It seems that every week we are introduced to a new 'superfood', but did you know that the majority of these have something in common? It's not their obscure origin in the Amazon rainforest or an unpronounceable name, but the fact that they are rich in polyphenols.
Polyphenols are a type of chemical found in plants that are praised for their many health benefits, antioxidant activity, and potential protective benefit against a number of devastating chronic conditions, like heart disease and cancer.
Polyphenol Rich Foods
These valuable chemicals occur in various concentrations in a large number of everyday plant foods. Good sources include leafy greens, the skin or peel of many fruits and vegetables, a number of cereal grains, tea, coffee, and chocolate. So-called superfoods often attract the title because they are a comparatively concentrated source of polyphenols, antioxidants, vitamins and minerals, but these valuable chemicals are widely distributed through a number of healthy foods.
The polyphenol content of food is important, but scientists have started to realise that there are a huge number of variables that govern the amount of these chemicals that our bodies actually absorb. A recent review article, published in the journal Nutrition Reviews compiled a large number of studies and produced some very interesting conclusions about factors that affect polyphenol absorption.
Some of these findings were expected, including the discovery that physical factors, including large amounts of dietary fibre and viscous, protein-rich foods can inhibit polyphenol absorption, as can the presence of certain minerals, like magnesium and calcium. These supplements are best taken on their own, because they compete for absorption with many other minerals and nutrients.
Factors that enhanced the absorption of polyphenols include the presence of digestible carbohydrates like starches and sugars, the presence of antioxidant vitamins C and E, and in the case of lipid-soluble polyphenols like curcumin, which is the main polyphenol in turmeric, the presence of dietary fats enhances nutrient absorption.
But one of the most interesting findings in this review is that polyphenols exert a synergistic effect on each other when it comes to use by the body. The author found ample evidence to suggest that ingesting more than one polyphenol at the same time increases absorption, and also the proportion of both nutrients that the body is able to use. A variety of reasons have been postulated to explain this effect, which is a fertile area for future research, but even without the full explanation, this knowledge of the way our bodies absorb polyphenols gives us a good opportunity to get the greatest benefit from our diets.
Eating a balanced diet made up of a wide variety of fruits, vegetables and whole grains is one of the best ways to maintain health, but it can be hard to prepare three, nutrient dense, healthy meals per day, particularly for people with busy lifestyles.
As a result of this research review, many pundits are putting supplements forth as a superior way to ingest polyphenols. This is because superfood and greens supplements generally contain a blend of different polyphenol-containing ingredients, are rich in antioxidants, and contain low levels of ingredients that inhibit polyphenol absorption, like protein and excessive dietary fibre.
There are a lot of fantastic, polyphenol-rich superfood supplements on the market that are easy to prepare and taste great. On top of this, supplements now come with scientific endorsement as the superior way to get your daily dose of nutrients.
Bohn T. Dietary factors affecting polyphenol bioavailability. Nutr Rev. 2014 Jul;72(7):429-52.