With all the dietary advice out there today, how can you know what is right for your body?
I’ve boiled down 5 quick ways that you can use your genetic data (23andMe, AncestryDNA, etc) to optimize your diet to fit your genes.
#1) Are you genetically lactose intolerant?
Lactase is the enzyme that breaks down the sugar, lactose, that is found in milk products.
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 23andMe results for rs4988235
(v.4, v.5 of 23andMe; AncestryDNA):
A/A: Still produces lactase as an adult
A/G: Still produces lactase as an adult (less than those with A/A – study
G/G: No longer produces lactase as an adult
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.
#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.
: 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%.[study]
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.
#3) Is saturated fat increasing your risk of high blood pressure?
A recent study
looked at the influence of a higher fat diet (mainly from saturated fat) on blood pressure. The study found that the higher saturated fat diet caused higher blood pressure only in those with a genetic variant known as A/CE deletion.
Check your 23andMe results for rs4343 (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
Lifehacks: 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.
Read more about the interaction between high-fat diet, blood pressure, and your genes.
#4) Will drinking coffee in the morning decrease your risk of heart attack?
Coffee is the number one source of antioxidants in the US diet. Our ability to metabolize the caffeine in coffee varies quite a bit according to our genes. About half of Caucasian populations are fast metabolizers of coffee, with the other half being slower metabolizers.
Studies have linked coffee consumption to an increased or decreased risk of heart attacks — depending on your caffeine metabolism genes.[study
Check your 23andMe results for rs762551 (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
Common sense dictates if you have a family history of heart disease and slow caffeine metabolism genes, you should consider keeping your coffee consumption at 2 or fewer cups of coffee on an average daily basis. Alternatively, if you are a fast metabolizer of caffeine you can reduce the risk of heart attack with 3 cups of coffee a day. The study
also showed that for those younger than age 59 who were fast metabolizers of caffeine, drinking 4+ cups a day also decreased the risk of heart attack.
Looking for a way to pep up your morning coffee? Here are a couple of options:
#5) What about 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 of 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.
Your genes also play a role in how carbohydrates are likely to affect your blood glucose levels.
Check your 23andMe results for rs2943641 (v4, v5) IRS1 gene:
- T/T: women had lower T2D risk with low-carb, men had lower T2D risk with lower fat diet[study]
- 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)[study]
Check your 23andMe results for rs1800849 (v4) UPC3 gene:
- A/A: no decrease in glucose or insulin levels on high protein/low carb diet [study]
- 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
Lifehacks: 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.
Read more about amylase genes and carb metabolism and blood glucose genes.
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 lead 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 the vitamin A by stopping the supplement for a month, at which point the bumps came back.) While getting rid of bumpy skin isn’t earthshattering, 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.