Coffe and Endo

I've been contemplating whether coffee needs to be the next thing to go from my diet. I'm almost four weeks into ditching wheat, but I've known all along that there are a number of other items endo sufferers avoid because of their potential to aggravate endometriosis symptoms. And one is coffee.

Photo via Flickr by rore

I've already been convinced by recent research on the benefits of a gluten-free diet for endometriosis sufferers, but I wasn't clear on why exactly coffee was a no-no, too. So before I made any rash decisions, I decided to investigate why I might need to ditch my favorite beverage.

(Because I love coffee. Although I don't necessarily need the caffeine—I had no trouble going off of it cold turkey when pregnant—the flavor of coffee, the act of drinking a hot cup, is a pleasure and one of the highlights of my often very early mornings. I like tea, too, and drink it often. But coffee is my morning must-have.)

In general, medical opinion on coffee has shifted in recent years. There used to be a laundry list of reasons why people should not drink coffee or should reduce their consumption, but now a lot of research has actually shown that coffee may have health benefits to the general population. (I say "general population" because, of course, people with certain illnesses or ailments may be the exception to that rule.)

The American Medical Association recommends that "moderate tea or coffee drinking likely has no negative effect on health, as long as you live an otherwise healthy lifestyle."

That's all well and good, but not really that helpful for me. I did find some interesting information on recent general health research on coffee in an article published in The Atlantic. For starters, as I mentioned before, researched has found that coffee may actually have a slew of benefits, including reducing the risk of type 2 diabetes in women, raising good cholesterol and lowering bad cholesterol, and even possibly helping you live longer. And a recent study even found that drinking four cups of coffee a day may reduce risk of endometrial cancer. Plus coffee contains antioxidants, which are substances that help remove potentially damaging oxidizing agents from our bodies.

Perhaps most interesting for women suffering from endometriosis, a recent study found that caffeine might function as a pain reliever—office workers who had back, neck, and shoulder pains reported less intense pain if they drank coffee before the experiment. And another small study found that concentrated amounts of caffeine can briefly reduce depression rates among women (the study looked at nurses in particular, who understandably are under a lot of stress).

So at this point in my research, I was thinking that perhaps not only was coffee not bad for me, but it might even help relieve pain and make me happier. But I knew I needed to dig into specifics on how coffee affects endometriosis sufferers before I jumped to any conclusions.

Photo via Flickr by amanda28192 

Unfortunately, the explanations I found in my small stack of endo books didn't help much. One listed a slew of general health reasons why coffee isn't good, but none really related specifically to endo sufferers—and, I discovered as I investigated coffee further, much of the health reasons cited in the book have since been disproved by research. Another endo book didn't mention coffee at all. 

One said to avoid coffee (along with black tea, hot chocolate, and sodas, although green tea is OK), but did not explain why. (Although in another part of the book, I did find a brief mention that drinking "a great deal" caffeine can result in a vitamin B1, or thiamine, deficiency, which can cause a slew of symptoms including gastrointestinal disturbances, constipation, loss of appetite, enlarged liver, water retention, fatigue, and more.) I'm not sure what constitutes "a great deal" of caffeine, though. The same idea—that coffee reduces the body's store of B complex vitamins and negatively affects liver function—also came up in Living Well with Endometriosis. According to the author, the problem for endo sufferers is that hindering liver function makes it harder for the body to get rid of excess estrogen.

Living Well with Endometriosis also mentioned a study that brought me closer to the type of information I was looking for. It cited research published in the October 2001 issue of Fertility and Sterility that found higher levels of estradiol (a form of estrogen) in women who drank at least 500 mg of coffee a day (equivalent of four or five cups). During the early follicular phase of their menstrual cycles, these women had nearly 70 percent more estrogen than women who consumed no more than 100 mg (less than 1 cup) of coffee daily.

Now I was getting somewhere. But I needed more information. That was just one study conducted more than 10 years ago. I wanted to know if there was more research, and particularly if anything had been done more recently.

Here's a rundown of what I found—which was actually quite a bit more research than I expected to uncover.

