Wild blueberries may counteract adverse effects of high-fat diet

Wild blueberries have beneficial effects on blood pressure and the nutrition-derived inflammatory responses that are caused by a high-fat diet, find researchers from the University of Eastern Finland.

Bilberries have significantly higher levels of anthocyanins than commercially cultivated blueberries.

Blueberries are associated with many benefits to health, which are thought to be explained by the presence of polyphenols within the berries - especially polyphenols called anthocyanins.

Wild blueberries - also known as bilberries - have significantly higher levels of anthocyanins than commercially cultivated blueberries.

Bilberries are used by some people to treat a range of conditions, including: chronic fatigue syndrome, hemorrhoids, diabetes, osteoarthritis, gout, skin infections, gastrointestinal disorders, kidney disease,varicose veins, hardening of the arteries, chest pain and urinary tract infections.

However, evidence on their effectiveness to treat other conditions has been mixed.

The new study, published in PLOS ONE, is the first to show that bilberries have beneficial properties against obesity-related low-grade inflammation and elevated blood pressure.

New study looked at effect of bilberries on mice fed a high-fat diet

In the study, mice were fed a high-fat diet for 3 months. However, 5-10% of the diets of some of the mice were made up of bilberries.

Fast facts about bilberries

• Bilberries are thought to be effective for reducing symptoms of circulation problems and retina problems associated with diabetes or high blood pressure
• Bilberry jam was eaten by British pilots during World War II because they believed it improved their night vision - though it probably was not effective
• Other conditions that some people think are improved by eating bilberries - though there is insufficient evidence - include painful menstruation, glaucoma and irritable bowel syndrome.

To measure the effects of the diets on the mice, the researchers measured inflammatory cell and cytokine levels, systolic blood pressure, glucose tolerance, insulin sensitivity and weight gain.

The team found that the high-fat diet caused the mice to experience significant weight gain and adverse changes in glucose and lipid metabolism, inflammation factors and blood pressure.

However, the mice who were fed bilberries had an altered cytokine profile and a lower prevalence of inflammation-supporting T-cells than the mice that did not receive bilberries.

The researchers say the bilberries also prevented the elevated blood pressure caused by the high-fat diet.

In 2007, the University of Leicester in the UK led an investigation to see whether a commercially produced bilberry extract, Mirtoselect, could prevent or delay the onset of some cancers.

The Leicester team initially found that Mirtoselect slowed the development of colorectal cancer in a laboratory model. When they followed that up with a clinical trial in humans, the researchers reported that Mirtoselect reduced tumor proliferation by 7% in colorectal tumor samples taken from all patients who received the product.

References:

1.  Wild blueberries (vaccinium myrtillus) alleviate inflammation and hypertension associated with developing obesity in mice fed with a high-fat diet, Otto T. Mykkänen, et al., PLOS ONE, doi: 10.1371/journal.pone.0114790, published online 12 December 2014,abstract.
2.  Additional source: University of Eastern Finland news release, accessed 18 December 2014 via AlphaGalileo.
3.  Additional source: MedlinePlus, Bilberry, accessed 18 December 2014.