An informed & useful view of soy foods:
Welcome to our health & self help blog.
In it we post health commentary & reviews of books, eBooks, & other things that improve or protect your health or which enable you to live longer, to be more prosperous, & to be more effective.
Today's post: Wednesday, 7-26-2006
An informed & useful view of soy foods:
Most of today’s post is by UltraMetabolism author Dr. Mark Hyman.
He does NOT address the two objections that I raised in saying why I did not include it as a Superfood as others have done.
But he does make quite a number of points I think you should know if you already like or eat soy foods or are considering it.
In fact, his points about what kinds of soy foods to eat & why are extremely valuable.
So if you eat soy foods or think you might, here’s his article.
(I edited out a few things that were not soy related from his email that I got. But all of his key points about soy are here & are exactly as they were in his email.):
**************
Scan some media reports and surf the Internet…. and
you're bound to come across scary claims like:
- Soy will give you breast cancer...
- Soy formula is dangerous to babies...
- Genetically modified soy foods may modify you...
- Soy foods block your thyroid function...
- Soy prevents the absorption of minerals and blocks
digestion...
- Tofu causes Alzheimer's disease.
Let me clear things up for you.
I have reviewed reams of research and many claims for and
against soy foods.
What have I discovered?
Well, there's some good news and some bad news.
From the studies available, I can tell you that soy is
neither as good as the proponents say, nor as evil as the
critics claim. I wish we had more convincing science to
report, but we don't.
The key is to take all the available evidence together and
see what shakes out. I have done that for you.
If you want an excellent, unbiased, scientifically sound
review of all the relevant human data on soy, I recommend
reading the 100-page report from the Agency for HealthCare
Research and Quality entitled, "The Effects of Soy on Health
Outcomes" (www.ahrq.gov), which reviewed thousands of
studies based on rigorous criteria for scientific validity.
Its conclusion was this: There is no evidence of
significant benefit or harm based on the quality of evidence
that exists today.
So what's a confused consumer to do? Give up on soy until
we know for sure? Or chow down on soy nuts?
Don't panic.
To me, there ARE some things we do know about soy, both good
and bad.
First, you should know that the amount of soy used in many
of these studies was much higher than what we normally
consume -- the average dose of soy was equivalent to 1 pound
of tofu or 3 soy protein shakes a day.
That's a lot of soy!
Most people just don't eat like that. So when you read
negative things about soy, remember that many of those
claims are based on poorly designed studies that don't apply
to real-world consumption.
You could apply that thinking to other studies, too -- like
those that show that broccoli contains natural pesticides or
that celery is high in toxins. Sure, those foods might cause
you some problems -- but not in the amounts that most of us
eat. The same is true for soy.
Now I'd like to talk to you about 4 common claims about soy.
==> "Soy causes breast cancer."
Because soy foods contain natural plant compounds (called
isoflavones) that appear to work like hormones, some people
worry that they could increase hormonally driven conditions
like breast cancer.
But that doesn't seem to be the case.
In fact, research findings suggest just the opposite:
- All population studies (studies of groups of people) of
soy either show reduced breast cancer risk or no effect.
- The only studies to show increased cancer risk are on mice
with no ovaries or damaged immune systems and who eat high
amounts of processed soy.
- Studies in mice WITH ovaries and functioning immune
systems show inhibition of tumor growth.
- Mice studies may not reflect the effect of soy on humans
(in case you didn't notice, mice and humans are not the same
species).
- High breast tissue density is linked to a higher risk of
breast cancer. Breast tissue density increases with estrogen
replacement, but decreases with isoflavone consumption in
postmenopausal women. That's a good thing.
- Eating soy foods at an early age (childhood and the teen
years) appears to have a significant protective effect
against breast cancer.
If you really want to reduce your risk of breast cancer,
drink less alcohol and eat less trans and saturated fats -
all of these compounds may raise risk in high amounts.
If it's a choice between chicken nuggets and tofu, I
recommend tofu!
==> "Soy formula could harm a baby's development."
Some 20 million infants have used soy formula since the
1960s -- but some people are concerned that the isoflavones
it contains could affect a child's growth and reproductive
development.
Yet the only large, long-term study on humans, published in
the Journal of the American Medical Association, found that
there were no major health differences in 811 men and women
between the ages of 20 and 34 who had been fed either soy or
milk formula as infants.
