by Eating bananas is more effective in lowering blood pressure than reducing salt intake, a study has found.
Scientists have discovered that a simple way for a person to combat high blood pressure is to eat an extra gram of potassium, which is equivalent to two medium bananas, a cup of spinach or a large sweet potato.
In the UK, 90 per cent of adults do not consume the recommended 3.5 grams of potassium each day, and the average adult consumes 8.4 grams of salt, which is 40 per cent more than the maximum recommended intake of six grams in the face of the day.
Experts from the George Institute of Global Health at Imperial College London analyzed data from their Salt Center and Stroke Study, which spent five years monitoring 20,995 people in China who had suffered a stroke or were over 60 years old high blood pressure.
While half of the participants continued to use regular table salt in their cooking and meals, the other half were given a “salt substitute” in which a quarter of the salt, chemically known as sodium chloride, was replaced with potassium chloride.
The research found that those who ate the potassium-enriched salt had lower blood pressure levels, as well as a reduced chance of stroke and heart disease.
The new analysis, published in the Journal of Human Hypertension on Wednesday, showed that up to 80 percent of the reduction in blood pressure was due to an increase in potassium, rather than a reduction in salt intake.
It is the first study to directly compare the benefits of the two and used the “gold standard” measurement of sodium and potassium in participants’ urine to determine how much was wasted.
The research showed that increasing daily potassium intake by a gram reduced systolic blood pressure levels – the higher of the two figures from a blood pressure reading – by an average of two millimeters of mercury (mm Hg).
During the five-year study, 3,000 people suffered a stroke, but the researchers found that those who took potassium-enriched salt were 14 percent less likely to suffer one.
After further analysis, they found that the benefits to blood pressure from increasing potassium consumption were about 10 percent of the reduced risk of stroke, while the reduction in salt intake was about four percent.
Salt substitute ‘treats both problems’
Dr Polly Huang, lead author of the paper from The George Institute, said: “High levels of sodium intake and low levels of potassium intake are widespread, both of which are associated with high blood pressure and increased risk of stroke, heart disease and premature . death
“Using a salt substitute where some of the sodium chloride is replaced with potassium chloride addresses both problems at the same time.”
She said the research showed how important potassium intake could be in controlling blood pressure.
“The results of this study may be very positive because people started at low levels of potassium consumption, but there are probably billions of people around the world with similar levels of consumption,” said Dr. Huang.
International experts are now calling for official advice on high blood pressure to be reformed to include safeguards against increased potassium intake.
A global collaboration of researchers from the US, Australia, Japan, South Africa and India called for potassium to be added to international health guidelines, while only Chinese and European guidelines are recommending it as an effective way to lower blood pressure.
Potassium is found in a variety of foods, including leafy greens, legumes and nuts, but quantities are often reduced when food is processed.
Too much potassium can lead to hyperkalemia, and excessive levels in the blood can affect heart function.
However, the condition is very rare and would require someone to eat hundreds of bananas in one sitting, according to experts.
‘Cost-effective and practical’
Around a third of adults in England have high blood pressure, which is defined as having a reading of 140mm Hg or higher.
Up to five million people are thought to be living with it undiagnosed, according to the British Heart Foundation.
It is a major risk factor for developing heart disease or stroke.
Around 34,000 Britons die each year from stroke, which is the leading cause of disability, and heart attacks account for more than 100,000 hospital admissions each year.
Dr Elisa Pineda, research fellow at Imperial College, said high blood pressure was the biggest risk factor for premature death after smoking and poor diet.
“A balanced diet, low in salt and high in potassium, can help prevent high blood pressure, stroke and cardiovascular disease,” she said.
“In the UK, efforts to reduce sodium intake have shown limited progress. Potassium-enriched salt substitutes emerge as a cost-effective and practical opportunity to reduce the population’s risk of high blood pressure.”
