Preventing high blood pressure with a salt substitute
Quick Boost #10, and a wee salt alternative from Scotland that I personally like
Two back-to-back quick boosts! A chance to introduce a pretty tasty salt substitute made in Scotland! According to my analytics data, there are 96 subscribers to Examined from the UK, and I’m guessing maybe ~15 of those are from Scotland? I’ve been to Edinburgh, tried to remember how to say “the Firth of Forth,” and tasted Talisker Whiskey right from the source on the Isle of Skye. But I digress. Back to the study, and then to the Scottish salt substitute, which I hope will make this post more interesting.
We know that low sodium diets help people with high blood pressure. One way to achieve this is by using a salt substitute. These can be purchased at the grocery store and are usually on the shelf next to regular salt. Substitutes use less sodium chloride and more potassium chloride (which still tastes “salty”).
But for people without a diagnosis of high blood pressure: could using a salt substitute help prevent hypertension?
A new study was just published in the Journal of the American College of Cardiology, and finds that the answer is likely yes. In older adults they found that using a a salt substitute reduced the risk of developing high blood pressure by 40%.
The study
Researchers looked at 600 people, average age of 71 years old, living in elder care facilities in China. Half were given a salt substitute (made up of 62.5% sodium chloride, 25% potassium chloride, and 12.5% other flavorings), while the other half used regular sodium chloride.
Over two years, the salt substitute group saw about a 1 point decline in their average systolic blood pressure readings, and were 40% less likely to develop hypertension.
The regular salt group saw their average systolic blood pressures go up by about 7 points, with almost double the rates of developing hypertension.
The salt substitute group did not suffer any significant increased risk of low blood pressure events (referred to as hypotension episodes).
In pictorial form:
“In a separate editorial, also published in the Journal of the American College of Cardiology, one specialist said this research supports the ongoing trend of encouraging people to use salt substitutes as opposed to simply consuming less salt. Reducing salt intake would still be beneficial, of course, but it has also been difficult to get large groups of people to embrace this change.”
Sodium chloride and hypertension in general
I’m going to paraphrase summary recommendations from the clinical reference UpToDate here, in an effort to keep this quick:
Effect of sodium on blood pressure – A high dietary intake of sodium is associated with elevated blood pressure (BP) and the development of hypertension.
Rationale for dietary sodium reduction – Dietary sodium reduction can lower BP in both hypertensive and normotensive individuals, prevent hypertension, and enhance the BP response to most antihypertensive therapies.
In general, the extent of BP reduction as a result of reduced sodium intake is greater in Black patients, middle- and older-aged persons, individuals with hypertension, and, likely, patients with diabetes or kidney disease.
Dietary sodium reduction should decrease the risk of cardiovascular disease through its effects on BP and other effects that are independent of BP.
Clinical recommendations – In hypertensive individuals, we recommend reducing dietary sodium intake (Grade 1B). A reasonable goal is to reduce daily sodium intake to < 2.3 g of sodium/day, or <100 meq/day.
Further reductions have an even greater effect on BP but are difficult to achieve given the prevailing food supply.
In persons without hypertension, we also suggest reducing dietary sodium intake to the same level with the goal of preventing hypertension and decreasing the risk of stroke and other cardiovascular events (Grade 2B).
That salt substitute from Scotland
I picked up this salt substitute a while back from the Whole Foods on 10th and South in Philly. I bought it so I could try it out for my patients, maybe lower my own blood pressure a bit, and to get some iodized salt as the usual sea salt I cook with does not have much iodine at all. Iodized salt is an important source of iodine for the thyroid.
This salt works quite well. It still has sodium chloride, but the first ingredient is potassium chloride. It also provides magnesium chloride and potassium iodide.
Ingesting 1/4 teaspoon results in 170 mg of sodium intake. Looking at the label of my regular table salt, that’s much less than the 530 mg I usually get from a 1/4 teaspoon.
And it’s produced by a company based in East Kilbride, Scotland, which is the 6th largest locality in Scotland, has been inhabited since the Neolithic period, and takes its name from an Irish saint named St. Bride (or Brigit).
Precautions
Taking in too much potassium is a theoretical concern. People with kidney disease or medications that seriously increase potassium levels should discuss salt substitutes with their doctors. But another study published in The NEJM in 2021 found that salt substitutes were ok in terms of high potassium risks in the general population, including those who took ACE inhibitors and ARBs for high blood pressure:
The rate of serious adverse events attributed to hyperkalemia was not significantly higher with the salt substitute than with regular salt (3.35 events vs. 3.30 events per 1000 person-years; rate ratio, 1.04; 95% CI, 0.80 to 1.37; P=0.76).
That study, by the way, concluded:
Among persons who had a history of stroke or were 60 years of age or older and had high blood pressure, the rates of stroke, major cardiovascular events, and death from any cause were lower with the salt substitute than with regular salt.
Bottom line
Trying to eat less salt in the form of sodium chloride is beneficial for people with high blood pressure and people trying not to develop it. Salt substitutes still taste salty, but use potassium chloride to varying degrees, which has been associated with better cardiovascular outcomes. I cook with both regular salt and a salt substitute, and figure I’m lowering my total sodium intake this way. Everything, even dry topics like salt substitution, is more interesting when read with a Scottish accent.
So interesting! I'm on meds for high blood pressure. Growing up in a Chinese American household, we used a lot of salt, saltish stuff like soy sauce, pickled items. I watch my salt intake but could lower it more I think with your suggestion. Thanks!
😅Great recommendation, how does it taste?