Culprit found for lower sperm counts: soy (contains estrogen-like chemical)(guardian.co.uk)
guardian.co.uk
Culprit found for lower sperm counts: soy (contains estrogen-like chemical)
http://www.guardian.co.uk/science/2008/jul/24/foodtech.medicalresearch
10 comments
Do you happen to know if soy protein (as opposed to whole soy flour) has a significant amount of phytoestrogens?
Depends, I guess, on what it's in.
Traditional tempeh is fermented, and so is generally quite friendly. Tofu, as I mentioned, is basically soy milk curd.
But most instances, in US groceries, where something contains "soy protein" it's going to be in the form of soy flour, or soy milk (which is generally soy flour, water, sugar), which, unless fermented for soy sauce and tempeh or made into tofu, has phytoestrogens to one degree or another.
I've never actually found good data on this topic, and it's an area of interest since I'm vegetarian. I enjoy some of the soy-based meat alternatives (Boca Burgers, Morning Star Farms products, etc.), but many contain soy (as well as wheat gluten) in forms that are poorly defined, so I suspect they are subject to this problem. I generally avoid them for that reason. I'd be curious to know what processes do break down those compounds, if any others besides fermentation and turning into tofu do. Simply cooking seemingly does not, however.
Traditional tempeh is fermented, and so is generally quite friendly. Tofu, as I mentioned, is basically soy milk curd.
But most instances, in US groceries, where something contains "soy protein" it's going to be in the form of soy flour, or soy milk (which is generally soy flour, water, sugar), which, unless fermented for soy sauce and tempeh or made into tofu, has phytoestrogens to one degree or another.
I've never actually found good data on this topic, and it's an area of interest since I'm vegetarian. I enjoy some of the soy-based meat alternatives (Boca Burgers, Morning Star Farms products, etc.), but many contain soy (as well as wheat gluten) in forms that are poorly defined, so I suspect they are subject to this problem. I generally avoid them for that reason. I'd be curious to know what processes do break down those compounds, if any others besides fermentation and turning into tofu do. Simply cooking seemingly does not, however.
Let's see: the Chinese have been eating soy products since the beginning of time, and China is the most populous country on Earth -- I would guess they have a high fertility rate, otherwise the one-child policy would not have been enacted...something seems amiss here...
As I mentioned, tofu does not have these elements, and is the major source of soy protein consumed in Asian nations (boiled young soybeans, called edamame in the west, are eaten as a snack by some folks in Japan and to a lesser degree in other Asian cultures, and I believe there have been a couple of studies in Japan that indicate that men who consume it do have a lower sperm count and lower levels of testosterone, but I may be misremembering).
As is usual in US culture, with it's love of fads and quick-fix solutions, the soybean industry has convinced everyone that soy, in general, is astonishingly healthy. On paper, it actually does look really good: high protein, high fiber content, low fat, low carbohydrates, and no cholesterol (a positive when comparing to other animal-derived protein sources). But, really, soybeans in most forms are quite hard on the body. Since Americans don't, generally, eat tofu, the industry has found other ways to sell its products...as "healthy" additions to breakfast cereal, as a milk alternative, a protein source for meat alternative products like hot dogs, etc. I'm leery of anything that has been pushed that hard by huge corporations (corn being the most obvious example of an industry gone mad with power, and the entirety of the nation suffers for it). But I do loves me some tofu, and eat it all the time. As you note, if the Chinese can eat it for thousands of years without negative impact, I reckon it's safe.
As is usual in US culture, with it's love of fads and quick-fix solutions, the soybean industry has convinced everyone that soy, in general, is astonishingly healthy. On paper, it actually does look really good: high protein, high fiber content, low fat, low carbohydrates, and no cholesterol (a positive when comparing to other animal-derived protein sources). But, really, soybeans in most forms are quite hard on the body. Since Americans don't, generally, eat tofu, the industry has found other ways to sell its products...as "healthy" additions to breakfast cereal, as a milk alternative, a protein source for meat alternative products like hot dogs, etc. I'm leery of anything that has been pushed that hard by huge corporations (corn being the most obvious example of an industry gone mad with power, and the entirety of the nation suffers for it). But I do loves me some tofu, and eat it all the time. As you note, if the Chinese can eat it for thousands of years without negative impact, I reckon it's safe.
> As you note, if the Chinese can eat it for thousands of years without negative impact, I reckon it's safe.
That's a dangerous statement. Your lifestyle is different to the lifestyle of the Chinese over the past few millennia.
