Eating blueberries may help guard against high blood pressure or hypertension, a new study by the University of East Anglia and Harvard University researchers suggests.
High blood pressure or hypertension is one major risk factor for cardiovascular diseases such as stroke and heart disease. About one third of the U.S. adults suffer the condition.
The study scheduled to appear next month in the American Journal of Clinical Nutrition suggests bioactive compounds in blueberries called anthocyanins help protect against high blood pressure.
Compared with those who did not eat blueberries, those eating at least one serving a week were 10 percent less likely to develop high blood pressure.
Anthocyanins, a type of bioactive compounds called flavonoids, are found in high amounts in blackcurrants, aubergines, raspberries, blood orange juice and blueberries.
Other flavonoids are also found in other fruits, vegetables, grains and herbs. The flavonoids found in tea, red wine, fruit juice, and dark chocolate have been associated with reduced risk of cardiovascular disease.
For the study, the researchers compared 134,000 women and 47,000 men enrolled in the Nurses’ health Study and the Health professionals Follow-up Study for their dietary habits during a period of 14 years to investigate the effect of flavonoids on high blood pressure.
All subjects were free of high blood pressure at baseline. Health surveys on diagnosed hypertension were conducted every two years and dietary intake surveys were conducted every four years.
During the follow-up, 35,000 participants were diagnosed with high blood pressure. Tea was found to be the main source of flavonoids, and other sources included apples, orange juice, blueberries, red wine, and strawberries.
Highest intakes of anthocyanins found mainly in blueberries and strawberries were correlated with a 8 percent reduced risk of high blood pressure, compared the lowest intakes.
The association was stronger among those at 60 or older.
When intake of blueberries was considered alone, the researchers found those who ate at least one serving of blueberries per week were 10 percent less likely to develop high blood pressure compared with those who did not eat the fruit.
“An achievable dietary intake of anthocyanins may contribute to the prevention of hypertension,” said Aedin Cassidy of UEA’s Medical School.
It should be noted that the study was observational and it did not prove that eating blueberries was the cause for the lower incidence of high blood pressure.
One possibility is that those who eat blueberries follow an overall healthier lifestyle, which provides some protection against cardiovascular disease.