The soy debate is far from over, but men who are worried about
consuming soy foods might find these snippets interesting
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From:
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=11303585
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1: Cancer Epidemiol Biomarkers Prev. 2001 Mar;10(3):179-84. Related
Articles, Links
Erratum in:
* Cancer Epidemiol Biomarkers Prev 2001 Sep;10(9):1013.
Effect of soymilk consumption on serum estrogen and androgen
concentrations in Japanese men.
Nagata C, Takatsuka N, Shimizu H, Hayashi H, Akamatsu T, Murase K.
Department of Public Health, Gifu University School of Medicine,
Japan.
Soy consumption has been associated with a reduced risk of
prostate cancer. The mechanism for this association may involve the
effect of soy on the endocrine system. We conducted a randomized
dietary intervention study to determine the effects of soy consumption
on serum levels of steroid hormones in men. Thirty-five men were
randomly assigned to either a soymilk-supplemented group or a control
group. The men in the soy-supplemented group were asked to consume 400
ml of soymilk daily for 8 weeks. The men in the control group
maintained their usual diet. Blood samples were obtained just before
the initiation of the dietary period and thereafter every two weeks
for 12 weeks. Changes in hormone concentrations were analyzed and
compared between the two groups using the mixed linear regression
model against weeks from the start of the dietary period. The mean
(SD) soymilk intake estimated from dietary records during the dietary
study period was 342.9 (SD, 74.2) ml in the soymilk-supplemented
group. There was a significant difference between the two groups in
terms of changes in serum estrone concentrations, which tended to
decrease in the soy-supplemented group and increase in the control
group over time. None of the other hormones measured (estradiol, total
and free-testosterone, or sex hormone-binding globulin) showed any
statistical difference between the two groups in terms of patterns of
change. The results of the study indicate that soymilk consumption may
modify circulating estrone concentrations in men.
Publication Types:
* Clinical Trial
* Randomized Controlled Trial
PMID: 11303585 [PubMed - indexed for MEDLINE]
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From:
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=11880595
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1: J Nutr. 2002 Mar;132(3):570S-573S. Related Articles, Links
Hormonal effects of soy in premenopausal women and men.
Kurzer MS.
Department of Food Science and Nutrition, University of Minnesota,
St. Paul, MN 55108, USA. [email hidden]
Over the past few years, there has been increasing interest in the
possible hormonal effects of soy and soy isoflavone consumption in
both women and men. Soy consumption has been suggested to exert
potentially cancer-preventive effects in premenopausal women, such as
increased menstrual cycle length and sex hormone-binding globulin
levels and decreased estrogen levels. There has been some concern that
consumption of phytoestrogens might exert adverse effects on men's
fertility, such as lowered testosterone levels and semen quality. The
studies in women have provided modest support for beneficial effects.
One cross-sectional study showed serum estrogens to be inversely
associated with soy intake. Seven soy intervention studies controlled
for phase of menstrual cycle. These studies provided 32-200 mg/d of
isoflavones and generally showed decreased midcycle plasma
gonadotropins and trends toward increased menstrual cycle length and
decreased blood concentrations of estradiol, progesterone and sex
hormone-binding globulin. A few studies also showed decreased urinary
estrogens and increased ratios of urinary 2-(OH) to 16alpha-(OH) and
2-(OH) to 4-(OH) estrogens. Soy and isoflavone consumption does not
seem to affect the endometrium in premenopausal women, although there
have been weak estrogenic effects reported in the breast. Thus,
studies in women have mostly been consistent with beneficial effects,
although the magnitude of the effects is quite small and of uncertain
significance. Only three intervention studies reported hormonal
effects of soy isoflavones in men. These recent studies in men
consuming soyfoods or supplements containing 40--70 mg/d of soy
isoflavones showed few effects on plasma hormones or semen quality.
These data do not support concerns about effects on reproductive
hormones and semen quality.
Publication Types:
* Review
* Review, Tutorial
PMID: 11880595 [PubMed - indexed for MEDLINE]
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From:
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=12094627
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1: Nutr Cancer. 2001;41(1-2):41-6. Related Articles, Links
Soy milk intake in relation to serum sex hormone levels in British
men.
Allen NE, Appleby PN, Davey GK, Key TJ.
