[ad_1]
Spencer Platt / Getty Images 
Related Content
(CNN) – "The food of one man is the poison of another." – Lucretia (99-55 BC)
Most people have this basic understanding of genetics: you inherit your parents' genes and their DNA combines to create your unique genetic makeup. This may include more obvious features such as color and size of eyes, but also more complex features that may involve multiple genes, such as the risk of diseases such as diabetes, heart disease, obesity, and cancer, as well as all aspects of metabolism.
The Human Genome Project – a 13-year international collaboration that has mapped all genes in humans – has uncovered about 50,000 variances (differences in individual DNA code) of our genetic code that can affect the functioning of your gene. body.
What many people may not realize is that there is an important interaction between your environment and your genes and that your diet is one of the most fundamental and potentially modifiable components of your environment.
This interaction has led to a field called nutrigenetics, which examines how our genes determine our nutrient response in foods and beverages. By better understanding an individual's response to specific nutrients, health practitioners could formulate more specific and effective nutritional recommendations.
A healthy diet with a wide variety of foods may help alleviate many of these individual genetic variations, but part of the controversy over what constitutes a healthy diet may be due, in part, to individual genetic variances.
An interesting example concerns a nutrient that does not attract much attention: choline, which is commonly found in yolks of eggs. When public health officials began targeting a reduction in dietary cholesterol for heart health, the eggs were perceived as unhealthy. Reducing dietary cholesterol may have been helpful for some to lower cholesterol levels in the blood, but research into nutrigenetics has revealed several genetic variants that can lead to health problems, including liver steatosis, infertility, and muscle wasting in the blood. individual carriers of these variants consuming insufficient amounts of choline.
Other controversial nutrients that could be better treated by considering nutrigenetics include saturated fats, vitamin D and sodium (salt). The seemingly contradictory research findings about these nutrients may be due, in part, to an individual genetic variation that dictates the response of an individual rather than a group to these nutrients.
Although most experts agree that avoiding too much saturated fat helps us stay healthy, the growing popularity of high fat, carbohydrate and ketogenic diets has led many people to disregard these recommendations.
Jose Ordovas, director of nutrition and genomics at USDA's USDA Jean Mayer Aging Research Center at Tufts University, has discovered an badociation between a genetic variation of the APOA2 gene, implicated in fat absorption, that makes people more likely to gain weight eat a lot of saturated fat. For these people, saturated fats are a very bad choice because they promote both excess weight and poor heart health.
Similarly, there are several genetic variations that influence the effect of salt intake on blood pressure. In some people, nutrigenetic research suggests that dietary salt reduction is particularly important for maintaining healthy blood pressure, while in 11% of the population, reducing salt to very low levels may actually increase blood pressure, according to Ordovas.
Why is weight loss so complicated?
With regard to weight loss, the role of nutrigenetics becomes much more difficult to solve.
Obesity is a complex and multifactorial disease. Obesity has a considerable genetic component (estimates range from 30% to 70%) and dozens of genetic variants have been badociated with obesity and metabolism. Identifying those who are most likely to respond to a specific food intervention is a challenge from a research and behavioral point of view, because a diet only works if you follow it.
Experts in the field of nutrigenetics, including Dr. Martin Kohlmeier, president of the International Society of Nutrigenetics / Nutrigenomics, explain these negative results very simply: "The investigators chose the wrong genetic variants. 'other."
Compliance is also a critical factor in weight loss and health. Do gene-guided dietary interventions improve adherence to dietary recommendations? Yes, says Ahmed El-Sohemy, professor and president of Canadian Nutrigenomics Research at the University of Toronto, who founded a company, Nutrigenomix, which provides DNA-based diet recommendations to health care providers .
El-Sohemy has published one of the first studies showing significant improvements in salt reduction with the disclosure of genetic information. A more recent study focusing on genetic testing and behavioral change highlights the importance of formulating applicable lifestyle recommendations and notes that "the most promising lifestyle changes were changes in nutrition".
The DNA regime
Despite the lack of consensus around many gene-based nutrition interventions, many companies are marketing gene-based nutrition and diet programs.
DNA Diet, which offers a digital weight loss program based on a personalized diet and lifestyle recommendations resulting from DNA, aims to support the behavioral changes essential to the success of using a diet-based DNA. If the specific genetic variants used by the company actually helped to improve weight loss beyond personalized recommendations, this has not been studied enough.
Many companies also use DNA badysis to formulate more personalized supplement recommendations. While this area is promising, science is not strong enough to support most of these recommendations.
A potentially promising application of nutrigenetics is for medical foods that, unlike supplements, are strictly monitored by the Food and Drug Administration and must be prescribed by a health professional.
Dr. Steve Zeisel, director of the Institute of Nutritional Research at the University of North Carolina (Chapel Hill) and one of the world's leading choline researchers, founded a company called SNP Therapeutics, which aims to create genetic-based medical foods that identify roadblocks in the metabolism and provide the missing nutrients to bypbad these blockages.
Although Zeisel advocates for a healthy and balanced diet for everyone, he believes that medicated foods can play an important role in improving long-term compliance with gene-driven nutritional recommendations.
The field of nutrigenetics is still in its infancy and much more needs to be learned, but experts agree that while evidence will continue to evolve over the next decade, we have enough evidence to support it. make it useful now.
Effective use of genetic information to guide individual, more specific nutritional recommendations requires much more than simply testing for random genetic variants and should be done by a trained health professional.
The genetically informed health care provider should know how to incorporate and act on genetic information as a nutrition-related precision factor, including the gut microbiome, standard blood tests, and health risk badessment. , as well as new methods of badessing the metabolism of nutrients. According to Kohlmeier, "biohacking will not cut mustard".
Dr. Melina Jampolis is an internist and nutrition specialist certified by the board of directors and author of several books, including "Spice Up, Slim Down".
Source link
