Yogurt may have a beneficial effect on women's blood pressure, especially when part of a healthy diet.
This was the conclusion of a study recently presented at the American Heart Association's (AHA's) Epidemiology/Lifestyle 2016 Scientific Sessions in Phoenix, AZ.
The researchers found that women who consumed five or more servings of yogurt a week had a lower risk of developing high blood pressure than similar women who hardly ever ate yogurt.
According to the AHA, high blood pressure - defined as higher than 140/90 mm/Hg - is potentially dangerous because it strains the heart, hardens arteries and raises the risk of brain hemorrhage and kidney problems.
If not controlled, high blood pressure can result in heart and kidney disease, stroke and blindness.
Previous studies have already shown that dairy products can reduce the risk of high blood pressure in at-risk adults, say the researchers, but few long-term studies have looked at the independent effect of yogurt alone.
"I believe that this is the largest study of its kind to date to evaluate the specific effects of yogurt on blood pressure," says lead author Justin Buendia, a PhD candidate at Boston University School of Medicine, MA.
For the study - which was funded by the National Dairy Council - Buendia and his colleagues used data from the first and second cohorts (NHS and NHS II) of the Nurses' Health Study, where the participants were mainly women aged 25-55, and also from the Health Professionals Follow-up Study (HPFS), where the participants were mostly men.
Over 18-30 years of follow-up, 75,609 of the participants developed high blood pressure.
20% lower risk of high blood pressure with higher yogurt intake
After adjusting for other factors that might influence the link to high blood pressure, such as age, race, family history of high blood pressure, physical activity and diet, the researchers examined the link between yogurt and the development of high blood pressure in the three groups.
They found that compared with women who ate fewer than one serving per month, women who ate five or more yogurt servings per week had a statistically significant 20% lower risk of developing high blood pressure.
A serving of yogurt is a cup, or around a scoop the size of a baseball.
There was a much weaker link between regular yogurt consumption and high blood pressure in men, but this could be because the men in the groups they examined consumed far lower amounts of yogurt than the women, say the researchers. It does not necessarily mean that yogurt has no beneficial effect on men's blood pressure.
The team then looked at the women's data again and focused on diet. They assigned a score to each participant, depending on how closely her diet matched one designed to lower blood pressure, called Dietary Approaches to Stop Hypertension (DASH).
Yogurt's strongest effect is as part of healthy diet
The DASH diet is rich in fruits, vegetables, fat-free or low-fat milk and milk products, whole grains, fish, poultry, beans, seeds and nuts.
The results showed that women whose diets most closely matched DASH and who ate five or more servings of yogurt a week had a 31% lower risk of developing high blood pressure. This was compared with women with the lowest DASH scores and who had the lowest yogurt intakes (one serving or less per week).
The team also looked at the links between other dairy foods and high blood pressure. They found a positive link between daily servings of milk and cheese and lower risk of high blood pressure, but according to Buendia, this was not as strong as the effect of yogurt.
The researchers suggest the beneficial effect of yogurt on lowering risk of high blood pressure, especially when consumed as part of a healthy diet, could be by lowering body mass index (BMI - a measure of obesity); the links were weaker when they adjusted for BMI.
This reinforces the idea that you are unlikely to reduce your risk of high blood pressure just by adding yogurt to your diet. It is when yogurt is part of a diet plan designed to reduce high blood pressure, which also has a positive effect on helping you reach a healthy weight, that it appears to have the most benefit. As Buendia concludes:
"No one food is a magic bullet but adding yogurt to an otherwise healthy diet seems to help reduce the long-term risk of high blood pressure in women."
Meanwhile, from another study presented at the same meeting, Medical News Today learned that cutting the price of fruits, vegetables and grains by 10%, and marking up sugary drink prices by the same amount, could prevent more than half a million Americans dying prematurely of cardiovascular disease between now and 2035.