With all the dietary advice out there today, how can you know what is right for your body? Your genetic makeup is actually a good tool to use to start your own personalized nutrition journey to optimize your diet.
How does genetics affect nutrition?
Relating your genetics to your diet affords a unique new approach to improve health with specific customized dietary interventions.
I’ve boiled down 5 quick ways using your genetic data (23andMe, AncestryDNA, etc) to optimize your diet based on your genes.
#1) Are you genetically lactose intolerant?
While most people of European Caucasian ancestry produce lactase as an adult, about 10% of that population doesn’t produce lactase. For people of other ancestries, the majority do not produce lactase as adults.
Check your genetic data for rs4988235 (23andMe v4, v5; AncestryDNA):
A/A: Still produces lactase as an adult
A/G: Still produces lactase as an adult (less than those with A/A)[ref]
G/G: No longer produces lactase as an adult
Members: Your genotype for rs4988235 is —.
If you don’t produce lactase as an adult, you are relying on your gut microbiome to break down the lactose in milk. Drinking less milk at one time, switching to lactose-free milk, or boosting your gut microbiome with some lactose-digesting probiotics are all options for those without the ability to produce lactase.
Read Article: Genetics of lactose intolerance
#2) Are fruits and vegetables giving you enough vitamin A?
Beta-carotene, which makes carrots and sweet potatoes orange, is often considered to be a great source of vitamin A. But some people are much better at converting beta-carotene into vitamin A than others.
A deficiency in vitamin A can cause skin issues (dry scaly skin, acne, keratosis pilaris, cracked lips) and eye issues (dry eyes, problems with night vision).
There are two main genetic variants to check in the BCMO1 gene to see how well you convert beta-carotene.
C/T: decreased beta-carotene conversion
T/T: decreased beta-carotene conversion
Members: Your genotype for rs7501331 is —.
A/T: decreased beta-carotene conversion
T/T: decreased beta-carotene conversion
Members: Your genotype for rs12934922 is —.
If you have a “T” in both of the SNP’s above, your beta-carotene conversion is almost 70% less than normal. A “T” in just one SNP from above decreases your conversion by about 32%.[ref] Eating liver is a great way to get the retinol form of vitamin A that your body needs. Can’t stomach liver? A vitamin A supplement that includes retinol palmitate may work for you.[ref]
You don’t want to go too far overboard with supplementing with vitamin A since it does get stored by the body.
Related Article: BCO1 Gene: Converting Beta-Carotene to Vitamin A
#3) Is saturated fat increasing your risk of high blood pressure?
Check your genetic data for rs4343 (23andMe v4, v5):
- A/A: A/CE insertion/insertion
- A/G: A/CE deletion/insertion
- G/G: A/CE deletion/deletion – saturated fat intake may increase blood pressure
Members: Your genotype for rs4343 is —.
This is definitely a case where if you have the A/CE deletion and higher blood pressure, you should experiment with reducing saturated fat and see if your blood pressure comes down. The study showed approx. a 10 point average difference in systolic blood pressure for those with the A/CE deletion and high-fat diet.
Related Article: Interaction between high-fat diet, blood pressure, and your genes
#4) Will drinking coffee in the morning decrease your risk of a heart attack?
Check your genetic data for rs762551 (23andMe v4, v5):
- C/C: Slow metabolizer of caffeine, increased risk of heart attack with more than 2-3 cups of coffee per day
- A/C: Slow metabolizer of caffeine, increased risk of heart attack with more than 2-3 cups of coffee per day
- A/A: Fast metabolizer of caffeine, decreased risk of heart attack with 2 – 3 cups of coffee a day
Members: Your genotype for rs762551 is —.
Looking for a way to pep up your morning coffee? Here are a couple of options:
- Try Bulletproof coffee with Brain Octane oil.
- Try Four Sigmatic Lion’s Mane and Chaga mushroom extracts for cognitive benefits (my new favorite!):
- Roast your own green coffee beans. It is fairly easy to do, and the taste of freshly roasted coffee is outstanding. You can use an air popper or simply a skillet on a propane burner (outside, ’cause it is a bit smoky to roast it).
#4) Can I eat carbs?
A study came out recently showing that both low carb and low-fat diets were equally effective for weight loss. There are other studies showing differences in dieting results of low carb or low fat that depend in part on genetic variants. Looking at your genes may give you an idea of which diet would work best for you.
Amylase is the enzyme that digests carbs, starting in your mouth. A genetic variant in the amylase gene (AMY1-AMY2) predicts whether you are likely to produce a lot of the enzyme or less of the enzyme to break down carbs.
Check your genetic data for rs11185098 (23andMe v4 only):
- A/A: higher amylase activity
- A/G: intermediate amylase activity
- G/G: lower amylase activity
Members: Your genotype for rs11185098 is —.
Your genes also play a role in how carbohydrates are likely to affect your blood glucose levels.
Check your genetic data for rs2943641 (23andMe v4, v5): IRS1 gene:
- T/T: women had lower T2D risk with low-carb; men had lower T2D risk with lower fat diet[ref]
- C/T: women had lower T2D risk with low-carb; men had lower T2D risk with lower fat diet
- C/C: better results with high carb diet (weight loss, insulin)[ref]
Members: Your genotype for rs2943641 is —.
Check your genetic data for rs1800849 (23andMe v4): UPC3 gene:
- A/A: no decrease in glucose or insulin levels on high protein/low carb diet[ref]
- A/G: no decrease in glucose or insulin levels on high protein/low carb diet
- G/G: lower glucose levels, better weight loss on high protein/low carb diet
Members: Your genotype for rs1800849 is —.
