Bioactive Nutrient Compounds Naturally Present In Berries Can Reduce High Blood Pressure

Eating blueberries can guard against high blood

pressure, according to new research by the

University of East Anglia (UEA) and Harvard University.

High blood pressure (hypertension) is one of the major

cardiovascular diseases worldwide. It leads to stroke and

heart disease and costs more than $300 billion each year.

Nearly a quarter of the adult population is affected globally

including 10 million people in the United Kingdom and 33%

of adults in the United States.

Published in the American Journal of Clinical Nutrition, the

new findings show that bioactive compounds in blueberries

called anthocyanins offer protection against hypertension.

Compared with those who do not eat blueberries, those

eating at least one serving a week reduce their risk of

developing the condition by 10 per cent.

Anthocyanins are the bioactive compounds called flavonoids

and are found in high amounts in blackcurrants, raspberries,

blood orange juice and blueberries. Other flavonoids are found

in many fruits, vegetables, grains and herbs. The flavonoids

present in tea, fruit juice, red wine and dark chocolate are

already known to reduce the risk of cardiovascular disease.

This is the first large study to investigate the effect of different

flavonoids on hypertension. The team of UEA and Harvard

scientists studied 134,000 women and 47,000 men from the

Harvard established cohorts, the Nurses' Health Study and

the "Health Professionals Follow-up Study" over a period of

14 years. None of the participants had hypertension at the

start of the study

Subjects were asked to complete health questionnaires every

two years and their dietary intake was assessed every four

years. Incidence of newly diagnosed hypertension during the

14-year period was then related to consumption of various

different flavonoids.

During the study, 35,000 participants developed hypertension.

Dietary information identified tea as the main contributor of

flavonoids, with apples, orange juice, blueberries, red wine,

and strawberries also providing important amounts. When the

researchers looked at the relation between individual flavonoids

and hypertension, they found that participants consuming the

highest amounts of anthocyanins (found mainly in blueberries

and strawberries in the US-based population) were eight per cent

less likely to be diagnosed with hypertension than those

consuming the lowest amounts. The effect was even stronger

in participants under 60.

The effect was stronger for blueberry rather than strawberry

consumption. Compared to people who ate no blueberries,

those eating at least one serving of blueberries per week were

10 per cent less likely to become hypertensive.

"Our findings are exciting and suggest that an achievable

dietary intake of anthocyanins may contribute to the prevention

of hypertension," said the researchers from the Department of

Nutrition at UEA's Medical School.

"Anthocyanins are readily incorporated into the diet as they are

present in many commonly consumed foods. Blueberries were

the richest source in this particular study as they are frequently

consumed in the US. Other rich sources of anthocyanins in the

UK include blackcurrants, blood oranges, aubergines and

raspberries."

The next stage of the research will be to conduct randomised

controlled trials with different dietary sources of anthocyanins

to define the optimal dose and sources for hypertension

prevention. This will enable the development of targeted public

health recommendations on how to reduceblood pressure.

Story Source:

University of East Anglia (2011, January 15). Bioactive

compounds in berries can reduce high blood pressure.

Editor's Note: This article is not intended to provide medical

advice, diagnosis or treatment.