Endometriosis – what about dairy?

Since I started changing my diet I have red in different endometriosis patient directed and internet sites that dairy products should be avoided for women with endometriosis. There is little evidence to support this. What I actually found was several studies showing the opposite: Dairy is associated with a lower risk of endometriosis.

Topic for discussion: Endometriosis and dairy, the fatty acids, vitamins and minerals, allergy and intolerance, glycemic load and hormones.

Fatty acids

In our diet we get too much omega-6 fatty acids relative to omega-3 fatty acids. This leads to the formation of a number of different eicosanoids, which can increase pain and inflammatory responses. A balanced relationship between these two groups of fatty acids is important, especially when you have an inflammatory disease. You can read more about omega 3: omega-6 balance here. Milk fat has a favorable ratio of omega-6 fatty acids and omega-3 fatty acids. Normal milk has a ratio of approximately 4:1, while the ratio in milk from grass fed cows is even more favorable, approximately 2:1(1)

Milk fat is rich in oleic acid*, and there is a high ratio of oleic acid and the polyunsaturated fatty acids. Milk fat can therefore help to increase the ratio of monounsaturated fats and polyunsaturated fats in the diet. Oleic acid is much more stable against oxidative attack than omega-6 and omega-3 fatty acids and can partially replace these in the corresponding positions in both triglycerides and membrane lipids. A high ratio of oleic acid and polyunsaturated fatty acids in LDL (the bad cholesterol) and other plasma lipoproteins and cell membrane lipids may therefore contribute to better resistance to attack by oxidative stressors (2).

*Oleic acid is a mono-saturated fatty acid, also found in for example olives and avocados. Results from recent research shows that oleic acid may be the cause of the beneficial health effects from these oils. It is believed to lower LDL (the bad cholesterol) and increase HDL (the good cholesterol), increase insulin sensitivity, lower the blood pressure and have a preventive effect on cancer and inflammation.

Milk also contains unique short fatty acids. Several of these have a positive impact on health; Butyric acid has anti-cancer properties, the saturated fatty acids with eight to ten carbon atoms are believed to have antiviral effects, and may inhibit tumor growth. Lauric acid increases HDL (the good cholesterol), and has antiviral and antibacterial activity(1).

In the first human study that examined dietary intake and Endometriosis, Parazzini et al. (3), there was found no association between milk or cheese intake and endometriosis risk.

In another study done by Missmer et al. (4) found that total fat consumption was not associated with endometriosis risk, but women who had a high intake of long-chain omega-3 fatty acid consumption were less likely to be diagnosed with endometriosis compared with those with the lowest intake. In addition, those in the highest quintile of trans-unsaturated fat intake were 48% more likely to be diagnosed with endometriosis.

Trabert et al. (5) also found a suggestion of decreased endometriosis risk associated with the consumption of dairy products.

Vitamins and minerals

Milk is rich in vitamins and minerals, such as several B-vitamins, vitamin-A, calcium, magnesium, zinc, and iodine. Milk can also be a rich source of selenium, but this is geographically determined by the soil. Selenium is important for our health because it is part of the immune system, antioxidant system and the synthesis and repair of DNA.

Some micronutrients, especially calcium and vitamin-D, follow cyclical fluctuations during the menstrual cycle. This is because the ovarian hormones, particularly estrogen, affect the vitamin-D and calcium metabolism.

Vitamin-D plays a central role in bone metabolism and in the mineral-homeostasis. In addition to its importance for the regulation of calcium it has been observed correlations between low Vitamin D-levels and several female diseases, such as endometriose. Vitamin-D is a seco-steroid hormone, which regulates expression of a large number of genes in reproductive tissues.

Vitamin-D has also been shown to influence immune function. Women with endometriosis exhibit changes in cell-mediated immunity, with altered T-helper cel l: T- suppressor cell ratios and concentrations, and vitamin-D may influence the development of endometriosis through its immune modulatory effects.

Estrogen regulates the calcium metabolism, the calcium absorption from the intestine and the parathyroid gland gene expression and secretion, and is responsible for the fluctuations of the menstrual cycle. When the estrogen level is rising, the calcium level decreases.

Dietary calcium has also been inversely related to inflammatory stress, suggesting that dairy foods and nutrients concentrated in these foods may influence endometriosis risk.

Magnesium relaxes smooth muscle and may thus be related to endometriosis through its influence on retrograde menstruation.

Last year, 2013, Harris et al. (6) studied dairy food, calcium, vitamin-D, magnesium and endometriosis, and they concluded that greater predicted plasma 25(OH)D** levels and higher intake of dairy foods where associated with a lower risk of endometriosis. Calcium, vitamin D, and magnesium intakes from foods (including fortified foods) were also inversely related to endometriosis.

** 25(OH)D (calcidiol) is a blood test used to determine how much vitamin D is in the body. The blood concentration of calcidiol is considered the best indicator of vitamin D status.

