There is some evidence suggesting that endometriosis is an inherited disease: the risk of disease is 6-9% higher in 1^st-degree relatives of women suffering from endometriosis^1,2(The risk increases to 15% in cases of severe endometriosis^3,4). In twin sisters, the frequency and age of onset of the disease are similar⁵. However, the identification of the genetic factors associated with the disease is, for the time being, incomplete. It is likely that there is no single gene or single aetiology explaining the majority of cases⁶.

It is believed that the frequency of endometriosis has increased in the recent years, however, there is no universally accepted reason why⁷. It could be secondary to the increased number of menstrual cycles during a woman’s reproductive years, the modern lifestyle (younger age of first menstruation, older age of menopause, older age of first pregnancy, shorter period of lactation). Environmental factors may also play a role in this.

On a daily basis, we are exposed to a number of chemical pollutants that can interfere with normal body functions, causing diseases⁸. It has been demonstrated that the exposure starts during foetal life⁸. Special attention has been paid to the role of dioxins.

Dioxins (organic pollutants) accumulate in the body mainly as a result of consumption of animal fat. They appear to play a role in the development of endometriosis through a combination of mechanisms, causing a change in the levels of cytokines and growth factors, remodelling of enzymes (metalloprotease) and changes in the expression and activity of cytochrome P450⁹. Therefore, a balanced diet with reduced levels of animal fat and antioxidant properties is indicated in the prevention as well as the improvement of symptoms in women with endometriosis.

References:

2. Coxhead D, Thomas EJ. Familial inheritance of endometriosis in a British population. A case control study. J Obstet Gynecol 1993; 13:42–4.
3. Kennedy S. The genetics of endometriosis. J Reprod Med 1998; 43:263–8.
4. Kennedy S, Hadfield R, Westbrook C, Weeks DE, Barlow D, Golding S. Magnetic resonance imaging to assess familial risk in relatives of women with endometriosis. Lancet 1998; 352:1440–1.
5. Treloar, S. et al. The international endogene study: a collection of families for genetic research in endometriosis. Fertil. Steril. 78, 679–685 (2002.
6. Vassilopoulou L, Matalliotakis M, Zervou MI, et al.: Defining the genetic profile of endometriosis. Exp Ther Med. 2019, 17:3267-3281.
7. Scioscia M, Roman H, Somigliana E, Robillard PY. Increasing number of menstruations in recent generations may contribute to the development of endometriosis: an evolutionary view from a critical analysis of National Health data. Hum Reprod. 2019 Dec 1;34(12):2549-2550.
8. Carpenter DO. Polychlorinated biphenyls (PCBs): routes of exposure and effects on human health. Rev Environ Health. 2006;21(1):1-23.
9. Sherry Rier, Warren G. Foster, Environmental Dioxins and Endometriosis, Toxicological Sciences, Volume 70, Issue 2, December 2002, Pages 161–170.