Wednesday Bubble: Soy takes a hit (again). But what about S-equol?
Soy is back in the news again, with newly published data suggesting that isoflavones may not be particularly effective when it comes to menopausal symptoms. But I can’t stress enough on this blog that sources are as important as substance; in other words, not all sources are equal and neither are the women who use these alternatives.
So, let’s talk again about S-equol. But first, a bit of context is needed.
We know that soy isoflavones, primarily genistein, daidzein and glycitein have been suggested as an effective strategy for combating menopausal symptoms such as hot flashes or night sweats. The beneficial effects of soy are believed to be associated with the ability to soy isoflavones to attach themselves to estrogen receptors. Importantly, our brains contain certain estrogen receptors in hippocampus, which is responsible for consolidating both short and long-term memory and spatial navigation. Moreover, both genistein and daidzein have been shown to have a particular affinity for the very type of estrogen receptors that reside in the hippocampus, which is why researchers have been so interested in determining if ingesting soy can help combat the natural decline in memory and cognition. While findings have been mixed, some women appear to be better metabolizers of S-equol, a metabolite of a major soy isoflavone called daidzein. It has a particular affinity for estrogen receptors and possesses some estrogen-type activity of its own. S-equol is produced in the GI tract however the ability to actually manufacture it depends on the presence of certain microflora. Consequently, only 30% to 60% of individuals are actually able to produce S-equol on their own (although this figure is believed to be higher among Asians and vegetarians).
I’ve been writing about S-equol for a number of years and you can revisit those posts here. Interest in S-equol is in part, related to its potential for augmenting the benefits of isoflavones; in fact, it is possible that women who are naturally producers of S-equol actually experience greater effects from soy products, and this is especially true when it comes to bone health. Hence, vasomotor symptoms — night sweats and hot flashes — aside, you may not want to give up on soy just yet.
So let’s talk bone health. It’s so critical as we age.Declining levels of estrogen are a primary cause of bone loss and resulting osteoporosis in women; indeed, one in five American women over the age of 50 have osteoporosis and about half will experience a fracture in the hip, wrist or spine as a result. What’s more, because osteoporosis is silent in its early stages, causing no symptoms, it’s critical that bone loss is halted or at least slowed either before or during the most critical phases strike. There is no time like the present to take preventive measures, even if you are in your 30s and 40s.
Where does S-equol fit in?
Last year, researchers demonstrated the daily S-equol supplements taken by women who are not naturally producers of S-equol, may improve bone metabolism and attenuate bone loss. And I reprinting this information because it’s too early for a soy verdict.
In this 1 year study of 356 healthy, postmenopausal Japanese women between the ages of 41 and 62, daily intake of 10 mg S-equol via supplement markedly reduced markers of bone resorption in blood and urine compared to women taking placebo pills or 2 mg or 6 mg of S-equol daily. In fact, in women taking the 10 mg dose for a year, declines in a urinary marker of bone resorption (i.e. DPD) were roughly 21% greater compared to placebo. Measures of whole body bone mineral density also showed that S-equol supplementation protected against bone loss, although not to the extent as bone resorption. These results remained even after changes in height, weight, body mass index, lean and fat mass were accounted for. No participant experienced serious side effects from taking S-equol and hormone levels were not adversely affected.
Does this mean that you should rush out and purchase S-equol supplements?
One of the primary limitations of this study is that the process of bone recycling can take as long as 18 months and the time required to complete a cycle may actually increase with age. Thus, the duration of time that the women were studied might be too short to draw any definitive conclusions. Hence, you may want to wait before you start taking S-equol. However, the evidence that’s building continues to put the weight on the benefits versus risks side. Only time will tell. Meanwhile – remember that the source of S-equol is important. If you are going to look for supplements, go for products that state that they are standardized on the label. Food sources, e.g. tofu, are always a good bet but again, not every woman will metabolize soy the same way. Still, here’s to yourhealth. Keep on doing all you can do to keep the faith and stay the course.
