From an apple a day to mustard for cramps, we check the science behind six classic health claims
- Do you believe that eating fish is good for your brain? Does turkey make you feel tired?
- Nutritionist Cara Rosenbloom puts beliefs about the health-giving properties of foods under the scientific microscope

Questionable nutritional advice is easily amplified in our digital world, but older generations have always passed down health claims that younger generations found difficult to believe.
Did your parents ever encourage you to drink fish oil to boost brain power before an exam, or offer mustard when you had a muscle cramp? My folks believed ginger relieves nausea.
I was curious whether these folk remedies could withstand the scrutiny of science – or whether they’re bunk.
So I set out to research a few of them.
An apple a day keeps the doctor away
This well-known statement is based on an 1860s Welsh proverb that eating apples will diminish doctor visits. And it has actually been put to the test – in a 2015 April Fools’ Day issue of JAMA Internal Medicine, in which the topics were zany but the studies were real.