The Effects of Hormones in Milk on Infertility in Women
Dairy consumption is associated with years of advanced ovarian aging, thought to be due to the steroid hormones or endocrine-disrupting chemicals in cow milk.
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The video I mentioned about the effects of these estrogens and progesterone in men and prepubescent children is The Effects of Hormones in Dairy Milk on Cancer (http://nutritionfacts.org/video/the-effects-of-hormones-in-dairy-milk-on-cancer).
I talk about the effect of dairy estrogen on male fertility in Dairy Estrogen & Male Fertility (https://nutritionfacts.org/video/dairy-estrogen-and-male-fertility).
How else might diet effect fertility? See:
• Male Fertility and Diet (https://nutritionfacts.org/video/male-fertility-and-diet/)
• The Role of Diet in Declining Sperm Counts (https://nutritionfacts.org/video/The-Role-of-Diet-in-Declining-Sperm-Counts)
• Dietary Pollutants May Affect Testosterone Levels (https://nutritionfacts.org/video/dietary-pollutants-may-affect-testosterone-levels)
• Yellow Bell Peppers for Male Infertility and Lead Poisoning? (http://nutritionfacts.org/video/Yellow-Bell-Peppers-for-Male-Infertility-and-Lead-Poisoning)
• Do Cell Phones Lower Sperm Counts? (http://nutritionfacts.org/video/Do-Cell-Phones-Lower-Sperm-Counts)
• Does Laptop Wi-Fi Lower Sperm Counts? (https://nutritionfacts.org/video/does-laptop-wi-fi-lower-sperm-counts/)
• The Effects of Marijuana on Fertility & Pregnancy (https://nutritionfacts.org/video/the-effects-of-marijuana-on-fertility-and-pregnancy/)
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"The Effects of Hormones in
Milk on Infertility in Women"
¶
0:10.42
When it comes to the amount of
steroid hormones we are exposed to
0:13.69
in the food supply, milk
products and dairy products
0:16.47
supply about 60 to 80% of
ingested female sex steroids.
0:22.07
I've talked about the effects of these
estrogens and progesterone in men
0:26.26
and prepubescent children,
0:29.28
how milk intake can spike estrogen
levels within hours of consumption.
0:34.08
But in terms of effects on women,
I talked about the increased
0:39.17
endometrial cancer risk
in postmenopausal women,
0:41.76
but what about reproductive-age women?
0:44.82
Might dairy hormones affect reproduction?
0:48.09
We've known dairy food intake
0:49.78
has sometimes been
associated with infertility.
0:52.34
However, little is known with regard
to associations with reproductive
0:56.64
hormones or anovulation,
meaning how might dairy do it,
1:00.65
by affecting how the uterus prepares,
or affecting the ovary itself.
1:05.47
The researchers found that women
who ate yogurt or cream had about
1:09.21
twice the risk of sporadic anovulation,
meaning failure of ovulation,
1:14.03
so some months there was just
no egg to fertilize at all.
1:18.34
Now we know most yogurt these
days is packed with sugar.
1:21.74
Even plain Greek yogurt
can have more sugar
1:24.68
than a double chocolate
glazed cake Dunkin' donut.
1:29.75
But they controlled for that, and
the results remained after adjusting
1:33.56
for the sugar content, which suggests
that the risk of anovulation
1:37.15
was independent of the sugar
content included in many yogurts.
1:42.85
Now we don't know if this is just a fluke
or exactly what the mechanism might be,
1:47.99
but if women skip ovulation here
and there throughout their life,
1:52.51
might they end up with a larger
ovarian reserve of eggs?
1:57.46
Women are starting to have
their first baby later and later;
2:00.79
there's been a rise in women having
babies in their late 30s and 40s.
2:05.74
We used to think that women's ovarian
reserve of eggs stayed relatively stable
2:11.82
until a rapid decline at about age 37,
2:14.94
but now we know it appears to be more
of a gradual loss of eggs over time.
