Behind the headlines

Blueberries are not the only fruit

News articles about health benefits of blueberries

A few handfuls of blueberries a day could protect against a host of lifestyle illnesses, research shows.

- Daily Express 7 November 2013

The BHF ’s view

This research was on lab rats, but the results were reported as if they have been proved to be applicable to humans.

This story was also covered in The Daily Telegraph, which ran the headline “Diet of blueberries may ward off diabetes,” and the Daily Mail, which said: “A bowl of wild blueberries a day could protect against a range of health problems.”

The researchers, from the University of Maine, looked at 36 obese rats and 36 lean rats. The type of rat used is prone to metabolic syndrome if it becomes obese.

This research highlights some benefits of blueberries, although further research is needed

Metabolic syndrome is a cluster of linked risk factors, which dramatically increase the risk of developing diabetes and cardiovascular disease. It can be diagnosed from cholesterol levels, blood sugar levels, blood pressure, waist circumference and, in particular, the state of the endothelium – the inner lining of blood vessels.

The researchers fed all the rats the same diet but in half the rats, 8 per cent of their food (in this case, sugar) was substituted with freeze-dried wild blueberry powder.

After eight weeks, the blood vessels of the lab rats were studied. Their ability to constrict and relax worked less well in obese rats, but this was improved in the rats that had been fed blueberry powder.

The researchers speculate that the effects of blueberry powder are due to its antioxidant and anti-inflammatory properties, but the research doesn’t conclude what this may mean for humans.

The Telegraph and the Mail also suggested that blueberries could protect against obesity, but the researchers found no difference in weight gain between the two rat groups.

The Telegraph didn’t make it clear that the research looked at wild blueberries, described by the researchers as “one of the richest fruit sources of anthocyanins and other polyphenols”. Wild blueberries are not readily available in the UK, and we don’t know whether using cultivated blueberries might have changed the results.

This isn’t a reason for people to swap their medication for blueberries

The authors declared that their work was supported by the Wild Blueberry Association of North America.

Christopher Allen, one of our senior cardiac nurses, said: “A healthy, balanced diet is essential in reducing your risk of cardiovascular disease. This research highlights some benefits of blueberries, although further research will be needed to investigate the impact on humans.

“Blueberries count towards your 5-a-day, and are a good source of vitamins, minerals and fibre, and some research suggests they could reduce blood pressure.

“This isn’t a reason for people to swap their medication for blueberries. Talk to your GP to understand how your diet can help your health.”

Read Lyn Rodney's story of living with diabetes

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