Diet and Endometriosis: What Does The Evidence Say? Part 1
There is very little known about what causes endometriosis, but what is known is that endo is an inflammatory condition that is fueled by estrogen.
Many women with endometriosis report using diet as a therapy to keep their symptoms in check, but is there any evidence around what you should and shouldn't eat? Unfortunately, evidence is limited around diet for endometriosis, however, there is some research and the results might not be quite what you expect - so in this article we'll examine the evidence for soy, meat, and fats:
Soy is often claimed to be bad for endometriosis, but the evidence is actually mixed. Endometriosis is an estrogen-dependent disease and soy contains phyto-estrogen (or plant-based estrogen), however soy also has anti-estrogenic effects on the body.1
Some studies have shown a link between soy consumption and an increased risk of endometriosis.2,3 Other studies have shown that soy consumption is associated with a decreased risk of endometriosis.4,5
But it’s important to note that some of these studies are based on animal research (on rats) which have a very different physiology to humans, so the evidence is limited.
The bottom line on soy:
Soy may or may not be linked to an increased risk of endometriosis and it may even be protective. If you’re concerned or feel it triggers your symptoms, then try not to eat too much soy. If you do eat it, aim for organic and traditionally fermented soy products such as miso or tempeh.
There have been four studies looking at red meat consumption and risk of endometriosis. Two found no association and two found an increased risk.6,7 The most recent study identified that women consuming two or more serves of red meat per day had a 56% higher risk of endometriosis compared to those consuming one or less serves per week.7 Additionally, women who ate the most amount of processed red meat had the highest risk of endometriosis.
In theory, red meat and processed meat may be bad for endometriosis, as they're associated with increased levels of estrogen in the blood, and since endometriosis is an estrogen-dependent disease, it could be a risk factor.8 Additionally, red meat and processed meat intake is associated with increased levels of inflammation, therefore it may worsen endometriosis symptoms.9
The bottom line on meat:
Red and processed meat are linked to increased levels of estrogen and inflammation and some studies have shown it may also lead to an increased risk of endometriosis, so if you eat red meat, try to reduce your intake.
Omega 3 fats found in fish and other plant and animal sources have an anti-inflammatory effect on the body and can reduce pain.6 Researchers have also found that taking fish oil supplements can help lower period pain.10
Other types of fats such as omega 6 fats may be pain promoting and the increased consumption of saturated and trans fats are linked to an increased risk of developing endometriosis.6
So, where are these fats found? Omega 3 fats are found in fatty fish such as anchovies, sardines, tuna, and wild salmon, but also from plant sources such as seaweed, chlorella, and spirulina. Omega 6 fats are found in a variety of foods but are especially high in seed and vegetable oils, such as soybean oil. Saturated fats mainly come from animal products such as fatty cuts of meat and tropical oils such as coconut oil and trans fats are commonly found in fried foods, margarine and processed foods.
However, it should also be noted some studies have found no correlation between fat intake and endometriosis risk.6
The bottom line on fats:
Given that endometriosis is linked to increased pain and inflammation, eating a diet rich in omega 3 fats and low in saturated or trans fats may help with pain and may be associated with a lower risk of endometriosis.
Read Part 2 here.
Have you altered your diet to try and reduce your endometriosis symptoms? If so, did it help?