Composite photo of citrus slices
The whole fruit, and nothing but the whole fruit - is the key to getting all the antioxidants you need

Antioxidant activity of whole foods higher than previously thought

5 January, 2015

Natural Health News — The antioxidant activity of citrus juices and other foods is often underestimated, according to Spanish researchers.

Using a new technique developed by researchers from the University of Granada for measuring antioxidant activity, the resarchers found that values can be ten times higher than those indicated by current  methods. The results suggest that tables on the antioxidant capacities of food products that dieticians and health authorities use must be revised.

The researchers say that this means that foods like orange juice and juices from other citrus fruits already considered healthy due to their high content of antioxidants, which help to reduce harmful free radicals in our body, could bring benefits are greater than previously thought.

In order to study these compounds in the laboratory, techniques that simulate the digestion of food in the digestive tract are used, which analyse only the antioxidant capacities of those substances that can potentially be absorbed in the small intestine: the liquid fraction of what we eat.

“The problem is that the antioxidant activity of the solid fraction (the fibre) isn’t measured, as it’s assumed that it isn’t beneficial. However, this insoluble fraction arrives at the large intestine and the intestinal microbiota can also ferment it and extract even more antioxidant substances, which we can assess with our new methodology,” says José Ángel Rufián Henares, professor at the University of Granada.

His team has developed a technique called ‘global antioxidant response’ (GAR), which measures the antioxidant capacity of both the liquid and solid fraction of food. Details were published in  journal Food Chemistry.

Upon applying the technique to commercial and natural orange, mandarin, lemon and grapefruit juices, it has been proved that their values greatly increase.

“The antioxidant activity is, on average, ten times higher than that which everyone thought up until now, and not just in juices, but also in any other kind of food” says Rufián Henares, who notes its possible application: “This technique and the results derived from it could allow dieticians and health authorities to better establish the values of the antioxidant capacity of foods.”

The new data reinforces the importance of whole foods in the diet, suggesting that every part of the food has something to offer in terms of health. Refining foods, removes many important nutrients.