What is it?
Sugar comes in many forms and is found in a wide variety of foods. Sugars may be naturally occurring (e.g. the sugar found in fruits) or refined and added to foods (e.g. the white sugar you add to a cake when baking). Cutting out refined sugar from the diet has been proposed to help depression in some cases, and recently there has been a rise in the popularity of sugar free diets.
How does it work?
There is evidence that eating foods rich in carbohydrates (sugar is a simple carbohydrate) produces a temporary improvement in mood. However, it has been proposed that some people have a sensitivity to refined sugar which can lead to lead to depression and overall reduction in wellbeing. In these cases, it is suggested that cutting out refined sugar may improve mood.
Is it effective?
There is very little scientific evidence on sugar avoidance for the treatment of depression. More studies of better quality are needed.
One small study has been carried out on patients whose depression was thought to be due to dietary factors. The researchers asked half of these patients to cut out caffeine and sugar from the diet and the other half to cut out red meat and artificial sweeteners. Depressed people who cut out caffeine and sugar showed more improvement. However, only a minority of the patients appeared to benefit specifically from cutting out sugar. There is no evidence on the effects of cutting out sugar in the majority of people who are depressed.
Are there any disadvantages?
There are no known disadvantages.
Where do you get it?
If you would like to know more about the role of sugar in your diet, you can seek the help of a dietitian who can assess whether you have any sensitivity to sugar and advise you on any changes to your diet. Private dietitians are listed in the Yellow Pages, or you could ask your GP for a referral.
Given the lack of evidence on sugar avoidance, it cannot be recommended as a treatment for depression.
- Benton D, Donohoe RT. The effects of nutrients on mood. Public Health Nutrition 1999; 2: 403-409.
- Christensen L, Burrows R. Dietary treatment of depression. Behavior Therapy 1990; 21: 183-193.
Last reviewed and updated: 1 December 2016