Excess sugars are not good for mental health. A study from the University College of London highlights an increased risk of depression with chronic excessive consumption of sugars.
The data is accumulating in favor of a harmful long-term effect on health in general, from an excessive consumption of sugary products. A new study shows a very strong association between sugar consumption and the common mental disorders of anxiety and depression.
23% more depression and anxiety with sugar
The study concerns a follow-up of a cohort of the Whitehall Study II in the United Kingdom. This included a sample of 5,000 men and 2,000 women, assessed several times between 1983 and 2013. Dietary sugar intake was quantified by frequency questionnaires, and mental health.
The analysis reveals positive associations: after 5 years, with more than 67 g of sugars per day. For sugar intake from sugary foods and sugary drinks, there is a 23% increase in the risk of anxiety and depression in men.
Sugar: cause of depression and not the consequence
The authors then wanted to know if this high consumption of sugars was not in fact the consequence of depression. But this is not the case, insofar as the authors did not observe an increase in the consumption of sugars in individuals identified at risk of depression at the start of the study.
To explain the relationship with depression, scientists point to 4 potential mechanisms. The first two are an influence of sugars on inflammation and levels of BDNF (Brain-Derived Neurotrophic Factor or brain-derived neurotrophic factor), which would be directly linked to the development of depression. The second are postprandial hypoglycemia, as well as the addiction associated with certain neurotransmitters stimulated by sugars.
Knüppel A et al. Sugar intake from sweet food and beverages, common mental disorder and depression: prospective findings from the Whitehall II study. Scientific Reports 7, Article number: 6287 (2017).