Do different dietary components affect endometriosis risk? Original paper

Via their effects on hormones, inflammation, oxidative stress, and the menstrual cycle, dietary factors could play a role in the pathogenesis of endometriosis. However, studies examining the links between the dietary intake of different food groups and nutrients and the risk of endometriosis have produced conflicting results. What does the totality of the available observational evidence suggest?

This meta-analysis of 8 observational studies (5 cohort and 3 case-control) examined the links between the intake of different dietary components and the risk of endometriosis in a total of 492,964 women. The following dietary components were assessed:

• Dairy: total dairy products (4 studies), low-fat dairy (3 studies), high-fat dairy (3 studies), cheese (3 studies), and milk (3 studies)
• Fats: total fat (3 studies), monounsaturated fatty acids (MUFAs; 3 studies), polyunsaturated fatty acids (PUFAs; 3 studies), saturated fatty acids (SFAs; 3 studies), and trans fatty acids (TFAs; 3 studies)
• Fruits (4 studies)
• Vegetables (4 studies)
• Legumes (3 studies)
• Animal protein sources: eggs (3 studies), fish (4 studies), poultry (3 studies), and red meat (4 studies)

The studies were conducted in the United States (6 studies), Italy (1 study), and Iran (1 study). The average age of the participants ranged from 18 to 41 years. In all studies, the dietary intakes were assessed using food frequency questionnaires.

The highest (compared to the lowest) intake of total dairy was linked to a 10% lower risk of endometriosis. The highest (compared to the lowest) intakes of SFAs, TFAs, and red meat were linked to 6%, 12%, and 17% higher risks of endometriosis, respectively.