deficiency, and for others it's simply a heuristic to take a favorite vitamin and feel better as a result.
The same sort of 'either/or' mindset also manifested when omega-3 fatty acids became fashionable. "Omega 3" became the only acceptable number for unsaturated fatty acids, and whether or not consumers knew what the '3' meant, it didn't matter - they heard they should take it. Then things became a little more complicated in the supplement aisle: Of course because there are different forms of omega 3 fatty acids, having to translate alpha-linolenic acid (ALA - not to be confused with linoleic acid, an omega 6), docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA) seemed, according to one patient I spoke with, to "require a chemistry degree."
Obviously, nutrients exert their effects whether or not the public knows what they do or how to pronounce them. But these nutritional heuristics make it difficult for consumers to have a good working grasp of what exists in the pantheon of supplements.
An omega by any other name
Nature generally doesn't care much for what we think either: There are no 'good' vitamins or 'bad' vitamins. Similarly, omega 3 isn't better or worse than any other of the other unsaturated fatty acids. Omega 6 and omega 9 fatty acids are important for metabolism as well; it seems again to be the balance between fatty acid proportions that makes an important difference in the body. So what about the 'overlooked-by-being-underrepresented' omega 7 fatty acid? Rest assured there is, in fact, a series of omega 7 fatty acids, and the way the supplement industry is trending at the moment, this is one that will receive more mention, marketing, and advertising dollars soon. Targeted at you.
All omega fatty acids are numbered based on where the unsaturated carbon atom is along the chain. So in this case, omega 7s are unsaturated at the seventh carbon atom from the end. There are many different omega 7 monounsaturated fatty acids, ranging in length from 12 carbon atoms to 24 carbon atoms. Most commonly, omega 7s are found in certain meats and dairy products, higher plant seeds like macadamia nuts, sea buckthorn berries and cold-water fish. So indeed omega 7s can be found in nature, and can be found in fatty tissues as part of the glycerides.
What are the effects of omega 7s?
Omega 7 fatty acids, palmitoleic acid in particular (a cis- fatty acid), have been found to reduce inflammation, reduce insulin resistance in muscle cells (and be predictive of insulin sensitivity), and potentially mitigate the death (apoptosis) of pancreatic beta cells, which secrete insulin. Some research in mice indicates that cis-palmitoleic acid is involved in chemical signaling in the body and perhaps is associated with reduced fat cell growth.
Another form of omega 7, vaccenic acid (a trans- fatty acid), has shown some promise in reducing LDL cholesterol and triglycerides in small sample sizes during supplementation, impacting the structure of adipose, as well as appearing to impact differential regulation of the genes SREBP1 and FAS. Vaccenic acid itself can be converted in the body endogenously to conjugated linoleic acid (CLA), which has been researched for its use in reducing fat mass among other effects.
Ultimately, understanding that no nutrient in isolation guarantees longevity, having a balanced and varied diet can ensure that you have access to what's important.
Ben Locwin, PhD, MBA, MS, is a contributor to the Genetic Literacy Project and is an author of a wide variety of scientific articles in books and magazines. He is an expert contact for the American Association of Pharmaceutical Scientists (AAPS), a committee member of the American Statistical Association (ASA), and has been featured by the CDC, the Associated Press, The Wall Street Journal, Forbes, and other media outlets. Follow him at @BenLocwin.
For more background on the Genetic Literacy Project, read GLP on Wikipedia.