High intake of sugar is linked to increased risk of depression in men, according to a new study. Scientists at the University College London (UCL) in the UK, found that men who consumed more than 67gms of sugar each day – the equivalent of two cans of Coke – were at an increased risk of developing depression, anxiety, and other common mental disorders after 5 years, compared with men who consumed less than 39.5 gms of sugar.
“High sugar diets have a number of influences on our health but our study shows that there might also be a link between sugar and mood disorders, particularly among men. There are numerous factors that influence chances for mood disorders, but having a diet high in sugary foods and drinks might be the straw that breaks the camel’s back,” says lead study author Anika Knuppel, of the Institute of Epidemiology and Health at UCL.
Consuming too much sugar may heighten the risk of a range of health problems, including type 2 diabetes, tooth decay, obesity, and heart disease.
Previous studies have also linked high sugar intake to increased risk of depression, though the researchers had suggested the association may be down to “reverse causation.”
“Reverse causation refers, in this context, to the possibility that a mood disorder may lead to higher sugar intake, so that the diet-mental health association is wholly or partly the result of poor mental health rather than of high sugar intake,” the authors explain. [Read more Drinking coffee daily may lead to a longer life, new study shows]
For the new study, Knuppel and colleagues set out to investigate whether sugar consumption might influence the development of mental health problems.
The team analysed data of 10,308 participants, of whom 66.9 percent were men. All participants were aged between 35-55 years and were part of the Whitehall Study II in the 1980s.
Over the follow-up period of 22 years, the subjects completed food frequency questionnaires at four time points. The information from these questionnaires were used to calculate the participants’ daily sugar consumption from 15 sweetened foods and beverages, which included cakes, soda, tea and coffee.
During the follow-up, the participants also completed general health questionnaires and interviews at numerous time points. These information were used to identify the individuals’ development of common mental health disorders, such as anxiety and depression.
The researchers found that the men who had the highest amount of daily sugar intake (more than 67 grams) were 23% more likely to develop common mental disorder five years later, compared with men who consumed 39.5 grams daily. [Read more Chocolate may boost cognitive skills within hours]
This finding remained even after the researchers accounted for several likely confounding factors, which included other dietary factors, sociodemographic factors, and the presence of other health problems. [Read more Adherence to a Mediterranean diet linked to lesser chance of developing ADHD]
The team did not find any link between sugar intake and mental health disorders in women.
Now, why the results were much stronger in men than women? One of the reasons, Knuppel explains, could be that women aren’t represented strongly in the research, which recruited civil servants in the 1980s. But according to national dietary surveys, men consume more sugar than women do, in spite of the popular assumptions about “Bridget Jones sitting there with her ice-cream bucket.”
The researchers also discovered that compared with participants who consumed low amount of sugar, the individuals with mood disorders who consumed high amount of sugar daily were more likely to develop depression after 5 years. But, this link subsided once the researchers considered sociodemographic and other dietary and health factors.
“Our findings provide yet further evidence that sugary foods and drinks are best avoided … The physical and mental health of British people deserves some protection from the commercial forces which exploit the human ‘sweet tooth’,” says co-author Professor Eric Brunner, also from UCL.
The findings were published in the journal Scientific Reports.