Satisfying our sweet tooth might make us feel better in the short term, but new research has furthered growing evidence that eating sugar is linked to mood disorders, such as depression.
The study from University College London, has established a link between a diet that is high in sugar and an increased risk of developing mental health problems later in life.
The NHS currently recommends that adults have no more than 30g of sugar per day (roughly seven sugar cubes), and WHO suggests that further reducing this to less than 25 grams (5% of your daily energy intake) would give “additional health benefits”.
But data has shown that, despite this official advice, the population still consumes, on average, double the recommended RDA, and not only is this causing Type 2 diabetes and obesity, but has now been shown to cause mental health problems too.
The newest study found that men without a pre-diagnosed mood disorder, who consumed over 67g of sugar, had a 23% increased risk of suffering from a mood disorder five years later, compared with those who ate less than 40g.
They also found both men and women who already had a mood disorder and high intake of sugar were at higher risk of becoming depressed again five years later, compared with those who consumed less sugar.
The effect was independent of socioeconomic status, physical activity, drinking, smoking, other eating habits, body fatness and physical health.
This data supports several earlier studies, that came to the same conclusion.
A 2002 study examined the link between depression and sugar consumption in six countries, and found higher rates of refined sugar consumption were associated with higher rates of depression.
In 2011 researchers in Spain found that participants who ate the most baked food had a 38% increased chance of developing depression compared with those in the group who had the lowest intake.
In 2014, an American group found that sugar-sweetened and artificially sweetened drinks could increase a person’s risk of developing depression.
A 2015 study found higher chances of depression in those with a high added sugar intake, but not in those with a high intake of naturally occurring sugars, such as those in fruit.
The team propose several reasons why sugar could be having this effect; it could be because it stimulates the production of BDNF proteins thought to be involved in the development of depression and anxiety.
Another possible cause is inflammation as high sugar diets can cause inflammation - a protective reaction of the body, normally directed against microorganisms or foreign substances.
Dopamine could be another culprit, as sweet foods have been shown to be as addictive as cocaine, and effects the chemical reward system in the brain.