People in northern Europe eat very large quantities of cholesterol-rich foods: salted/cured pig fat, and a thick meat-based jell-o made by boiling pig legs for hours, are two popular dishes in Russia. This diet is not only tolerable, but is recommended during the colder months, as (1) fat is the best energy store we have, and (2) cholesterol reduces the freezing point of lipid cell membranes, helping maintain their fluidity. On the other hand, such a diet would be outright suicidal for an average middle-American.
The same cultures also eat large quantities of heavily-salted preserved vegetables during the winter; the salt is not particularly good for you, but the negatives are outweighed by the benefits of vitamins in the vegetables, which would otherwise be unavailable in the winter months. Again, not recommended for the average American who has access to fresh fruit and vegetables all year.
In Australia, people are hospitalised every year from over-eating after a rich Christmas turkey meal in 40C heat. The tradition evolved in the English winter, where energy demands are higher and digestive systems operate at a greater efficiency.
I do agree with you on the fads. Human metabolism is still sufficiently misunderstood that any claim that advocates particular extreme dietary behaviour will ultimately be proven wrong. The sequence of events usually goes something like this: x provides essential nutrients -> x is added to every product on the market -> scientists claim x causes cancer! -> scientists discover a way to emulate x with y, a healthy alternative! -> y is added to every product on the market -> scientists claim y causes cancer! -> ...
Those claim are generally true, technically. Everything you eat kills you; the trick is balance and moderation.
That's a dangerous statement. Your lifestyle is different to the lifestyle of the Chinese over the past few millennia.
People in northern Europe eat very large quantities of cholesterol-rich foods: salted/cured pig fat, and a thick meat-based jell-o made by boiling pig legs for hours, are two popular dishes in Russia. This diet is not only tolerable, but is recommended during the colder months, as (1) fat is the best energy store we have, and (2) cholesterol reduces the freezing point of lipid cell membranes, helping maintain their fluidity. On the other hand, such a diet would be outright suicidal for an average middle-American.
The same cultures also eat large quantities of heavily-salted preserved vegetables during the winter; the salt is not particularly good for you, but the negatives are outweighed by the benefits of vitamins in the vegetables, which would otherwise be unavailable in the winter months. Again, not recommended for the average American who has access to fresh fruit and vegetables all year.
In Australia, people are hospitalised every year from over-eating after a rich Christmas turkey meal in 40C heat. The tradition evolved in the English winter, where energy demands are higher and digestive systems operate at a greater efficiency.
I do agree with you on the fads. Human metabolism is still sufficiently misunderstood that any claim that advocates particular extreme dietary behaviour will ultimately be proven wrong. The sequence of events usually goes something like this: x provides essential nutrients -> x is added to every product on the market -> scientists claim x causes cancer! -> scientists discover a way to emulate x with y, a healthy alternative! -> y is added to every product on the market -> scientists claim y causes cancer! -> ...
Those claim are generally true, technically. Everything you eat kills you; the trick is balance and moderation.
That's a dangerous statement.
Really? Dangerous? Like loaded gun in the hands of an angry monkey dangerous, or just riding a bike while wearing flip flops dangerous?
Your lifestyle is different to the lifestyle of the Chinese over the past few millennia.
I dunno, is it? China is a big place with lots of lifestyles represented. Most climates are represented on mainland China (because it is so big), so that factor is less important than contrasting constantly frozen Russia to constantly hot Australia. China and the US aren't all that different climatically speaking. I've been a vegetarian for 14 years...which is pretty common in China, due the large Buddhist population, but not all, or even most, Buddhists are vegetarian. America has had Chinese restaurants for three generations now. How different are my eating habits, really?
I sit around more than the Chinese did in the past...but I sit around more than my American parents and grandparents did at my age, too. We're a much more sedentary culture than prior generations. But, on the whole we don't eat anything like our parents or grandparents, either.
If the option is: Eat like an average American, because it is what we're accustomed to (where "accustomed" equals "roughly one generation of eating corn in every processed nugget of fatty sugar-laced goodness the mass-market food industry serves up"); or eat like folks did in some other culture 100, 500, or 1000 years ago, because it seems to be a healthier diet based on what we do know, then I'll take the latter option.
The average American diet is, to use your inflammatory language, "outright suicidal for an average middle-American". It's high fat, high sugar, low fiber, and low in nutrients (unless "fortified" with artificial concentrations of vitamins and minerals), and it is nothing like previous American generations diet. Dramatic change is probably exactly what Americans need.
