Can a Diet Really Help Solve Your Period Problems?
Can a Diet Really Help Solve Your Period Problems?
Q&A: What diet advice for period pain and endometriosis gets wrong
It’s Q&A time! You can ask your own question here for a chance to have it answered in an upcoming edition.
Just a reminder that these answers are for educational and informational purposes only, and aren’t a substitute for medical or mental-health advice. Although I am a registered dietitian, I’m not your dietitian (unless you happen to be one of my 1:1 clients—hi!—but even then, this email isn’t a session).
The first question today is available to all subscribers (about period pain), and there’s a bonus one for paid subscribers (about endometriosis).
Hi Christy,
I have horrible period pain, and I got a recommendation to eat an anti-inflammatory diet. Is it a real thing? Does certain food really cause inflammation in the body?
And also, do I really need to cut out gluten and dairy for my cramps to be less intense?
Thank you so much for your job!
—Christelle
Thanks for this question, and I’m so sorry you’re dealing with this level of pain. I know it’s incredibly tempting when you have a chronic condition to try to “fix it with food,” especially when nothing else feels like it’s working.
Unfortunately, in this case—as in so many others—there’s no good evidence to support using an “anti-inflammatory” diet or cutting out gluten and dairy. In fact, doing those things could potentially even make the situation worse.
A 2019 systematic review of observational studies from 1990 to early 2018 found that in general there’s no link between period pain (or “dysmenorrhea,” in medical jargon) and most foods—though weight-loss dieting and meal skipping tend to increase the risk.
In terms of gluten, the review found no association between painful periods and the consumption of pasta, and pasta, rice, white bread, cookies, pastries, or grains—all of which typically contain gluten (though none of the studies specifically addressed gluten per se). Elsewhere there’s no research to support cutting gluten for general period pain. (One study does look at the effects of gluten for endometriosis pain, which I’ll unpack in the answer to the bonus question.)
There’s also no solid evidence for cutting out dairy to manage period pain. One observational study from 1997 found that although milk consumption didn’t differ between people with dysmenorrhea and those without the condition, the painful-period group did have a slightly higher cheese intake. But the difference was only 0.5 servings per week—and the researchers didn’t actually collect information on portion size! They just asked people to estimate how often they consumed certain foods, which is of course wildly imprecise (as most food-frequency questionnaires used in nutrition research are).
In fact, all the other dairy-related observational studies included in the 2019 systematic review found that people who consume several servings of dairy a day are actually less likely to have painful periods than those who consume none.
Of course, it’s not possible for observational research to tell us whether dairy actually has a protective effect—we’d need randomized controlled trials (RCTs) for that, because observational studies can only tell us about correlation, not causation. But if dairy were a risk factor for period pain, we’d expect to see a strong correlation in the data, and we don’t.
Speaking of RCTs, there are a handful of them examining diets for period pain, but none on gluten, dairy, or “anti-inflammatory” diets. Christelle, that means whoever recommended those diets to you wasn’t basing that advice on solid evidence. (And to answer your broader question: no, there isn’t very good evidence for anti-inflammatory diets in general, as I discuss in the linked piece.)
RCTs—specifically those that are placebo-controlled and double-blind (where neither the participants nor the researchers know who’s getting the treatment and who’s getting the placebo)—are the “gold standard” in biomedical research. That’s because they’re the only type of study that can possibly determine if there’s a cause-and-effect relationship between treatments and outcomes.
Yet even RCTs can have their limitations and should be examined critically—especially in nutrition science, where placebo effects are rampant and hard to control for.
Take this RCT, which was published in 2020 in a low-impact journal (the first clue that it’s probably not the most solid evidence). The study included 30 or so women who were assigned to eat dried figs during their period, another 30ish who were assigned to take cinnamon mixed in warm water, and finally a placebo group that was assigned to take empty capsules.
The study found that during the three menstrual cycles of the intervention, people in the dried-fig group had lower pain severity and a shorter pain duration (by about 7 to 8 minutes) than people in the cinnamon and placebo groups. The cinnamon group also had lower pain scores than those in the placebo group.
But I don’t think that’s necessarily because of any special properties of dried figs (or cinnamon).
Instead, it may have been because the placebo didn’t fool people. Empty capsules feel suspiciously light, which is why most placebo studies use capsules filled with an inert ingredient like sugar or starch. And when people figure out that they’re getting a placebo, it makes it impossible to know whether the differences between the groups are due to the interventions themselves—or simply to the fact that some participants believe they’re getting an effective treatment, while others don’t.
The placebo effect is powerful, especially when it comes to pain.
There are only a few other RCTs in this area, and most don’t find any benefit to diets for period pain. The only other one I found that does is a small 2000 study conducted by doctors with the Physicians Committee for Responsible Medicine, a nonprofit advocacy group that promotes a vegan diet and an end to animal research. The study was published before conflict-of-interest statements were widespread in reputable scientific journals, but it probably would (and should) carry one today due to the clear pro-vegan agenda of the researchers.
Perhaps unsurprisingly given those conflicts, the study found that women who were asked to go on a low-fat vegan diet had about one less day of menstrual pain per month than those same women did on their usual diet plus a placebo pill (which was billed as a “supplement”).
The researchers also used some unusual interpretations of statistical significance to claim that pain intensity was lower for people on the vegan diet. For data nerds, the researchers deemed those intensity scores significant at P = .05 instead of the customary P < .05 (even though they used P < .05 in the rest of the paper). The choice to reframe borderline but technically non-significant results as significant is interesting, to say the least.
There’s also this: “When asked to guess, 25 [out of 33] participants believed the supplement to be a placebo.” Again, the inert pill didn’t fool people, which means the so-called placebo group didn’t really experience a placebo effect. And yet the intervention group did, because any diet that makes you feel like you’re doing something for your health inevitably produces a placebo effect. That makes it difficult to know whether the diet had any benefits over and above a placebo.
In short: I would take the advice to modify your diet for period pain with a huge grain of salt (or cinnamon?). And given the potential links between painful periods and dieting, meal skipping, and perhaps other forms of disordered eating, going on a diet could even be counterproductive.
Thanks so much for the great question, Christelle, and thanks to all the free subscribers for reading! Paid subscribers can stick around for the bonus Q&A, and everyone can ask their own questions for a chance to have them answered in an upcoming newsletter.
Hi Christy,
I’ve been following your Food Psych podcast for about 3 years now, and it has been an extremely useful resource for me in recovering from anorexia and disordered eating. I have a long history of disordered eating and IBS [irritable bowel syndrome]. I started experiencing IBS symptoms at age 14, and I’m now 30. And I have just been diagnosed with endometriosis.
As you can imagine, I have tried many things to help manage my bowel symptoms—cutting out gluten and dairy, going on food elimination diets, and more. Nothing has really eradicated my symptoms, although cutting out dairy does seem to have helped.
Since going through the process of being diagnosed for endometriosis and since having surgery to treat it, I’ve done a lot of research on how to manage endometriosis through diet. I was quite shocked to find that a lot of the books and online materials are riddled with diet culture. There are lots of recommendations to do a monthlong food elimination diet, to give up alcohol, to follow a low-FODMAP diet.
I don’t really know where to start, and I’m quite worried about slipping back into anorexic behaviors if I follow one of these diets. Do you have any advice when it comes to endometriosis and diet? It’s a minefield!
—Maria