• A study published online in the February 2012 issue of the American Journal of Clinical Nutrition looked at the connection between caffeine consumption and estrogen levels in white, black, and Asian women. The results indicate that caffeine consumption among women of child-bearing age influences estrogen levels. Interestingly, it appears that caffeine effects estrogen levels differently among women of different races. Moderate caffeine intake—about two cups of coffee or 200 mg a day—lowered estrogen levels among white women; however, black and Asian women who drank the same amount of caffeine experienced elevated estrogen levels. And consumption of caffeinated soda or tea was associated with higher estrogen in all three groups.
• Research published in the August 2004 issue of Human Reproduction analyzed data collected in the framework of two case-control studies conducted in Northern Italy between 1984 and 1999 that looked at 504 women less than 65 years of age (median age 33 years) with laparoscopically confirmed diagnoses of endometriosis. The research found that green vegetables and fresh fruit resulted in a significant reduction in risk of endo, whereas high intake of beef and other red meat and ham was associated with the highest risk. Consumption of milk, liver, carrots, cheese, fish, whole-grain foods, coffee, and alcohol were not significantly related to endometriosis.
• The March 2002 issue of Annals of the New York Academy of Sciences discusses ways of furthering understanding of the epidemiology of endometriosis and briefly mentions caffeine use as a risk factor.
• As mentioned above, an October 2001 study published in Fertility and Sterility found that coffee use greater than 1 cup per day was associated with higher estradiol levels during a woman's early follicular phase.
• Prevalence of minimal or mild endometriosis was higher in women with caffeine intake of 300 mg per day or more in research reported in the Journal of Epidemiology in September 1998.
• An study published in the February 1998 issue of American Journal of Public Health found no significant association between caffeine consumption and fertility the 210 women studied, all of who reported on caffeinated beverage consumption and pregnancy status monthly. However, the study did find that drinking one-half cup or more of tea daily approximately doubled the odds of conception per cycle.
• A summary of epidemiologic literature on the effect of lifestyle factors including caffeine on female infertility published in the July 1997 issue of Journal of Epidemiology found that caffeine is one of many possible risk factors for various types of fertility.
• Researchers reported in the October 1996 American Journal of Epidemiology a positive association between caffeine and estrone (an estrogenic hormone) and an inverse association with bioavailable testosterone, suggesting that caffeine's reported association with several chronic conditions including endometriosis may be mediated by an effect on endogenous sex steriods. 
• A case-control study published in the Nov/Dec 1993 issue of Family Planning Perspectives focused on the association of caffeine consumption among women with infertility and found that women who consume high levels of caffeine (an average of more than 7 grams per month—the equivalent of about two cups of coffee per day) were more likely than other women to become infertile because of tubal disease or endometriosis. The investigators hypothesized that caffeine causes blood vessels to constrict.
• An examination of caffeine use in 1,050 women with primary infertility and 3,833 women who had recently given birth from 1981-1983 in the U.S. and Canada published in American Journal of Epidemiology in June 1993 found that upper levels of caffeine intake (5.1–7 grams or more per month) led to a significant increase in the risk of infertility due to tubal disease or endometriosis.
• A study from the September 1990 issue of American Journal of Public Health revealed that consumption of caffeine-containing beverages is strongly related to prevalence of premenstrual syndrome, based on 841 responses to a questionnaire probing menstrual and premenstrual health sent to female university students in Oregon. Among women with more severe symptoms, the relation between consumption of caffeine-containing beverages and premenstrual syndrome was dose-dependent (in other words, the more caffeine the women drank, the more severe the symptoms).

Photo via Flickr by @Doug88888

Whew. What do I make of all this research? Well, I'm not a doctor and I don't play one on TV. But it certainly seems as if there is a connection between caffeine intake and increased levels of estrogen in women. However, it appears that association is highest (not surprisingly) with high levels of caffeine intake. So I wonder if perhaps, at least for starters, my goal should be simply to cut back to only one small cup of coffee a day, given that at that level my coffee consumption (as I am a white female) may actually lower estrogen levels—or at the very least, from my research, it appears that small amount of caffeine does not appear to drastically increase estrogen levels.

For now, I think that's a great first step. And later? Maybe I'll cut out coffee altogether. But I can't deny the feel-good effect a hot cup of coffee has on me in the morning, so I'm not quite ready to ditch it.

Have you cut coffee or caffeine out of your diet completely? Have you seen a positive effect on your endometriosis symptoms as a result? Or have you decided not to ditch coffee yet? Please share!