A new study from the University of Eastern Finland shows that blackcurrantsbeneficial to glucose metabolismafter every meal. The required portion size is also much smaller than previously thought, according to the study authors. In addition, the blood sugar response of the ingested sugar balances itself, with the fruits weakening its rise and delaying its fall.
How do blackcurrants affect insulin levels?
The observed effect is likely due to the berry-derived polyphenols and anthocyanins that are abundant in this type of currant. The positive health effects of the fruits were supported by the study results of the Finnish researchers. In the clinical study, the beneficial effect on the postprandial glucose response was achieved by 75 g (1.5 dl) of black currants. So this is a noticeably smaller portion size than previous studies. Blackcurrants are often consumed with added sugar due to their natural acidity, which can be a cause for concern for health-conscious consumers. However, it seems that sugar consumed with it is not that unhealthy.
Berries are an important part of a healthy diet and are rich in vitamins, minerals, fiber and polyphenols. However, so far the EU has not approved any health claims in this regard. In recent years, numerous studies have been conducted to monitor their effects on glucose metabolism. Dark berries such as blackcurrants and blueberries achieved the most convincing results. So black-colored berries, which are rich in anthocyanins, appear to blunt the blood sugar response to added sugar compared to a control product with the same amount of sugar. The same effect is shown by anthocyanins extracted from black currants. Polyphenols can slow the absorption of glucose from the small intestine by interacting with digestible enzymes from carbohydrates and glucose transporters. In addition, polyphenols can reduce oxidative stress and associated inflammation.
Study results
In the so-called Maqua study, 26 healthy participants (22 women, 4 men) consumed three different test products and sugar water as a control product at four different study visits. The test products were a blackcurrant puree with added sugar, a blackcurrant product containing fermented quinoa, and a blackcurrant product base without blackcurrants. Each of them and the control product contained 31 g of available carbohydrates and had a similar composition of sugar components. Blood samples were collected before meals in the fasting state and postprandially at 15, 30, 45, 60, 90, 120, and 180 minutes after meal consumption and analyzed for glucose, insulin, and free fatty acids.
Compared to sugar water, both products in the blackcurrant study had a blunted glycemic response after consumption. This effect was observed with reduced peak glucose and insulin, delayed fall in glucose, and delayed rise in free fatty acids due to hypoglycemia. The advantage was also increased for the blackcurrant product due to the innovative product base. The resultsof the studysupports previous findings on the positive effects of blackcurrants on blood sugar response after a meal and shows the effect of a smaller portion size. Over time, minor fluctuations in blood sugar and insulin levels and improved insulin sensitivity can reduce the risk of type 2 diabetes. Blackcurrants are an interesting raw material for the food industry due to their high anthocyanin content and their easy availability. In addition, these foods can be processed into new healthy and tasty products.
