Saturated Fat and Your Genes

SaturatedFatGenesRecent articles on coconut oil and saturated fat being bad for you have been making waves lately via social media.  It has brought up once again the decades-long debate about which type of fat is best.  Those in the paleo and ketogenic world are quickly pointing out the flaws in the article, while most people remain just a bit confused.

Is it possible that both sides are both right and wrong? It depends on your genes.  There have been several studies that investigated the effects of a high saturated fat diet on cardiovascular disease stratified by genetic variants.

ACE gene:
The angiotensin converting enzyme plays a role in maintaining blood pressure at a normal level.  A recent study looked at the interaction between a common variant (ACE deletion) and saturated fat.  It found that for those with the ACE deletion, a diet higher in saturated fat was associated with increased blood pressure and heart disease.  For those who were not homozygous for the variant, there was no effect on heart disease due to a diet higher in saturated fat.  About 20% of Caucasians are homozygous for the variant (a little more or a little less for other populations).

Check your 23andMe results for rs4343:

  • AA: ACE insertion/insertion
  • AG: heterozygous – ACE deletion/insertion
  • GG: ACE deletion/deletion  — increased risk of high blood pressure and heart disease on a diet higher in saturated fat.

APOA2 gene:
The protein produced by APOA2 is a type of high density lipoprotein (HDL).  Variants of the gene can result in either APOA2 deficiency or hypercholesteremia.  The most commonly studied variant, rs5082, decreases the level of APOA2.  It has been linked, in a number of different populations, to increased BMI, visceral fat, HDL levels and a lower risk of heart disease.  The studies that looked at this variant in conjunction with diet found that the risk for obesity was only for those who had a higher saturated fat intake, specifically, greater than 22g of saturated fat.  The variant is also linked to ghrelin levels, so it is thought that impaired satiety signaling from the saturated fat may play a role in the higher intake of food for those with the variant.[study] [study]  Studies have also found that this variant is linked to a lower risk of heart disease.

A study in the journal Nutrition took the link between saturated fat, APOA2 variant, and obesity one step further and looked into the role of saturated fat from dairy.  The conclusion was that higher fat dairy did play a role in the risk of obesity with rs5082.

Check your 23andMe results for rs5082:

  • AA: normal (wildtype)
  • GG: increased risk of obesity, especially with high saturate fat consumption; possibly lower risk of heart disease

TCF7L2 Gene:
TCF7L2 is a transcription factor gene that has been linked in many studies to type 2 diabetes risk.  A study looking at the effect of a high saturated fat meal on lipid levels found that for those with the minor allele there was a significant increase in triglycerides and total cholesterol.  Another study linked the variant to increased risk of metabolic syndrome in women with an even greater risk for those eating a diet higher in saturated fat.  Both metabolic syndrome and high triglycerides are linked to an increased risk of heart disease in many studies.

Check your 23andMe results for rs7903146:

  • CC: normal (wildtype)
  • TT: increased risk of metabolic syndrome especially with high saturated fat consumption; increased risk of T2D


Final thoughts:
We are all different in our dietary needs.  If you have the variants listed above, the American Heart Associations recommendations on cutting down on saturated fats may be worth considering.  I don’t necessarily agree with their recommendation to replace the saturated fat with PUFA, and I would also challenge you to read up on the inflammatory effects of high polyunsaturated fat (especially omega-6) consumption as well.

If you (like me!) don’t have any of the variants above and are looking for a good coconut oil, I really like the Carrington Farms coconut oil.  You can get it on Amazon, and I’ve also seen it at many grocery stores.

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