Does eating berries, like apples help to keep the doctor away? Eating blueberries can guard against high blood pressure, according to new research by Harvard University and the University of East Anglia in England.
Hypertension or high blood pressure is one of the most common cardiovascular diseases in the world. It is a risk factor for heart disease, stroke and heart attacks, kidney failure and costs more than $300 billion each year. Approximately 35 percent of the world’s adult population is affected including 33 percent in the US and about 10 million people in England.
The American Journal of Clinical Nutrition will publish in February, 2011, the new findings that found bioactive compounds in blueberries called anthocyanins protect against high blood pressure. People who consume at least one serving every week, are protected against hypertension. When compared to those who don’t eat blueberries, those eating at least one serving a week experienced a 10 percent reduction in their risk of developing the hypertension.
Anthocyanins Are Powerful Antioxidants
Anthocyanins are chemicals that are a part of flavinoid family of compounds called and are found in large amounts in fruit including blueberries, blackcurrants, raspberries, blood organges and aubergines. Other flavonoids are found in many fruits, vegetables, grains and herbs. Other flavonoids found in red wine, tea, fruit juice, and dark chocolate reduce the risk of cardiovascular disease.
These compounds are concentrated in berries as pigments, and have been the topic of numerous research studies. In 2007 they were the topic of research presented at a medical meeting on health benefits that may result from berry consumption. The research has determined that they provide potential health effects against:
- Bacterial infections
- Aging and neurological diseases
Within the cells, anthocyanins from berries have the ability to shut off genes involved in cancer development.
First flavinoid study on hypertension
This is the first large study to investigate the effect of different flavonoids on hypertension.
The team of UEA and Harvard scientists over 14 years evaluated 134,000 women and 47,000 men from the Harvard research groups the Health Professionals Follow-up Study and the Nurses' Health Study. When the study was launched, none had hypertension. The participants completed a health questionnaires every two years and their food consumption intake was measured 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 high blood pressure. Their diet history found that tea was the main source of flavonoids, with apples, orange juice, blueberries, red wine, and strawberries also providing important amounts.
When the researchers looked at the relation between individual subclasses of flavonoids and hypertension, they found that participants consuming the highest amounts of anthocyanins (found mainly in blueberries and strawberries in this 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 lead author Prof Aedin Cassidy of 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 researchers plan to conduct another study that will be a randomized 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 reduce blood pressure.