Genetics & Nutrition: Does every healthy diet work for you?
When we think about nutrition and a healthy diet, the first picture that comes to mind is probably the Food Pyramid. This graphic image of a balanced diet is studied at school and sticks with us whether we follow it or not. More recently, MyPlate was added to the Dietary Guidelines for Americans as an easy reminder for us to eat a healthy diet.
But while these same recommendations are intended for everyone above two-years of age, including those with a higher risk of chronic disease, they overlook the fact that genetically, we are all different.
This explains why some people eat seemingly healthy diets but have trouble controlling their weight, while others can eat french fries and burgers but remain thin.
Based on genetics, foods that may be good for one person’s diet may be harmful for another’s. That is not to say that we shouldn’t follow the Dietary Guidelines, but when looking at our plate up close, the ingredients may differ from one person to another depending on the individual’s genetic structure.
The influence of our diet
According to experts in this relatively new field, by tailoring nutrition to an individual’s genetics, we may keep at bay many common illnesses.
Jose M. Ordovas, Director of the Nutrition and Genomics Laboratory at Tufts University, Boston, explained this to us:
“The components of our diet are essential to determine the expression of many of our genes and that defines the working of our cells and our metabolism. However, this interaction or regulation varies from one individual to another because each genome is different. This is one of the reasons why some people eating the same may gain more or less weight or they may have different responses in terms of their cholesterol or glucose in blood.”
Advances in genomics, like the Human Genome Project, opened the door to study the interactions between genes and diet. Interaction being the key word in this relationship, since genes and diet influence each other.
Researchers know that what we eat, even before we are born, as part of our mother’s diet, has an influence on our genetic expression with potential consequences that can last a lifetime and have a significant impact on our health.
Experiments with mice have shown how important a mother’s diet is in the epigenome of the offspring.
The recipient of several awards including the Grand Prize on the Science of Food, Dr. Ordovas, a biochemist from Zaragoza, Spain, explains:
“The study of these interactions between diet and genes is called nutrigenomics and the practical objective of this research is to be able to provide more personalized dietary recommendations to improve disease prevention and maintain better health.”
How exactly would this work? For some conditions caused by a single dysfunctional gene, such as galactosemia or phenylketonuria, prevention can be achieved by modifying the consumption of certain nutrients. Unfortunately, other illnesses that reach epidemic proportions, like cardiovascular disease, diabetes or cancer, result as a combination of errors; in these cases, no one nutrient holds the key to prevention through nutrition, and discovering the link diet-gene is more complex.
The Nutrition and Genetics Laboratory at Tufts University is a pioneer in the study of the relationship between genes and diet in relation to cardiovascular disease. Listed among the labs objectives is to identify genetic factors that increase the risk of heart disease for populations of different ethnic backgrounds; along these lines, previous studies have analyzed Puerto Rican communities in the United States.
Looking forward to personalized healthy diets
Don’t expect any drastic changes in our nutritional habits, however. If nutrigenomics bring a revolution to our dietary guidelines, it is a silent one, according to Tufts Senior Scientist, Jose M. Ordovas:
“Despite what some may think, scientific progress is not made by ‘major discoveries.’ Rather, it is the result of small steps that keep building and solidifying the knowledge until it reaches the point that can be translated into practical applications, such as ‘personalized nutrition.’ However, I don’t think this personalization will bring new ways of eating. The hope is that we can use traditional or enriched foods to provide each individual with the proper ‘mix’ that will be healthier for his or her genome.”
While improving our health through a personalized diet seems a concept of the future, the promise of nutrigenomics is just around the corner. Yet scientists are cautious about the so-called genetic test currently offered by dieticians and other health practitioners. They warn their claims may be misleading and the promise of reducing specific health risks conditioned to buying their supplements. The FDA and Centres for Disease Control and Prevention (CDC) have also alerted consumers in the past about these direct-to-consumers genetic tests.
For more information about genetics and a healthy diet, ask your physician. If you would like to be a part of this research, click here to contact the Human Nutrition Research Centre on Aging, at Tufts University, to participate in one of their studies.