More recently, a report issued this year by the National
Toxicology Program Center for the Evaluation of Risks to
Human Reproduction concluded that there just isn't enough
human or animal data to say for sure whether soy formula
harms a baby's developmental or reproductive health.
So what should a mother do?
First, breastfeed if at all possible, for as long as
possible -- ideally until your child is one year old.
If that's not possible and you have to use soy- or dairy-
based formula, don't beat yourself up about it. If there are
any risks, they are likely to be very small. Hopefully,
continuing research will shed more light on this question.
==> "Soy is a thyroid poison."
I think this claim makes a mountain out of a molehill. Yes,
there's no doubt that soy can affect your thyroid gland --
the real question is, how much does it take?
If you've read that soy is bad for your thyroid, you're
probably reading claims based on a few poorly-designed
studies that have been blown out of proportion.
Instead, consider this:
A recent review of the research published in the journal
Thyroid found no significant effects of soy on the thyroid -
- except in people who are iodine deficient, which is rare
in this country.
Another well-designed study in the American Journal of
Clinical Nutrition studied the effect of realistic amounts
of soy protein on hormones, including thyroid hormone. It
found that soy had no significant effects on these hormones.
Based on my assessment of this and other research, I am
convinced that normal amounts of traditional soy foods pose
no risk to thyroid function.
==> "Fermented soy is better than non-fermented soy."
Now here's a claim that DOES have some basis in fact.
That's because soybeans -- along with other beans, nuts, and
seeds -- contain compounds called phytates, which bind to
minerals inside your body and contain some potentially
harmful compounds.
The Asian cultures that have traditionally consumed soy
typically ferment it first. This process breaks soy down and
makes it easier to digest. Plus, fermentation adds extra
nutrients and probiotics ("good" bacteria) to soy.
For these reasons, I prefer fermented soy foods, like miso,
natto, tempeh, tofu and some brands of soy milk.
So, should you eat soy?
My answer is YES -- but with two very important guidelines:
Guideline #1: Say YES to whole, real soy.
The Okinawans are the world's longest-lived people, probably
in part because of their diet. For more than 5 millennia,
they've eaten whole, organic and fermented soy foods like
miso, tempeh, tofu, soy milk, and edamame (young soybeans in
the pod). One to two servings a day are fine.
Guideline #2: Say NO to processed soy.
That includes soy protein isolate and concentrates,
genetically engineered soy foods (typically made from
Monsanto's Roundup soybeans), soy supplements, and soy junk
foods like soy cheese, soy ice cream, soy oil, and soy
burgers. They don't have the thousands of years of
traditional use that whole soy foods do, are processed, and
contain unhealthy fats and other compounds.
I have real concerns about THESE types of soy.
Yes, good human studies on soy are limited -- but those we
do have suggest that soy may help lower cholesterol, prevent
cancer, increase bone density, protect the kidneys of people
with diabetes, and relieve menopausal symptoms like hot
flashes.
Here are some things I want you to remember about soy:
1. The dangers of soy are overstated (and the benefits may
be, too).
2. We eat FAR too much processed soy (and processed foods in
general). Stay away from those in your diet including soy
protein concentrates or isolates, hydrolyzed or textured
vegetable protein, hydrogenated soy bean oil, non-organic
sources of soy, and soy junk food like soy cheese and ice
cream. Don't eat them.
3. Whole soy foods can be a source of good quality protein
and plant compounds that help promote health.
4. Eat only organic soy -- stay away from genetically
modified versions.
5. Replace soy oil with olive oil, fish oil, nuts, and
seeds.
6. Breastfeed your child. I prefer that no one feed dairy
or soy formula to their babies, but if you have to, try not
to worry about it.
7. Don't worry about soy's effect and breast cancer if you
eat it in the forms and amounts I recommend. It has even
shown to protect against breast cancer if you start eating
it at a young age.
8. The effects on the thyroid are not significant or
relevant unless you are deficient in iodine (which you can
easily get from eating fish, seaweed or sea vegetables, or
iodized salt).
I'm eager to see more research on the effects of soy on our
health. But as we wait for more studies, there's no need to
pass up this healthful and delicious food.
To your good health,
Mark Hyman, MD
UltraMetabolism Media LLC
45 Walker Street
P.O. Box 1810
Lenox, MA 01240
http://www.ultrametabolism.com
In it we post health commentary & reviews of books, eBooks, & other things that improve or protect your health or which enable you to live longer, to be more prosperous, & to be more effective.
