Endometriosis-the cause of many a painful period-might be triggered by a common sunscreen chemical, according to new evidence from America.
Scientists have long suspected that chemical toxins could be a contributing cause of endometriosis, which can lead to infertility and depression, but this is the first time that the research has focused on sunscreen chemicals-specifically, the benzophenone (BP) type of ingredients that are widely used in a variety of personal-care products to protect the skin and hair from the sun's ultraviolet (UV) rays.
Small amounts of BPs can pass through the skin and be absorbed into the bloodstream, where they are known to mimic the effects of oestrogen. As endometriosis is an oestrogen-dependent condition, chemicals like BPs could potentially have a role to play in its development.
Kurunthachalam Kannan and colleagues at the New York State Department of Health's Wads-worth Center in Albany analyzed BP levels in the urine of over
600 women living in Utah and California who were being evaluated for endometriosis. They found that high levels of one BP-known as '2,4OH-BP'-were associated with a significantly increased risk of an endo-metriosis diagnosis. Women with the highest amounts of 2,4OH-BP in their urine had a 65-per-cent greater chance of having endometriosis compared with women with the lowest levels.
Although the researchers did not question the women on their sunscreen use, they did discover that BP levels tended to be higher during the summer months and in those who lived in sunny California, further suggesting an association with sunscreens.
"Our results invite the speculation that exposure to elevated 2,4OH-BP levels may be associated with endometriosis," the researchers said (Environ Sci Technol, 2012; 46: 4624-32).
These worrying findings add to a growing body of evidence linking endometriosis to environ-mental chemicals. In fact, another new study from the US found that women were more likely to be diagnosed with endometriosis if they had high levels of the oestrogen-like pesticide hexachlorocyclohexane (HCH)-a type of persistent organochlorine pollutant (POP) -in their blood compared with women with low levels (Environ Health Perspect, 2012; 120: 811-6).
HCH is the byproduct of an insecticide that has been banned in the US for more than 30 years, but it persists in the environment and can still be found in the food supply.
Endometriosis has also been linked to dioxins and polychlorinated biphenyls (PCBs), the toxic byproducts of burning household and industrial waste, and from vehicle exhausts (Environ Health Perspect, 2009; 117: 1070-5).
The good news about this research is that it gives us clues for how to prevent and possibly treat endometriosis. As well as using safer sunscreens that don't contain hormone-disrupting chemicals, eating an organic wholefood diet low in animal fats may be beneficial. This is because much of our exposure to some of these oestrogenic chemicals is through food-mainly animal fat.
You can also minimize your toxic chemical exposure by being careful about what products you use on your skin, in your home and in your garden (see the WDDTY Safe Living e-book for some useful tips, available for purchase at www.wddty.com/shop/e-books).
Besides avoiding potentially harmful chemicals, the evidence suggests that a number of other lifestyle changes may help as well as some promising natural treatments.
Cut the caffeine.
There might be a connection between caffeine intake and endometriosis and infertility. Women who consumed more than 5 g/ month of caffeine (about 1.5 cups of coffee a day) were nearly twice as likely to have endometriosis and be infertile as a result (Am J Epidemiol, 1993; 137: 1353-60).
In one study, the risk of endometriosis was around half as high in women who indulged in any amount of alcohol intake compared with teetotallers (Am J Public Health, 1994; 84: 1429-32).
Eat more fruit and veg.
In more than 1,000 women in northern Italy, those with low intakes of fresh fruit and green vegetables had a significantly higher risk of endometriosis, while those who ate a lot of beef and red meat were more likely to have the disease (Hum Reprod, 2004; 19: 1755-9).
Levels of physical activity appear to be related to the risk of endometriosis. In one study, women who reported frequent, high-intensity, physical activity had a 76-per-cent lower risk of having the condition than those not engaging in any such intense physical activity (Am J Epidemiol, 2003; 158: 156-64).
