The most eye-catching health claims for superfoods tend to be associated with particular groups of compounds: the glucosinolates in kale and broccoli, for instance, or the anthocyanins in blueberries.
Trouble is, although we can study how isolated compounds act on cells in a dish or in mice, it’s much trickier to get a grip on what foods containing these ingredients do inside the human body.
“The way we do experiments is almost like a drug trial, testing one nutrient against something that doesn’t contain that nutrient, says Duane Mellor, a nutrition scientist at the University of Canberra in Australia. “Randomised controlled trials are good for drugs, but we don’t eat foods in isolation.”
Trendy foods like wheatgrass and goji berries are lauded for their miraculous