Another blackcurrant blog for you today, it would seem that adding blackcurrants to your diet could help reduce body weight and improve glucose metabolism, but only if the gut is functioning normally, i.e. has not been given a blast of antibiotics.
Published in the Journal of Agricultural and Food Chemistry, the researchers were interested in the effect of blackcurrant powder, which is rich in anthocyanins, on the body weight and glucose metabolism of lean and diet induced obese mice. They were also interested in what effect a “disrupted” gut microbiome would have on the bioavailability of the anthocyanins, in other words, can your gut still absorb the anthocyanins when you have taken a dose of antibiotics?
Over an eight week period, adding 1% blackcurrant powder to the diet of mice improved the glucose metabolism and reduced weight gain in both groups of mice when their guts were functioning normally. After an antibiotic treatment the amount of anthocyanins in the faeces increased 16-25 fold. This suggests that the gut fauna play a vital role in biotransforming the anthocyanins so they can be absorbed into your body.
But the story is not as simple as that. It was also observed that the antibiotic treatment affected the absorption of different anthocyanins to different degrees, with cyanidin anthocyanins being more affected than delphinidin anthocyanins. Basically different fruit have different levels of these anthocyanins and the researchers suggest this discrepancy in absorption could explain why “cyanidin type anthocyanins are less effective in preventing metabolic and inflammatory disorders in animal and human studies”. So the health of the gut should be considered when carrying out these types of studies.
According to Wikipedia, Cyanidin is found in red berries such as grapes, bilberry, blackberry, blueberry, cherry, cranberry, elderberry, hawthorn, loganberry, acai berry and raspberry, while delphinidin anthocyanins are found in cranberries, concord and Cabernet Sauvignon grapes and pomegranates.