Blue is the new black when it comes to studying the health benefits of fruits like blueberries. More precisely, a group of compounds called anthocyanins have attracted the interest of researchers.
Anthocyanins are a type of flavonoid found naturally in a number of foods that have antioxidant and anti-inflammatory properties. They are also the pigments that give red, purple, and blue plants their rich colouring with the colour changing depending on the pH (the acidity) of the food.
Because blueberries contain high amounts of anthocyanins, the fruit has already received some research focus on their potential to slow cognitive decline with ageing. With heart disease, observational research points to regular blueberry eaters having lower rates of heart attacks.
Extending the research into blueberries and anthocyanins further, scientists from King’s College in London looked at their effects on the vascular health of 40 healthy volunteers.
Over one month, the volunteers were given a daily blueberry powder extract drink equivalent to around 100 grams of fresh wild blueberries or a placebo drink. An additional study also looked at the effect of a drink containing purified anthocyanins versus placebo.
Each person had their blood pressure measured. In addition, flow-mediated dilation (FMD) testing was done. FMD is a measure of vascular health and cardiovascular disease risk as it assesses how an artery widens when blood flow increases.
A study where healthy volunteers drank a concentrated blueberry extract every day for a month led to a fall in their blood pressure and improvement in their vascular health.
Both studies found a benefit of the blueberry extract and the purified anthocyanins on blood vessel function. The onset of action was fast with changes in FMD seen two hours after consumption and this was maintained for the month. Blood pressure dropped as well by 5 mmHg.
The changes in blood vessel health and blood pressure were clinically meaningful and could result in a significant fall in the risk of developing cardiovascular disease if they were maintained long term.
Implications
Anthocyanins are emerging as a powerful natural plant chemical that can have meaningful human health benefits. Considering the delicious way nature has packaged these chemicals in fruits like blueberries, they can be enjoyed in any diet while waiting for the research to develop.