Endometriosis sufferers seem to have lower intakes of anti-oxidants (vitamins A, C and E, zinc and copper) than women without the disease. So getting more of these nutrients through either diet or supplements should help (Reprod Biol Endocrinol, 2009; 7: 54). And in women with pelvic pain possibly due to endometriosis, taking vitamins E (1200 IU/ day) and C (1000 mg/day) for two months led to improve-ment in pain in around 40 per cent of cases. In contrast, none of the women taking a placebo reported pain relief (Townsend Letter, 2004; 253/254: 36).
Boost omega-3 fats.
Animal and test-tube studies show that omega-3s can help by reducing inflammation (Fertil Steril, 2008; 90 [4 Suppl]: 1496-502; Fertil Steril, 2001; 76: 717-22), although whether supplements will benefit women in real life remains to be seen. However, a daily dose of omega-3 (1080 mg of eicosapentaenoic acid and 720 mg of docosahexa-enoic acid) plus 1.5 mg of vitamin E improved symptoms of dysmenorrhoea (painful menstruation), which may be related to endometriosis (Am J Obstet Gynecol, 1996; 174: 1335-8).
Take Chinese herbs.
A review of the evidence found that Chinese herbal remedies were just as effective as the hormone drugs gestrinone and danazol for the relief of endometriosis symptoms, but came with fewer side-effects (Cochrane Database Syst Rev, 2012; 5: CD006568). A variety of herbs can be used, so be sure to consult a qualified herbal practitioner for advice.
This well-known pain treatment was both safe and effective for endometriosis-related pelvic pain in young women aged 13 to 22 years (J Pediatr Adolesc Gynecol, 2008; 21: 247-57).
In another study, acupuncture was just as effective, if not more so, than the drug danazol in relieving symptoms and, again, with far fewer side-effects (Zhongguo Zhen Jiu, 2006; 26: 863-5).
Derived from the popular Indian spice turmeric, curcumin has properties that may be beneficial for endometriosis sufferers. A study in mice showed significant antiendo-metriosis effects, but bear in mind that these results may not necessarily apply to humans (Indian J Biochem Biophys, 2009; 46: 59-65).
A small preliminary study of five women reported that thermal biofeedback (monitoring skin temperature) helped to improve the pain and other symptoms of endometriosis (Appl Psychophysiol Biofeedback, 2003; 28: 279-89). Other mind- body techniques like hypnosis and meditation may also help to control endometriosis-related pain.
The gummy substance collected by bees from leaf buds and tree bark could be helpful for treating the infertility associated with endometriosis.
In a preliminary trial of women with infertility and mild endometriosis, supple-mentation with bee propolis (500 mg twice a day for six months) was associated with a pregnancy rate of 60 per cent compared with only 20 per cent in those taking a placebo (Fertil Steril, 2003; 80 [suppl 3]: S32).
What is endometriosis?
This is a gynaecological condition where cells in the mucous membrane lining the womb become deposited elsewhere in the body. It affects around 10 per cent of women of reproductive age, causing symptoms such as painful, heavy or irregular periods, bowel and bladder problems, tiredness, insomnia and depression. But some women have no symptoms at all.
The endometrial deposits are most commonly found on the ovaries, fallopian tubes and peritoneum, but other sites may be involved-even, in rare cases, the eye. The cells then behave just as they do in the womb-bleeding during menstruation-causing inflammation and often forming fibrous adhesions, causing organs to stick to each other. Inflammation or scarring of the reproductive organs, particularly the fallopian tubes, can result in infertility.
No one knows exactly what triggers endometriosis or how to cure it, so the goals of conventional medicine are pain relief, slowing its progression and relieving infertility when present. However, the treatments usually prescribed-painkillers, hormonal drugs and surgery-all come with high rates of recurrence and significant health risks (Cochrane Database Syst Rev, 2009; 3: CD006568).
Gonadotropin-releasing hormone (GnRH) agonists, for example, one of the most popular drugs for the condition, can induce 'pseudo-menopause', complete with hot flushes, vaginal atrophy, mood swings and osteoporosis (Aust Fam Physician, 2006; 35: 864-7).
October 2012 vol. 23.7