Anyway, you've taken an extreme example of epicurean culture clash and compared it to a quite mild example. Extremely high fat, high salt, foods are not good for anybody. They may be the lesser evil of limited options, but they aren't healthy and no one is claiming they are (at least no one who limits their claims to that which has scientific backing).
Tofu has quite a lot of good science behind it, in addition to thousands or hundreds of years of consumption in China, Korea, Japan, Vietnam, Hong Kong, etc.
Anyway, I'm not saying you're wrong, just saying I think maybe you're conflating two very different things, and I've certainly never suggested anyone take up bizarre eating habits of other cultures merely because those other cultures have been doing it for years...just that it probably won't hurt you, if a nation of a billion people has been eating that way for dozens of generations. And, if we take a bit more moderate view on things, even the things I avoid (corn/HFCS, soy in non-tofu or fermented forms, heavily processed foods of any sort, etc.) aren't going to kill you tomorrow.
Everything on the shelf at a modern American grocery is roughly "safe". We live in a time when we have the privilege of dying of historically bizarre age-related diseases, even if we eat like crap most of our lives. So, you can shave ten years off of your life by eating lots of meat...but, putting it into perspective there was a time, just a couple hundred years ago even in modern cultures, when eating one piece of not-quite-fresh or not-quite-cooked meat could kill you within hours or days (assuming you're already weakened by poor nutrition, illness, etc.). Starvation can take you out in a few days to a couple of weeks. Parasites certainly contributed to many an early demise before modern medicine.
We now have the opportunity to see what long-term effects of foods are--something most of our ancestors didn't have the privilege of doing. Though, it is interesting that some things that were considered good for longevity based purely on anecdotal evidence (green tea, for example) have turned out to actually be good for longevity, as far as we can tell. Then again, many other such anecdotal longevity solutions will probably turn out to be unhealthy. Wives tales are funny that way.
Really? Dangerous? Like loaded gun in the hands of an angry monkey dangerous, or just riding a bike while wearing flip flops dangerous?
Your lifestyle is different to the lifestyle of the Chinese over the past few millennia.
I dunno, is it? China is a big place with lots of lifestyles represented. Most climates are represented on mainland China (because it is so big), so that factor is less important than contrasting constantly frozen Russia to constantly hot Australia. China and the US aren't all that different climatically speaking. I've been a vegetarian for 14 years...which is pretty common in China, due the large Buddhist population, but not all, or even most, Buddhists are vegetarian. America has had Chinese restaurants for three generations now. How different are my eating habits, really?
I sit around more than the Chinese did in the past...but I sit around more than my American parents and grandparents did at my age, too. We're a much more sedentary culture than prior generations. But, on the whole we don't eat anything like our parents or grandparents, either.
If the option is: Eat like an average American, because it is what we're accustomed to (where "accustomed" equals "roughly one generation of eating corn in every processed nugget of fatty sugar-laced goodness the mass-market food industry serves up"); or eat like folks did in some other culture 100, 500, or 1000 years ago, because it seems to be a healthier diet based on what we do know, then I'll take the latter option.
The average American diet is, to use your inflammatory language, "outright suicidal for an average middle-American". It's high fat, high sugar, low fiber, and low in nutrients (unless "fortified" with artificial concentrations of vitamins and minerals), and it is nothing like previous American generations diet. Dramatic change is probably exactly what Americans need.
Anyway, you've taken an extreme example of epicurean culture clash and compared it to a quite mild example. Extremely high fat, high salt, foods are not good for anybody. They may be the lesser evil of limited options, but they aren't healthy and no one is claiming they are (at least no one who limits their claims to that which has scientific backing).
Tofu has quite a lot of good science behind it, in addition to thousands or hundreds of years of consumption in China, Korea, Japan, Vietnam, Hong Kong, etc.
Anyway, I'm not saying you're wrong, just saying I think maybe you're conflating two very different things, and I've certainly never suggested anyone take up bizarre eating habits of other cultures merely because those other cultures have been doing it for years...just that it probably won't hurt you, if a nation of a billion people has been eating that way for dozens of generations. And, if we take a bit more moderate view on things, even the things I avoid (corn/HFCS, soy in non-tofu or fermented forms, heavily processed foods of any sort, etc.) aren't going to kill you tomorrow.
