Our genes impact our bodily responses to different nutrients

Written by Emily Chow, Student in the Nutrition and Food Science program at the University of Alberta and reviewed by our Health Stand Nutrition Dietitian Team  

How well does your body absorb vitamin D from the sun? How well does your body respond to caffeine? Nutrigenomics may provide you with that answer. Nutrigenomics focuses on the relationship between nutrition and genomic expressions. It explains the influence of genetic variations on the response to food and how it could contribute to disease susceptibility. You may also hear the term “nutrigenetics” used interchangeably.

The idea of nutrigenomics has opened up the idea of personalized diets based on your genetic makeup. The difference in genes can predict how your body will respond to certain nutrients. Even people of the same gender, age and lifestyle can all metabolize and utilize nutrients distinctly. For example, variations in the MTHFR gene have been studied to affect the capacity to process folate. Another example includes the inflammatory TNF-alpha gene which has been researched to be inhibited by allium foods i.e. garlic, leeks, etc. Variations in this gene could alter this interaction and how you may respond to it. 

In this blog post, we’ll be discussing how nutrigenomics testing is done, the potential benefits and drawbacks of nutrigenomics as well as asses its validity based on research studies.  

Nutrigenomics Testing 

Nutrigenomic testing kits are widely available within Canada through commercialized businesses. These genetic assessments analyze the user’s genetic variations and provide information on how the user responds to different nutrients. This is often completed through a saliva sample, cheek swab sample or finger-prick blood sample. The sample is then sent off to a laboratory for analysis. Results can provide information on your likelihood to crave sweets, your ability to lose weight with increased protein or bodily responses to caffeine. These tests sometimes include a session with a healthcare professional to guide you through recipes and meals that cater to your DNA. Nutrigenomix is one of the few companies that is administered by a medical professional because CEO Ahmed El-Sohemy wanted to “restore credibility to the field”.  

Potential Benefits of Nutrigenomics  

Now that we’ve looked into what nutrigenomics is and nutrigenomics testing, we will now look into some of the potential benefits of nutrigenomics:

1. Individualized information 

Nutrigenomic diet suggestions can offer a better understanding of how certain foods and nutrients will affect each individual. 

2. Diet-related diseases 

Nutrigenomic data can provide information for the prevention or delay of chronic diet-related diseases. 

3. Allergies and food intolerances 

Nutrigenomics data can reveal undiagnosed food sensitivities and intolerances. 

4. Supplements 

Nutrigenomics data can help determine which supplements your body needs for optimum health. 

Potential Drawbacks of Nutrigenomics 

1. Costly and timely 

Testing and reporting can be a costly and timely process that may not be worthwhile. 

2. Nutrigenomics won’t solve every nutrition issue 

Genes are just one factor that influences your health. Other key factors include lifestyle, health history and personal preferences. 

3. Validity 

Genetic testing and reports must be interpreted by a healthcare professional to make qualified decisions on the patient. There also may be a lack of sufficient research for this diet to be considered valid.  

4. Privacy 

These testing companies have a vast collection of DNA which may become a privacy concern. Some of these companies’ privacy policies indicate they may share personal data with third parties. The Federal Trade Commission warns that hacking is very possible.  

5. Disappointing results 

Testing could also lead to unexpected health results because users may be dissatisfied with how unactionable the data is. Genes are responsible for less than 10% of diet-related disorders 

Is Nutrigenomics Valid? 

Research on nutrigenomics is limited, but some studies suggest that personalized DNA diets can be favourable to the health of the population. Research by the British Medical Journal suggested individuals with personalized nutrigenomic interventions were able to “motivate long-term improvements in dietary fat intake above and beyond gold standard population-based interventions”. Other studies have shown that this concept may not be as promising as thought. One study found that a nutrigenomic diet did not have any dietary weight loss effects in a group of overweight individuals.

While the nutrigenomics diet can be promising, there is a lack of sufficient evidence to be considered valid clinically. More research is also required to determine how long these dietary changes will persist in the long run. While researchers insist there is no inherent harm to nutrigenomic testing, premature or unrealistic claims of testing can be aversive to credible research. While some studies suggest that personalized genetic diet interventions may be more effective than general diet interventions, the actual effect of nutrigenomic diets is largely uncertain. 

The Bottom Line about Nutrigenomics

The nutrigenomic diet involves a genetic test to offer personalized diet suggestions based on your genetic variations. This educates people to consume optimum levels of certain nutrients based on their genetic needs. The nutrigenomics diet is a way for us to personalize nutrition to each individual and it may replace the one-size-fits-all diet. While there may be no harm in completing a genetic nutrigenomic test, recall that genetics are not the sole factor in determining your health status.  

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