Hormone hit list
These chemicals control almost everything we do and feel. By Lisa Salmon
Help to understand how the body works
What are the chemicals that control our lives? Randi Hutter Epstein, author of Aroused (Norton, £19.99), explains that hormones are “loopy chains of amino acids” produced in the nine key endocrine glands. These are the hypothalamus, pineal and pituitary in the brain, the thyroid and parathyroids in the throat, adrenals in the kidneys, pancreas in the abdomen, and the ovaries and testes in the pelvis.
Every cell has markers that direct hormone signals to precisely where they need to go, she says – but hormones rarely work alone, and a dip in the amount of one hormone interferes with other hormones, in a domino effect that can throw a host of bodily functions off-kilter.
Here, Epstein, a respected medical writer, Yale University lecturer and adjunct professor at Columbia University’s journalism school in the US, outlines nine ways hormones affect our health and wellbeing...
‘I-feel-full’ hormone affects fertility
“The world was wowed with the discovery of leptin, the ‘I-feel-full’ hormone,” says Epstein. “New evidence suggests it not only controls appetite, but may be linked to infertility. Leptin increases after meals, and chronic low levels of the hormone due to severe starvation alters other brain hormones that, in turn, dampen hormones necessary for conception.”
So, people who eat very little and have lower leptin levels may also be less likely to conceive. This may help explain why women who have anorexia or other eating disorders often have trouble getting pregnant.
Obesity reduces testosterone
If you lose weight, you’ll help boost your testosterone levels, the male sex hormone that plays a key role in the development of male reproductive tissues such as the testes and prostate, as well as promoting increased muscle and bone mass, and the growth of body hair. “Contrary to popular notion, taking testosterone doesn’t burn fat,” stresses Epstein. “You need to cut calories, not take testosterone shots.”
Hormones produced by being
overweight make you eat more
You think the fat cell is just a blob of fat? Think again; it secretes hormones too, altering your drive to eat. “The fatter you get, the more your hormones will lure you to the kitchen,” says Epstein.
Growth hormone isn’t just for growing
As well as stimulating growth, cell reproduction and cell regeneration, human growth hormone (HGH) helps balance sugar, metabolise proteins and fats, maintain heart and kidney health and stimulate the immune system.
Childbirth hormone promotes love and trust
Oxytocin, the hormone that ‘squeezes’ the womb to help in childbirth and gets the breast milk flowing, also influences feelings of love, trust and empathy, says Epstein.
Man boobs result from too much testosterone
Testosterone converts into oestrogen in the body, so men who are taking too much testosterone are likely to get unwanted man boobs – even though testosterone has been advertised as helping boost libido.
Lower menopausal oestrogen affects much more than periods
As well as a woman’s periods stopping at the menopause, lower oestrogen levels can lead to changes in the brain and nervous system, leading to things like mood swings, memory loss, problems focusing, irritability, fatigue, hot flushes, night sweats, stress and anxiety and vaginal dryness, triggering painful sex.
Embryos all look alike until hormones kick in
Around six to eight weeks after conception, the human foetus has two sets of ducts. If the foetus is genetically male (XY chromosomes), the embryonic testes will produce anti-mullerian hormone causing the Mullerian (female) ducts to disappear.
Progesterone can make you sad
Changing progesterone levels can contribute to abnormal menstrual periods and menopausal symptoms, and the hormone is also necessary for implantation of the fertilised egg in the uterus and for maintaining pregnancy. But progesterone can also trigger moodiness and sadness.
“That’s why some women may feel glum on the birth control pill, which is a mix of oestrogen and progesterone,” she explains. “For some, progesterone can trigger depression, others get moody, and some don’t seem bothered. But if you go on birth control or hormone replacement therapy and start to feel depressed or sad, you should let your doctor know. There’s a link between hormones and moods.” n