2:21.06
Here's what the graph looks like,
2:23.20
where there's a steady loss starting
at peak fertility at one's 20s.
2:27.80
This is measuring antral follicle count,
which is an ultrasound test
2:32.78
where you can just count the number of
like next-batter-up eggs in the ovaries.
2:38.06
It's probably the best reflection
of true reproductive age.
2:43.42
It's a measure of ovarian reserve:
how many eggs a woman has left.
2:48.51
OK, so what does this
have to do with diet?
2:51.79
Researchers at Harvard looked
at the association between
2:54.51
various protein intakes with
ovarian antral follicle counts
2:58.13
among women having
trouble getting pregnant.
3:01.38
Even though diminished ovarian
reserve is one of the major causes
3:05.93
of female infertility, the process
leading to reproductive deterioration
3:10.46
with age is still poorly understood.
3:13.82
In light of women delaying
pregnancy until older age,
3:17.16
the identification of reversible factors
that may affect the individual decline
3:21.67
might be of significant clinical value.
3:24.95
So they did ultrasounds on all the
women and studied their diets,
3:27.86
and concluded that higher dairy
protein intake was associated
3:31.43
with lower antral follicle counts, in
other words: accelerated ovarian aging.
3:36.43
Here's what the graph looked
like in nonsmokers.
3:40.27
Significantly lower ovarian reserve
at the highest dairy intake,
3:43.19
which would be like three
ounces of cheese a day,
3:45.39
compared to the lowest dairy intake.
3:48.24
OK, but what do these numbers
mean in terms of biological age?
3:52.23
Is 16.9 down to 12.7 really
that much of a difference?
3:57.97
If you look at women with really robust
ovaries, a follicle count of 16.9
4:01.89
would be like what you might
see in a 36 or 37-year-old.
4:06.28
Whereas 12.7—what you can see
in women eating the most dairy—
4:10.24
is like what you might see
in a really fertile 50-year-old.
4:14.36
So we're talking years'
worth of ovarian aging
4:16.52
between the highest and
lowest dairy consumers.
4:19.73
While it wasn't possible
4:20.83
for the researchers to identify
the underlying mechanism
4:23.98
linking higher dairy protein intake
with lower follicle count,
4:27.22
they had several educated guesses.
4:30.43
One: it could be the steroid
hormones and growth factors.
4:33.54
Two: the contamination of milk products
with pesticides and endocrine-disrupting
4:38.26
chemicals that may negatively
affect the development
4:41.07
of these ovarian follicles
and egg competence.
4:45.05
Regarding the hormones, studies
suggest that commercial milk,
4:48.54
derived from both pregnant
and non-pregnant animals,
4:52.10
contains large amounts
of estrogens, progesterone
4:54.68
and other placental hormones
that are eventually released
4:57.45
into the human food chain,
with dairy intake accounting
5:00.84
for 60-80% of the estrogens
consumed, as I mentioned before.
5:06.26
Dairy estrogens survive processing,
appear both in raw and commercial
5:10.36
milk products, are found in
substantially higher concentrations
5:13.74
with increasing amounts of milk
fat, with no apparent difference
5:17.88
between organic and conventional dairy
products; that's important to realize.
5:22.17
It's not just cows that have been
injected with growth hormones.
5:25.68
There hormones are just in their bodies
naturally, and once inside the human body
5:30.64
these bovine hormones get
converted to estrone and estradiol,
5:34.19
the main active human estrogens.
5:36.63
And following absorption, bovine steroids
may then affect reproductive outcomes.
5:43.12
It is imperative that further studies
are designed to clarify the biology
5:47.50
underlying the observed associations.
5:49.71
This might be crucial given that
consumption of another species' milk
5:54.29
by humans is an evolutionary novel
dietary behavior that has the potential
5:59.29
to alter reproductive parameters and may
have long-term adverse health effects.