Allergy and Intolerance 

If you have endometriosis it does not mean you have milk allergy, or are lactose intolerant, but some women with endometriosis can be more sensitive. These conditions, ignored, could aggravate the pain related to endometriosis.


Milk protein allergy is a condition where the immune system reacts to one or more of the proteins in milk. When you are allergic the body’s immune system react to proteins in the food you eat. The cells think the protein are ” foreign” and initiate a reaction with antibodies to defend the body. Most people will find that their symptoms come quickly, from a few minutes to half an hour. It may still take longer, but rarely more than a few hours.

It is over 25 different proteins in milk that can cause reactions. Some are allergic only to one of them, while most people with milk protein allergy have allergies to several.

If you have endometriosis it does not mean you have milk allergy, but some women with endometriosis can be more sensitive to allergens. You can’t make a diagnosis of milk allergy or other allergies yourself; it must be done by a qualified healthcare provider. If you are uncertain, take a test.

Milk intolerance

Milk and dairy products contain natural milk sugar called lactose. Lactose intolerance means that you have impaired digestion of lactose, which can cause gastrointestinal symptoms.

Normally lactose is digested in the small intestine where it is broken into two, glucose and galactose, by the enzyme lactase. If you have a reduced lactase activity, some of the undigested lactose will pass through to the colon cause intolerance symptoms. The most common symptoms of lactose intolerance stomach ache, bloating and diarrhea. The symptoms are caused when bacteria digest the lactose and produce methane and hydrogen gas (flatulence), a typical symptom of lactose intolerance. The symptoms of lactose intolerance can be confused with symptoms of other food allergies and intolerances, or various diseases and disorders of the intestine. Therefore, it is important to consult a doctor and get a proper diagnosis if you have symptoms that make you suspect you are lactose intolerant.

Cheese, cheese spreads, tube cheeses, mozzarella and French cheeses like Brie and Camembert is low in lactose. Dairy butter also contains a little lactose. Yogurt and fermented milk contains some lactose, but is normally well tolerated by those with lactose intolerance. This is because the bacteria in the products has an enzyme (beta-galactosidase) similar to lactase and can help digest lactose.

There are both lactose reduced and lactose free dairy products on the market. This can be a good alternative for those with lactose intolerance. The lactose free and lactose reduced products contain the same calcium and other nutrients as the normal products, but the lactose content is reduced or removed.

Glycemic load

Large fluctuations in blood glucose can lead to formation of reactive oxygen species and oxidative stress, lead to activation of several pro-inflammatory pathways. These reactions contribute to increased inflammation and pain by up regulating the expression of inflammatory mediators. Inflammatory mediators have many roles in endometriosis. They lead to increased inflammation, maintenance and/or development and spread of the implants. They react with the nerves and causes increased sensitivity and pain. The inflammatory mediators also work in such a way that they lead to increased production of the same and other inflammatory mediators, they can for example contribute to up regulated prostaglandin synthesis.

Insulin also plays a role in estrogen levels, both in the formation and breakdown. To avoid excess estrogen is important to maintain a stable blood glucose and insulin levels.

Choose dairy products without added sugar. Fermented products like buttermilk and yoghurt has a lower pH, which leads to delayed emptying from the stomach into the intestine. This contributes to keeping a more stabile blood glucose level.

Fermented dairy products have also been shown to strengthen the immune system by affecting the Th1 and Th2 immune responses and thereby strengthen the defense against cancers, viral infections and protects against allergy (1).


When it comes to hormones, it is the same as for meat, choose dairy from organic and grass fed production. You can read more about this here.


(1) Anna Haug, Arne T. Høstmark, and Odd M. Harstad. Bovine milk in human nutrition – a review. Lipids Health Dis. 2007; 6: 25.

(2) Zemel MB, Sun X. Dietary calcium and dairy products modulate oxidative and inflammatory stress in mice and humans. J Nutr. 2008;138(6):1047–1052

(3) Parazzini F, Chiaffarino F, Surace M, et al. Selected food intake and risk of endometriosis. Hum Reprod. 2004; 19(8):1755–1759.

(4) Missmer SA, Chavarro JE, Malspeis S, et al. A prospective study of dietary fat consumption and endometriosis risk. Hum Reprod. 2010; 25:1528–1535.

(5) Britton Trabert, Ulrike Peters, Anneclaire J. De Roos, Delia Scholes, and Victoria L. Holt. Diet and risk of endometriosis in a population-based case– control study. Br J Nutr. 2011 February ; 105(3): 459–467.

(6) Holly R. Harris*, Jorge E. Chavarro, Susan Malspeis, Walter C. Willett, and Stacey A. Missmer. Dairy-Food, Calcium, Magnesium, and Vitamin D Intake and Endometriosis: A Prospective Cohort Study. American Journal of Epidemiology Vol. 177, No. 5. February 3, 2013

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