Sunbathing and tanning beds may be associated with a greater risk of developing endometriosis, stated new research published in Human Reproduction.
Endometriosis is a chronic painful disorder with endometrial tissue found at abnormal sites such as the ovary and tubes. It causes pelvic pain and fertility issues.
The study of over 116,000 women in the USA found that women living in parts of the country with high ultraviolet light levels throughout the year, such as southern parts of the US, were less likely to be diagnosed with endometriosis.
Prof. Farland and her colleagues at the Harvard T.H. Chan School of Public Health, Michigan State University College of Human Medicine (USA), and the French National Institute for Health and Medical Research (INSERM), Université Paris-Saclay, Villejuif (France), studied 116,429 women who joined the US Nurses' Health Study II in 1989 when they were aged between 25 and 42 years.
Every two years, up until June 2015, the participants completed questionnaires about their medical history and their exposure to risk factors for several chronic diseases.
When they joined the study in 1989, the participants were asked about their tendency to sunburn, the number of moles on their legs, and their number of severe sunburns between 15 and 20.
In 1993 they provided data on their use of sunscreens, and in 2005, they reported on their use of tanning beds during their teenage and early adult years and between the ages of 25-35 years.
From 1993 onwards, the participants were asked whether they had endometriosis, diagnosed by laparoscopy, which is the gold standard for correctly diagnosing the condition.
The researchers excluded women who reported having endometriosis or diagnosed with cancer.
Among the 95,080 women, there were 4,791 cases of endometriosis diagnosed with laparoscopy over the follow-up period.
Tanning Beds and Endometriosis Risk
Women who used tanning beds:
- Six or more times a year, when they were teenagers and young adults had a 19% increased risk of endometriosis.
- Six or more times a year between the ages of 25-35, they had a 24% increased risk.
- Three or more times a year throughout both periods of their lives, they had a 30% increased risk of endometriosis.
- A history of five or more sunburns between the ages of 15-20 was linked to a 12% increased risk of endometriosis than women who were never sunburnt.
- People who used sunscreen before sunbathing had a 10% increased risk of endometriosis.
Professor Stacey Missmer, a professor at Michigan State University College of Human Medicine and the Harvard T.H. Chan School of Public Health and co-lead author of the study, said: "We know very little about ways to modify behaviour in order to reduce risk of developing endometriosis. There is still a lot we don't understand about the relationship between recreational and residential sun exposure and risk of endometriosis. However, our findings suggest that avoiding excessive recreational sun exposure and tanning beds may reduce your endometriosis risk."
"Over the past 30 years, more people have been diagnosed with skin cancer than all other cancers combined," said Prof. Farland. "From a public health perspective, we already know women should avoid tanning beds to reduce their risk of melanoma. This study reinforces the advice to avoid using tanning beds and suggests that there may be an additional benefit of reducing the risk of endometriosis. Women should follow the health advice never to use tanning beds, to avoid being sunburnt, and to protect your skin from exposure to the sun by covering up, seeking the shade, and by using a broad spectrum UVA/UVB sunscreen."
Endometriosis Facts and Figures
- Endometriosis affects 1.5 million women.
- It is one of the leading causes of fertility.
- On average, it takes 7.5 years from the onset of symptoms to get a diagnosis.
- There is no cure for endometriosis.