What's more, researchers found that olive oil had a protective effect against the disease.
To investigate, researchers studied more than 12,000 volunteers over a period of six years. Volunteers had their diet, lifestyle and ailments analyzed at the beginning of the project, over its course and at the end of the project.
Researchers report that none of the volunteers suffered from depression at the start of the study; at the end of the study 657 new cases of depression had been detected.
Researchers found that participants with an elevated consumption of trans-fats, found mostly in processed and fried food, were 48 percent more likely to be depressed, compared to people with diets low in trans fat.
In fact researchers report finding a dose-response relationship, whereby the more trans-fats consumed, the greater the harmful effect in the volunteers. On the other hand, researchers found that study participants with the highest intake of olive oil had the lowest rates of depression.
Researchers note that trans fat increases inflammation, whereas olive oil contains some chemicals with anti-inflammatory properties, and suggest that depression may be related to low- grade inflammation, which is commonly observed in patients with the disease.
While further studies are needed on the subject, the health risks of trans fat are well known. Studies show a diet high in trans fat can increase the risk of heart disease by lowering blood levels of good cholesterol (HDL-cholesterol), and raising blood levels of bad cholesterol (LDL-cholesterol).
While many restaurants and food companies are making efforts to eliminate trans fat from their products, the main sources of trans fat in the diet include hard margarine, commercially fried foods and bakery products that are made with shortening, margarine or oils containing partially hydrogenated oils and fats.
Products that tend to contain trans fat include crackers, cookies, donuts, cakes, pastries, muffins, croissants, snack foods and fried foods, such as French fries and breaded foods.
For more information on the health risks of trans fat, click here.
All research on this web site is the property of Leslie Beck Nutrition Consulting Inc. and is protected by copyright. Keep in mind that research on these matters continues daily and is subject to change. The information presented is not intended as a substitute for medical treatment. It is intended to provide ongoing support of your healthy lifestyle practices.