Boffin scoffing

"Hmm," the doctor tells his patient. "You need change in your diet. I recommend an ice-cream sundae at least once a week. Don't forget to add a Flake - and of course a cherry on top."

This scenarioAn imaginary situation. The word was originally Italian and referred to the plot of a stage drama. is unlikely ever to become reality. But an article in the new issue of The Atlantic has caused a stir by highlighting the idea that ice-cream could indeed have some benefits.

The author, David Merritt Johns, first came across the idea in a thesisA long essay involving personal research. written in 2018 by a student at Harvard University. Andres Ardisson Korat concluded that people with diabetesA medical condition causing there to be too much sugar in the blood. who ate half a cup (64g) of ice-cream a day had a lower risk of heart trouble.

Since ice-cream is full of saturated fat and sugar, which are generally agreed to be very unhealthy, the academics judging his thesis were deeply sceptical. According to one, they did every possible test to disprove his research - but in vain.

Digging deeper, Johns discovered that an assistant professor at HarvardA top US university, founded in 1636. had reached a similar conclusion in 2002.

Mark Pereira found that ice-cream helped prevent overweight people from developing insulinA hormone which controls blood sugar levels and helps your body to turn food into energy.-resistance syndrome, which leads to diabetes.

In 2005 another Harvard study found that men who ate two or more servings of ice-cream per week had a 22% lower risk of diabetes. But the authors did not publicise this fact. Instead, they emphasised the benefits of yoghurt, which were similar but not quite as effective. Why?

"A scientist," Johns suggests, "may worry over how their story fits with common sense, and whether they have sufficient evidence to back it up. They may also worry that it poses a threat to public health, or to their credibility."

But Dr Duane Mellor of Aston Medical School is adamantSure, certain. that we should not eat too much ice-cream. Though it might contain some beneficial nutrients, such as calcium, these are probably outweighed by the sugar and calories it contains.

Ice-cream is not the only food on which scientific opinion has been divided. At one stage people were advised not to eat more than two eggs a week. Now it is considered OK to eat as many as you like.

Johns quotes an English epidemiologistA person who studies diseases and how they spread between people., Michael Marmot: "Scientific findings do not fall on blank minds that get made up as a result. Science engages with busy minds that have strong views about how things are and ought to be."

Yes: Science is based on evidence, not opinion. Most scientists work in teams and have their work checked by others before it is published, so errors or false claims have little chance of getting through.

No: As Michael Marmot says, scientists tend to find evidence for things they already believe and want to prove. History is full of scientific claims which turn out to be complete nonsense.

Or... There is no final answer in science - we are always finding out new things. So we should view all research as work in progress, and realise that each new discovery is only part of the truth.