If you are a lower amylase producer but want to try a higher carb / lower fat diet, you can supplement with the amylase enzyme. I recommend actually testing your blood glucose levels to see how you react to different foods/meals. Blood glucose testing kits are not all that expensive and will give you a way to quantify and keep track of your response.
Related Article: Digesting Carbohydrates: Amylase variants
I hope you have found something here that is useful. Personally, I’m often frustrated by the one-size-fits-all approach that so many health and wellness websites proclaim. While I didn’t have huge health problems, the little diet adjustments based on my genes have made a noticeable difference for me. For example, figuring out that I don’t convert beta-carotene to vitamin A led me to try a supplement of the retinol form of vitamin A. A month later I noticed that I didn’t have the little bumps (keratosis pilaris) on the back of my arms that had been there since childhood. (And yes, I did test it out to make sure it was vitamin A by stopping the supplement for a month, at which point the bumps came back.) While getting rid of bumpy skin isn’t earth-shattering, all the little tweaks to my diet and lifestyle based on what I’ve learned from my genes have added up to me being healthier and mentally sharper.
Related Articles and Genes:
Top 10 Genes to Check in Your Genetic Raw Data
These are 10 genes with important variants that can have a big impact on health. So check them out, cross them off your list if you don’t have them — and read the articles to learn more if you do carry the variant.
At the top of my supplement list is melatonin, and it has nothing to do with how well I sleep! Instead, the benefits of this ‘sleep hormone’ are many and varied, including boosting immune function, preventing Alzheimer’s disease, and staving off osteoporosis.
Carbohydrate metabolism: Your genes play a role in insulin and blood glucose levels
Genetic variations play a role in how people react to carbohydrates in the diet. Learn about a few genes that affect insulin or glucose levels based on carbohydrate consumption. Use your genetic raw data and discover how your body handles carbohydrates.
Debunking the “blood-type diet”
Reviewing the current research studies on the blood type diet, which show that there is a lot of doubt around whether you can base your diet on your blood type.
Cornelis, Marilyn C., et al. “Coffee, CYP1A2 Genotype, and Risk of Myocardial Infarction.” JAMA, vol. 295, no. 10, Mar. 2006, pp. 1135–41. PubMed, https://doi.org/10.1001/jama.295.10.1135.
—. “Coffee, CYP1A2 Genotype, and Risk of Myocardial Infarction.” JAMA, vol. 295, no. 10, Mar. 2006, pp. 1135–41. PubMed, https://doi.org/10.1001/jama.295.10.1135.
Dzialanski, Zbigniew, et al. “Lactase Persistence versus Lactose Intolerance: Is There an Intermediate Phenotype?” Clinical Biochemistry, vol. 49, no. 3, Feb. 2016, pp. 248–52. PubMed, https://doi.org/10.1016/j.clinbiochem.2015.11.001.
Ericson, Ulrika, et al. “Sex-Specific Interactions between the IRS1 Polymorphism and Intakes of Carbohydrates and Fat on Incident Type 2 Diabetes.” The American Journal of Clinical Nutrition, vol. 97, no. 1, Jan. 2013, pp. 208–16. PubMed, https://doi.org/10.3945/ajcn.112.046474.
Leung, W. C., et al. “Two Common Single Nucleotide Polymorphisms in the Gene Encoding Beta-Carotene 15,15’-Monoxygenase Alter Beta-Carotene Metabolism in Female Volunteers.” FASEB Journal: Official Publication of the Federation of American Societies for Experimental Biology, vol. 23, no. 4, Apr. 2009, pp. 1041–53. PubMed, https://doi.org/10.1096/fj.08-121962.
—. “Two Common Single Nucleotide Polymorphisms in the Gene Encoding Beta-Carotene 15,15’-Monoxygenase Alter Beta-Carotene Metabolism in Female Volunteers.” FASEB Journal: Official Publication of the Federation of American Societies for Experimental Biology, vol. 23, no. 4, Apr. 2009, pp. 1041–53. PubMed, https://doi.org/10.1096/fj.08-121962.
“Low-Fat vs. Low-Carb? Major Study Concludes: It Doesn’t Matter for Weight Loss.” Examine.Com, 7 Feb. 2020, https://examine.com/nutrition/low-fat-vs-low-carb-for-weight-loss/.
Luis, Daniel Antonio de, et al. “Effect of -55CT Polymorphism of UCP3 on Insulin Resistance and Cardiovascular Risk Factors after a High Protein/Low Carbohydrate versus a Standard Hypocaloric Diet.” Annals of Nutrition and Metabolism, vol. 68, no. 3, 2016, pp. 157–63. www.karger.com, https://doi.org/10.1159/000444150.
Schüler, Rita, et al. “High‐Saturated‐Fat Diet Increases Circulating Angiotensin‐Converting Enzyme, Which Is Enhanced by the Rs4343 Polymorphism Defining Persons at Risk of Nutrient‐Dependent Increases of Blood Pressure.” Journal of the American Heart Association: Cardiovascular and Cerebrovascular Disease, vol. 6, no. 1, Jan. 2017, p. e004465. PubMed Central, https://doi.org/10.1161/JAHA.116.004465.
Debbie Moon is the founder of Genetic Lifehacks. Fascinated by the connections between genes, diet, and health, her goal is to help you understand how to apply genetics to your diet and lifestyle decisions. Debbie has a BS in engineering and also an MSc in biological sciences from Clemson University. Debbie combines an engineering mindset with a biological systems approach to help you understand how genetic differences impact your optimal health.