Type-2 diabetes affects about 9% of the US population and millions of people worldwide.
For the over 65 crowd, the statistics are even more startling: one in four has type-2 diabetes.
While the overall numbers are scary, it is interesting to note that the peak for new cases was in the ’90s, with a decrease in cases from 2005-2017.[ref]
Diabetes is thought to be caused partly by the environment and partly due to genetics. Genetic susceptibility has been linked to a number of different genes, but one that stands out as being particularly relevant to almost all population groups is the TCF7L2 gene.
The TCF7L2 (transcription factor 7-like 2) gene is involved in the regulation of blood glucose level with insulin by affecting the expression of pro-glucagon. Variants in TCFL2 are tied to type-2 diabetes, obesity, higher BMI, and larger waist circumference.
The SNPs listed below have been found to up-regulate TCF7L2 in pancreatic beta cells.[ref] The up-regulation is thought to impair insulin secretion from the beta cells rather than causing insulin resistance. [ref] [ref]
Why is this important? If you have one of the TCF7L2 variants that increase your risk of diabetes, there are lifestyle and diet choices that have been shown in studies to negate that increased risk.
Genetic Variants in TCF7L2:
Check your 23andMe results for rs7903146 (v4, v5):
Studies on rs7903146 show:
Check your 23andMe results for rs12255372 (v4, V5):
Studies on rs12255372 show:
Check your 23andMe results for rs4506565 (v4, v5):
Cut out fried food:
Quite a few studies (above) looked at the amount and type of fat and the effect on the risk of type 2 diabetes. Overall, decreasing fat, specifically omega-6 polyunsaturated fats such as sunflower, safflower, corn, cottonseed, sesame, soybean and peanut oils, seems to reduce the risk of diabetes for those with the risky genotypes.
Check your glucose:
The above variants can lead to higher fasting blood glucose levels. Blood glucose meters aren’t expensive and are widely available. Watch your glucose levels and look into a lower glycemic index diet. Everyone has individual differences in how their blood glucose levels change in response to foods, so regular testing can help you know if you are on the right track.
Blame your mom:
Inheriting the TCF7L2 variants from your mother instead of your father may increase your risk of diabetes. [ref]
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