14 Mar 2019 — Within the personalized nutrition space the field of nutrigenomics is touted as being able to tailor nutrition to an individual’s specific genetic makeup. With direct-to-consumer (DTC) services such as at-home genetic testing, consumers may now gain better insights into health and disease predisposition, as well as case-specific nutritional recommendations. Industry experts weigh in on the potential of nutrigenomics on well-being and the hurdles to be overcome.

Confusion as to what exactly nutrigenomics offers has led some to believe that nutrigenomics are able to predict disease risk, however, what nutrigenomics actually does is “provide the right recommendations for an individual so they can reduce their risk [of disease],” Dr. Ahmed El-Sohemy, Canada Research Chair in Nutrigenomics Department of Nutritional Sciences, University of Toronto and Founder and CSO of Nutrigenomix, tells NutritionInsight.

The field of nutrigenomics studies how an individual’s genes interact with their diet to affect their physiology and, consequently, their health. Research in this field can help uncover why some people respond differently from others to the same foods, beverages and supplements, Dr. El-Sohemy explains.

“As such, the most significant benefit of nutrigenomics is its practical application for individuals, i.e., the potential for improving health and performance through DNA-based, personalized dietary recommendations,” he notes.

Dr. Christine Houghton Managing Director and CSO at Cell-Logic tells NutritionInsight that nutrigenomics has greatly extended our view of the effect of food molecules in human cells. “The term, ‘nutrigenomics’ simply translates to ‘food talking to your genes,’” she says.

The role of genes in nutrition
Diet is arguably one of the most important determinants of health. Yet, it isn’t clear exactly what we should eat to optimize our health and performance. Current dietary recommendations are based on the “one-size-fits-all” population health model, which was developed decades ago, Dr. El-Sohemy notes.

Each person is born with many variations in their DNA, called “single nucleotide polymorphisms” (SNPs). The presence of SNPs means that the enzyme a gene codes for does not do its job at 100 percent efficiency. “It may only operate at 50 percent or 70 percent, for example. But because enzymes do not usually function at their peak capacity under an ‘ordinary’ load, there is scope to increase that activity. That means that if we can use the right phytochemical to increase that activity, the enzyme can function at close to normal capacity,” Dr. Houghton explains.

“Nutrigenomics can create the evidence base necessary for healthcare professionals to develop personalized nutrition recommendations for each person based on their genetic profile. This will allow individuals to optimize their health through diet,” Dr. El-Sohemy says.

“The knowledge that the presence of certain SNPs may impede the normal function of human cells can be incredibly empowering for people who may have lived with a condition that they have been unable to resolve, in spite of extensive medical investigation,” Dr. Houghton notes.

Once an SNP is identified as interfering with the aspects of cellular function that influence a certain disease, then nutritional recommendations can be targeted to those particular SNPs.

“This personalizes the patient’s treatment program and we would expect to see a rapid response. This is quite unlike the ‘one size fits all’ dietary advice one would otherwise receive,” Dr. Houghton says.

Innovations in nutrigenomic testing
Nutrigenomic testing has progressed to the point where different tests cater to different health and well-being issues. DTC tests may be delivered at one’s door, but the most trustworthy testing is carried out by a trained professional, says Dr. Houghton.

Canada-based Nutrigenomix has developed the first genetic test kit to be used exclusively by healthcare professionals. “Clinicians can use it as a tool to incorporate personalized, DNA-based dietary recommendations into their practice. Our genetic test kits examine genes that affect not only the metabolism of various nutrients but also cardiometabolic health, body weight, eating habits, food intolerances and physical activity,” he explains.

In addition to Nutrigenomix’s health and wellness test, which was developed for individuals seeking to improve their overall health, the company also offers a sports and performance test for athletes and a fertility test for couples who are trying to conceive.

“We have recently launched a genetic test for weight management, and we will soon be adding more markers to our current tests, based on the latest scientific discoveries,” Dr. El-Sohemy says.

In the same space, Australian Cell-Logic has created a “nutrigenomic intervention” supplement from whole broccoli sprout raw material. Houghton left her clinical practice as she saw an opportunity in sulforaphane and its nutrigenomic potential, “especially when comparing it with the available plant extracts like curcumin and resveratrol which dominated the prescribing habits of clinicians at the time,” she says.

“We now know that the most potent antioxidant compounds that cells use are the antioxidant enzymes made by the cell and which are readily activated nutrigenomically,” Dr. Houghton notes.

Cell-Logic has developed and launched EnduraCell, which delivers 20mg of sulforaphane per gram. “It is capable of readily matching the amounts used in a series of successful clinical trials – in asthma, COPD, Helicobacter pylori infection, autism and Type 2 diabetes,” she says.

Negative aspects 
Despite a boom in DTC testing, industry experts have highlighted the importance of genetic testing to be done via the supervision of a trained professional.

There are DTC nutrigenetic testing companies focusing on just a few genes and subsequently offering inappropriate and incorrect advice, Dr. Houghton says. A case in point is the gene MTHFR which about 60 percent of the population carries.

“MTHFR is being exploited in a way that has consumers believing this single gene is responsible for all their ills; they then take online ‘advice’ that sees them taking megadoses of certain supplements that can cause serious biochemical imbalances. This approach is not what personalized medicine and nutrigenomics is about,” she notes.

“The interpretation of a nutrigenetic profile needs to be done by a trained clinician who has knowledge of the genes, the enzymes for which they code and then the nutrigenomic solution,” Dr. Houghton continues. “As the number of clinicians with these skills continues to grow, we expect to see rapid expansion in the clinical application of nutrigenomics.”

Dr. El-Sohemy maintains that there is still a lot of knowledge to be discovered on nutrigenomics and improve the understanding we have of it, and he highlights that DTC testing should be closely monitored for efficacy.

“Virtually none of the commercial genetic test kits in the market today have been rigorously evaluated for their efficacy on robust clinical outcomes using gold standard randomized controlled trials,” he says.

“We need more high-quality nutrigenomics research to better understand the complexities of gene-diet interactions in humans, and to develop the scientific evidence necessary to build sound and effective personalized recommendations. Only then will the potentially considerable benefits of nutrigenomics be realized fully,” he adds.

Looking ahead
Dr. El-Sohemy says that as nutrigenomics continues to increase in popularity, it will become an integral part of nutritional interventions and he expects that colleges will add it to their curriculum so that future clinicians are better trained in it.

He supports that nutrigenomics must become a part of the curriculum in professional training programs, and opportunities for continuing education must be made available for practitioners interested in incorporating nutrigenomics tools into their practice.

“Nutrigenomix offers extensive training and support to providers of its genetic test kits, and we have partnered with the Dietitians of Canada to develop a course on nutrigenomics and personalized nutrition, which is available online to healthcare providers worldwide,” he says.

Cell-Logic, on the other hand, is working on formulations that will enhance the penetration of their nutrigenomics ingredients.

“We are in the process of launching a new program for gut and metabolic health which includes our sulforaphane-yielding supplements as its core intervention. The opportunity to spread the nutrigenomics and sulforaphane stories to a wider community continues to be one of our primary goals,” Dr. Houghton says.

The field of nutrigenomics promises to change the way we perceive personalized nutrition and offer insight that wasn’t accessible until now. Personalized nutrition is changing and becoming even more targeted in a bid to increase its potential benefits.

By Kristiana Lalou

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