It ain’t over til the fat lady stops sweating!
Read MoreDem bones! Isoflavones, S-equol and aging
I love it when readers of this blog point me to research that I might have missed or just not stumbled across. That happened a few weeks ago after I wrote a post on soy and safety. By following the links, reader Carol Land directed me to a newly published study on S-equol and bone health.
S-equol is a metabolite of a major soy isoflavone called daidzein. It has a particular affinity for estrogen receptors and possesses some estrogen-type activity of its own. S-equol is produced in the gastrointestinal tract however the ability to actually manufacture it depends on the presence of certain microflora. Consequently, only 30% to 60% of individuals are actually able to produce S-equol on their own (although this figure is believed to be higher among Asians and vegetarians).
The surge in interest in S-equol is related to its potential for augmenting the benefits of isoflavones; in fact, it is possible that women who are naturally producers of S-equol actually experience greater effects from soy products, and this is especially true when it comes to bone health.
I cannot stress enough the importance of bone health as we age. Declining levels of estrogen are a primary cause of bone loss and resulting osteoporosis in women; indeed, one in five American women over the age of 50 have osteoporosis and about half will experience a fracture in the hip, wrist or spine as a result. What’s more, because osteoporosis is silent in its early stages, causing no symptoms, it’s critical that bone loss is halted or at least slowed either before or during the most critical phases strike. There is no time like the present to take preventive measures, even if you are in your 30s and 40s.
Where does S-equol fit in?
For the first time, researchers have shown the daily S-equol supplements taken by women who are not naturally producers of S-equol, may improve bone metabolism and attenuate bone loss!
In this 1 year study of 356 healthy, postmenopausal Japanese women between the ages of 41 and 62, daily intake of 10 mg S-equol via supplement markedly reduced markers of bone resorption in blood and urine compared to women taking placebo pills or 2 mg or 6 mg of S-equol daily. In fact, in women taking the 10 mg dose for a year, declines in a urinary marker of bone resorption (i.e. DPD) were roughly 21% greater compared to placebo. Measures of whole body bone mineral density also showed that S-equol supplementation protected against bone loss, although not to the extent as bone resorption. These results remained even after changes in height, weight, body mass index, lean and fat mass were accounted for. No participant experienced serious side effects from taking S-equol and hormone levels were not adversely affected.
Does this mean that you should rush out and purchase S-equol supplements?
One of the primary limitations of this study is that the process of bone recycling can take as long as 18 months and the time required to complete a cycle may actually increase with age. Thus, the duration of time that the women were studied might be too short to draw any definitive conclusions. Hence, you may want to wait before you start taking S-equol. However, the evidence that’s building continues to put the weight on the benefits versus risks side. Only time will tell. Meanwhile – here’s to your bone health. Keep on doing all you can do to keep dem bones.
Read MoreWednesday Bubble: Is S-equol the next big thing?
Last year I wrote a few posts about the potential of the isoflavone S-equol for addressing menopausal symptoms, including hot flashes and mood swings.
If you are unfamiliar with S-equol, it is actually a metabolite of a one of the three soy isoflavone compounds (i.e. daidzein), and is produced by bacteria that live in the intestines. One of the most interesting things about S-equol is that is one of the principal types of isoflavones that are found in soybeans and most soy foods. However, up to 80% of the U.S. population and about half of the Japanese population (who consume inordinate amounts of soy) cannot manufacture S-equol on their own and need to obtain it in supplement form.
This month’s Journal of Nutrition has devoted an entire supplement to S-equol research, and I’ve been fortunate to take a more detailed look at the evidence supporting the role of S-equol for menopausal symptoms. Notably, some of the researchers actually say that “to conduct menopausal medical care appropriately [which, in their opinion, should be geared towards a better quality of life on an individual basis), it is necessary to provide evidence-based alternative medicines as much as possible.” It is wonderfully refreshing to find such esteemed colleagues backing my view of how menopause should be approached.
