You might remember hormones from your sex-crazed teen years. Or your
partner's most recent crying jag. But if you're sitting there smugly
thinking that you're immune from hormonal chaos just because you're (a)
no longer a teenager and (b) male, think again. In fact, if you knew all
the ways hormones could mess up your life, you'd probably start crying
like a little girl. Off-kilter hormone distribution can make you store
too much fat, hamper your ability to fight stress, and cause you to eat
when you're full. It can lead to metabolic syndrome and diabetes and can
adversely affect your sleep and sex life.
That's a lot that can go wrong. This is due to the vast reach of your
endocrine system, which commands body activity utilizing powerful
hormones. "It's like your body's internal Internet," says pharmacologist
John McLachlan, Ph.D., director of the center for bioenvironmental
research at Tulane University. "Your hypothalamus and pituitary glands
are the control centers, like servers sending out messages going back
and forth among your organs. Your pancreas, adrenal glands, thyroid, and
testes are all part of this finely tuned system."
That fine-tuning increases the system's vulnerability, as it relies on
complex feedback to regulate itself. "If that feedback is distorted, it
can disrupt the process," says Vivian Fonseca, M.D., chief of
endocrinology at Tulane University's health sciences center.
Use our guide to ensure your hormones are doing their jobs.
Stress hormones: Cortisol and epinephrine
Whether you're fending off an angry rottweiler or an angry client, your
body's response to stress is the same: Your hypothalamus floods your
blood with hormones to frighten you into action. "Cortisol and
epinephrine are your body's alarm-system hormones," says Dr. Fonseca.
They make your heart beat faster and dilate your bronchial tubes so they
can feed oxygen to your brain and keep you alert. They also release fat
and glucose into your bloodstream to provide emergency energy.
Are your hormones in tune?
Too much stress can keep your cortisol levels consistently elevated,
which disrupts your metabolic system. This, in turn, signals your cells
to store as much fat as possible. Worse, the fat tends to accumulate in
your belly as visceral fat, which resides behind your abdominal muscles
and has more cortisol receptors than other fat does.
To defend yourself against stress-hormone disruption, make a habit of
exercising for an hour a day, 3 days a week. Doing so helps regulate
your cortisol levels, say researchers at Ohio State University. Also try
to eat organic foods as much as possible in order to steer clear of the
common pesticide atrazine. This chemical has been shown to affect
hormonal balances in amphibians, reptiles, birds, and mammals. A
National Health and Environmental Effects Research Laboratory study
showed that atrazine produced extreme increases in stress-hormone levels
in rats. In fact, the stress reaction was similar to that seen when the
animals were restrained against their will, the study noted.
Weight hormones: Leptin, ghrelin, CCK, insulin
You have an army of hormones telling you when to eat and when to put the
fork down. The hormone ghrelin begins the cycle when your stomach is
empty by prompting neurons in your hypothalamus to make you feel hungry.
Then when you start eating, your stomach stretches and you secrete
cholecystokinin (CCK), an appetite suppressant.
Hormones now begin working overtime to help you back away from the
table. Your intestines produce peptide YY, which tells your brain you've
had enough to eat, and your pancreas sends out insulin. This signals
that you're metabolizing a meal and that you shouldn't consume any more.
Leptin, a hormone produced by fat cells, also tells your hypothalamus
that you're full by prompting the secretion of alpha-MSH, which is
another appetite-suppressing hormone.
All this helps your body maintain a balance between hunger and
satiation. Why so many hormones in the game? "Energy regulation is
necessary for survival, so we have many redundant pathways in case any
fail," says Robert Lustig, M.D., an endocrinologist at the University of
California at San Francisco. "But we were never supposed to have so
much food so readily available, and certainly not this much sugar."
Are your hormones in tune?
Hungry? Full? You may not be able to trust your gut. When you put on
extra weight, you start secreting excess leptin. "And if you secrete a
lot of leptin on a chronic basis, it should tell your brain, 'Look,
you're putting on weight; you need to cut back,'" says Dr. Fonseca. But
disruptions in leptin (mostly from too much sugar) instead tell your
brain to send out hunger signals, even if you've just eaten. This can
lead to fatty liver disease and insulin resistance. "When your insulin
goes up, it blocks leptin signaling, which means your brain thinks
you're starving," Dr. Lustig says. This, of course, sets up a wicked
feedback cycle as you pack on the pounds.
Beyond losing weight, your best defense against leptin disruption is to
reduce your sugar intake. Americans consume an average of 22 teaspoons
of sugar a day; the American Heart Association recommends that men eat
no more than 9. And it's not just high-fructose corn syrup that you need
to avoid; table sugar and fruit juice can be as bad as soda. In fact,
100 percent fruit juice has 1.8 grams of fructose per ounce, while soda
has 1.7 grams per ounce, Dr. Lustig notes.