Today's post: Wednesday, 7-26-2006
An informed & useful view of soy foods:
Most of today’s post is by UltraMetabolism author Dr. Mark Hyman.
He does NOT address the two objections that I raised in saying why I did not include it as a Superfood as others have done.
But he does make quite a number of points I think you should know if you already like or eat soy foods or are considering it.
In fact, his points about what kinds of soy foods to eat & why are extremely valuable.
So if you eat soy foods or think you might, here’s his article.
(I edited out a few things that were not soy related from his email that I got. But all of his key points about soy are here & are exactly as they were in his email.):
**************
Scan some media reports and surf the Internet…. and
you're bound to come across scary claims like:
- Soy will give you breast cancer...
- Soy formula is dangerous to babies...
- Genetically modified soy foods may modify you...
- Soy foods block your thyroid function...
- Soy prevents the absorption of minerals and blocks
digestion...
- Tofu causes Alzheimer's disease.
Let me clear things up for you.
I have reviewed reams of research and many claims for and
against soy foods.
What have I discovered?
Well, there's some good news and some bad news.
From the studies available, I can tell you that soy is
neither as good as the proponents say, nor as evil as the
critics claim. I wish we had more convincing science to
report, but we don't.
The key is to take all the available evidence together and
see what shakes out. I have done that for you.
If you want an excellent, unbiased, scientifically sound
review of all the relevant human data on soy, I recommend
reading the 100-page report from the Agency for HealthCare
Research and Quality entitled, "The Effects of Soy on Health
Outcomes" (www.ahrq.gov), which reviewed thousands of
studies based on rigorous criteria for scientific validity.
Its conclusion was this: There is no evidence of
significant benefit or harm based on the quality of evidence
that exists today.
So what's a confused consumer to do? Give up on soy until
we know for sure? Or chow down on soy nuts?
Don't panic.
To me, there ARE some things we do know about soy, both good
and bad.
First, you should know that the amount of soy used in many
of these studies was much higher than what we normally
consume -- the average dose of soy was equivalent to 1 pound
of tofu or 3 soy protein shakes a day.
That's a lot of soy!
Most people just don't eat like that. So when you read
negative things about soy, remember that many of those
claims are based on poorly designed studies that don't apply
to real-world consumption.
You could apply that thinking to other studies, too -- like
those that show that broccoli contains natural pesticides or
that celery is high in toxins. Sure, those foods might cause
you some problems -- but not in the amounts that most of us
eat. The same is true for soy.
Now I'd like to talk to you about 4 common claims about soy.
==> "Soy causes breast cancer."
Because soy foods contain natural plant compounds (called
isoflavones) that appear to work like hormones, some people
worry that they could increase hormonally driven conditions
like breast cancer.
But that doesn't seem to be the case.
In fact, research findings suggest just the opposite:
- All population studies (studies of groups of people) of
soy either show reduced breast cancer risk or no effect.
- The only studies to show increased cancer risk are on mice
with no ovaries or damaged immune systems and who eat high
amounts of processed soy.
- Studies in mice WITH ovaries and functioning immune
systems show inhibition of tumor growth.
- Mice studies may not reflect the effect of soy on humans
(in case you didn't notice, mice and humans are not the same
species).
- High breast tissue density is linked to a higher risk of
breast cancer. Breast tissue density increases with estrogen
replacement, but decreases with isoflavone consumption in
postmenopausal women. That's a good thing.
- Eating soy foods at an early age (childhood and the teen
years) appears to have a significant protective effect
against breast cancer.
If you really want to reduce your risk of breast cancer,
drink less alcohol and eat less trans and saturated fats -
all of these compounds may raise risk in high amounts.
If it's a choice between chicken nuggets and tofu, I
recommend tofu!
==> "Soy formula could harm a baby's development."
Some 20 million infants have used soy formula since the
1960s -- but some people are concerned that the isoflavones
it contains could affect a child's growth and reproductive
development.
Yet the only large, long-term study on humans, published in
the Journal of the American Medical Association, found that
there were no major health differences in 811 men and women
between the ages of 20 and 34 who had been fed either soy or
milk formula as infants.
