Dr's Casebook column with Dr Keith Souter: More beans and soya can cut the risks of high blood pressure

Keeping blood pressure under control can literally be a life saver. This is why I want to highlight a major analysis of studies from around the world that suggest eating legumes and soya foods can both significantly lower the risks.

The essence of this analysis published in the BMJ Nutrition Prevention and Health is that people with the highest intake of legumes – beans, peas, lentils and chickpeas were found to be 30 per cent less likely to develop high blood pressure, compared to those with the lowest intakes. And people with the most soy foods – tofu, soy milk and miso – in their diet had almost 35 per cent lower risk.

They found that the most benefit appeared with a daily intake of legumes of 170 grams of legume. The same benefit was reached with a daily intake of 60 to 80 grams of soy foods.

To give this some context, a rule of thumb is that 100 grams of legumes or soy is roughly equal to one cup of cooked beans, peas, lentils, chickpeas, or soybeans, or about a palm sized serving of tofu.

Global Studies

The analysis included ten published papers from studies conducted in the United States, Europe, and Asia. After pooling all the data, they found a clear connection between higher intake of legumes and soy foods and a reduced likelihood of developing high blood pressure. That is, the risk rates dropped with increasing amounts of either group of foods. So, you don’t have to increase the amount you take drastically, as it would mean significantly increasing fibre intake.

Possible reasons

Legumes and soy foods are rich in potassium, magnesium, and dietary fibre, all nutrients already known to support healthy blood pressure.

Recent research also suggests that soluble fibre from legumes and soy can be fermented in the gut to produce short chain fatty acids, which may help blood vessels relax and widen. Soy foods also contain isoflavones, plant compounds are thought to lower blood pressure.