A diet rich in the vital element affects the sexes differently.
These include apricots, bananas, avocados, tomatoes, salmon, lots of nuts and dark chocolate: they are all foods with a high potassium content. A diet that contains plenty of it can protect women in particular from high blood pressure – and reduce the risk of cardiovascular disease for both sexes, as researchers led by Liffert Vogt from the University Hospital Amsterdam have found out. They published their findings in the European Hart Journal.
For their investigations, the scientists used data from the British observational study Epic-Norfolk, which included almost 25,000 patients aged 40 to 79 from general practices in the British county of Norfolk. They had been thoroughly medically examined and questioned, and urine samples had also been taken. The study ran from 1993 to 1997, with a follow-up of nearly 20 years.
The daily excretion of sodium and potassium could also be calculated from the urine samples of the participants. The Dutch researchers compared these values with the blood pressure values of the test subjects. It was shown that there was a connection between the amount of potassium and the systolic blood pressure (upper value) in women – in the form that the blood pressure fell with increasing potassium intake; for example, every one gram increase in daily potassium intake was associated with a 2.4 mmHg lower systolic reading.
In men, on the other hand, such a correlation between the amount of potassium and blood pressure could not be found. However, in both sexes, higher potassium intake was associated with a lower incidence of cardiovascular events such as heart attack or stroke, for which high blood pressure may be a cause.
Diet too high in salt
However, the risk was reduced more in women than in men. During the almost 20-year follow-up period of the Epic Norfolk study, 55 percent of the participants had to be treated in hospital for cardiovascular disease or even died from it. After taking into account other factors such as age, weight, diabetes, smoking or alcohol consumption, the analysis showed that women who consumed a particularly large amount of potassium suffered a cardiovascular event 11 percent less frequently than women who consumed little potassium. In men, the risk was reduced by only seven percent.
High sodium consumption, i.e. eating too much salt, is considered a risk factor for both high blood pressure and cardiovascular disease (as a possible consequence). The German Society for Nutrition recommends adults a maximum of six grams of table salt a day, this amount corresponds to about one teaspoon. The World Health Organization puts the amount even lower at five grams per day. In fact, according to the website of the consumer center, men in Germany consume an average of ten grams and women 8.4 grams of salt a day – not only through their own seasoning, but also through the high salt content in many foods.
Potassium, in turn, promotes the excretion of sodium in the kidneys. The researchers see this and the fact that this corrects the state of “hypervolaemia” caused by too much salt as possible reasons for the positive effects of potassium on blood pressure and the cardiovascular system as a whole. Hypervolemia refers to an increased volume of blood in the bloodstream, for example because too little water is excreted through the kidneys.
However, a connection between potassium and fewer cardiovascular incidents could also be determined independently of the salt intake – potassium should therefore have another effect in addition to the increased sodium excretion, concludes Liffert Vogt’s team.