"Maternal Diet May Affect Stress Responses in Children"
In a critique of the scientific validity
of the dietary advice in Men’s Health magazine,
they discovered nuggets like this,
claiming meat can give men a testosterone boost,
which we’ve known for a quarter century
that a meal with that much fat drops testosterone levels
nearly a third within hours.
In fact, a significant drop of both free and bound testosterone
in the bloodstream within just an hour of it
going in one's mouth,
whereas a low-fat meal of mostly carbs has no such effect.
Based on in-vitro studies on the effects of fat
on testicle cells in a petri dish,
they suspect fat in the blood may actually
suppress testosterone production in real time.
But even holding fat levels the same,
if you feed people lots of meat, fish,
poultry, and eggs, and then switch them
to a diet with about the same amount of fat,
but instead bread, fruit, vegetables, and sugary junk,
all their testosterone levels go up,
but even more importantly, all their cortisol levels go down.
Cortisol is a stress hormone produced by our adrenal glands.
Having low stress hormone levels is a good thing,
because high cortisol levels may strongly predict cardiovascular death
in men and women both with and without
preexisting cardiovascular disease.
In fact, this may help explain “death from a broken heart,”
the heightened heart attack and stroke risk
in the immediate weeks following losing a spouse.
The higher cortisol levels, days, months, or even years
after losing someone you love may increase cardiac risk,
and reduce immune function.
And you’ll note the rise in stress hormone levels losing a spouse,
a bump of about 50 points, is less than the bump
you may get eating a high meat diet.
Cortisol may also help explain why those who are depressed
tend to put on abdominal fat.
The reason obesity around the middle
is associated with elevated cortisol secretion may be
that abdominal fat kind of sucks it up,
and so the accumulation of fat around our internal organs
may be an adaptation by which our body deals with excess stress.
These spikes in stress hormone levels every time we eat a lot of meat
may not just affect our health,
but that of our children.
Substantial evidence now suggests
that high protein diets during pregnancy
has adverse effects on the fetus.
For example, back in the 60’s,
an experiment was performed on pregnant women in Motherwell, Scotland,
in which they were told to eat a high meat diet
in hopes of preventing preeclampsia, a disease of pregnancy.
It didn’t work.
In fact, the lowest preeclampsia rates I’ve ever seen
were among women eating strictly plant-based diets—
only 1 case out of 775 pregnancies.
Pre-eclampsia normally strikes about 5% of pregnancies,
so there should have been dozens of cases,
suggesting a plant-based diet could alleviate most,
if not all, of the signs and symptoms of this potentially serious condition.
But what did happen when pregnant women
went from eating about one portion of meat a day
to like two portions of meat every day?
Mothers who ate more meat and fewer vegetables during pregnancy
gave birth to children who grew up to have higher blood pressures.
One explanation for the adverse effects
of high meat and fish consumption
is that this may have increased maternal cortisol concentrations,
which, in turn, affected the developing fetus,
resetting his or her own stress hormone thermostat to like a higher level.
But, you don’t know until you put it to the test.
And indeed, researchers found higher blood cortisol levels
in both the sons and daughters of women
who had reported higher meat and fish consumption,
about a 5% increase for every daily meat serving.
Such diets may present a metabolic stress to the mother
and kind of reprogram the adrenal axis of their children,
leading to lifelong hypercortisolemia,
elevated levels of stress hormones in the blood.
This may help explain why every daily portion of meat
during late pregnancy may lead to a 1% greater fat mass
in their children by the time they've reached adolescence.
So this could increase the risk of their children
becoming obese later in life,
and so have important public health implications
in terms of prevention of obesity.
Now, if they’re already born,
you may be able to bring down their stress hormone levels
with similar dietary changes.
But this is just baseline stress hormone levels.
Do children of mothers who ate more meat during pregnancy
also have exaggerated responses to life stressors?
Researchers put them through a stressful challenge,
public speaking, mental arithmetic,
and measured their cortisol responses.
If their moms ate less than two servings
of meat and fish a day while she was carrying them
they got little shots of stress hormones
from their adrenal glands.
But those whose mom’s ate more really got stress out,
and those whose moms ate the most—
17 or more servings a week,
(that's more than 2 servings of meat a day)
appeared to really be quaking in their boots.
So, in a way you are what your mother ate during pregnancy.