‘Cheese is “as addictive” as heroin, say scientists’. ‘Cheese is like crack, according to research’. ‘Shock study reveals cheese is addictive like crack cocaine’. These are just a few of the headlines that have appeared in recent days thanks to comments from Dr Neal Barnard, founder and president of America’s Physicians Committee for Responsible Medicine.
Barnard happens to be a vegan and his organisation promotes the vegan diet. His claim that cheese acts on the brain like hard drugs is based on the fact that it contains casomorphins. ‘Casomorphins attach to the brain’s opiate receptors to cause a calming effect in much the same way heroin and morphine do’, says Barnard. ‘You might call it “dairy crack”.’ You might, and he certainly does. He’s been calling cheese ‘dairy crack’ for years.
It’s not entirely clear why Dr Barnard’s views have suddenly become newsworthy. It appears that a supportive study has recently been published by the US National Library of Medicine, but I have struggled to find any trace of it online and news reports have been suspiciously short on details. I have, however, found a study on rats which found that casomorphins have ‘very limited or no reinforcing properties similar to those of morphine’.
According to a dietitian quoted in the Sun, casomorphins ‘really play with the dopamine receptors and trigger that addictive element’. Casual references to dopamine should always get the alarm bells ringing. Pretty much everything we enjoy ‘plays with’ dopamine receptors in the brain. For good evolutionary reasons, food triggers the brain’s pleasure receptors and high-calorie food triggers them more than low-calorie food. That is their legitimate purpose. It is what they are there for. The fact that drugs also stimulate these receptors does not mean that food is like heroin, it means that heroin tricks the brain into thinking it is like food. This is one reason why heroin addicts tend to be skinny.
Claiming that pleasurable activities are comparable to crack cocaine on the basis that they stimulate the brain’s reward centres is a cheap trick that has been used to make ludicrous claims about everything from biscuits to sunshine over the years. The fact that the same reward centres are stimulated does not prove that they are ‘as addictive as heroin’ any more than the fact that the word casomorphin is derived from morphine proves that cheese is an effective painkiller.
Insofar as addictive properties can be measured at all, it is by observing withdrawal symptoms. These can be extreme-to-fatal for heavy users of drugs and alcohol, but trivial-to-non-existent for heavy users of cheddar (with the emphasis on non-existent). I like cheese as much as the next man, but I can’t imagine ever burgling somebody’s house to get money for a wedge of Edam. As for cheese being an opiate, try undergoing surgery with nothing but a slab of Wensleydale for pain relief and see how that goes.
Dr Barnard is upfront about his anti-cheese agenda. In an interview with Vegetarian Times in 2009, he urged people to ‘do what you do with any drug you’re hooked on, you get away from it. You don’t look at it, you don’t smell it, and you certainly don’t eat it.’ Campaigners against sugar, pasties, bananas, sex, sport or — most topically — meat could make the same silly claims about the brain’s reward centres being stimulated like ‘crack cocaine’. Never forget that they are supposed to be stimulated by these things. It is crack cocaine that hijacks them.