Hence, without further ado, following is what you need to know about the recap of study findings, and what still needs to be explored before we all start taking S-Equol.
In three randomized studies conducted in pre-, peri- and menopausal Japanese women who were or were not able to produce S-equol naturally, researchers found specific benefits in three areas:
- Mood improvement: 134 women who produced S-equol naturally and took a 10 mg daily S-equol supplement had significant reductions in anxiety; those who took 10 mg three times a day had significant declines in tension-anxiety and fatigue, and an increase in overall energy. Note that these women also limited their daily intake of soy products to no more than 20 mg/day.
- Hot flashes and other symptoms: In 320 women taking 10 mg S-equol daily or placebo for 12 weeks, S-equol supplements reduced the frequency of hot flashes by as much as 58%. Decreases in muscle and neck stiffness were also reported.
- Bone health: In 54 women who had undergone menopause within 5 years of the study, those who were able to produce S-equol naturally and took 75 mg isoflavones daily supplement (mostly consisting of daidzein) lost a significantly lower percentage of bone in their hip area than women who were not able to produce S-equol naturally but also took the daily supplement. Researchers believe that S-equol actually mimics the action of estrogen in the body in terms of its ability to maintain bone mass and the balance between the build up of bone (bone formation) and the loss of bone (bone resorption). However, studies looking at how it acts in the body have only been conducted in mice and at relatively high doses. Information reported in the Journal supplement does show that at higher dosages, S-equol can negatively affect the tissues lining the uterus.
A few key take-away points to think about when we think about S-equol:
Researchers believe that the research in S-equol helps to show that soy isoflavones work best in individuals whose bodies are able to produce S-equol naturally. However, you’ve read the stats – the majority of people who live in the US do not produce S-equol naturally. Dosing and the exact type of S-equol may also influence outcomes. Likewise, They still aren’t sure how bacteria in the intestines influence S-equol’s effects and wonder if somehow, some other mechanism is at play. Further research is also needed to see if the beneficial effects of S-equol on menopausal symptoms can be extended to women who do not produce it naturally.
It’s too early to boost this bubble and I’m excited by this evidence-based alternative. Naysayers love to point out that alternative therapies are sham and snake oil. While this may be true of some preparations, it’s clear that researchers are taking natural substances to a higher level to see if they offer efficacy without the risks of hormone replacement.
Read MoreWednesday Bubble: your brain on soy
Aging and estrogen. Gotta love it. It can signify the loss of reproduction, skin elasticity, vaginal lubrication, bones and even parts of our brain, at least hypothetically. Yet, can ingesting soy help improve attention, focus, problem solving and memory? A newly published study in Neurology journal counters claims that it can, but adds further evidence that certain factors may influence benefits, such as reproductive age or if menopause comes on naturally or not.
A bit of context is needed. We know that soy isoflavones, primarily genistein, daidzein and glycitein have been suggested as an effective strategy for combating menopausal symptoms such as hot flashes or night sweats. The beneficial effects of soy are believed to be associated with the ability to soy isoflavones to attach themselves to estrogen receptors. Importantly, our brains contain certain estrogen receptors in hippocampus, which is responsible for consolidating both short and long-term memory and spatial navigation. Moreover, both genistein and daidzein have been shown to have a particular affinity for the very type of estrogen receptors that reside in the hippocampus, which is why researchers have been so interested in determining if ingesting soy can help combat the natural decline in memory and cognition. While findings have been mixed, some women appear to be better metabolizers of S-equol, which is related to daidzein, produced in the gut and targets estrogen receptors in beneficial ways that other soy isoflavones do not. If you click on the links posted above, you will find a wealth of information on soy and the research that has been done.
In this particular study, healthy, postmenopausal women received either 25 g daily of isoflavone-rich soy protein (more than 3/4 of which contained genistein and daidzein) or milk-protein daily; both were offered in the form of a powder or bar. Over the next two and half years, the participants visited the clinic at various intervals to participate in tests that measure their cognitive skills, including:
- Executive function (working memory, expression, general intelligence), and,
- Verbal learning, verbal memory and visual memory.
