Raspberry ketone

Raspberry ketone, more specifically, 4-(4-hydroxyphenyl)butan-2-one, is an organic compound, a phenolic or ketonic compound depending on which end you focus on, present in red raspberries, it’s the main chemical that gives them their distinctive aroma. As such, it is used widely in perfumery, cosmetics, and the food industry, giving products a fruity, raspberry odour. It is present in raspberries only at very low concentration and as such has to be synthesised so that the additive costs about $20,000 per kilogram.

What makes raspberry ketone rather interesting is that it is now at the heart of a fat-loss scam based on the fact that when mice are fed very high doses (up to 2% of their body weight!) Such mice then don’t get fat when given a high-fat diet. The high dose effect is reported to stem from the alteration of lipid metabolism, increasing norepinephrine-induced lipolysis. But, there is no evidence of the effect in people and even if there were you weigh 100kg you would have to eat 2 kilograms of the stuff neat. Or you could try eating raspberries, but given that 1 kg of raspberries can be used to obtain a mere milligram of raspberry ketone, you’d have to eat 2000 tonnes of the fruit…that right?

Earlier this year Andrew Lessman criticized the hype about raspberry ketone in a blog post: “America’s epidemic of obesity finds us willing to try almost anything to lose weight. It is this desperate struggle with obesity that makes us so vulnerable to the latest miracle weight-loss pills,” he says, adding that: “Any doctor knows that fat-burning miracles do not exist and such a statement is reckless and harmful to public health.”

Lessman concludes: “To lose weight, we must change the quality, quantity and nature of the food we eat, while also attending to physical activity. It is never easy. A supplement can offer some nutritional support for these efforts, but ultimately, the miracle resides in our ability to make significant life changes. Never in a supplement. There are no weight-loss miracles.”