When the German philosopher Ludwig Feuerbach uttered the phrase “You are what you eat” back in the 1800s, little did he realise the real truth behind his words. Not only does food affect one’s health and state of mind, but it impacts on our very genetic potential.
Nutrigenomics refers to the study of how food affects our gene expression and how our gene expression affects our responses to food and nutrients.
While we cannot change our genetic make-up, we can influence our genetic expression through personalized nutrition. Being able to "switch genes on and off" through nutrition is the true mechanism behind "you are what you eat”…or more accurately “what you eat can change who you are”
The human diet includes macronutrients (such as fats and proteins), micronutrients (vitamins) and natural chemical substances found in plants and animals. All these components of the diet can affect how genes act. The body uses many nutrients in metabolic reactions (body’s chemical reactions) that regulate hormones, immunity (how the body resists disease), and how the body uses nutrients for fuel and growth.
Some natural chemicals directly affect gene expression. One example is resveratrol, a substance found in red wine. Other essential nutrients, such as choline (found in eggs and liver, for example) indirectly affect gene expression. In short, the nutrients in your diet may increase or decrease your risk of developing a disease.
How and to what extent these nutrients affect our gene expression varies from person to person and hence requires either trial and error, or knowledge of an individual’s genetic profile.
Nutrigenomics allows us to understand how to use nutrients to prevent medical conditions such as obesity, diabetes, cancer and neurodegenerative diseases. While a number of diet and genetic relationships have been identified, it’s hard to entirely predict how diet affects health and research continues to uncover the incredibly complex relationships between nutrients and gene expression.
Gaining insight into our own genetic code will help us identify many of these interactions, in particular how our diet affects inflammation, intrinsic cellular defence and cardiovascular health. While many nutrients and food types share similar patterns of benefit (and harm), we are all different and our responses to specific diets, foods and nutrients can vary widely. This knowledge means that we can take the guesswork out of which diet is optimal for us and explains in part why some diets seem to work for some but not others. Armed with this knowledge, you will never have to follow the current fad diet in the hope it's the right one for you.
Instead, through precision medicine and personalised nutritional advice, your health team can now help you along this culinary road of discovery by designing meals and menus specific to your genes.
Dr Brett Gerrard