Food science: should we believe anything we read about nutrition?

One morning about a year ago I spotted a headline that made my heart sink. It claimed eggs can give you a heart attack.

It wasn’t that I was about to eat eggs for breakfast. Rather, it was because, as a medical journalist, I knew friends and family would soon be asking me what to make of this claim. And I would have a tough time answering. Advice about what to eat seems to change every week.

Eggs are a classic example. They were once seen as whole­some packages of protein and vitamins, a…