Trans-Fats Giving You the Blues?

February 25, 2011

Will a diet rich in whole foods lower your risk of depression? A new study points to an ingredient that can leave you feeling blue.

Will a diet rich in whole foods lower your risk and the overall occurrence of depression? Researchers from University College in London (UCL) say quite possibly. The study, published in the British Journal of Psychiatry, examined the link between diet quality and mood among 3,486 civil service employees over a five-year period, with some interesting results.

The UCL researchers found that those who consumed diets high in processed foods, meat, chocolate, sweetened desserts, fried foods, refined cereals and high fat dairy products were more likely to experience depression versus those whose diets consisted of more whole foods, such as fruits, vegetables and fish. While there was no specific conclusion or food thought to be the main actor in this link, a new study based on results from the SUN project – a study which included over 12,000 Spanish volunteers – may have in fact found the culprit to be trans-fats. (Trans-fats can be found in processed foods, but are currently being phased out.) 

Participants with the highest level of trans-fat consumption had up to a 48 percent increase in the risk of depression compared to those with the lowest intake. Furthermore, polyunsaturated and monounsaturated fats as well as olive oil were associated with lower incidence of depression. 

It should be noted that the population studied has generally a very low trans-fat intake, approximately 0.4 percent of total energy. The US average intake of trans-fats is about 2.5 percent of total energy – that’s over six times the amount of the population studied! 

It’s well known today that trans-fats increase levels of LDL-cholesterol, reduce levels of HDL-cholesterol, can promote inflammation, and influence other risk factors for cardiovascular diseases (CVD). Both cities (trans-fats are banned in NYC restaurants, Chicago and more) and the food industry have been working to reduce and remove trans-fats from their products and reformulate due to the negative health outcomes associated with their intake. 

SUN study researchers comment on the observation of a rising incidence of depressive disorders paralleled by a dramatic change in the sources of fat in the Western diet. The change has consisted of the replacement of polyunsaturated or monounsaturated fatty acids by saturated and trans-fats. They also note that beyond adherence to an overall dietary pattern, very little is known about the effect of specific types of major fat sources for the risk of depression risk (except omega-3s).

Findings suggest that existing healthy eating policies like the 2010 Dietary Guidelines for Americans that advise people to consume fewer solid fats and more nutrient dense foods, will generate additional benefits to health and well being and may even decrease the staggering statistics regarding depression in the US. Including more fresh fruits and vegetables, legumes and whole grains is sure to get you in a good mood!

Major depressive disorder is the leading cause of disability for those aged 15 to 44 in the United States, affecting approximately 6.7% of adults, according to The National Institute of Mental Health. For more information on depression, visitThe National Institute of Mental Health.