Bruised and scabbed apples have more antioxidants and sugars because they've fought off natural stressors.

April 27, 2016

Grocery shoppers don't generally make a beeline to the scabbed and blemished apples. But maybe they should. New research shows that trauma to the fruit—stresses from fighting heat, bugs, and fungus—forces apples to produce antioxidants such as flavonoids, phenolic acids, anthocyanins and carotenoids. And these compounds have all kinds of nutritional value.

Orchardist Eliza Greenman recently performed an informal test on pocked and dimpled fruit and found that they were 2 to 5 percent sweeter than unblemished apples from the same tree. That led her to wondering if plant stress creates natural superfruits.

It looks like it does; her results align with several previous studies on antioxidants. In one published paper, researchers concluded that organic produce—free of pesticides—contains 20 to 40 percent more antioxidants than conventional produce. In another study from Nature magazine, the authors found that organic apples have higher antioxidant phenols and fruit acids compared to non-organic apples. And it is these antioxidants and fruit acids that help prevent illness and metabolic disorders.

This theory—stress is good for the fruit—has also been tested with grapes. When grape leaves have been infected with fungi, or exposed to a lot of ultraviolet light, they contain surprisingly high levels of resveratrol—an antioxidant that has cardiovascular value.

So how do the chemicals in the fruit work with the chemicals in our human bodies? Microbiologist Martin L. Pall, professor emeritus at Washington State University, believes that the chain of events looks something like this: Stressors shape the look, feel and taste of apples. When we consume these partially blemished fruits, we activate our own protective mechanisms, alighting a molecule in our cells known as Nrf2—which triggers more than 500 cell-protecting genes.

Organic food, therefore, is good for us because it removes the pesticides that would normally relieve apples of having to fight off stress. Once those apples have created extra fruit acids (antioxidant phenols), they are ingested by humans, and kick our repair mode into full gear. And fruit acids, we know, are helpful in preventing illness and metabolic disorders.

Think about that the next time you put a blemished apple back on its shelf. You may have just sacrificed an inexpensive superfood with healing powers.

[h/t NPR]