Sex hormones: Testosterone, LH, FSH
That rock-hard erection you're so proud of? Thank your
hormones—specifically, testosterone, the key ingredient for normal
sexual health in men. Its production is prompted by something called
luteinizing hormone (LH), while the follicle-stimulating hormone (FSH)
helps produce the actual sperm. When you're aroused, your adrenal glands
pump out epinephrine and norepinephrine, raising your heart rate and
moving blood into your muscles, brain, and penis. Then the hormone
dopamine increases your sexual appetite and communicates with the
hypothalamus to orchestrate your erections.
Are your hormones in tune?
Elevated estrogen levels can eclipse your testosterone, zapping sex
drive. Yes, men have estrogen too. "In fact, the most widely spread
hormone receptor in the body is the estrogen receptor," says McLachlan.
When a man is exposed to estrogenic chemicals—such as bisphenol A (BPA),
the endocrine disruptor found in plastics and food-can linings—he can
experience erectile dysfunction and weight gain.
Your best defense against an estrogen invasion is to lose weight and
build muscle. "Fat converts your testosterone to estrogen," says Jack
Mydlo, M.D., chairman of the department of urology at Temple University
school of medicine. Dropping pounds will improve your
testosterone-to-estrogen ratio, which improves your sex drive as well as
your erections. And when you're actively building muscle, you become
more sensitive to insulin, which means you can push more glucose into
the muscle, says Dr. Fonseca. This produces more fat-burning,
libido-boosting energy.
Energy hormone: Thyroxine
Your thyroid gland controls your metabolism, which is your body's
mechanism for turning calories into energy. It's yet another chain of
command: Your hypothalamus detects fatigue and then your pituitary gland
signals your thyroid to secrete thyroxine. This hormone enters almost
every cell in your body. "It boosts sugar burning and oxygen intake in
cells," says McLachlan. "This raises your body temperature and increases
your heart rate."
Are your hormones in tune?
When this system is out of whack, the result can be muscle breakdown,
weakness, fatigue, and weight gain. While most thyroxine disruptions are
genetic, there is growing evidence that some environmental compounds
can block thyroxine, says McLachlan. A 2009 study suggests that BPA can
displace thyroxine from its receptor and block it. Brominated flame
retardants (BFRs) and polychlorinated biphenyls (PCBs) also both
interfere with your thyroid. (BFRs are found in clothes, furniture, and
electronics; PCBs, which are no longer in use in the United States, can
still be found in the environment, particularly in farmed salmon.) "If
you're exposed to these, you could end up with a form of
hypothyroidism—an underproduction of thyroxine that causes low energy
and weight gain," says McLachlan. On the other end of the spectrum,
hyperthyroidism, or overproduction of thyroxine, can cause anxiety,
increased heart rate, weight loss, an enlarged thyroid, and swelling
behind the eyes. Your doctor will be able to identify thyroid problems
by prescribing a thyroid-stimulating hormone (TSH) blood test; fixes for
both may include surgery or dietary changes, as well as lifelong daily
doses of prescription drugs.
Sleep hormone: Melatonin
When the sun goes down, your pineal gland switches on like clockwork to
secrete melatonin, a hormone that helps you fall asleep and regulates
your circadian rhythm. It lowers your core body temperature, which if
too high promotes wakefulness. Production of melatonin peaks in the
middle of the night, and the process can be disrupted by even very low
levels of artificial light.
Are your hormones in tune?
Mounting evidence suggests that exposure to light at night—whether
you're asleep or awake—might play a crucial role in cancer, diabetes,
and obesity. The World Health Organization classified "circadian
disruption" as probably carcinogenic, and light at night is considered
by some to be an endocrine disruptor that may affect melatonin,
cortisol, ghrelin, leptin, and testosterone. "Most people think, and the
drug companies want you to think, that waking up at night is bad for
you," says Richard Stevens, Ph.D., a cancer epidemiologist at the
University of Connecticut health center. But that's not the case, he
says—it's exposure to light at night that's the problem. "If you wake up
at night, as most of us do, that is a period of quiet wakefulness—stay
in bed, in the dark, and enjoy it," Stevens suggests.
You don't have to be asleep to have good melatonin rhythm, but you do
need to be in the dark. Buy heavy curtains, cover your alarm clock, and
turn off gadgets. "Make it dark enough that you can't see your hand,"
Stevens says. "If you go to the bathroom and turn on that bright light,
you'll lower melatonin almost immediately," says Stevens. "I actually
have a red night-light in my bathroom, because red light has less effect
on melatonin than white or blue light," he says.
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