I’ve long been fascinated by the idea of “messages” in the milk. Check out my article published this week in Nautilus. Illustration by the talented Vahram Muradyan.
You’re pregnant and can’t sleep. Miserable, you ask your doctor what to take. “Diphenhydramine,” you’re told. It’s the active ingredient in sleep aids such as Benadryl, Unisom, Sominex, Exedrin PM and Tylenol PM. An antihistamine, it’s also an over-the-counter drug that pregnant women take when they have a cold or allergies.
“Why not? The FDA classified diphenhydramine as a “Category “B” drug in pregnancy, meaning that there’s no evidence of risk in humans.
Here’s why not. A study published this week in JAMA Internal Medicine found that the cumulative use of Benadryl and other similar nonprescription medications is linked with dementia and cognitive impairment in older people. This study is not the first to find a connection, but it’s the largest one to date. The researchers tracked nearly 3,500 people for seven years. Around 800 of them developed dementia by the end of the study, and those who used Benadryl were likelier to have cognitive impairment than those who did not.
In particular, the study estimated that people taking at least 4 mg/day of diphenhydramine for more than three years are at a greater risk of developing dementia. (The average dose of Benadryl for use as a sleep aid is 50 mg.)
The reason: this drug is an anticholinergic, which works by blocking the action of the neurotransmitter acetycholine. In the brain, acetylcholine is necessary for learning and memory.
Wait!, you might think. The study participants were seniors. The causal link isn’t proven. And the risk, if real, appears to be accumulative.
On the other hand, science has not studied the effects of these drugs on fetuses, infants, or children. Couldn’t the same anticholinergic effects disrupt a baby’s developing nervous system? What might it be doing to a fetus’s brain; the infrastructure of its neural pathways? Even a minor decrease in cognitive function would be alarming.
This study warrants a good, hard look at the effects of common anticholinergic drugs on the developing brains of fetuses, babies, and children. If I were a doctor, I would urge my pregnant and pediatric patients to seriously consider alternatives. Or take it only in emergencies. After all, we now know there’s a lot that we don’t know.
And if were pregnant again, I’d never take Benadryl or anything else with diphenhydramine. Not even if I were struck with insomnia and a killer cold, as I was last November and December in third trimester of my pregnancy. The fact that we now know that this drug may impair the elder brain but haven’t yet explored its effect on the young brain…. If I took it, I’d never be able to sleep.
Now that I’m nursing a newborn again, I’ve renewed my fascination with the science of breast milk. In particular, “lactocrine programming;” the idea that hormonal signals in Mama’s milk can “program” Baby’s body and behavior. So many new developments in the last few years since UJ was born!
Today’s question: Does breastfeeding make kids more fertile later in life?
Theories abound with evidence accumulating from various studies on humans and other mammals. Researchers Katie Hinde and Danielle LeMay, at Harvard and UC David respectively, offer some intriguing insights in their SPLASH! Milk Genomics blog.
The upshot: The first few days after birth are a crucial window for the development of reproductive tissues that will become part of the cervix, uterus, endometrium, and other parts. These tissues start growing when they receive signals from a hormone called relaxin (a multipurpose hormone, it also relaxes blood vessels and ligaments during pregnancy, opens the cervix, and much more).
There’s relaxin in the milk! report Hinde and LeMay, referring to a study on pig milk:
Here’s the crazy part: relaxin is delivered by the mother via her milk. Piglets that are allowed to suckle have relaxin in their blood stream, but not piglets fed a milk-replacer . Relaxin activity in pig milk is highest in the first few days of lactation, and is similar to findings from dogs and humans. Experimental manipulations have shown that as little as one colostrum feeding in the first 12 hours after birth can make a difference. For example, just a single colostrum feeding bout in the first hours after birth allows for typical cervical cell proliferation and development—an important predictor of future litter size.
But does access to milk really predict future fertility? It did in a recent pig study involving over 1,500 litters, say Hinde and LeMay:
Female pigs with limited access to maternal-origin hormones via milk as piglets had reduced litter size as adults. So, it is safe to conclude, at least in pigs, that the number of babies born in any generation was partly programmed by their grandmothers via milk hormones.
It’s mind-boggling, the possibility that access to breast milk in infancy — or at least colostrum (the thick milky fluid produced in the first days after birth, which also contains relaxin) may have an impact on our kids’ reproductive development.
