Most people don't consume enough potassium from their diet, and eating more potassium, not less sodium, may be the best advice for better blood pressure for many people, according to a new study.
It was estimated that doubling sodium intake without a change in potassium intake elevates blood pressure by 1–4%, while doubling potassium intake reduces blood pressure even when sodium intake was also doubled.
Less than 2% of adults in the U.S. are hitting the recommended daily potassium intake.
Even though the study was based on a modeling analysis of sodium and potassium intake, it calls into question blanket recommendations to cut salt intake; rather, the findings suggest that guidelines should emphasize dietary potassium and the ratio of sodium to potassium in the diet.
For most people, that may mean just getting more potassium.
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Should You Eat Less Salt?
Sodium and potassium are two electrolytes that help with fluid and blood pressure regulation in the body—maintaining balanced levels of both is crucial.
Most people probably eat too much salt (sodium) due to the highly processed nature of modern diets. The average intake in the U.S. is about 3,400 mg per day even though recommendations suggest 1,500–2,300 mg per day for most people.
Eating more salt increases blood pressure. And reducing sodium intake lowers blood pressure. However, this does not mean that everyone should eat as little salt as possible—less is not necessarily better.
For example, athletes and heavy exercisers should probably consume more sodium because they excrete more through sweat. Sodium needs are highly individual, and so is everyone's blood pressure response to sodium. Some people are salt-sensitive due to the presence of certain single-nucleotide polymorphisms (SNPs). For them, limiting sodium intake is probably wise in order to reduce their risk of developing hypertension and other cardiovascular diseases. (You can find out whether or not you have these SNPs by running your data through our genetic report).
How much sodium is safe? It depends a lot on your lifestyle and genetics, but according to some observational research, 3–6 grams of sodium per day minimizes cardiovascular disease risk, while less than 3 or more than 6 grams per day elevates it. Both too high and too low sodium intakes are associated with increased risk.
But what if a high sodium intake isn't the problem but instead, a low potassium intake?
Potassium regulates blood pressure in several ways:
- It causes our body to reabsorb less sodium and reduces fluid volume, which is one of the main drivers of high blood pressure.
- Increasing potassium intake also reduces the activity of a hormone known as aldosterone, which normally promotes sodium and fluid retention.
- Potassium promotes vasodilation—a relaxation and widening of arteries—thereby lowering blood pressure.
The problem? Less than 2% of adults in the U.S. are hitting the recommended daily potassium intake—that’s about 3,400 mg for men and 2,600 mg for women. Unlike sodium, when it comes to potassium, more does seem to be better (when it comes from the diet). An estimated intake above 1,500 mg per day is associated with a progressively lower risk of cardiovascular disease. (I discuss sodium and potassium intakes in relation to cardiovascular disease events in member Q&A session #7).
The fact that modern diets have too much sodium and not enough potassium is a major issue because the ratio of sodium and potassium intake seems to be the most important factor for blood pressure control—even more important than how much of these nutrients one consumes in isolation.
What constitutes "too much salt" might depend entirely on one's potassium intake.
