Dear Science,
Why is it that some nights I can have two beers after eating a solid dinner and feel super tipsy, and other nights have two martinis after barely eating and barely feel anything? I’ve heard that alcohol affects women differently at different times of the month (I am a woman) because of hormone fluctuations, but I have no idea if that’s true. Thank you!
An Unpredictable Drunk
Before we launch into an exploration of lady times and liquor, let us take a moment to appreciate the liver. Aside from the moments it’s trying to kill you, your liver is quite possibly the organ that loves you the most—keeping you from bleeding to death; devouring and rendering harmless almost all toxins you eat, drink, and breathe; and helping you digest fat. Life with a sick liver is not a good place to be. When it becomes sickly, your liver shrivels up, becoming tough and fibrous—rather than its healthy squishy and brown cheer. Your belly fills up with body fluids; veins in your neck, belly button, and rectum swell; and you run a decent chance of dying from massive bleeding from your throat. In short: Be good to your liver—or else.
For your question, we must consider the toxin-clearing efforts of the liver. A lovely family of proteins—the cytochrome P450s—make it their business to fuss with just about anything floating in your blood. These proteins use an angry iron ion to splat oxygen atoms onto toxins—in a sense burning them. Different P450 proteins handle different toxins. As you’d expect, if you flood your body with toxins, the liver tries to respond in kind by increasing the production of these poison clearers. Conversely, some toxins target and block some of the P450 proteins—protecting themselves from the liver’s ire. Into this lovely battle enter alcohol and the sex hormones.
Alcohol is mostly processed through its own special mechanism, eventually becoming vinegar (that your cells gleefully consume as food). The P450 proteins, however, chip in on this process. How do lady cycles fit in with this? Estrogen and progesterone both fuss with the expression of the P450 proteins in your liver, turning some up and others down. The overall changes mean that in the first half of the menstrual cycle (when progesterone is king), your alcohol-clearing powers are different than the later half (of estrogen predominance). Science would expect your alcohol tolerance to switch with the time of the month for this reason.
In the spirit of empiricism, work with your observation. Keep track of basal body temperature (to figure out where you are in your cycle) and how many drinks it takes to put you down. Are you more affected during the progesterone or the estrogen time? Science wants to know. Write back with the results.
Oxidizingly yours,
Science
Send your science questions to
dearscience@thestranger.com.
P450? That’s all you can come up with?
In my opinion, one of the better answers to this question is found in one of the (many) alcohol receptors in the brain, the GABA(A) receptor. This receptor is the major inhibitory neurotransmitter receptor of the central nervous system, and serves to dampen overall neurotransmission.
Progesterone signaling (and other metabolites, like pregnanolone and allopregnanolone) change the the subunit composition of this receptor and thus, its sensitivity to alcohol, over the course of the female menstrual cycle.
It’s all in the brain, baby.
Some references: http://www.ncbi.nlm.nih.gov/pubmed/17290…
http://www.ncbi.nlm.nih.gov/pubmed/11744…
Hi Science. I think you got the estrogen/progesterone phases reversed.
It’s official, I will start making these observations now and report back to you in several months in order to have a statistically viable sample number. Cheers!
@biogirl. Excellent! I was going to talk about the GABA receptor work, but ran out of space. Perhaps a slog post sometime soon.
Do similar things occur in men’s bodies? I swear there are times like the writer’s when I can down 3 martinis with little effect, then others when a weak gin&tonic bowls me over.
Great column, as always!
@ science. also, the drinking thing throws off your basal body temperature so unless you are pretty familiar with your cycle, the drinking would make it harder to tell where you are in the cycle. the more you drink, the higher your basal body temperature is.
I am so pleased that Science answered this! We’ve worked out a plan to keep track of my alcohol consumption, ability to do things, and approximate hormone levels and will definitely let you know how it goes.