Can you be addicted to sugar?
Shoes, chocolate and shopping; we can apparently be 'addicted' to anything. The concept of food and specifically sugar addiction has gained a lot of media interest. Scientific researchers have taken up the focus in an attempt to explain behaviours associated with obesity. So where does the evidence now sit?
'Food addiction' can offer a convenient excuse for unhealthy eating behaviour. Although food usually provides pleasant sensation and reward, this natural process is essential for survival to encourage us to seek an adequate supply of energy. This is in vast contrast to the reward gained from alcohol or drugs of abuse, one that is not essential for life.
In medical terms it is not possible to classify 'food addiction'. The most recent diagnostic manual for classification refers to 'substance-related disorders', rather than behavioural disorders such as overeating or addictive eating disorder. In the context of substance use, it appears that there was little evidence to include a classification for human food addiction. This is further confirmed by a recent comprehensive review of the evidence, from a wide range of perspectives by a consortium of scientists from 8 European countries. In looking at the evidence they recommend a focus on the behavioural component of food addiction (addictive behaviour) rather than the substance itself (addiction to food). They conclude that 'eating addiction' is a more helpful concept than 'food addiction', and that future research should focus on investigating the criteria for diagnosis on this basis.
Evidence for whether sugar is an addictive ingredient comes mainly from rat studies, where binge eating was observed when sugar availability was limited. Withdrawal symptoms were noted, however it is not clear if this effect is unique to sugar or to palatable foods in general. Similar studies have not been carried out in humans, and so caution needs to be applied when extrapolating these outcomes. In addition, there is no evidence of tolerance (increasing amounts needed to produce the effect) or withdrawal symptoms in relation to sugar consumption in humans. It seems that humans who overeat generally do so over a range of palatable foods and do not restrict themselves to just one ingredient such as sugar or fat.
Studies of brain activation patterns have suggested sugary foods engage the same nerve pathways in the brain as drugs of abuse. Indeed, they clearly show similarity in the areas of the brain stimulated, however this is not surprising, as it merely indicates the response to pleasure. These studies, which were carried out in normal and obese subjects, generally lack consistent outcomes and so it is difficult to form a balanced conclusion.
Craving may be a more accurate term to describe the desire to consume a particular food or food type that is difficult to resist. Research has shown when foods that are intensely liked but consumption is resisted, a strong desire to eat these foods results. Complex psychosocial mechanisms appear to be involved. Depression, boredom, anxiety and stress may all contribute to addictive-like behaviour in people who overeat.
While food addiction does not seem to be proven in the scientific evidence and is therefore unlikely to blame for most cases of obesity, further research on the criteria which encourage overeating and binge eating is warranted. The implication is that it may be necessary to address obesity as a behavioural disorder, focussing on a person's relationship with eating, rather than the food itself. Research in this area is emerging fast and in the future it may generate important answers for prevention and treatment of obesity and related conditions.