A review in the British Journal of Sports Medicine suggesting that sugar should be considered an addictive substance, and could even be on a par with abusive drugs such as cocaine, has sparked a furious backlash with experts describing the claims as 'absurd'.
The Guardian reports that in a narrative review, the authors write that sugar could act as a gateway to alcohol and other addictive substances, adding that like sugar, like cocaine and opium, is refined from plants to yield pure white crystals – a process they say “significantly adds to its addictive properties.”
The article was co-authored by cardiovascular research scientist James J DiNicolantonio and cardiologist James H O’Keefe, both from Saint Luke’s Mid America Heart Institute in Kansas, together with William Wilson – a physician with the nonprofit US group practice Lahey Health.
“Consuming sugar produces effects similar to that of cocaine, altering mood, possibly through its ability to induce reward and pleasure, leading to the seeking out of sugar,” they write, citing rodent studies which show that sweetness is preferred even over cocaine, and that mice can experience sugar withdrawal.
DiNicolantonio said that the consumption of sugar was a grave concern. “In animals, it is actually more addictive than even cocaine, so sugar is pretty much probably the most consumed addictive substance around the world and it is wreaking havoc on our health.”
The report says the trio are not the first to explore whether sugar should be considered addictive, but the article has come under fire from some in the field, who say while sugar consumption can lead to problematic health issues, it is not addictive or a drug of abuse.
Hisham Ziauddeen, a psychiatrist at the University of Cambridge, said that the rodent studies had been misunderstood by the authors, and added that a review of the matter he co-authored last year did not support the idea that sugar was addictive to humans.
“The rodent studies show that you only get addiction-like behaviours if you restrict the animals to having (sugar) for two hours every day. If you allow them to have it whenever they want it – which is really how we consume it – they don’t show these addiction-like behaviours,” he said.
“What this means is that it is the combination of that particular kind of intermittent access and sugar that produces those behaviours. Further you get the same kind of effect if you use saccharin … so it seems to be about sweet taste rather than sugar.”
Ziauddeen added that it was not surprising that even rats hooked on cocaine might prefer sugar, pointing out that many animals would naturally look for sweet things, not cocaine.
Maggie Westwater, a co-author of the study with Ziauddeen, said that the anxious behaviour sometimes shown by rodents after eating sugar was far from a clear sign of addiction. “Since such ‘withdrawal’ often occurs in the context of extended fasting, we cannot say if the behaviours were precipitated by previous sugar consumption or by hunger,” she said, adding that unlike for cocaine, rodents would not seek sugar if it was paired with an unpleasant event, like an electric shock
The report says the authors of the latest study also point to parallels between the effect of cocaine and sugar on the brain, pointing out that both interact with the same reward system. But Ziauddeen said that was not surprising. “The reality is that quite simply the brain’s rewards system and the circuits that control eating behaviour are the same ones that respond to drugs of abuse,” he said. But, he added, unlike sugar “drugs of abuse seem to hijack those systems and turn off their normal controls.”
Tom Sanders, emeritus professor of nutrition and dietetics at King’s College London said that it was “absurd to suggest that sugar is addictive like hard drugs.” “While it is true that a liking for sweet things can be habit-forming it is not addictive like opiates or cocaine,” said Sanders. “Individuals do not get withdrawal symptoms when they cut sugar intake.”
However, DiNicolantonio said that while sugar consumption in humans didn’t lead to physical withdrawal signs, there were biochemical signs of withdrawal in the brain – a point contested by Ziauddeen.
But, the report says, not everyone disagreed with the authors. Robert Lustig, professor of paediatrics at the University of California San Francisco said he shared the concerns of DiNicolantonio and colleagues. “I do believe that sugar is addictive, based on its metabolic and hedonic properties,” he said. Lustig has previously argued that sugar is the “alcohol of the child”. However, while he said he believed sugar was a drug of abuse, he considered it a weak one, on a par with nicotine, rather than drugs like heroin.
Ziauddeen cautioned that sugar, in itself, is not dangerous. “From an eating, metabolism and obesity point of view, sugar is not this terrific demon by itself, because of some innate property of it,” he said. “Where the problem lies is that there are huge amounts of sugar that are put into various foods that substantially boost the calorie content of those foods.”
Sanders agreed, noting that our taste for sugar is a trait that humans are born with and that sweetness helps us recognise foods rich in vitamin C. “The main health hazard from sugar is dental decay – it only contributes to obesity directly via over-consumption of sugar-sweetened beverages,” he said.
In animal studies, sugar has been found to produce more symptoms than is required to be considered an addictive substance. Animal data has shown significant overlap between the consumption of added sugars and drug-like effects, including bingeing, craving, tolerance, withdrawal, cross-sensitisation, cross-tolerance, cross-dependence, reward and opioid effects. Sugar addiction seems to be dependence to the natural endogenous opioids that get released upon sugar intake. In both animals and humans, the evidence in the literature shows substantial parallels and overlap between drugs of abuse and sugar, from the standpoint of brain neurochemistry as well as behaviour.
James J DiNicolantonio, James H O'Keefe, William L Wilson
[link url="https://www.theguardian.com/society/2017/aug/25/is-sugar-really-as-addictive-as-cocaine-scientists-row-over-effect-on-body-and-brain?CMP=Share_iOSApp_Other"]The Guardian report[/link]
[link url="http://bjsm.bmj.com/content/early/2017/08/23/bjsports-2017-097971"]British Journal of Sports Medicine narrative review[/link]