Although the women were not required to change anything about their diet, they were asked to refrain from taking soy supplements over the study course.
The findings? Researchers failed to observe any differences in cognitive function between women taking soy and women taking milk protein, even though scores did improve over the two+ year time period. Yet, they did note differences in improvements in visual memory scores, with women in the soy isoflavone group better able to recall faces both immediately and with a short delay compared to their milk protein peers. The group of younger, postmenopausal women in the study did not appear to have any advantages over the older women (note that age range was as broad as 49 to 94 years).
So, what to make of this? Is your brain on soy an improvement? Apparently, not really. What the researchers do say, however, is that surgical menopause may eventually cause a larger decline in cognitive function over time (these group of women actually showed a worsening in cognition regardless of whether or not they took soy). They also note that soybeans contain active constituents other than isoflavones (e.g. lignans) that may boost or detract from isoflavones effect on cognition.
Still, there is a wee bit of a silver lining. Although it’s true that if you are seeking a better functioning brain, you may wish to look elsewhere, a high soy diet can be consumed without fear of any adverse effects on memory skills that are associated with dementia in later life, and may possibly even improve them. The verdict is still out for women who are naturally high S-equol producers. In so far as hot flashes and night sweats? The evidence looks much better.
Estrogen’s a bitch, isn’t it? But who says that the bitch can’t be tamed or at least, kept at bay?!
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Soy…revisited
It’s been a rough ride for soy, with studies often at odds regarding its effectiveness in ameliorating or preventing hot flashes. Some reviews have shown that soy isoflavones, in particular S-equol and genistein can alleviate hot flashes while others fail to finding anything conclusive. Still, the original observation that Japanese women appear to suffer less frequently from hot flashes and have a high consumption of soy isoflavones has led researchers to keep trying to tease out the benefits of soy.
I am glad that they have. In fact, in a study published online in Menopause just a few weeks ago, researchers reported that an extensive review of 19 scientifically sound trials has shown that soy isoflavones are significantly more effective than placebo in reducing both the frequency and severity of hot flashes.
Here’s what you need to know:
- 19 trials were included for analysis and a variety soy isoflavone supplements in different doses ranging from 30 mg to 135 mg daily were studied. Some of these were natural formulations and others, chemically synthesized to match key ingredients believed to have a health effect.
- Hot flash severity and frequency were examined in women that were either premenopausal, perimenopausal or menopausal (i.e. postmenopausal) although definitions used to define this group differed between studies.
- The number of women in these studies totalled over 1,200.
The results showed that taking 30 to 80 mg soy isoflavones daily for 6 months to a year significantly reduced the frequency of hot flashes by roughly 17%. Moreover, the 10 trials analyzed for hot flash severity showed a significant reduction by as much as 30%. In both cases, these figures increased depending on how the researchers teased out and analyzed the data.
The researchers say that even though there is a common perception that results from soy trials have been mixed, there has been a “consistent and clear pattern in favor of isoflavones over placebo” when properly plotted on a graph. Moreover? The scientifically designed studies that were included in their analysis helped to insure that all populations, including women with breast cancer, were included. Additionally, they analyzed studies that were as short as 6 weeks in duration, namely to determine if women with cancer not receiving treatment would respond the same as healthy women. Additionally, there is some indication that the effectiveness of soy actually increases over time with continuous use.
What about the type of soy isoflavone? This review actually shows that genestein is more effective than daidzein for alleviating hot flashes.
The key take away is that for women who don’t want to use hormone replacement or are ineligible to do so, there is a scientifically proven effective alternative: soy. And while soy may disturb the GI tract in some women, it is actually quite safe, even among women with breast cancer.
So far, so good. The next step is to determine which factors matter most to gain benefit, e.g. dose, formulation, hot flash frequency and how long a woman needs to remain on treatment.
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