Can eating the right foods reduce menopausal symptoms?
We don't know and scammers should stop pretending we do
Most of us want to stay healthy, active and sharp for as long as we can. Sadly, for some women menopause can throw all our plans up in their air - though hopefully for a limited time. Women going through the perimenopause or menopause can report symptoms ranging from crushing fatigue, weird arthritic-type symptoms, bowel issues, night sweats, and inability to concentrate and more. Unfortunately, the human body is incredibly complicated, and we don't always understand the biochemical or physiological basis of some symptoms- especially fairly non-specific symptoms like fatigue and brain fog. And this leaves women - desperate for resolution, and often feeling fobbed off by a medical profession who don’t always have all the answers - the perfect pray for scammers.
I've noticed lots of nutrition companies and specialists claiming their product or service can improve menopausal symptoms. It’s really frustrating to see this, and it's not women's fault that they're taken in by people with credentials who claim they have “finally” found the solution to “brain fog”, “hot flashes” or “dizziness". I feel a real responsibility to do what I can to help people realise when they're being duped (hopefully before parting with their money), and this is one thing that I try to do with this blog.
For this article, I thought it might be quite useful to show people how you can look up scientific studies yourself and get an idea of whether something seems “legit” or not. Now, properly reading the scientific literature on a subject involves doing a lengthy and thorough systematic review, and then carefully going through each study looking at study design, power calculation, control group, blinding and so forth. Nevertheless, in areas where there is very little evidence, this can become quickly evident when you go and look for clinical trials. And if there is very little evidence, then on what basis are people making claims about their product or service or diet?
And I think this is certainly the case when we think about the effect of diet and nutrition on particular menopausal symptoms: there are very few (none…? as I’ll show below) high quality trials done, and therefore anyone making claims with any certainty is probably making things up or exaggerating.
So let me show you how we might go about looking for clinical trials. (We're going to ignore observational data, rodent studies, and cell-based studies here as these types of designs either cannot tell us whether a diet is causing an effect or definitively what happens in humans). Then I'll briefly review the trials I find, to hopefully give you an idea of what they can and can't tell us.
Let's start by looking at clinical trial registration databases.
Clinicaltrials.gov, ISRCTN or ANZCTR registry
Clinicaltrials.gov is a US database, run by the Federal government (National Institutes of Health), ISRCTN is a registry recognised by WHO and ANZCTR is the Australian and New Zealand one. (I’m sticking to English-language only here for obvious reasons). These websites are really useful to look for good quality nutrition trials and serious researchers will register their trial on one of these databases*. In fact in the UK if you get any funding from Medical Research Council or National Institute of Health Research, they make it a condition of their funding that you register your trial on one of these databases.
Let’s look in clinicaltrials.gov as an example. You can add in various search terms but you might have to play around a bit as some researchers might register a condition/disease/symptoms differently. Eg, they might use menopause or hot flashes or vasomotor symptoms as their key words.
.Our results:
The search using menopause found 8 trials. I won’t bore you with the details. They are on various things like osteoporosis, cardiovascular risk, or are generic interventions to help women in “middle age” do more exercise but none of them are primarily designed to look at one or more menopausal symptoms.
Let’s try and get more specific:
Now we get 9 studies.
Here’s one: Effect of Aerobic Exercises With Selected Phytoestrogen Product on Hot Flushes in Post-menopausal Women. They randomised women to exercise plus soy products or exercise alone (so this design can’t tell us anything about the effect of soy per se because there’s no control group without soy). The reporting of this study wasn’t great - looks like an abstract and not full paper here but they claim the exercise group helped lower frequency of hot flashes. Other studies have found exercise might be able to help with hot flashes like this one.
We’ve got this one on Herbal Alternatives for Menopause Symptoms (HALT Study). This was a huge study with 350+ women enrolled, and were randomised to one of four groups:
Drug: Black cohosh
Drug: Multibotanical preparation
Drug: Multibotanical preparation + dietary soy counseling
Drug: Conjugated equine estrogen +/- medroxyprogesterone acetate
(There’s no placebo but oh well).
These were their primary outcomes:
This means the main purpose of their trial was to test the effect of black cohosh, their multibotanical preparation plus soy etc on vasomotor symptoms (hot flashes, dizziness, sweating etc).
So what did this study find, did black cohosh or their multibotanical preparation reduce hot flashes? I can’t see that the results were ever published. (If I am stupid and just couldn’t find them someone please tell me that sarcastically in the comments haha). If these results were not published, could it be because the botanical preparations and supplements simply had no effect? My guess would be yes. It’s worth noting that a Cochrane Review found there was no significant difference between black cohosh and placebo in reducing the frequency of hot flushes.
