Soy Isoflavones Linked With Decreased Hot Flashes, Review Finds

Consuming two servings of soy a day may help to ease hot flashes from menopause, according to a new review of studies.

Researchers from the University of Delaware analyzed the results of 19 studies, which included 1,200 women, and found that soy isoflavones are linked with a decrease in hot flash severity. Their study was published in Menopause: The Journal of the North American Menopause Association.

Women who consumed 54 milligrams of soy isoflavones -- which are found in soy, and are estrogen-like -- each day for anywhere from six months to a year experienced a 20.6 percent decrease in the frequency of their hot flashes, and a 26 percent decrease in the severity of their hot flashes.

For comparison, two 16-ounce glasses of soy milk or 7 ounces of tofu contain 50 milligrams of soy isoflavones, the researchers noted.

In particular, researchers found that supplements with at least 19 milligrams of genistein -- a kind of isoflavone -- seemed to be more effective at decreasing the number of hot flashes the women had.

Genistein is found in soybeans and soy foods, so researchers noted that eating those foods instead of taking supplements could be a way for women to get that particular isoflavone.

The role of soy in easing menopausal symptoms has long been debated, mainly because many studies on the subject haven't produced clear-cut results. However, the researchers said that the reason for the inconclusive results is because scientists may be inconsistent in how they conduct the studies, or the sample sizes are too small.

But “when you combine them all, we’ve found the overall effect is still positive,” study researcher Melissa Melby, a medical anthropology professor at the University of Delaware, said in a statement.

Earlier on HuffPost:

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Comments

[loki]

01:57 AM on 04/13/2012

Who knew?


http://www.ellenskitchen.com/clearlight/soyfoods.html

Some processors use ammonia gas at the final stages of processing freeze dried tofu to improve softness and absorbency. Don't be put off by strong ammonia fumes when you open the packet - they will disappear when you reconstitute the tofu in hot water. The stronger the ammonia fumes, the fresher the batch of freeze-dried tofu. Tofu.


http://www.newsdaily.com/stories/bre8331b4-us-food-ammonia/

[lick my feet]

10:40 PM on 04/11/2012

soy is bad for you. Carcinogenesis
Thyroid disease
Reproductive health problems including infertility

[Saddness]

06:13 PM on 04/11/2012

Shelly in BC, my doctor warned me about unfermented soy, below is one of many links...just google dangers of unfermented soy
http://www.naturalnews.com/022630.html

[Anne Siperek]

09:57 PM on 04/08/2012

BS! NO! It certainly does NOT stop, minimalize or prevent Hot Flashes. I eat it all the time, I get hot flashes all the time. I'm beginning to wonder if the stuff may be causing them!

[lick my feet]

09:42 PM on 04/08/2012

Modern soy foods block mineral absorption, inhibit protein digestion, depress thyroid function and contain potent carcinogens. the only safe way to eat soy is if its properly fermented. 99.9999% of the soy in the US is not properly fermented.

[Shelley in BC]

12:28 AM on 04/11/2012

would you please tell us where you got this information so we can read about it ourselves?

[lick my feet]

10:41 PM on 04/11/2012

sure Shelley. http://www.westonaprice.org/search/search?q=soy

[birdinanest]

06:04 PM on 04/08/2012

Please educate me....I thought that there was some type of controversy linking soy consumption to breast cancer. could women with breast cancer who began consuming soy as an adult develop a more resistant tumor to treatment?

[NotEve]

07:50 PM on 04/08/2012

The relationship between soy and breast cancer is related to the relationship between estrogen therapy and breast cancer. The concept is the same as what the article describes above, essentially that components (isoflavones) in soy act as estrogen supplements.

But, the relationship between estrogen and breast cancer is a bit complicated. Basically it depends on the genetic composition of the specific breast cancer. Some breast cancers are stimulated by estrogen, others are not (it depends on whether or not they express a receptor for estrogen). So hypothetically (because I havent read any conclusive studies linking soy to breast cancer, but its consistent with the results of the above study), soy would exacerbate estrogen sensitive breast cancers.

Here's a good resource for you: http://www.cancer.gov/cancertopics/understandingcancer/estrogenreceptors

[NotEve]

08:17 PM on 04/08/2012

I should clarify one point that the above article is very vague on:

Isoflavones are a classification of organic molecule. They come in many, many forms with many, many bio-chemical properties. The type of isoflavones that this article is about are 'phytoestrogens,' which are molecules with chemical properties that mimic estrogen.

It should also be pointed out that the benefits of estrogen replacement therapy are controversial. This study is not simply saying that 'eating soy is good,' its saying that eating soy may be an alternative form of estrogen replacement and therefor subject to the discussion of the pros and cons of estrogen replacement therapy in general.

[birdinanest]

09:12 PM on 04/08/2012

thanks, NotEve, for a very clear explanation and for the link, which looks quite helpful.
I am trying to navigate my way around the pros and cons of estrogen replacement therapy, as well as trying to understand the soy controversy.
many thanks.

[alykatma]

04:59 PM on 04/08/2012

I wonder who paid for this study? I wonder if they tried any other isoflavins. The only good soy is fermented soy, the rest is garbage.

[Shelley in BC]

12:27 AM on 04/11/2012

can you please share where you got that information from?

[Lindsgrace33]

10:46 AM on 04/08/2012

Wow, great info for my mom. Thanks.

