Sweet dreams

Not since Marie Antoinette has cake caused such a stir.¹ Earlier this week Professor Susan Jebb, the chair of Britain's Food Standards AgencyA department of the British government, responsible for protecting public health on food matters. , compared bringing cake into the office to smoking inside. 

She implied that those who bring sweet treats into work all-but-force others into eating them, just as people in the same room as a smoker passively breathe in some of the smoke. Jebb said: "If nobody brought in cakes into the office, I would not eat cakes in the day, but because people do bring cakes in, I eat them."

The reaction was swift and vicious. The Sun called her a "health fussbucket" and "an egg short of a Victoria sponge". Former politician Nigel Farage even told her to "shut up". Prime minister Rishi Sunak even waded in to assure people the government would not ban treats.

The message behind Jebb's remarks should be uncontroversial. Cakes are low in nutrients and high in sugar, fuelling obesityThe medical condition of being very overweight. There are many ways of measuring this, including a BMI of 30 or more. (You can work out your BMI by dividing your weight in kilograms by your height in metres squared.). And doctors link obesity to health problems such as diabetesA medical condition causing there to be too much sugar in the blood. and heart disease.

Yet some people are scepticalTo have doubts or reservations. The philosophical theory of scepticism holds that some knowledge is impossible. about following health guidance. And they might have a reason to be. SophoclesA 5th Century BC Athenian believed to have written 123 plays, seven of which survive. said: "No enemy is worse than bad advice." Health advice has often been downright dreadful.

In the 19th century, Austrians drank ratsbane - a form of the poison arsenicA chemical element which is very poisonous. - in their coffee. Victorian women ate tapeworm eggs.

Smoking is now universally agreed to be linked to numerous appalling diseases. As a result, many countries have made cigarettes expensive and banned smoking in public spaces.²

Yet in the 1930s and 40s, before the connection between smoking and lung disease was discovered, doctors actually recommended cigarettes as a way to soothe sore throats. In 1954, 45% of American adults smoked.³

More recently, there has been a debate over the health effects of cholesterolA type of blood fat produced by the liver.. The American Heart Association tells people that eating more than three eggs a week would raise it to dangerous levels. Yet a 2013 study claimed that cholesterol was good for us. It even advised eating three eggs a day.

Some say we should ignore past mistakes. Research is getting more and more accurate. As Psychology Today's Temma Ehrenfeld says: "Think of nutritionThe process of taking food into the body that you need to live and grow.  as like a detective story, with twists and turns. Over time, scientists are developing a better understanding of how food affects us." 

Organisations like the Food Standards Agency act with a genuine desire to help people live longer and healthier lives.

Others are less generous. Health advice does not always come from a benign source. In 2015, professor Marion Nestle uncovered 168 health studies that year funded by food and drink companies. As many as 156 of these showed bias toward their funder.⁴

Scientists also use advice to generate interest. As child health expert Aaron E Carroll says: "Medical scientists and academics must publish their research to advance. Medical organisations must release health recommendations to remain relevant." In doing so, they often take the cake out of the oven before it is fully baked.

Yes: Health advice is science. And science is always evolving. There will of course be mistakes here and there. But it comes from a sound basis and good intentions, and gets things right more than not.

No: Advice is seldom infallibleIncapable of making mistakes. or without an ulterior motive. Even if we choose to follow a health recommendation, we should always treat it with a dose of scepticism, whatever its source. 

Or... Cake may well be bad for us. But people have eaten cake for centuries and lived full lives. The true issue is not whether health advice should be trusted, but the extent to which we should follow it.