Here at the IFIC Foundation and in my time spent as a nutrition researcher, I’ve read piles of studies showing that some research subjects showed a health benefit from a dietary intervention, while others responded in the opposite way or didn’t change at all. One of the typical explanations is that “genetic variation” played a role in the differences. But what are these genetic variations? How do the foods we eat interact with our genes? And how does this relate to our overall health? These questions are at the heart of a developing area of science called nutrigenomics. 

First Things First, Let’s Talk Genetics

Before we can really dig into the details, a little Genetics 101 might be helpful (I know, I know…). Thinking back to high school science class, remember that genes are the tiny bits of information that code for everything from “make your hair curly” to “make a new muscle cell” – basically, they’re the body’s instruction manual. Genes are what make up our DNA, and the genome is our entire set of DNA. When the info coded in our genes is activated, it’s called gene expression. While we can’t change our genes, we can change is our gene expression through doing things like exercising, sleeping, or, in our area of interest, eating.

What is Nutrigenomics?

Now that we’ve covered some the basics of genetics, let’s talk about nutrigenomics. Nutrigenomics studies how our individual genetic makeup contributes to how we process what we eat and drink, and how this may affect health outcomes like obesity or cardiovascular disease risk. It looks at the interaction between nutrients and other dietary compounds with the human genome - all the way down at the molecular level. Work in nutrigenomics began about 15 years ago after the conclusion of the Human Genome Project, where we learned that while 99.9 percent of everyone’s genes are the same, the remaining 0.1 percent are responsible for the vast array of differences between individuals. This includes our response to diet.

Genes + Diet = Health Status

We’ve known for a while that there are a few specific genes associated with lactose intolerance, sensitivity to caffeine and alcohol, and health conditions like celiac disease. But when it comes to disease prevention or treatment, a nutrigenomics approach has most often been applied in the study of obesity. While obesity is a complex condition with no one specific cause, there are several obesity-associated genes whose expression can be altered by dietary choices. For example, one variation of the gene that codes for the fat mass and obesity-associated protein (FTO) is connected to having a higher BMI and increased risk for type 2 diabetes. Research has shown that when following a Mediterranean diet (think plant-based foods, lean protein, whole grains, olive oil, and nuts), people with this gene variation tend to have lower diabetes risk as compared to people who aren’t eating Mediterranean-style.

Understanding these connections means that we may no longer have to play a guessing game every time we try out a new food or eating pattern. By knowing our genetic makeup, we could predict our body’s response to food before it even graces our lips. But of course, we can’t ignore the effects of other aspects of our lives, like age, gender, and physical activity. These characteristics play a big role in our overall health aside from the specific foods and beverages we consume.

What it Can’t Do (Yet)

While all of this sounds really exciting (the future is now!), it’s important to remember that the field of nutrigenomics is still in its infancy – we’ve only just begun to unravel the intricate ties between diet, metabolism, and our genetic makeup. Advances in technology have allowed nutrigenomics research to quickly expand, but much more work needs to be done before your designer diet is ready for prime-time. Several studies have attempted to customize diets for weight loss or reducing cholesterol based on the genetic information of research participants, but many have been met with disappointing results.

That being said, it’s not hard to imagine a future where going to the doctor or a registered dietitian involves taking a look at your genetic profile and walking out of their office with a meal plan optimized to lower your risk for conditions like obesity or diabetes, complete with recipe ideas and a grocery list. There’s a lot of work to do before we reach that point, and when we get there, the question still remains: Will we actually follow it?