Cancer Research UK Epidemiology Unit, University of Oxford, Oxford
OX2 6HE, UK. [email hidden]
Soy beans contain high levels of the isoflavones genistein and
daidzein and their glycosides and have been implicated in the
prevention of prostate cancer, possibly via their effects on sex
hormone metabolism. The aim of this study was to assess the relation
between dietary soy intake and sex hormone levels in a cross-sectional
analysis of 696 men with a wide range of soy intakes. Soy milk intake
was measured using a validated semiquantitative food frequency
questionnaire, and serum hormone concentrations were measured by
immunoassay. Multiple regression was used to investigate the
association between soy milk intake, an index of isoflavone intake,
and hormone levels after adjustment for pertinent confounders. Soy
milk intake was not associated with serum concentrations of
testosterone, free testosterone, androstanediol glucuronide, sex
hormone-binding globulin, or luteinizing hormone. These results
suggest that soy milk intake, as a marker of isoflavone intake, is not
associated with serum sex hormone concentrations among free-living
Western men.
PMID: 12094627 [PubMed - indexed for MEDLINE]
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From:
http://www.postgazette.com/pg/04167/331753.stm
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Eat your soy, boys
A food that's good for girls is good for guys, too
Tuesday, June 15, 2004
By Sally Squires, The Washington Post
Yes, it's true that your wife, girlfriend or significant other has
been eating a lot of soy lately, mainly to boost her female hormones.
That doesn't mean it's bad for you, fella. Instead of pushing aside
that soy milk, go ahead and pour some on your morning cereal. Dig into
the soy burgers at the office cafeteria and the tofu that appears in
your takeout stir-fry.
There is strong evidence that the risk of prostate cancer may be
reduced by eating soy products such as these: plain soy milk and
organic soy non-dairy frozen dessert.
Click photo for larger image.
Benefits for men of a diet that includes soy
It turns out that soy, at least in the doses most people will consume
it in food, may be good for guys, too. A growing number of studies
suggest that soy has plenty of health benefits for men -- from
lowering cholesterol levels to protecting against prostate cancer --
and few downsides.
"Real men should eat soy," said Kenneth Setchell, professor of
pediatrics at the Cincinnati Children's Medical Center, who has
studied soy for 30 years. "Generally, men are put off by soy. It tends
to be sort of a woman's thing. That's a great pity, because the
evidence that soy protects against prostate cancer is quite strong."
While there have been worries that men who consume large quantities of
low-carb soy bread, soy cereal or other soy-filled foods may get a
little too in touch with their feminine sides, research findings have
generally not borne out those fears.
"Soy is a very healthy food," said physician James Anderson, who has
studied soy for 15 years at the University of Kentucky in Lexington
and is convinced enough of its benefits to eat about a dozen servings
per week. "It's very safe."
Most concerns about soy have centered around the fact that it is a
rich source of isoflavones, substances that mimic the effects of the
female hormone estrogen. To determine what these plant-based chemicals
might do, Steven Zeisel and his colleagues at the University of North
Carolina at Chapel Hill fed megadoses of soy to men as part of a
recent National Cancer Institute study.
Nipple discharge, breast enlargement and slight decreases in
testosterone occurred with the megadoses. But "we still couldn't find
anything that was serious, and we went up to doses that are probably
30 times what you could get from normal foods," Zeisel said.
And if you stick with foods rich in soy as opposed to supplements,
researchers say, there's no evidence of harm, unless you happen to be
among the one in every 1,000 people who are allergic to soy.
Not only is soy a rich source of high-quality protein, it also
contains complex carbohydrates that don't raise blood sugar as high as
more processed carbohydrates. It has fiber, folic acid (a key B
vitamin), healthy fat and antioxidants that help protect against
cancer.
There's also evidence that soy acts as a probiotic in some people,
promoting growth of healthy bacteria in the gastrointestinal tract
that in turn produce health-promoting substances. It only takes a
small amount of soy to produce health benefits. Less than a handful of
soy nuts, about a fifth of a cup, provides 12 grams of protein, said
Anderson, who keeps a stash near his desk for snacks.
Just resist any urge to eat raw soy. Uncooked soybeans contain a
substance that inhibits trypsin, a key enzyme required for protein
digestion.