Suboptimal Potassium Intake and Potential Impact on Population Blood Pressure FREE

Small reductions in blood pressure (BP) on a population level could have a substantial impact on cardiovascular disease risk.¹ This is especially relevant considering that the majority of the population has suboptimal BP levels. Dietary sodium reduction is a clearly established lifestyle change that has great potential to improve public health. Potassium, on the contrary, received much less attention. Nevertheless, a substantial body of data shows that increasing potassium intake lowers BP.² We reviewed population data on potassium intake and estimated the potential impact of increased potassium intake on population BP levels.

We searched PubMed and contacted health authorities worldwide for national population-based dietary surveys conducted from 1990 to 2009 that included data on potassium intake in more than 1000 adults. We defined the recommended level of potassium intake at 4.7 g/d, based on the Dietary Reference Intakes from the Institute of Medicine.² The effect of dietary potassium on systolic BP was set at 1.0–mm Hg reduction per 0.6 g/d increase in intake, based on estimates from the INTERSALT study,³ and we assumed this relation to be linear. Population BP data were obtained for Finland, the United Kingdom, and the United States, representing populations with relatively high, medium, and low potassium intakes.^4- 7 For these countries we estimated the potential impact of increasing potassium intakes on population systolic BP levels and classification in different systolic BP categories, assuming a uniform shift in the population BP distribution, independent of initial BP level.

In 21 countries spread across North America, Europe, Asia, and Oceania, the mean potassium intakes ranged from 1.7 g/d (China) to 3.7 g/d (Finland, the Netherlands, and Poland) (Figure) (references and data are available at http://www.wageningenuniversity.nl/UK/newsagenda/news/). Mean intakes in women were generally lower than in men. Based on our assumptions and intake data from Finland, the United Kingdom, and the United States, a hypothetical increase in potassium intake to 4.7 g/d would shift the population systolic BP distributions to 1.7– to 3.2–mm Hg lower levels in Western countries. This is in the same order of what can be predicted for a reduction in salt intake from 9 to 5 g/d. This theoretical increase in potassium intake in these countries would increase the percentage of men and women in the optimal systolic BP category (<120 mm Hg) by approximately 2% to 5% and 4% to 8%, respectively, and decrease the percentage of men and women with systolic BP levels in the higher range (≥140 mm Hg) by approximately 2% to 5% and 4%, respectively.

Increasing current potassium intakes in populations to recommended levels may lower population systolic BP in Western countries by 1.7 to 3.2 mm Hg, which can be predicted to reduce the risk of stroke mortality by 8% to 15% and the risk of heart disease mortality by 6% to 11%.¹ This is of similar magnitude to what can be achieved by lowering sodium intake and highlights the importance of dietary strategies focusing on both reducing sodium intake and increasing potassium intake. There are various ways to improve intakes of minerals in the population. Adherence to dietary guidelines, with ample fruit and vegetables, whole grains, and low-fat dairy products, should be promoted. Food companies can help by promoting the availability of healthier foods and also by improving the type and content of minerals in their products.

Correspondence: Dr Geleijnse, Division of Human Nutrition, Wageningen University, PO Box 8129, 6700 EV Wageningen, the Netherlands (marianne.geleijnse@wur.nl).

Author Contributions: Dr Geleijnse had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. Study concept and design: van Mierlo, Greyling, Zock, and Geleijnse. Acquisition of data: van Mierlo and Greyling. Analysis and interpretation of data: van Mierlo, Greyling, Zock, Kok, and Geleijnse. Drafting of the manuscript: van Mierlo and Greyling. Critical revision of the manuscript for important intellectual content: van Mierlo, Greyling, Zock, Kok, and Geleijnse. Statistical analysis: van Mierlo. Administrative, technical, and material support: van Mierlo and Greyling. Study supervision: van Mierlo, Zock, and Geleijnse.

Financial Disclosure: Ms van Mierlo, Mr Greyling, and Dr Zock are employees of Unilever R&D, Vlaardingen, the Netherlands. Unilever markets foods, some of which are enriched with potassium.

Additional Information: Detailed information on methods and additional results are available at http://www.wageningenuniversity.nl/UK/newsagenda/news/.

Additional Contributions: Arne Jol, MSc (Unilever R&D, Vlaardingen, the Netherlands), provided expert statistical advice, and Petra Verhoef, PhD (Unilever R&D, Vlaardingen, the Netherlands), critically evaluated the manuscript.

This article was corrected for errors on November 18, 2010.