I had a bit of a play around with search terms, but basically I didn't find much evidence that many trials have been done specifically looking at the effect of diet on menopausal symptoms. Conversely in areas where there is a lot of evidence you will find lots of trials. For example, putting in “diet” and “cholesterol” as search terms brings up 200+ trials. So this tells me diet and menopausal symptoms hasn't been studied that much.
Pubmed
Another place we can look is PubMed. Pubmed is a database of [nearly] all medical, nutrition and biological journals. You can put in search terms and find papers (of wildly varying quality mind you) in whatever area you are interested in. For this example, let’s try “diet” and “vasomotor” (basically meaning symptoms like hot flashes, dizziness, night sweats) in menopause.
This search pulled up 87 papers including observational studies, reviews and so forth. We can use the filter function on the left hand side to specifically look for randomised controlled trials.
And now we have 15 trials. Two are on exercise, two were post-hoc or observational analyses of trials (I’ll explain why this is poor evidence in a separate post), two were looking at CVD risk factors, not vasomotor symptoms, four were on soy or other typed of supplementation alone (overall these had no effect on symptoms), one was a pilot trial, and one was a duplicate publication (authors presented their initial trial data in a subsequent publication which I've reported below). So that leaves us with only three trials looking at diet (not supplements) on vasomotor symptoms in menopausal women:
The Women's Health Initiative Dietary Modification trial found that a low-fat diet, high in fruits and veg and wholegrains reduced vasomotor symptoms compared to the control group, but a large part of the effect is probably due to weight loss. The intervention group also got a ton more contact, support and attention from the study team which may also have influenced the behaviour and well-being of the women in the intervention group compared to the control (who got a leaflet on healthy eating).
This study compared a vegan, low-fat diet with soybeans to a “no intervention” control group and found a significant reduction in hot flashes and other vasomotor symptoms in the intervention group. Again, a limitation of this study is that any intervention where you are paying attention to, counselling and supporting patients may improve their behaviour, well-being and symptoms - so we don’t know exactly what specific role diet plays. In addition the intervention diet was plant-rich + low-fat + soy-rich, and the study design can’t tell us which of these dietary factors was having any effect.
This study compared a lactoovo- vegetarian (LOVe) diet rich in omega-3 fatty acids vs. a lacto-ovo-vegetarian diet rich in EVO (extra-virgin olive oil) on reducing vasomotor symptom frequency and found the omega-3 rich diet to be superior at reducing the Kupperman Index compared to the EVO rich diet. The Kupperman score is a composite score of commonly reported menopausal symptoms including fatigue, arthralgia and myalgia (joint and muscle aches), nervousness, insomnia and vasomotor symptoms. But on the specific outcome if vasomotor symptoms, the difference did not look statistically significant. This is also quite a curious study design because both diets tested in the study were both pretty healthy and rich in phytonutrients etc. It would've been interesting to compare these diets to a highly processed, low-fibre diet for example.
This is basically all the good trial data I could find, and what can it tell us? Nothing with a ton of confidence. The studies suggest that a plant-rich diet could be helpful, but as I've noted above there are important limitations to these trials. The data on specific nutritional supplements is also conflicting, and there is no consistent evidence that any herbal or botanical preparation significantly improves menopausal symptoms.
Anyone claiming any different probably has something they want to sell you.
So if women are struggling with menopausal symptoms, what would I suggest? Trying a plant-rich diet, with oily fish twice a week (or an appropriate vegan source of omega-3s) and getting a good amount of exercise might help. And for women who are really suffering, it's certainly worth a try. And just as important - it’s not going to do any harm. (Which I can’t say about unregulated dietary supplements). There are good mechanistic reasons to think this type of dietary approach could be helpful for cognition and mental health in particular and we have trial data demonstrating the benefit of exactly this type of diet on depression.
Finally, if someone is trying to sell you a product or a service, don't be shy about asking for trial evidence. If they believe in their product or service, they shouldn't be afraid of putting it to the test.
* The fact a trial is registered on this database does not make it a good trial, but if it’s a fairly recent trial (eg after 2010) if it’s not registered it’s a major red flag. Registration of trials in this way has been an important initiative to try and improve the conduct and reporting of clinical trials. In the olden days people might test their new supplement or product on eg liver function, find out it didn’t work and then not report and publish their findings in a journal. For obvious reasons it’s as important to know whether something does work as it is to know whether it doesn’t work. So trial registration is supposed to prevent this and other types of poor practice.
I appreciate your exploration of this topic, Dr. Guess, since it is a very important topic. There’s so much mystery and misery for so many of us before, during and after the menopause transition.
I’m tired of scammers and influencers whose sole interest is to find a way into my pocket on the promise of dubious claims. Fortunately, Dr. Jen Gunter wrote the Menopause Manifesto and shared current (at the time of publication) information that I found useful and helpful.
I’m grateful to have a no nonsense gynecologist who shared options for me when the symptoms got terrible. It certainly has made the transition more bearable.