Why are blueberries a 'superfood'?
Published 18/06/2015 | 02:30
A "superfood" is a food, usually fruit or vegetable, whose nutrient content confers a health benefit above that of other foods.
Blueberries are one such superfood.
Blueberries (Vaccinium corymbosum) are native to North America (they are also grown in Ireland) and are full of flavour and nutrients.
They are a good source of fibre, micronutrients, such as vitamins C and K, and they are free of saturated fat. But, what really makes them stand out, is their potent antioxidant properties.
So, what is it about blueberries that give them their powerful antioxidant potential? The answer lies in the most investigated bioactive compounds naturally found in plants, called polyphenols.
Polyphenols are phytochemicals made by plants (phyto=plant) that protect the plant from physical challenges and allow it to interact with its environment.
There are more than 9,000 different polyphenols mainly belonging to two groups - flavonoids and non-flavonoids. In blueberries the most plentiful flavonoids are anthocyanins and tannins.
Studies have shown that polyphenols may protect us against heart-related diseases, diabetes, inflammation, osteoporosis, neurodegenerative diseases, obesity and cancer. This is because they are antioxidants which protect our cells against dangerous free radicals.
Some of the polyphenols we eat are absorbed in the small intestine but many reach the large intestine where studies have shown that they may stimulate the growth of good bacteria and promote good microbial balance.
The gut bacteria break down the polyphenols further and it may be the results of this process that are responsible for the health benefits.
There is evidence that diets rich in polyphenols have beneficial effect on brain health with respect to cognition, learning and memory. Whether the polyphenols found in blueberries have such effects remains to be conclusively clarified.
My research is focused on the potential of polyphenols to protect the brain from a variety of insults, such as stress.
Other studies are focusing on whether polyphenols derived from fruits, teas, seaweed and vegetables could be suitable functional foods (foods and food components that provide a health benefit beyond basic nutrition) for improving health and whether the amount consumed is compatible with health promoting activity.
Nutrition plays a very important role in disease prevention, and balanced nutrient intake and a healthy microbiota are essential for good physical and mental health.
Clara Seira-Oriach is a PhD student at the Alimentary Pharmabiotic Centre and Department of Psychiatry, UCC.