An increased intake of 'good' potassium salts could contribute significantly to improving blood pressure at the population level. The favorable effect brought about by potassium is even estimated to be comparable with the blood pressure reduction achievable by halving the intake of 'bad' sodium salts (mostly from table salt). Those are the conclusions drawn by Linda van Mierlo and her colleagues at Wageningen University, the Netherlands, and Unilever in their investigation of the consumption of potassium in 21 countries. An article describing their findings appeared in the journal Archives of Internal Medicine on 13 September.
The risk of developing cardiovascular diseases rises as blood pressure increases. In Western countries only 20-30% of the population has 'optimal' blood pressure, with the systolic (maximum) pressure being lower than 120 mm Hg and the diastolic (minimum) pressure lower than 80 mm Hg. Blood pressure increases with age in most people. Men more often have a higher blood pressure than women.
Diet and lifestyle plays an important role in managing blood pressure. High intakes of sodium and low intakes of potassium have unfavorable effects on blood pressure. Therefore, reducing the consumption of sodium and increasing the consumption of potassium are both good ways to improve blood pressure.
The study carried out by food researchers from the Human Nutrition department at Wageningen University and from the Nutrition & Health department at Unilever demonstrates that the average potassium intake in 21 countries including the US, China, New Zealand, Germany and the Netherlands varies between 1.7 and 3.7 g a day. This is considerably lower than the 4.7 g a day, which has been recommended based on the positive health effects observed at this level of intake.
A hypothetical increase in the potassium intake to the recommended level would reduce the systolic blood pressure in the populations of these countries by between 1.7 and 3.2 mm Hg. This corresponds with the reduction that would occur if Western consumers were to take in 4 g of salt less per day. The intakes of both potassium and sodium are therefore of importance in preventing high blood pressure.
Earlier studies have shown that salt reduction of 3 g per day in food could reduce blood pressure and prevent 2500 deaths per year due to cardiovascular diseases in the Netherlands. In Western countries, salt consumption can be as high as 9-12 g a day whereas 5 g is the recommended amount according to WHO standards. Most household salt is to be found in processed foods such as bread, ready-made meals, soups, sauces and savoury snacks and pizzas. An effective way of increasing potassium intake is to follow the guidelines for healthy nutrition more closely, including a higher consumption of vegetables and fruit. In addition, the use of mineral salts in processed foods - by which sodium is partly replaced by potassium - would contribute to an improved intake of both sodium and potassium.
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Van Mierlo LAJ, Greyling A, Zock PL, Kok FJ, Geleijnse JM. Suboptimal potassium intakes and potential impact on population blood pressure. Archives of Internal Medicine 2010; 170 (16): September 13.