Potassium-fortified foods to lower blood pressure

Food and drink products designed specially for people with hypertension could soon be available on the market, after researchers claimed this week to have found the optimal amount of potassium needed in foods to reduce blood pressure.

The study, published in the current issue of The British Journal of Nutrition​, showed that a sustained low dose of potassium (24mmol daily) can lower blood pressure, thus decreasing the risk of strokes and cardiovascular disease. Technology commercialisation firm BTG said it will work with King's College London, which carried out the recent study, to licence technology for addition of potassium to foods to major food and beverage companies.

Hypertension is a serious and growing problem in many developing countries. A risk factor for stroke and cardiovascular disease, it is known to affect more than 100 million individuals throughout the world. It is thought to involve multiple risk factors including familial history of the disease, race, obesity, tobacco smoking, stress, and a high-fat or high-sodium diet in genetically susceptible individuals.

Donald Naismith, Emeritus Professor at King's College, said: "Potassium's health benefits have been known of for some time, but due to difficulties in defining optimal doses, its application has not been exploited beyond recommendations to eat foods naturally rich in it, such as bananas, oranges and potatoes. This new study will enable manufacturers to provide supplemented foods that have been proven to help decrease hypertension."​

Previous research has shown that foods with 10 per cent or more of the recommended daily allowance of potassium and a low level of sodium may reduce the risk of high blood pressure and strokes. However, most trials were too short, used a high dose of potassium, and produced conflicting results, noted researchers.

The team at King's College​ studied the effects of a daily dose of 24 mmol of potassium, equivalent to five portions of fruits and vegetables, on two groups of adults - 30 receiving potassium and 29 receiving a placebo - for a period of six weeks. The potassium group experienced a marked and significant decrease in mean arterial pressure (MAP), systolic blood pressure (SBP) and diastolic blood pressure (DBP) when compared with the group given the placebo. (Hypertension is recognised when systolic blood pressure is above 140mm Hg, diastolic blood pressure is above 90mm Hg, or a systolic and diastolic pressure of 20mm Hg is above normal baseline pressure.)

The differences in mean changes of blood pressure between the two groups were highly significant and achieved gradually during the length of the study. The changes observed in the treated group (7mm Hg in SBP and DBP) are far higher than the mean reported by previous studies or for severe salt restriction (2mm Hg) in hypertensive patients, said the researchers.

They conclude that a low daily dietary supplement of potassium, equivalent to the content of five portions of fresh fruits and vegetables, induced a substantial reduction in MAP, similar in effect to single-drug therapy for hypertension.

BTG​ is currently seeking to expand its portfolio of nutraceutical products.