Salt: Is it good for you? Or is it putting you at risk of high blood pressure?

There is an interesting new book out by Dr. Jame DiNicolantonio called The Salt Fix that makes the argument that the experts got it wrong as far as the salt and blood pressure connection goes.  In contrast, the American Heart Association tells us that our sodium intake causes our high blood pressure.  Either argument could be valid, depending on your genetics.

A recent study found that approximately 25% of people with mild hypertension had their blood pressure increase on a low sodium diet.    And a 2015 review fount that salt sensitivity for blood pressure is “estimated to be present in 51% of the hypertensive and 26% of the normotensive populations”.

Serious disclaimer timeout:
Everything written here is just for informational purposes. While some of the genetic variants that make a difference in salt intake are presented, there are more that aren’t covered by 23andMe or Ancestry data and are not discussed here.  If you have a heart condition or high blood pressure, don’t assume that you can know everything about your response to salt just from the information presented here.  The info here is a good starting point but may not be the whole picture for you.

Back to the topic at hand…

In the US, the FDA recommends 2,300 mg of sodium per day, which is about 6 g of salt.  The CDC’s sodium fact sheet claims that the average salt consumption is the US is around 3,400mg/day and recommends that everyone should cut back on sodium.

One thing to note when looking at studies on salt consumption is that many studies have different definitions of low-salt vs. high-salt depending on what is normally consumed for that population.

Quick Recap:
Some are sensitive to salt; it makes their blood pressure increase.
Some are insensitive to salt; it has no impact on blood pressure.
Some have blood pressure rise with a low salt diet.

Genetic variants for salt-sensitive blood pressure:

SLC4A5 (sodium-bicarbonate co-transporter gene ):
A study done on Caucasians and replicated in African Americans found that those with rs7571842 GG were protected from salt-sensitivity. [study]  Another study found that the G allele for rs7571842 or the G allele for rs10177833 significantly reduced the risk for salt-sensitive blood pressure changes (OR=.22).  [study]

Check your 23andMe results for rs7571842 (v.4 only):
GG: blood pressure less likely to be sensitive to salt
AG: blood pressure possibly not as sensitive to salt
AA: blood pressure likely to be sensitive to salt

 

Check your 23andMe results for rs10177833 (v.5 only):
GG: blood pressure less likely to be sensitive to salt
AG: blood pressure possibly not as sensitive to salt
AA: blood pressure likely to be sensitive to salt


LSS (lanosterol synthase) gene:
Endogenous ouabain ( EO ) is a vasoconstriction hormone that is sensitive to sodium levels.   For rs2254524, those with the AA genotype had the best response in terms of lowered blood pressure with a low salt diet.  Note that in this study, about 25% of people had an inverse response showing increased blood pressure with a low salt diet.  [study]

Check your 23andMe results for rs2254524 (v.4 only):
AA: blood pressure likely to decrease with low salt diet
AC: normal
CC: normal


RNLS gene:

rs12356177 (23andMe v.5 only) – those with the C allele had lowered blood pressure with a low salt diet. [study]

DDAH1 gene:
For rs11161637 (23andMe v.5 only) those with the GG genotype had less of a response to a low salt diet.  (Their blood pressure did decrease slightly, just not as much as those with the A allele, and, alternatively, their blood pressure didn’t increase as much with a high salt (18g/day) diet.) [study]

LSD1 gene:
“LSD-1 acts as a regulator of gene transcription through alteration in histone methylation.” For rs587168 (v.4, v.5)- AA (minor allele) carriers had a significantly higher increase in blood pressure with high salt in a study done with both African Americans and Hispanics [study]

Check your 23andMe results for rs587168  (v.4 and v5):
AA: blood pressure increases with high salt diet
CC: blood pressure likely not to increase all that much with high salt diet

 

Final thoughts…

As you can see, there are quite a few genes that play a role in blood pressure regulation.  The list above is in no way complete, and research is ongoing.  If you have high blood pressure, just because you have a gene that indicates you aren’t salt sensitive, doesn’t mean that you don’t have other genes that do increase your sensitivity to salt.

My big take away from this is that if a person has high blood pressure, there is about a 50/50 chance that reducing sodium intake will reduce blood pressure. If it were me, I would try a week of low salt intake while tracking blood pressure several times a day to see what, if any, effect reducing sodium actually has on my blood pressure.


Leave a Reply

Your email address will not be published. Required fields are marked *

Related Posts

Circadian Rhythm

Circadian Rhythms: Genetics at the Core of Our Internal Clocks

Circadian rhythms are the natural biological rhythms that shape our biology.  Most people know about the master clock in our brain that keeps us on a wake-sleep cycle over 24 hours.  This is driven by Read more…

Detox

Why Allegra may not work as well for you: genetics of ABCB1 proteins

Ever wonder why a certain medication may work great for a friend and do nothing for you?  One reason could be your genes. Let’s take fexofenadine (Allegra) for example.  You have watery eyes and a Read more…

Diet / Gene Interaction

Biohacks – Experiments and Optimizations Based on My Genetics

After three years of digging into genetics and learning all that I can about my genes, I wanted to get a little personal and share a few things that have worked for me. I would Read more…