Potassium is found mainly within body cells and plays a major role in ensuring normal cell function, proper nerve signals, heart beats and muscle contractions, as well as making sure nutrients are transported efficiently within the body (1 p109).
Australian and international research show that a diet high in potassium and low in salt helps to keep blood pressure at normal levels (18, 19). According to a review of all the scientifically published studies, a diet with plentiful potassium also reduces the risk of stroke (20). This report concluded that: Higher dietary potassium intake is associated with lower rates of stroke and might also reduce the risk of coronary heart disease and total cardiovascular disease. These results support recommendations for higher consumption of potassium-rich foods to prevent vascular diseases.
A diet high in potassium and low in salt is what humans have enjoyed naturally for thousands of years. Only recently, mainly in the last 60 years, have humans regularly eaten high salt foods. Those people eating a diet rich in fruits and vegetables, low in saturated fat, with plenty of low-fat diary foods generally have a lower blood pressure than those eating a typical Western diet.
Bananas are high in potassium and low salt, a perfect combination to help keep blood pressure healthy. Less than 10% of the Australia population get an adequate intake of potassium to reduce their risk of chronic disease, like stroke, which is frequently caused by high blood pressure (14). Eating more fruit and vegetables will bump up our potassium intake. In fact, adding an extra banana and a small side salad will get nearly half the population to a healthy potassium level (based on 14).
Another mineral that is found in the banana is magnesium, which is involved in more than 300 enzyme systems in the body, and is especially important in energy generation in the muscles.
You can see there is an important role for foods, like the banana, providing both magnesium and potassium. A medium banana will provide about 10% of daily potassium needs and about 7% of daily magnesium needs, yet it provides only 4% of the kilojoules of a mildly active adult. That is great “value for kilojoule”, especially when you add the vitamins, fibre and antioxidant power of the banana.
References:- 1. Mann J & Truswell AS. Essentials of Human Nutrition 3rd edition. Oxford University Press 2007
- 14. National Nutrition Survey. Nutrient Intakes and Physical Measurements. Australian Bureau of Statistics 1995
- 18. Nowson CA, Worsley A, Margerison C, Jorna MK, Frame AG, Torres SJ, Godfrey SJ. Blood pressure response to dietary modifications in free-living individuals J Nutr 2004; 134: 2322-2329
- 19. Adrogué HJ, Madias E. Sodium and potassium in the pathogenesis of hypertension. NEJM 2007; 356: 1966-1978
- 20. D’Elia L, Barba G, Cappuccio FP, Strazzullo P. Potassium Intake, Stroke, and Cardiovascular Disease. Journal of the American College of Cardiology 2011; 57 (10): 1210-1219
