“It’s in my genes” is a phrase most of us have uttered at one time or another. For some it might equate to eating a lot of fatty foods without ever gaining an ounce, while for others it might mean an increased risk to a certain disease because it “runs in the family.”
But what if your genes aren’t relegated to how you’re born, but can be changed by your own actions — namely, the foods you eat? That could have long-lasting impact into how we prevent or treat a variety of diseases.
What Are Nutrigenomics?
Although I’ve always advocated that food is medicine, this next level might sound like sci-fi or a field far in the future. In fact, this idea that food influences how our genes behave and that our genes respond differently to certain nutrients is the basis of nutritional genomics, more commonly known as nutrigenomics. While still a burgeoning scientific field, nutrigenomics is poised to become a game-changer in the health field.
According to the UC Davis NCHMD Center of Excellence for Nutritional Genomics, there are five tenets of nutrigenomics, which can be summarized as:
- Diet can be a serious risk factor for a number of diseases;
- Common dietary chemicals can act on the human genome to alter gene activity or gene structure;
- How much someone’s diet dictates whether they’re healthy or sick may depend on an individual’s genetic makeup;
- Some genes that are regulated by diets — and even their normal, common variants — likely play a role in the onset and progression of chronic diseases, along with how severe they become; and
- Using a personalized approach to a person’s diet, based on their nutritional requirements, nutritional status and their genotype can prevent, mitigate or even cure chronic disease. (1)
Essentially, nutrigenomics examines how what we eat affects our genes’ activity, like what proteins they produce according to our DNA.
Some of this isn’t entirely new. For example, researchers believe that only about 25 percent of the difference between how long people live is based on genes. (2) Instead, differences in nutrients and the amount of calories consumed seems to play a larger role than previously believed.
Take also the fact that some people are lactose intolerant, while others have no problems digesting cow’s milk. In babies who are intolerant to milk, it’s because of a mutation in the LCT gene. In adults who develop lactose intolerance later in life, gradually decreasing activity of the LCT gene is to blame. (3) Of course, many people experience no issues with lactose their entire lives — their LCT genes have not been affected in the same way.
Another example is how people react to caffeine. For years, drinking coffee was touted as a way to reduce the risk of heart disease. But for some coffee drinkers, the risk of heart disease seemed to increase, contrary to most major studies. In these bodies, coffee takes longer to metabolize, meaning the caffeine lingers in the bloodstream for longer, affecting blood pressure and effectively negating any positive benefits a cup of joe might have.
Along with nutrigenomics are also two closely related fields: nutrigenetics and nutrigenomics. Nutrigenetics studies how variations in our genes affects our health and nutrition — I think of nutrigenetics as the “inside out” approach, since it starts with how the genes inside our bodies affect how we use foods and nutrition, while nutrigenomics is “outside in,” or how the nutrients we consume outside the body affect our genes.
There’s also epigenetics, which considers how our environment, along with nutrition and exercise, affects genes that get turned off or on in the body.
But what kind of benefits will nutrigenomics have on your own health?
3 Potential Benefits of Nutrigenomics
1. Diet recommendations will no longer be “one size fits all.”
Diet guidelines are typically based on large-scale studies. While they work for most people, those statistical outliers get lost in the shuffle. That’s why some diets work really well for your co-worker, but don’t budge the scale when you try it.
With nutrigenomics, individuals will get a clearer understanding of how their body the foods they consume. By analyzing information on your genes and their variants, diet, lifestyle and environment, a nutritional expert will be able to create a nutrition plan that’s optimized for your body’s health.
2. Prescription medications will improve, too.
Just as some bodies react differently than the norm to certain foods, so do bodies and medications. By embracing nutrigenomics, we’ll see prescription drugs go the personalized route as well.
Currently, most doctors and patients don’t know whether a medication will cause an adverse drug reaction (ADR) in someone until it happens; and the incidence of serious and fatal ADRs in the U.S. is high and an important clinical issue. (4)
With nutrigenomics, as doctors better understand how a patient’s body handles nutrients and supplements, they’ll be able to better predict the effects of a particular drug or a dosage without having to take the “wait and see” approach that so often happens now.
3. We might be able to prevent obesity.
The implications for preventing and treating diseases like obesity with nutrigenomics is massive. For example, one study looked at how nutrigenomics could be used in weight loss. (5)
The researchers used 24 variants in 19 genes related to metabolism to design a personalized, calorie-controlled diet. They used this plan for 50 people who, along with it, were given exercise advice optimized for their genotype. A control group of 43 people was given just generic diet and exercise advice.
After nearly a year, those in the personalized group were more likely to have lost weight and kept it off. They also lost more weight than the control group, saw longer-term reduction in their body mass index and improved their blood glucose levels.
As great as nutrigenomics sound, there are several important considerations.
For starters, we’re still learning quite a bit about nutrigenomics. It’s dangerous to think of it as a cure-all fix for health problems. The amount of information available is overwhelming, and it will take time for scientists to determine what genes and gene expressions need to be focused on in order to achieve positive health outcomes.
Within genetic subgroups, it will also be critical to test whether personalized recommendations produce the expected outcome and benefits. This constant testing will be necessary to ensure the future of nutrigenomics.
It’s also important that this new nutritional approached is integrated into the training of nutritionists, dietitians and general practitioners, so that nutrigenomics becomes a part of the larger medical conversation and isn’t siloed away.
And speaking of, as nutrigenomics become more popular, how the information is made available to the public and used is also a topic of hot debate. For example, there are several companies that currently use a swab of the cheek to obtain DNA and promise to create a nutrigenomics profile for a person.
As of now, however, no physicians really endorse these programs; the complexities involved in interpreting nutrigenomics for each individual mean that, right now, it’s not really suited for a mail-in service. In fact, in 2006, the U.S. Government Accountability Office found that these tests lacked scientific credibility and were misleading. (6)
There are ethical issues involved with nutrigenomics as well. Who should have access to nutrigenomics — should insurance companies cover testing, or is it only available to those who can pay out of pocket? And what happens if someone is found to have a genetic susceptibility — that can be a major emotional burden and not one that everyone is ready to bear.
- Nutrigenomics looks at how what we eat affects our genes’ activity, like what proteins they produce according to our DNA.
- Nutrigenomics is an exciting, emerging field with a lot of promise in how we might treat and prevent disease through nutrition.
- Diet and medication recommendations will no longer be “one size fits all,” helping people avoid adverse reactions and find an individualized plan that works for their body.
- Because nutrigenomics is still a relatively new field, there are a lot of things to consider before it becomes a common, widespread way to treat people.