Everything on the shelf at a modern American grocery is roughly "safe". We live in a time when we have the privilege of dying of historically bizarre age-related diseases, even if we eat like crap most of our lives. So, you can shave ten years off of your life by eating lots of meat...but, putting it into perspective there was a time, just a couple hundred years ago even in modern cultures, when eating one piece of not-quite-fresh or not-quite-cooked meat could kill you within hours or days (assuming you're already weakened by poor nutrition, illness, etc.). Starvation can take you out in a few days to a couple of weeks. Parasites certainly contributed to many an early demise before modern medicine.
We now have the opportunity to see what long-term effects of foods are--something most of our ancestors didn't have the privilege of doing. Though, it is interesting that some things that were considered good for longevity based purely on anecdotal evidence (green tea, for example) have turned out to actually be good for longevity, as far as we can tell. Then again, many other such anecdotal longevity solutions will probably turn out to be unhealthy. Wives tales are funny that way.
> Really? Dangerous? Like loaded gun in the hands of an angry monkey dangerous, or just riding a bike while wearing flip flops dangerous?
Neither. More like making generalisations dangerous (Although I am sure you will be able to pick apart my post to find plenty of generalisations, too).
> The average American diet is, to use your inflammatory language, "outright suicidal for an average middle-American". It's high fat, high sugar, low fiber, and low in nutrients (unless "fortified" with artificial concentrations of vitamins and minerals), and it is nothing like previous American generations diet.
I did not at any point advocate that Americans eat the average American diet. Nor did I mean any offense to America, merely to the diet. I don't eat such a diet, nor do I eat the average Russian diet since leaving that region. The point I am making is that accepting any extreme view on dietary requirements is a strange thing to do considering how little we understand about the workings of our metabolism, regardless of how many cultures have enjoyed such a diet for countless millennia. [edit: I realise you did not advocate such a position, either. But plenty of people misinterpret statements like the one I quoted to do just that.]
I am sure tofu is great, and has lots of science behind it. So does consuming red meat. Or milk. They also have lots of science pointing to the contrary. But most of those scientific arguments apply to extreme cases. In the right environment, eating an occasional steak will not give you a heart attack or colon cancer, just as eating a few soy beans will not make you impotent. But excluding foods on the basis of current scientific understanding strikes me as more damaging, if it turns out that those foods carried nutrients we previously did not understand. Of course, dietary requirements based on religious or moral principles are something else entirely.
Seems like we agree on the general principles, the devil is in the implementation details, and one's risk profile.
Neither. More like making generalisations dangerous (Although I am sure you will be able to pick apart my post to find plenty of generalisations, too).
> The average American diet is, to use your inflammatory language, "outright suicidal for an average middle-American". It's high fat, high sugar, low fiber, and low in nutrients (unless "fortified" with artificial concentrations of vitamins and minerals), and it is nothing like previous American generations diet.
I did not at any point advocate that Americans eat the average American diet. Nor did I mean any offense to America, merely to the diet. I don't eat such a diet, nor do I eat the average Russian diet since leaving that region. The point I am making is that accepting any extreme view on dietary requirements is a strange thing to do considering how little we understand about the workings of our metabolism, regardless of how many cultures have enjoyed such a diet for countless millennia. [edit: I realise you did not advocate such a position, either. But plenty of people misinterpret statements like the one I quoted to do just that.]
I am sure tofu is great, and has lots of science behind it. So does consuming red meat. Or milk. They also have lots of science pointing to the contrary. But most of those scientific arguments apply to extreme cases. In the right environment, eating an occasional steak will not give you a heart attack or colon cancer, just as eating a few soy beans will not make you impotent. But excluding foods on the basis of current scientific understanding strikes me as more damaging, if it turns out that those foods carried nutrients we previously did not understand. Of course, dietary requirements based on religious or moral principles are something else entirely.
Seems like we agree on the general principles, the devil is in the implementation details, and one's risk profile.
I have an odd sense of Schadenfreude here, but I can't quite figure out why.
The interesting thing about soy, to me, is that it is one of the marketing miracles of our time. It was considered inedible in western culture until just the current generation, and now it is considered a "healthy" addition to just about any food. It was used for oil and other raw materials in industry, but not for food. While not as successful as corn (which is simply unavoidable in American foods), the soy industry has integrated its products into the daily diet of almost everyone. While I eat fresh tofu several times a week, I avoid mass-market foods that contain soy, and anything that contains soy in its various "raw" forms (soy flour/meal, soy milk, or whole soy beans). Soy sauce is problematic, as there are "quick ferment" processes used in most cheap soy sauce brands that do not break down the suspect compounds...properly slow fermented soy sauce is generally fine, though.