Stroke is the third most common cause of death in developed countries and annually, accounts for 10% of all deaths worldwide. Lowering Blood Pressure (BP) is seen as a significant approach to reducing stoke risk. The World Health Organization (WHO) has issued for the first time a target daily intake of potassium which is being examined as a novel way of reducing BP and therefore stroke risk.
A review of the current evidence of achieving a potassium intake target and its effect of stroke risk was published in the Journal of the American Heart Association. The problem is that there are many people who do not respond well to available antihypertensive therapies. As a result, they are not able to maintain a BP lower than 130/80 mm Hg to reduce their risk of stroke and new methods must be devised.
There has been much public attention on high sodium intake and its effect on BP and stroke risk. It has also been known since the 1950’s that the sodium-potassium ratio (Na+:K+) may be a more important predictor of BP and hence cardiovascular and stroke risk than sodium intake alone. This means that a low Na+:K+, achieved through proportionately low Na+ and high K+
intakes, may predict lower BP, cardiovascular, and stroke risk. The paper states that there is strong evidence to suggest that increasing dietary potassium intake reduces BP and stroke risk and that this is, in part, the justification for the current guideline for daily potassium intake issued by the WHO.
For example, the authors quote a study who increased the potassium intake of a group of well-controlled hypertensives through providing dietary advice. Antihypertensive medication was reduced in a stepwise manner during a 1-year period, providing that BP targets were maintained. At 12-month follow-up, BP was controlled with <50% of initial antihypertensive therapy in 80% of the subjects in the intervention group, compared with just 29% of the subjects in the control arm. These demonstrates the feasibility of BP-lowering through increasing potassium intake.
Achieving a higher potassium intake can be reached in three ways:
Dietary Modification – Appropriate dietary modification would involve substituting potassium-low foods for fruits, vegetables, beans, and nuts, as seen in the Dietary Approaches to Stop Hypertension (DASH) diet.
Salt Substitutes – Salt substitutes are commercially available salt mixtures, in which some of the sodium chloride is substituted for potassium and magnesium salts. The use of these products in place of salt can reduce sodium consumption while increasing potassium intake.
Potassium Supplementation – High risk stroke patients could use oral potassium supplementation. Supplementation with potassium chloride (KCl) could be a cheap intervention to easily achieve a minimum daily target. This is a area where more research needs to be careful done.
The authors conclude that evidence points to an important role that potassium intake may play both in contributing
to stroke incidents (low intake) and as an effective intervention tool (higher intake) for prevention of
stroke and its complications. While more clinical trials are needed to establish clinical guidelines, I will reach for my favorite coconut water to increase my potassium intake.