While the impact of diet on endometriosis has been studied for quite some time, most of the research focuses on risk (as in what dietary habits are most associated with women who develop endometriosis) and symptom reduction (as in what dietary habits reduce painful menstruation). There are few to none studies looking at the effect of diet on pregnancy rates.

Also, in these studies, it’s difficult to know what came first. For example, does coffee drinking lead to endometriosis? Or does fatigue caused by endometriosis lead women to drink more coffee? No one can say.

However, our discussion of fertility and diet would be incomplete without at least touching on the research on endometriosis.

Here’s what some of the research has found:

• Eating several servings of red meat or ham per week was associated with an increased risk of endometriosis
• Eating more trans fatty acids (as in some margarines and manufactured food products) was associated with an increased risk
• Drinking two or more cups of coffee per day was associated with an increased risk (though some studies found no correlation)
• Eating more green vegetables was associated with a decreased risk of endometriosis (though some studies found no difference)
• Eating more fruit was also associated with a decreased risk (though some studies found no difference)
• Getting more omega-3 fatty acids seemed to reduce risk, and fish oil intake seemed to reduce painful menstruation in some women
• Getting three or more servings of dairy daily seemed to decrease the risk of endometriosis

A note on eating dairy: There is anecdotal evidence that taking dairy out of the diet may improve symptoms of endometriosis, which has caused this particular bit of research to raise controversy. It may be that women whose painful menstruation symptoms improved when taking out dairy actually were lactose intolerant. In other words, it wasn’t that the endometriosis was improved, but that the lactose intolerance was resolved, and this decreased pelvic pain and discomfort.

Why might dairy improve endometriosis? The theory is that it’s related to calcium and vitamin-D levels. So if you’re sensitive to milk, talk to your doctor about taking calcium and vitamin-D supplements to replace the lack of dairy in your diet.