Ethics and Considerations about Personalized Nutrition
Nutrition research is nothing if not plentiful and inconsistent. It can make translating findings into advice vague and challenging and advice into action, well, overwhelming. And with so many different opinions, how do we answer the question, “which direction should I follow?”
Steering away from one-size-fits-all guidance, some academic and investigative thinkers point to nutrigenomics and nutrigenetics (from here, collectively referred to as “personalized nutrition”) for resolve. Others are skeptical, unsure of the field’s validity and unsettled with the lack of ethical guidelines. There are other considerations, too, like the effect on (perceived) ease to follow through on recommendations, the ability of eating facilities to accommodate needs, and the stress that this relieves (or does it cause it?) or the satisfaction it brings (or does it impede it?). How does this intersect with health disparities, or gender issues? Will populations with higher disease burden find relief in gene-based nutrition therapy? Or will they further be marginalized with low access to prescribed diets, or even little access to testing? Will personalized nutrition make meal planning for a family more difficult, and if it does, where does the burden of implementation fall?
These, and many other questions, may develop. To know what we are asking about, let’s cover some basic information on personalized nutrition, taken mostly from the Pavlidis et. al. reading, and to a lesser extent, other sources.
· Nutrigenomics describes “the way that gene expression as a response to the metabolic process could influence the health of a person and the interaction between genotype and environment/nutrient…” In this way, dietary signals may change the gene, protein, or metabolite expression. For example, fatty acids serve as a ligand to a nuclear receptor called PPARa, which then targets thousands of genes; these genes are involved in lots of different metabolic processes, like hepatic gluconeogenesis ((fancy for the liver makes some glucose). When there is an excess of fatty acid, hepatic gluconeogenesis is stimulated, basically because there was more PPARa activated to tell those genes to boot up. Of course, these processes are subject to genetic variation.
· Nutrigenetics, on the other hand, describes how genetic variation affects response to nutrients. Physiological response to nutrients, again, influences health outcome. In this way, the gene affects nutrition. An example of this may be postprandial glycemic response, or the way blood glucose level changes after a meal, as dictated by genetic factors.
· Studies report a wide range of attitudes on and perceptions of personalized nutrition (76% believing it would be beneficial vs. 27% willing to follow a personalized diet).
· Personalized nutrition, in the genetic sense, is not widely practiced in clinical settings. Meal plan services and counseling is quite common, as is the establishment of personal nutrition goals in combination with behavior change. However, at this point, doctors, nurses, and dietitians are not applying personalized nutrition recommendations based on genetic factors in their everyday routines. (They do, however, heavily rely on biomarkers.)
· Direct-to-consumer services are available for genetic and biomarker analysis, along with personalized nutrient-based recommendations. Two examples are Habit (www.habit.com) and My Diet Clinic (www.mydietclinic.com). Take a browse around their websites, and peruse through their sample results brochures.
In reality, our complex questions require some more in-depth insight into what personalized nutrition is, how it works, where the field is now, and what perceptions surround it. For this, I recommend the readings below, and invite you to bring to the table your own questions as we consider the future of personalized nutrition.
1. Görman U, Mathers JC, Grimaldi KA, Ahlgren J, Nordström K. Do we know enough? A scientific and ethical analysis of the basis for genetic-based personalized nutrition. Genes & Nutrition. 2013;8(4):373–381. doi:10.1007/s12263–013–0338–6.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3689893/
***highly recommended
2. Cristiana Pavlidis, George P. Patrinos, Theodora Katsila, Nutrigenomics: A controversy, Applied & Translational Genomics, Volume 4, March 2015, Pages 50–53, ISSN 2212–0661, https://doi.org/10.1016/j.atg.2015.02.003.
http://www.sciencedirect.com/science/article/pii/S2212066115000058
***pretty dense, skimming is probably sufficient
3. https://www.vox.com/2016/11/2/13453434/personalized-diet-nutrition-dna
4. https://well.blogs.nytimes.com/2016/01/11/a-personalized-diet-better-suited-to-you/?_r=0
5. Bragazzi NL. Situating Nutri-Ethics at the Junction of Nutrigenomics and Nutriproteomics in Postgenomics Medicine . Current Pharmacogenomics and Personalized Medicine. 2013;11(2):162–166. doi:10.2174/1875692111311020008.
***especially sections 1, 2, 5 and conclusion
