FULL CLAIM: “Salt does not raise blood pressure”; “White salt can raise blood pressure because of chemicals, NOT because salt is bad!”; “Himalayan sea salt and Celtic sea salt […] help lower your blood pressure.”
REVIEW
High blood pressure, also known as hypertension, can damage the arteries, leading to heart disease and stroke. According to a World Health Organization (WHO) report in 2023, one in three adults worldwide has high blood pressure, and it is a major cause of preventable deaths.
Sean Christopher, a health coach with half a million followers on Facebook, published two videos that were widely viewed on Facebook and Instagram in April 2024 claiming that salt doesn’t increase blood pressure. As this review will explain, there is clear evidence that excess salt in the diet increases blood pressure and that reducing salt consumption can lower blood pressure and the risk of related health conditions.
The body compensates for excess sodium
Salt, or sodium chloride, is vital for our bodies to function, but its levels must be kept in a careful balance. Sodium also comes from other sources in foods, such as baking soda (sodium bicarbonate), MSG (monosodium glutamate), and sodium nitrate (a preservative).
When too much salt is consumed, the body retains water to dilute the high sodium concentration in the bloodstream. This increase in water volume raises the blood volume, forcing the heart to work harder and increasing pressure in the arteries. Over time, this elevated blood pressure can lead to severe cardiovascular problems.
Globally, the average adult consumes the equivalent of 10.8 grams of salt per day, more than double the WHO’s recommended limit of five grams per day.
Long-standing evidence shows the causal effect of sodium on blood pressure
The fact that salt increases blood pressure has been established for decades and is supported by the results of many research studies.
A study in 1988 of over 10,000 people from around the world showed a clear correlation between sodium levels in urine and an increase in blood pressure with age[1]. Another study of over 100,000 people in 2014 quantified precisely how much blood pressure increases for every additional gram of salt consumed daily[2].
Other studies have confirmed the relationship between cause and effect by demonstrating the benefits of reducing dietary salt. A 1997 meta-analysis (systematic combination of data from multiple studies) of 32 randomized clinical trials showed that lowering sodium consumption reduced blood pressure[3]. The study concluded that:
“The blood pressure reduction that would result from a substantial lowering of dietary sodium in the US population could reduce cardiovascular morbidity and mortality.”
A randomized controlled trial published in 2001 showed that reducing sodium intake led to lower blood pressure within a month, with further improvements seen by lowering consumption below the recommended upper limit[4]. Further demonstrating the impact of dietary salt, a 2009 meta-analysis of 13 studies of adult populations showed that high salt intake was associated with significantly increased risk of cardiovascular disease and stroke[5].
Sea salt also contains sodium and will raise blood pressure
Christopher claimed that the bleaching agents in white table salt are responsible for raising blood pressure and that unbleached sea salts could lower blood pressure. However, regardless of the origin of the salt, it still consists primarily of sodium chloride and can raise blood pressure when consumed in excess.
The American Heart Association says there is “very little difference” between the amount of sodium in table salt and sea salt. As the research studies previously mentioned showed, it’s the quantity of sodium intake that increases blood pressure.
Low-sodium salts are available, where the sodium is replaced by potassium. A Cochrane review of published studies found that these substitute salts “probably reduce blood pressure, non‐fatal cardiovascular events and cardiovascular mortality slightly in adults”[6].
In conclusion, Christopher’s claims that salt doesn’t raise blood pressure, and that sea salt can reduce blood pressure, are inaccurate and potentially harmful. The effect of salt consumption on blood pressure is well-established by dozens of research studies and a clear biological mechanism. Interventions to reduce sodium intake can lower blood pressure and its related cardiovascular risks.
REFERENCES
- 1 – Intersalt Cooperative Research Group. (1988) Intersalt: an international study of electrolyte excretion and blood pressure. Results for 24 hour urinary sodium and potassium excretion. The British Medical Journal.
- 2 – Mente et al. (2014) Association of Urinary Sodium and Potassium Excretion with Blood Pressure. New England Journal of Medicine.
- 3 – Cutler et al. (1997) Randomized trials of sodium reduction: an overview. The American Journal of Clinical Nutrition.
- 4 – Sacks et al. (2001) Effects on Blood Pressure of Reduced Dietary Sodium and the Dietary Approaches to Stop Hypertension (DASH) Diet. New England Journal of Medicine.
- 5 – Strazzullo et al. (2009) Salt intake, stroke, and cardiovascular disease: meta-analysis of prospective studies. The British Medical Journal.
- 6 – Brand et al. (2022) Replacing salt with low‐sodium salt substitutes (LSSS) for cardiovascular health in adults, children and pregnant women. Cochrane Database of Systematic Reviews.
