Most of us know that we need to eat more fruits, vegetables and whole grains.
So why would the National Institutes of Health spend $ 150 million to answer questions such as “What and when should we eat?” and “How can we improve the use of food as medicine?”
The answer may be precision nutrition, which seeks to understand the health effects of the complex interaction between genetics, our microbiome (the bacteria that live in our gut), our diet and the level of physical activity, and others. social and behavioral characteristics.
This means that everyone could have their own unique set of nutritional requirements.
How is this possible? I asked three experts in precision nutrition research: Dr. Frank Hu, professor of nutrition and epidemiology and chair of the Department of Nutrition at Harvard TH Chan School of Public Health, and Martha Field and Angela Poole, both assistant professors at the division. of Nutrition Sciences at Cornell University College of Human Ecology.
How is precision nutrition different from current nutrition advice?
Dr. Frank Hu: The idea of precision nutrition is to have the right food, in the right amount, for the right person. Instead of providing general dietary recommendations for everyone, this precision approach adapts nutritional recommendations to individual characteristics, such as genetic background, microbiome, social and environmental factors, among others. This can help you achieve better health outcomes.
Why isn’t there a single recipe for what we should eat?
Hu: Not everyone responds to the same diet the same way. For example, with the same weight loss diet, some people may lose a lot of weight; other people may gain weight. A recent study at JAMA randomized a few hundred people who were overweight on a healthy low-carb or low-fat diet. After a year, there was almost identical weight loss for both groups, but there was great variation between individuals within each group: some lost 20 pounds. Others gained £ 10.
Martha Field: People have unique answers to diet, and the “fine-tuning” of precision nutrition is to understand those answers. This means understanding the interactions between genetics, individual differences in metabolism, and responses to exercise.
How do we eat now based on precision nutrition principles?
Hu: There are some examples of personalized diets for disease management, such as a gluten-free diet for celiac disease management, or a lactose-free diet if you are lactose intolerant. For people with a condition known as PKU (phenylketonuria), they should consume (a) a phenylalanine-free diet. It is a rare disease but a classic example of how your genes can influence what type of diet you should consume.
Angela Poole: If I had a family history of high cholesterol, diabetes, or colon cancer, I would increase my dietary fiber intake by eating many different sources, including a variety of vegetables.
Field: If you have high blood pressure, you should be more aware of your sodium intake. Anyone with a malabsorption problem may be in need of higher levels of micronutrients, such as B vitamins and some minerals.
There is research showing that people metabolize coffee differently. What are the implications here?
Hu: Some people carry genes that quickly metabolize caffeine; others wear slow genes. If you carry fast genotypes (metabolizers), you can drink a lot of caffeinated coffee because the caffeine breaks down quickly. If you are a slow metabolizer, you get nervous and may not be able to sleep if you drink coffee in the afternoon. If so, you can drink decaffeinated coffee and still reap the benefits of coffee polyphenols, which are associated with a reduced risk of heart disease and diabetes without the effects of caffeine.
What role do our individual genes play in our risk of disease? And can our behavior mitigate our risk of illness?
Hu: Our health is affected by both genes and diets, which constantly interact with each other because certain dietary factors can activate or deactivate some genes related to the disease. We published a study showing that reducing the consumption of sugary drinks can offset the negative effects of obesity genes. This is really good news. Our genes are not our destiny.
Another area of precision nutrition is measuring blood or urine metabolites, small molecules produced during the breakdown and ingestion of food. For example, having a higher concentration of branched chain amino acids (BCAAs) strongly predicts the future risk of diabetes and cardiovascular disease. BCAA blood levels depend on the diet of individuals, genes, and the gut microbiome. We have found that a healthy (Mediterranean-style) diet can mitigate the harmful effects of BCAAs on cardiovascular disease. Therefore, measuring BCAAs in the blood can help assess the risk of developing diabetes and cardiovascular disease and encourage dietary changes that may reduce the risk of chronic disease in the future.
Field: Environmental effects can sometimes be of the same magnitude as genetic effects in terms of disease risk.
Our individual microbiomes may be able to dictate what kind of diet we should consume. Can you tell us about this emerging research? And what do you think of microbiome testing?
Poole: Research has shown that in some people, their blood sugar will increase more if they eat bananas than to eat cookies, and this has been associated with the composition of the microbiome. Scientists have used microbiome data to create algorithms that can predict an individual’s glucose response, and this is a breakthrough. But that’s not an excuse to take out cookies instead of bananas. Similarly, if the algorithm suggests eating white bread instead of wholemeal bread because of the blood glucose responses, I would not just eat white bread all the time.
At the moment, I’m not ready to spend a lot of money to see what’s in my gut microbiome … and the microbiome changes over time.
Hu: Microbiome testing is not cheap, and I promise that this test can help you develop a personalized meal plan that can improve your blood sugar and blood cholesterol … right now, the data isn’t concluding.
How will the nutritional advice be different in 10 years?
Poole: I think you’ll get a personalized grocery list in one app: foods you want to buy and foods you want to avoid, based on your blood sugar responses to foods, your level of physical activity, and more.
Hu: We will have more and better biomarkers and more affordable and accurate nutrigenomics and microbiome testing, as well as better computer algorithms that predict your response to food intake.
But these technologies cannot replace general principles of nutrition, such as limiting sodium and added sugar and eating healthier plant foods. In a few years, you may be able to get a more helpful answer from Alexa by asking her what to eat, but like other Alexa answers, you’ll need to take a grain of salt.