Diet and endometriosis

While there currently is no clear link between one single food or eating pattern and endometriosis, there is a growing body of research in this area and it looks like changing nutrition and lifestyle may help in reducing symptoms and could optimise fertility. 

Can the Mediterranean diet help with endometriosis?

One of the most popular diets for those with endometriosis is adopting a Mediterranean-style eating pattern. The Mediterranean diet has long been promoted for heart health and to improve fertility and research is underway to see if it is also beneficial for those with endometriosis.  

The Mediterranean diet focuses on: 

• plenty of fruits and vegetables daily 
• enjoying beans, legumes, nuts, and seeds daily 
• having seafood, especially oily fish 2-3 times per week 
• limiting red meat 
• choosing whole grains 
• including more healthy fats, the main oil is extra virgin olive oil 
• limiting processed foods 

Following a Mediterranean-style eating pattern normally changes the types of fats and oils we eat. Seafood, especially oily fish, is rich in omega-3 fatty acids which are anti-inflammatory and as our body cannot make these, we need them in our diet. If you are vegetarian, good sources of omega-3s are walnuts, chia seeds, and ground flaxseeds, however, these are not as effectively used in our body compared to oily fish.  

On the other hand, this eating pattern decreases the amount of a fat we eat called palmitic acid which is mostly found in animal products such as red meat and is associated with an increased risk of endometriosis.  

The Mediterranean diet also increases the number of antioxidants we eat from colourful fruits and vegetables, nuts, seeds, oil, and legumes. Women with endometriosis have more free radicals than those who do not have the disease, and these compounds can cause cell damage and illness through a process called oxidative stress. 

Antioxidants can reduce the number of these free radicals and a study has shown that women who supplemented with antioxidants reduced their inflammatory markers. Supplementation is not routinely recommended though, as it is easy to increase antioxidants from food.  

How does fibre affect endometriosis symptoms? 

Fibre is the non-digestible carbohydrate part of plant foods and most of us are not getting nearly enough to meet the 30g per day that is recommended. Fibre not only keeps our bowels moving, but it’s also the food for our gut bacteria. 

Fibre is really important for our gut health and for those diagnosed with endometriosis as it helps by binding to oestrogen and excreting excess through our bowels. 

Does gluten affect endometriosis symptoms?

If you consider cutting out gluten for some time it is important to work with a qualified health professional such as a registered dietitian. You may need a test for coeliac disease before trialling this and there is a small risk of missing certain micronutrients if you cut out gluten without the right support.  

However, it is certainly something to consider for those with endometriosis. One study has shown that 75% of women with endometriosis had improvements in pain after one year on a gluten-free diet. While this is great, it is important to consider a few things. 

Firstly, cutting out refined sources of gluten such as biscuits, cakes, pastries and replacing these with whole foods may improve overall well-being without having anything to do with gluten. Secondly, it may not be gluten that is the culprit in these foods. Wheat is high in a carbohydrate called fructan, which is highly fermentable by our resident gut bacteria and may cause bloating in some people. It is therefore difficult to say if any improvements in bowel symptoms are due to the removal of gluten or the reduction of this carbohydrate called fructan.  

How does dairy affect endometriosis symptoms?

A quick online search will bring up hundreds of sites that say dairy is terrible for those with endometriosis and must be cut out of the diet. However, this is not really the case. So far, dairy has not been shown to be pro-inflammatory. It has even been reported that increased dairy consumption was associated with a decreased risk of endometriosis and may even support fertility. The problem with dairy is that many people are intolerant to lactose, the sugar in milk. Lactose is also a FODMAP. 

As people with endometriosis often have gastrointestinal symptoms it’s not surprising that they feel better once they cut out dairy from their diet, as they may be lactose intolerant or they respond well to the overall reduction in FODMAPs. If you think you’re lactose intolerant, change to calcium-fortified plant milk for a couple of weeks, then reintroduce dairy milk and reassess your symptoms. 

If you feel better without it, there are luckily plenty of calcium-fortified plant milks to suit all taste preferences. Be mindful that yoghurt and cheese are often much lower in lactose and therefore many people with lactose intolerance can still eat these products. Therefore, there is no need to cut out every trace of milk to manage your symptoms unless you have a diagnosed allergy. Excluding dairy long term can also lead to a reduced lactose tolerance which could be an issue if you are trying to re-introduce some dairy later in life.  

FODMAPs and endometriosis

Fructan is part of a group of carbohydrates called FODMAPs, which stands for Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols. That’s quite a mouthful. They’re certain types of carbohydrates and sugar alcohols that are poorly absorbed in our gut, resulting in abdominal pain and bloating in some people.  

The low FODMAP diet is a three-step diet that has been developed to manage the symptoms of medically diagnosed irritable bowel syndrome (IBS). IBS has many overlapping symptoms with endometriosis such as bloating, abdominal pain, diarrhoea, constipation, and visceral hypersensitivity. Women with endometriosis are two and a half times more likely to also be diagnosed with IBS.  

Given this overlap in symptoms between IBS and endometriosis, one study looked at trialling the low FODMAP diet on women diagnosed with both IBS and endometriosis. They found that 70% of people had significant improvements in their symptoms after four weeks on the low FODMAP diet.  

A word of warning though; the low-FODMAP diet is not going to be suitable for everyone. Is not intended for long term use as it has been shown to decrease our gut bacteria diversity (and we want diversity) and you may be missing out on some nutrients if you follow the diet long term. It should never be attempted without the guidance of a trained dietitian.  

What does this mean for you? 

What we really need are some well-designed research trials that look at the relationship between specific foods and endometriosis. Nutrition research is often difficult in practice as we do not eat single foods, but we consume a whole load of nutrients each day and our lifestyle also affects our health. 

What we do know is that nutrition and lifestyle changes can certainly help in improving endometriosis symptoms and can support fertility. However, it is best to take an individualised approach with the guidance of a nutrition professional as there is no one size fits all when it comes to diet and endometriosis.