I consider the results of studies showing remarkable health benefits attributed to single foods or single nutrients to be “nutrifluff”—fun, but not necessarily meaningful unless you are eating a healthy diet anyway.
Here are four recent examples:
Dark chocolate reduces heart disease risk: Everybody loves this one—an excuse to eat chocolate (but only the dark, bitter kind, alas). This comes from a Cochrane meta-analysis of studies on the role of flavonols in blood pressure. It concludes that chocolate eating is associated with a small reduction in blood pressure of 2 to 3 mm Hg—but only in short-term trials. How many of the studies were sponsored by chocolate companies? The report doesn’t say.
Apple peel extracts reduce blood pressure: Apples also have flavonols. These were test-tube studies. Note: Eating fruits and vegetables in general is associated with lower blood pressure.
Walnuts boost semen quality: Here’s a fun one. Eat 75 grams of walnuts a day, and you improve your sperm vitality, motility, and morphology, at least if you are age 21 to 35 (and male). This one was sponsored by the California Walnut Commission. One report on this study has the best title ever: “Nuts for your nuts.”
Goji berries promote immune function in the elderly: This one, done by researchers working for Nestlé (no relation), tested daily supplements of “lacto-wolfberry” on immune responses to influenza vaccine. I’m assuming Nestlé must be planning to market this supplement.
What does all this tell us? These kinds of studies confirm that eating fruits and vegetables is good for health (I think we might have known that already).
But the main (perhaps only) reason for doing such studies is for marketing purposes, which is why food companies sponsor them.