In a study of the effects of fruit and veggie intake on diabetes risk, kale and cabbage seem unusually protective.
Researchers writing today in the British Medical Journal found that — in data from six previous studies covering some 22,000 participants –people who ate lots of leafy vegetables were less likely to develop type II diabetes than people who didn’t. An increase of 1.15 servings per day is associated with a 14% decrease in new diabetes diagnoses, the researchers say.
The six different studies all used slightly different definitions of “leafy vegetables.” But the study authors say that the term should include:
brassicas, such as cabbage, brussel sprouts, and cauliflower; Compositae, such as lettuce; and umbelliferous vegetables, which are plants grown for their leaves and stems and are often consumed as herbs, such as parsley, dill, and fennel. Other leafy vegetables such as spinach are also included.
Some of the studies did not measure intake all of these veggies. Nevertheless, overall across all six studies, consumption of leafy greens was associated with lower rates of new diabetes diagnoses over time. Intake of other fruit and vegetables seemed less important.
It’s not clear what the leafy vegetables would provide that other fruit and veg would not. The research team suggests it may be something about the polyphenols that greens contain — a rich source of antioxidants — or the greens’ magnesium content. Or it may be something else entirely. But the researchers don’t seem to mind that uncertainty for now. They’re still recommending that people go ahead and “promote the consumption of green leafy vegetables.”