Not that these preliminary (porcine) studies say anything conclusive about humans. For that, we’d need to address many more questions: Do women whose mothers never attempted breastfeeding have more fertility problems — or fewer kids — than their breastfed peers? Do they have a different growth trajectory in puberty? How does relaxin affect reproductive development in sons? Can breastfeed girls bear children later in life than those who weren’t breastfed? How long does a kid need to nurse to receive reproductive benefits — the first day after birth, a few days, the first week? More?
Further research is warranted. Even if turns out that fertility is only slightly enhanced among breastfed kids (that’s my bet, anyway), it’s more fuel for the breastfeeding movement.
Just published: Do Gentlemen Really Prefer Blondes? in Croatian!
My latest gift book is MOM CANDY! It’s a stunning hardcover jewel box of a gift book (with two silk ribbons). Here’s what the press says about it:
“Witty and wise quotations about motherhood….This cute, colorful volume has everything a mother needs, including plenty of sweetness…and a little snark.” – Real Simple
And here’s an excerpt from the introduction:
Sweet and many are the musings about motherhood. Mom Candy is a selection of the choicest. One thousand assorted nuggets of parenting insight and inspiration are featured in this book, drawn from interviews, memoirs, literature, and verse.
The quotes and passages within channel our thoughts to the best things about being a mother: playfulness and purpose, connection and contentment, laughter and love. They speak to motherhood’s ephemeral and eternal joys; of strength, sacrifice, and courage; of limits and life balance; and a mother’s infinite value and legacy.
Dig into Mom Candy when seeking validation or inspiration. Indulge in a quick fix. Graze. Nibble. Binge. Or lift the cover, close your eyes, and just pick one. Motherhood is all about surprise. You never know what you’re gonna get. — From the introduction
What’s the connection between your facial appearance and your personality/character? Sometimes you can judge a book by its cover. Check out “What’s in a Face?, my cover article in the December 2012 issue of Psychology Today.
Not long ago, a group of Czech biologists embarked on an interesting experiment.Their inspiration was the enormous body of evidence that finds that human sweat carries information about a person’s gender, genetic compatibility, and reproductive state. We breathe in other people’s body odors, and, on a subconscious level, find them attractive, passable, or repulsive. This is the sexual selection theory behind body odors. We sniff out the best mates.
There’s even more going on under our noses, the researchers thought. From an evolutionary standpoint, we also ought to care about a mate’s nutritional status. After all, a good diet is an indicator of one’s overall condition — which is related to fertility and stamina. In the animal world, there’s plenty of evidence that eating healthily leads to more sex. Among meadow voles, both males and females prefer the odors of those that eat high-protein diets. Animals that haven’t eaten in a day produce less attractive smells than sated ones.
So, what would happen if you ate a lot of a strong-smelling healthy food? Garlic, say.
The researchers asked a group of subjects to eat bread laced with garlic cream cheese (the equivalent of 2-4 cloves) every day for one week. The next week, they ate their bread with plain cream cheese. At the end of the experiment, female raters were brought in to smell the pads that each man had worn in their armpits. Sniffing time was not restricted.
Which armpit pads were rated as more attractive-smelling — the garlic ones or the plain ones?
Garlic, of course. And here’s the shocker:
The odour of donors in the experimental (garlic) condition was judged as significantly more attractive, more pleasant and less intense than in the control (non-garlic) condition . These preliminary results unexpectedly suggest that garlic consumption positively influences body odour.
Several explanations are offered. Garlic influences body odor with antioxidants, which protect against bad-smelling metabolites, indirectly resulting in a healthier-smelling personal odor. Or, garlic’s bactericidal properties reduce the intensity of bad-smelling armpit odor. Either way, you’re advertising a healthy metabolism, and healthy smells better.
Have we evolved to be attracted to body odors from healthy food? The researchers weigh in:
It is thus plausible that human odour preferences were shaped by sexual selection to be sensitive to odour cues of current metabolic functioning in potential mates. These cues are affected by the amount and quality of food such as garlic digested by the producer.
The study warrants more research on other foods. But it supports the theory that what you eat makes you smell better — which whets others’ appetite for you.
*If you like this blog, click here for previous posts or follow me on Twitter. If you wish, check out my new book on what we don’t expect when we’re expecting: Do Chocolate Lovers Have Sweeter Babies?: The Surprising Science of Pregnancy.