The Science of Personalized Nutrition

In human beings, as in nature, there is a beautiful and complex array of diversity. Just like no two people are identical in physical appearance, neither are they precisely alike on a molecular level. Even the most mundane and essential processes are subject to slight individualized nuances. Your suspicion that somehow every carb you eat goes to your hips, while your best friend seemingly indulges with impunity is not your imagination. We now know some people process carbohydrates differently than others and these differences can be both advantageous or deleterious.

A single nucleotide polymorphism (SNP) or change occurs in nearly 1 in 1,000 base pairs and accounts for much of an individual’s uniqueness. Research on SNPs and other genetic variations like deletions, inversions, duplications and copy number variations (CNV), which represent up to 9.5 percent of the human genome, have changed the face of human nutrition and validated the concept that nutrition could and should be personalized. (Mullally, 2007)

It is now well established that our diet and genes interact. Our genes are not as intransigent, nor our diet as inert as we once believed. It is a radical concept that a lifestyle factor like nutrition may be the primary environmental influencer on human health over a lifespan.

Nutrigenetics or personalized nutrition delineates how the metabolic outcome of what we put in our mouth may be a little different for each person. These variations elucidate how one person might be impacted by a particular dietary intervention, while another is not. Polymorphisms explain why monitoring carbohydrates is the critical factor for some, and fat for others. It also offers an explanation for confounding data in large cohorts and other studies on vitamin use, weight loss, lipid metabolism, chronic disease development and longevity. Polymorphic populations (those with high genetic or epigenetic variability) in clinical trials may generate mixed data that doesn’t necessary mean an intervention won’t work in a more targeted group. Future population selection for these studies will be based upon the nutrient-gene paradigm of each subject helping to standardize results with a higher level of reproducibility.

Nutrigenomics is the umbrella encompassing epigenetics, proteomics and metabolomics. It explains how dietary factors can literally reprogram our genetic activity by changing which genes get turned on and off, their frequency, productivity and efficiency of expression. New science is revealing how these changes can be imprinted over a lifetime, and even passed to future generations.

Besides ameliorating gene expression, the eventual outcome of a gene can be mediated by how the resulting proteins are folded, where they are delivered, the timing of production, and with what corroborating elements they are complexed or metabolized into. Nutrient availability can modulate all of these factors. Altering how our genes are expressed can literally override our original genetic code. The potential exists to devise nutritional interventions for “bad" genes, but it is equally possible our lifestyle choices may ruin “good" genes. The implication is nutritional choices alone can make sick people well, and healthy people sick.

Certainly, prenatal and early childhood nutrition can exert a fundamental and long-lasting positive or negative impact. The development of many chronic diseases can be traced back to early epigenetic modifications in response to environmental stimuli during these formative life stages.

Most of us make our dietary choices using less scientific rigor. Food is a sensory and cultural experience that is also significantly impacted by our genes. We are motivated to choose our food by taste, sight, smell, expense, emotion and expediency, as well as by the delicate signaling of our body denoting hunger and satiety. We eat when we are not hungry, not knowing that routinely ignoring our body’s cues can cause long-term alterations in genetic expression in these metabolic pathways and modify the ability to provide “normal" signals in the future. The propensity to neglect important feedback from our body can be programmed—for better or worse, back into our genetic make-up through epigenetic adaptations, and possibly even passed to our children.

Dietary choices are not the only exogenous factors that may impact genetic integrity and expression. Our genes are exposed to both deliberate and random concomitant factors, like ultraviolet (UV) light exposure, pollution, smoking, stress, infection, drugs, exercise, etc.

The science of nutrigenetics and nutrigenomics is evolving. While initially very promising, even exciting, more randomized clinical trials are needed that demonstrate a health outcome for nutritional interventions based upon addressing a single genetic variation. The majority of SNPs and CNVs have not yet crossed over the clinical standard demonstrating the link between better nutritional advice specific to genetic aberrations and mitigating disease. A major impediment for advancing this kind of nutritional research has been the limitations inherent in accurately assessing dietary intake. For studies that monitor what might be small but meaningful changes, nutrigenomics needs to cultivate correspondingly sensitive biomarkers for validating food intake.

Dietary intake has been shown on a molecular level to mitigate inflammation, promote healthy aging, reduce the risk of cardiovascular disease, support bone maintenance, modulate lipid metabolism, change insulin sensitivity and influence the microbiome. Many promising phytonutrients, vitamins and minerals have already demonstrated potential benefits beyond their well-known, functional contribution to metabolic processes. For polyphenolics like resveratrol, their renowned antioxidant activity may just be the tip of the proverbial iceberg. It has long been recognized that the benefits of resveratrol cannot be explained by its antioxidant value alone, and emerging research suggests resveratrol may also exert epigenetic influence by blocking or inducing specific transcriptional effects.

The convergence of nutrigenetics, nutrigenomics, metabolomics and epigenetics holds the promise of meaningful interventions that will personalize nutritional recommendations based upon genetic predispositions, gene expression reprogramming and imprinting, inherited diseases or disadvantages, lifestyle choices, lifestyle diseases, stages of life, behavioral challenges, environmental exposure and organoleptic preferences.

Today the science may seem complex and even esoteric to the consumer, and yet consumers are easily able to understand and even embrace the truth that we are each different. It is human nature to want to be recognized and treated as special for those differences. The EU Food4Me project validated this idea. Regardless of whether a personalized dietary regime was accompanied by specific genetic counselling, subjects were simply more likely to comply with and stay on a dietary recommendation over six months if they believed it had been designed specifically for them. (Celis-Morales, 2015) Compliance to any regimen is more likely to be successful if the benefits are noticeable.

Personalized nutrition has the potential to revolutionize health care. It is an opportunity to intercede in disease before diagnosis, reprogram genetic destiny, and shift focus from broad-based population “standards of care" to tailored, nutritional modalities for the individual.

Learn more about the science of personalized nutrition from Jennifer Cooper during the Making Personalized Nutrition a Reality Panel Discussion on Thursday, Sept. 28 at 9 a.m. at SupplySide West in Las Vegas. The Panel is underwritten by SuperbaKrill and AkerBioMarine.

Jennifer Cooper is the vice president of research and development (R&D) and quality at TCC. Previously, she was at US Pharmacia—primarily focused in Poland and Eastern Europe—where she oversaw food supplements (natural products), traditional herbal medicines, medical devices and dermocosmetics. Prior firms include Dynova Laboratories and Twinlab. Cooper has experience managing all the technical functions for OTC/natural products distributed in the mass and specialty markets, including regulatory affairs, product formulating and testing, contract manufacturing, scientific and clinical research, intellectual property (IP) and quality assurance (QA). She has developed and brought to market more than 300 new products.