Blood pressure may not be something that you think much about – unless your doctor is harping about it being high or low. The CDC statistics, though, make a pretty compelling argument that a lot of us should be thinking about blood pressure. It is estimated that ~ 1/3 of US adults have high blood pressure, which contributes to more than 410,000 deaths each in the US in a year. [ref]
Genetics combines with diet and lifestyle factors to cause high blood pressure. There are quite a few genes that influence blood pressure, but this article only focuses on one (impactful) gene, AGTR1 (angiotensin I receptors).
Researchers, doctors, public health officials, etc all seem to have different ways of defining high blood pressure (hypertension). In general, the following blood pressure ranges are what are used in most studies for adults.
Systolic (top number):
Diastolic (bottom number):[ref]
The Mayo Clinic explains that high blood pressure can be due to the amount of blood pumped and the amount of resistance – or constriction – in the arteries.[ref]Your body’s blood pressure is a tightly regulated system that depends on a lot of factors.
Angiotensin is a hormone that is part of the renin-angiotensin-aldosterone system (RAAS) of blood pressure regulation. To increase blood pressure, angiotensin II causes the blood vessels to constrict, thus upping the pressure.
Angiotensin I is a precursor hormone that is converted into angiotensin II by the ACE enzyme (angiotensin-converting enzyme). Stopping that conversion of angiotensin I into II by blocking the ACE enzyme decreases blood pressure. ACE inhibitors are a commonly used type of blood pressure medication. (See article on ACE gene variants)
For angiotensin II to constrict blood vessels (and increase blood pressure) it must bind to its receptor. The AGTR1 gene codes for the angiotensin II receptor type-1. Common genetic variants increase the expression of the angiotensin II receptor 1 (AGTR1) gene — thus causing blood pressure to increase when there is abundant angiotensin II.
AGTR1 gene: Angiotensin II receptor type-1
Check your genetic data for rs5186 A1166C (23andMe v4, v5; AncestryDNA):
Note that the increased risk of high blood pressure seems to be the greatest in Caucasian populations. Some studies of other population groups find a smaller increase in the risk of high blood pressure[ref] or even no statistical risk. [ref]
Other studies on this variant show that the rs5186 A/C or C/C genotype is associated with:
Other AGTR1 genetic variants (less impactful but perhaps adding to above risk):
Check your genetic data for rs3772622 (23andMe v4, v5; AncestryDNA):
Check your genetic data for rs1492078 (23andMe v4; AncestryDNA):
Some studies suggest that a high-fat diet, in part, increases the rs5186 impact on blood pressure. [ref] If you have high blood pressure and carry the risk allele for rs5186, try experimenting with a lower-fat diet to see if it decreases your blood pressure.
You may be assuming that salt consumption would interact with this genetic variant… (I did!) But I could only find one research study that looked at salt sensitivity and the AGTR1 gene. It showed no interaction. [ref]
Blood pressure meds:
The commonly prescribed blood pressure medications losartan and valsartan act on the AGTR1 receptor, as do other angiotensin receptor blockers (ARBs).
Natural angiotensin-receptor blockers include:[ref]
If you are on blood pressure medication, check with your doctor before adding in any of the natural supplements that lower blood pressure. The interaction could cause your blood pressure to go too low.
More to read:
For some interesting reading on the topic of high blood pressure and heart disease, check out Dr. Malcolm Kendrick’s blog series on what causes heart disease. He has a bit of a contrarian view of the role of cholesterol in heart disease, and his writing is informative and thought provoking.