Potassium-rich diets – such as salmon, avocados and bananas – may be linked to lower blood pressure, especially in women who consume a lot of salt, a study by UK-based EPIC (European Prospective Investigation into Cancer) Norfolk has revealed.
“The use of potassium-enriched salts in processed foods would be a logical strategy to attenuate the negative effects of sodium in these foods. Eating more fresh foods instead of processed foods would presumably make more sense because of their low sodium-high potassium ratio,” Liffert Vogt, study author and professor at the Amsterdam University Medical Centers, tells NutritionInsight.
“Implementation of high potassium diets will be presumably easier than lowering daily salt consumption. Restrictions of ingredients in diets are usually very difficult, while just adding ingredients, potassium in this case, to foods will be easier. Nevertheless, low salt consumption remains crucial, together with increasing daily potassium intake.”
“It is well known that high salt consumption is associated with elevated blood pressure and a raised risk of heart attacks and strokes.”
The researchers examined the relationship between potassium intake and blood pressure. In women, daily potassium intake (measured in grams) was associated with blood pressure – as intake increased, blood pressure decreased.
“Food companies can help by swapping standard sodium-based salt for a potassium salt alternative in processed foods. On top of that, we should prioritize fresh, unprocessed foods since they are both rich in potassium and low in salt.”
Preserving heart health
The relationship between potassium and blood pressure was only found in women with high sodium intake when the association was analyzed according to intake (low, medium, high), with every 1 g increase in daily potassium being related to a 2.4 mmHg lower systolic blood pressure.
The correlation between potassium and blood pressure was absent in men.
“Our study shows that in the long run, high potassium consumption is beneficial for both men and women. Yet, because the association with better blood pressure control was strongest in women consuming lots of salt and no association was found in men, our data suggest that the explaining mechanisms for the high potassium benefits differ between both sexes,” adds Vogt.
“Experimental data show that potassium might also have beneficial effects independent of blood pressure.”
According to the World Health Organization, adults should consume at least 3.5 g of potassium and no more than 2 g of sodium (5 g of salt) daily.
Vegetables, fruit, nuts, legumes, dairy products and fish are among the foods high in potassium.
“Health advice has focused on limiting salt intake, but this is difficult to achieve when our diets include processed foods,” adds Vogt. “Potassium helps the body excrete more sodium in the urine. In our study, dietary potassium was linked with the greatest health gains in women.”
Analyzing potassium intake
The EPIC-Norfolk study recruited 24,963 people (11,267 men and 13,696 women) from general practices in Norfolk, UK, between 1993 and 1997. Participants ranged in age from 40 to 79. For men, the average age was 59, while for women, it was 58.
Participants completed a questionnaire about their lifestyle practices and checked their blood pressure and a urine sample. Participants were categorized into tertiles based on their potassium and sodium intake (low, medium and high).
The findings unveiled that participants who consumed the most potassium had a 13% lower risk of cardiovascular events than those who consumed the least potassium. The comparable risk reductions were 7% and 11%, respectively, when men and women were separately examined.
“The relationship between potassium and cardiovascular events was the same regardless of salt intake, suggesting that potassium has other ways of protecting the heart on top of increasing sodium excretion,” details Vogt.
The amount of salt consumed affected the link between potassium and cardiovascular events in both men and women.
Overall, 13,596 (55%) participants experienced cardiovascular disease-related hospitalizations or deaths throughout a median follow-up of 19.5 years.
After accounting for factors such as age, sex, body mass index, sodium intake, lipid-lowering medications, smoking, alcohol use, diabetes and history of heart attack or stroke, the researchers examined the relationship between potassium intake and cardiovascular risk events.