[Leslie Robinson Goldberg]

01:48 AM on 04/08/2012

If you don't like hot flashes go vegan. I never had even one! A few times of night sweats, but that was it. In Japan they didn't even have a word "hot flash." Could it be the plant-based diet as well as the miso soup and tofu? I think so.

[NotEve]

07:54 PM on 04/08/2012

Or could it be the natural variation of menopausal symptoms between people and populations, not to mention differing cultural concepts in describing experiences?

Or could it be any number of cultural, genetic, and/or environmental factors besides "diet...miso soup and tofu"?

Yes and yes.

Anecdotal evidence is not evidence.

[barnacle547]

02:45 PM on 04/10/2012

Anecdotal evidence is just that: evidence of a kind. On such evidence research projects are often launched.

[VPerry24]

03:27 PM on 04/12/2012

Took supplements since I was 30 years of age and never ever experienced hot flashes. Don't have an idea why not because the rest of my family suffered with them. I think my vitamins saved me from that.

[Danchi]

10:19 PM on 04/07/2012

Genetically modified soy can destabilize the thyroid which will not decrease hot flashes but can can a whole lot of other problems. Dealing with hot flashes is not a one size fits all remedy. If you want to really get a handle on what I consider the worst part aspect of menopause get your thyroid checked and make sure they check your free T3 & 4 and also the different estrogen's: estrone, estradiol, estrial. There are about 20-30 different estrogens. Ask your Dr. to write a prescription for a cream based on those findings. Good luck though, my Dr, had to experience chemo induced heart disease when she had breast cancer to realize there's a better way to treat people rather than cut, poison and burn. There are some online sites that offer this service based on a saliva test. GM soy will take your body out of balance and this is the last thing a woman wants when she dealing with all her body's systems shifting.

[GrandmaG]

02:13 PM on 04/10/2012

Exactly. I have thyroid disease and I avoid soy. I do have some menopausel symptoms and I take a version of Estroven (over the counter) which is the only one without soy and it helps a lot, but am beginning to have trouble finding it. : (

[Danchi]

09:21 PM on 04/10/2012

Have you tried adding progesterone cream to your regiment. It can help create balance because both hormones decrease. I experienced a chemical menopause starting about 10 years ago and I have found over time I've had to modify my regiment as symptoms changed. Use a chillow pillow or something similar to help sleep at night. I read on a site as you get older your blood thickens and this makes hot flashes more intense so use products to reduce inflammation which thins the blood. Stay away from spicy food or conditions that cause you to heat up like sitting next to heaters or lamps that put off heat. Just little thing make a big difference. Black cohosh works well.

[rivergirl301]

09:39 PM on 04/07/2012

I just can't help but think if men suffered hot flashes, they wouldn't be told to jack around with maybe adding soy might improve it a bit.

[spkninglsh]

08:29 PM on 04/07/2012

Not if it's cooked Szechuan style.

[maribelles]

01:50 PM on 04/07/2012

This study is another meaningless "biomedical" arrow slung into the morass of misunderstanding about true healing. "Isoflavones" are a part of the soybean (and tons of other plants!) , and reading this sets up a meaningless "market" for the sale of "isoflavones". The real truth is that women consuming tofu may very likely have been keeping a host of other healthy habits, (such as consistent exercise, higher dietary awareness and quality choices in general, lack of adverse habits) which result in them as a demographic group to be holistically healthier, and therefore less prone to the imbalance of hot flashes.

Who is to say (certainly this article is vague on many counts!) that "genistein" - all other things remaining the same, is responsible for a decrease in hot flashes and other menopause discomforts. Certainly this article shoots itself in the foot at the end admitting the "studies" were inconclusive and poorly designed.

[NotEve]

08:09 PM on 04/08/2012

Isoflavones are simply a classification of organic compound. The name for a category of organic molecules. The science and mechanism behind this study is actually quite sound.

Soy contains large amounts of specific isoflavones that are chemically similar to estrogen molecules (called phytoestrogens, "genistein" is a specific example). Therefor, it has been hypothesized and demonstrated in various studies (the one above is just one example) that consumption of these phytoestrogens through soy can be an alternative method of estrogen replacement/supplementation.

The "controversy" arises from the lack of sufficient (read "enough") studies that have been conducted. The article above is news because it is a larger and more scientifically credible study than has been done previously.

This is very normal in the progression of scientific inquiry. Based on knowledge of the physiology and bio-chemistry a hypothesis is developed, then a small (because small means cheaper to fund) study is conducted, if the results are interesting then larger, more credible studies are conducted (such as the one above) to look at the hypothesis and results in more detail.

[1swimmom]

12:49 PM on 04/07/2012

Unfermented soy inhibits your uptake of minerals. Not good for menopause and bones.....

[Shelley in BC]

12:32 AM on 04/11/2012

where do you get this information? so that we can check it out ourselves.

[yeswiican]

12:21 PM on 04/07/2012

The government subsidizes farmers to grow soy beans and would love to push their products onto consumers! And it appears the Huffington Healthy Living doesn't mind reporting on soy, which by most accounts, is difficult to digest, has a lot of calories, and NOT a complete source of protein!

[alykatma]

04:58 PM on 04/08/2012

They already do! Look at any industry prepared food and there will be several soy ingredients in there already. Just another plug to market GM soy, which is pervasive already.