Potassium Intake, Stroke and Cardiovascular Disease

Summary
The objective of this analysis was to evaluate the relationship between habitual potassium intake and the risk of cardiovascular disease. Eleven previous studies conducted between 1966 and 2009, with information on the levels of baseline potassium intake and presence of heart problems with follow-up for at least four years, were selected for this study. It was found that a 1.64 gram intake of potassium each day was associated with a 21 percent lower risk of stroke. Thus, higher potassium ingestion in diets could eventually lead to lower incidence of stroke and heart diseases.

Introduction
Many previous studies have proven a relationship between potassium and blood pressure. In one of the analyses, it was found that higher potassium intake by approximately 0.78 gram each day resulted in an average reduction of 4.9 mm Hg systolic blood pressure and 2.7 mm Hg diastolic blood pressure in hypertensive patients. In another study, those consuming high potassium diets for a year achieved and maintained blood pressure control. High blood pressure is one of the principal causes of death as well as sickness due to cardiovascular disease. High potassium intake could reverse these effects. The long-term effects of dietary potassium on heart diseases are unknown. Meta-analysis generally helps in the assessment of results from various studies; it helps increase the precision of the study estimates and its statistical power.  Therefore, a meta-analytical study of various previous studies was done to assess the relationship between dietary potassium intake, stroke and heart disorders to help obtain a risk analysis.

Methodology
Studies related to potassium intake, stroke, heart attacks and other associated medical terminology were identified from reputed databases. They included articles published between 1966 and 2009. Two reviewers analyzed each study independently. They found that out of 3,271 publications containing the search terms, only 42 articles were relevant. Thirty articles were removed owing to the absence of few data sets, leaving only 11 articles for the final study. The potassium intake was calculated based on responses to questionnaires on food frequency or 24-hour urinary measurement in the studies. Comprehensive data analyses were done to estimate the relation between high potassium intake and cardiovascular diseases.

Results
* The average potassium intakes ranged between 45 and 85 mmol each day. But the values were higher in one of the studies.
* Higher potassium intake of an average of 1.64 g was significantly associated with 21 percent lower risk of stroke.
* There was an inverse relation between high potassium intake and the incidence of vascular diseases and heart diseases. However, this was statistically insignificant.

Shortcomings/Next steps
The methods used to estimate the potassium levels were not very accurate in the studies analyzed. This could have altered results and led to an underestimation of the risk of stroke and vascular diseases. A few factors such as baseline blood pressure, presence of high blood pressure or obesity were not assessed in the studies. Only four of the 11 studies mentioned confounding factors such as sodium intake, which could affect potassium intake.

Conclusion
This extensive analysis shows that higher intake of potassium could lead to lower risks of heart diseases and stroke. The content of potassium is high in fruits and vegetables. In fact, increased consumption of fruits and vegetables has been shown to be protective against stroke. In a study, five or more fruit and vegetable servings daily were associated with a 26 percent lower incidence of stroke. Thus, it could be inferred that the high potassium content in fruit and vegetables could be beneficial and prevent the incidence of stroke. These results can be extended to the general population and not only to those at higher risks of stroke or heart diseases. The authors suggest that higher potassium intake should be synergistic with other preventive measures.

For More Information:
Meta-analysis: Potassium Intake, Stroke, and Cardiovascular Disease
Publication Journal: Journal of the American College of Cardiology, March 2011
By Lanfranco D’Elia PhD; Gianvincenzo Barba MD; University of Naples Medical School, Naples, Italy and the National Research Council, Avellino, Italy

*FYI Living Lab Reports Are Summaries of the Original Research.