More recently, a report issued this year by the National
Toxicology Program Center for the Evaluation of Risks to
Human Reproduction concluded that there just isn't enough
human or animal data to say for sure whether soy formula
harms a baby's developmental or reproductive health.
So what should a mother do?
First, breastfeed if at all possible, for as long as
possible -- ideally until your child is one year old.
If that's not possible and you have to use soy- or dairy-
based formula, don't beat yourself up about it. If there are
any risks, they are likely to be very small. Hopefully,
continuing research will shed more light on this question.
==> "Soy is a thyroid poison."
I think this claim makes a mountain out of a molehill. Yes,
there's no doubt that soy can affect your thyroid gland --
the real question is, how much does it take?
If you've read that soy is bad for your thyroid, you're
probably reading claims based on a few poorly-designed
studies that have been blown out of proportion.
Instead, consider this:
A recent review of the research published in the journal
Thyroid found no significant effects of soy on the thyroid -
- except in people who are iodine deficient, which is rare
in this country.
Another well-designed study in the American Journal of
Clinical Nutrition studied the effect of realistic amounts
of soy protein on hormones, including thyroid hormone. It
found that soy had no significant effects on these hormones.
Based on my assessment of this and other research, I am
convinced that normal amounts of traditional soy foods pose
no risk to thyroid function.
==> "Fermented soy is better than non-fermented soy."
Now here's a claim that DOES have some basis in fact.
That's because soybeans -- along with other beans, nuts, and
seeds -- contain compounds called phytates, which bind to
minerals inside your body and contain some potentially
harmful compounds.
The Asian cultures that have traditionally consumed soy
typically ferment it first. This process breaks soy down and
makes it easier to digest. Plus, fermentation adds extra
nutrients and probiotics ("good" bacteria) to soy.
For these reasons, I prefer fermented soy foods, like miso,
natto, tempeh, tofu and some brands of soy milk.
So, should you eat soy?
My answer is YES -- but with two very important guidelines:
Guideline #1: Say YES to whole, real soy.
The Okinawans are the world's longest-lived people, probably
in part because of their diet. For more than 5 millennia,
they've eaten whole, organic and fermented soy foods like
miso, tempeh, tofu, soy milk, and edamame (young soybeans in
the pod). One to two servings a day are fine.
Guideline #2: Say NO to processed soy.
That includes soy protein isolate and concentrates,
genetically engineered soy foods (typically made from
Monsanto's Roundup soybeans), soy supplements, and soy junk
foods like soy cheese, soy ice cream, soy oil, and soy
burgers. They don't have the thousands of years of
traditional use that whole soy foods do, are processed, and
contain unhealthy fats and other compounds.
I have real concerns about THESE types of soy.
Yes, good human studies on soy are limited -- but those we
do have suggest that soy may help lower cholesterol, prevent
cancer, increase bone density, protect the kidneys of people
with diabetes, and relieve menopausal symptoms like hot
flashes.
Here are some things I want you to remember about soy:
1. The dangers of soy are overstated (and the benefits may
be, too).
2. We eat FAR too much processed soy (and processed foods in
general). Stay away from those in your diet including soy
protein concentrates or isolates, hydrolyzed or textured
vegetable protein, hydrogenated soy bean oil, non-organic
sources of soy, and soy junk food like soy cheese and ice
cream. Don't eat them.
3. Whole soy foods can be a source of good quality protein
and plant compounds that help promote health.
4. Eat only organic soy -- stay away from genetically
modified versions.
5. Replace soy oil with olive oil, fish oil, nuts, and
seeds.
6. Breastfeed your child. I prefer that no one feed dairy
or soy formula to their babies, but if you have to, try not
to worry about it.
7. Don't worry about soy's effect and breast cancer if you
eat it in the forms and amounts I recommend. It has even
shown to protect against breast cancer if you start eating
it at a young age.
8. The effects on the thyroid are not significant or
relevant unless you are deficient in iodine (which you can
easily get from eating fish, seaweed or sea vegetables, or
iodized salt).
I'm eager to see more research on the effects of soy on our
health. But as we wait for more studies, there's no need to
pass up this healthful and delicious food.
To your good health,
Mark Hyman, MD
UltraMetabolism Media LLC
45 Walker Street
P.O. Box 1810
Lenox, MA 01240
http://www.ultrametabolism.com
posted by David at 12:39 PM
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