Hypertension: Soya Plays a Role

The International Journal of Epidemiology published a shocking finding that:

“South Africa has the highest rate of high blood pressure reported among people aged 50 and over for any country in the world, at any time in history.

It is estimated that 6.3 million people in South Africa are living with high blood pressure.

High blood pressure increases people’s risk of experiencing stroke, heart disease and other forms of serious illness, such as chronic kidney disease, with those over the age of 50 at significantly increased risk.

Without doubt South Africans are more susceptible to these life-threatening diseases. Statistics show that about 130 heart attacks and 240 strokes occur daily in South Africa. This means that 10 people will suffer a stroke and five people will have a heart attack every hour. 

Furthermore the survey found that less than one in 10 people were effectively controlling their condition with medication. 

In the past, hypertension was associated with rich, developed countries or with wealthier sectors of society. Today, high blood pressure is a condition that affects the majority of society, rich or poor, rural or urban.

Hypertension is often preventable and is definitely treatable with lifestyle and dietary changes.”

In this article we will focus on two important dietary facts currently dominating the scientific research: SALT AND SOYA. We will also cover basic dietary guidelines to manage hypertension.


The Heart and Stroke Foundation have indicated that the link between salt and high blood pressure is well-documented and accepted as medical fact.

What is less widely known, is that South African foods are laden with salt – or sodium.

Internationally accepted guidelines state that any food with more than 600 mg of sodium per 100g can be considered unhealthy. In South Africa, many products exceed this limit. And the biggest culprit is bread, followed closely by margarine, butter spreads, stock cubes, soup powders, breakfast cereals and savoury snacks. Consumers are often surprised to find high sodium content in foods that are sweet and not salty at all.

Another concern is that South Africans rate high on the list of discretionary salt use – that is the amount of salt they add to the food themselves. In most Westernised countries, discretionary use is small – only about 15%. But in South Africa, up to 40% of salt is added by individuals to their food. This shows the lack of awareness of the dangers that salt poses to health, especially those who suffer from high blood pressure.

It is stated that the number one black sheep is bread – both locally and internationally. It has been estimated that by reducing the sodium content of bread by 50%, along with other reductions, salt intake will be decreased by 0.85g a day, resulting in 7 400 fewer deaths due to cardiovascular disease annually in SA.

Bread manufacturers were mandated by Government in the Food Label Law to reduce salt in their bread recipes by May 2016, and this is being implemented currently.

Consumers can cut down on salt by reading labels carefully and also by becoming aware of salt, tailoring shopping habits to lower salt content foods. The aim should be to reduce salt slowly and to look out for high-salt foods and buy alternatives instead. In time the body will adjust and eating a healthy low-salt diet will become much less of a chore – and will actually become a pleasure instead.

Salty Facts:

  • Many so-called “health foods” are high in sodium
  • Most of the salt in our diet is found in processed foods
  • Bread is the single highest contributor to the total salt intake of South Africans
  • The World Health Organisation sees hypertension as a bigger health risk than smoking
  • A high-salt diet is a leading cause of high blood pressure and high blood pressure is the single most important risk factor for stroke.
  • A reduction of salt intake by 2 grams per day reduces cardiovascular events by 20%.


A meta-analysis done in 2012 showed that soy (isoflavones) had an effect of lowering blood pressure in people with hypertension (high blood pressure), but not in those with normal blood pressure.

Isoflavones — a compound found in soy foods — may help lower blood pressure in young adults, new research suggests.

The researchers also found that isoflavones may be of particular benefit for black adults, of whom 40-50 percent are estimated to have high blood pressure (hypertension).

One expert not connected to the study said there is reason to believe that isoflavones could also help the heart in the following manner:

The hypothesis is that isoflavones have the effect of dilating blood vessels by increasing the release of nitric oxide, and thus reduce blood pressure. The new study, brings to light a compelling dietary recommendation that can help control hypertension in younger patients.

In another study, investigators examined data from more than 5,000 participants, The analysis revealed that those who consumed the highest amounts of isoflavones per day (more than 2.5 milligrams [mg]) had an average 5.5 mmHg lower systolic pressure (the top number in a blood pressure reading) than those who consumed less than 0.33 mg of isoflavones per day.

To understand what that means to the everyday diet, 1 cup (250ml) soy milk has about 22 mg of isoflavones and 100 grams of roasted soybeans have as much as 130 mg of isoflavones, the researchers explained.

This study is the first to show a benefit in African-Americans, who have a higher incidence of high blood pressure, with an earlier onset and more severe end-organ damage.

The findings in these studies could mean that consuming soy protein, in combination with a DASH diet — one that is high in fruits and vegetables, low-fat dairy and whole grains — could lead to as much as a 10 mmHg drop in systolic blood pressure for pre-hypertensives [people on the threshold of high blood pressure], greatly improving their chances of not progressing to hypertension.

This is also significant for those hypertensives NOT adhering to drug treatment.

Further research will be necessary to verify these findings, but the research to date is very promising in this regard.


DASH stands for Dietary Approaches to Stop Hypertension, and the diet was developed for a research study in the early 1990s. The purpose of the study was to identify a food-based strategy to lower blood pressure. Even though the original research was quite a long time ago, scientists recently conducted a meta-analysis for a DASH diet review to summarize how much blood pressure can be reduced by the DASH diet. The study found, on average, people reduce their blood pressure by 6.7 mmHg systolic and 3.5 mmHg diastolic in just two weeks. The more sodium is restricted, the lower blood pressure goes.

The DASH diet plan includes eating more:

  • fruits and vegetables,
  • low-fat or nonfat dairy,
  • beans, and
  • nuts.

And eating less:

  • fatty meats,
  • full-fat dairy products,
  • sugar-sweetened beverages,
  • sweets, and
  • sodium (salt).

Since the original research, scientists also have found that they could apply the DASH diet plan for weight loss. When people follow the Dash diet in addition to increasing exercise, they lose weight and improve metabolic measures such as insulin sensitivity. However, the DASH diet alone was not as effective a strategy for weight loss. When the DASH diet is followed along with exercise and caloric reduction, people improved their blood pressure even more; lowering it by 16 mmHg systolic and 9mmHg diastolic; plus, they lost some weight. As people adopt the DASH diet and lower their blood pressure, they may have a reduced need for medication.

People with hypertension should discuss the diet-based changes they are making with their Dietician, and if their blood pressure reaches or is below goal (<140/80), they could then discuss reducing their medications and maintaining their blood pressure with diet alone, with their doctor / specialist.


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