Do you eat because you are depressed? Or are you depressed because of what you eat?

By Maria Zaretti BSc Hons DipION

Depression is very common with an estimated 5-10 per cent of the UK population affected to some degree at any one time. It is more typically thought of as strictly emotional or biochemical, but Nutrition can play a key role, contributing to onset of depression and exacerbating its severity.

New research by Fulton & Sharma (2012) shows that, in addition to causing obesity, excessive consumption of high-fat foods can cause chemical reactions in the brain ultimately leading to depression.

Reward and pleasure centres in the brains of both animals and humans are controlled by a chemical called dopamine. Dopamine enables people to see rewards and take actions to move towards them. Fulton & Sharma showed that mice fed a high-fat diet developed depressive symptoms with changes in the brain's reward and pleasure centres associated with depression.

The fat-fed mice developed high levels of CREB. CREB is a molecule that activates genes involved in brain function including genes that dampen the reward-circuitry. Having high CREB may make the same-old dose of a 'drug', in this instance high-fat food, less rewarding and promote a negative mood state. It seems that if you comfort eat fatty foods to improve your mood you may actually end up feeling worse!

Dr. Fulton draws a comparison with drug addiction whereby a vicious cycle sets in where “food-highs” are used as a way to combat depression. “In a similar way to illicit drugs” says Fulton “continually eating high-fat foods can lead to depression as the 'come-downs' take their toll”.

Whilst Fulton's research focuses on the relationship between high-fat diet and depression, there are plenty of other dietary patterns, including excess sugars, nutrient deficiencies and skipping meals that may contribute to or exacerbate depressive symptoms. The bottom line is that food often plays a key role in maintaining your mental health, and there is a lot that can be done naturally to help rebalance mood naturally if you are currently affected to some degree by depression.

References

Nestler E and Malenka R (2004) Scientific American ;290(3):78-85.

Petra Rattue. (2012, May 28). "Exploring The Relationship Between Depressive Symptoms And High-Fat Diets." Medical News Today. Retrieved from
http://www.medicalnewstoday.com/articles/245910.php. 

Sharma S & Fulton S (2012) Diet-induced obesity promotes depressive-like behaviour that is associated with neural adaptations in brain reward circuitry International Journal of Obesity 10.1038/ijo.2012.48.