Can Women Tolerate Coffee Better Than Men?

Many people enjoy a morning cup of coffee. It gives you a boost of caffeine to start your day while also carving out some much-needed quiet time by yourself before the rush of the routine comes rolling in. 

But it turns out, there's a reason why some people in your life just don't get the same "hit" as others from this beloved beverage, and it might have to do with their sex. According to a 2008 study published in Progress in Neuro-Psychopharmacology and Biological Psychiatry, men don't tolerate coffee as well as women do. In fact, the study found that women were more sensitive to decaf, while men felt the effects of regular caffeine more. 

Typically, caffeine can stay in your system for up to 5 hours, noted Healthline. But as Everyday Health reported, the side effects of caffeine on men might be felt for longer than for women. Even though men might be more sensitive to the effects of coffee, the consumption of coffee does affect estrogen levels in women. 

According to a study done by the National Institutes of Health, there is an association between estrogen levels and caffeine consumption. The study looked at coffee drinking habits of women of Asian, white, and black descent. 

Two cups of coffee a day (about 200 milligrams) resulted in elevated estrogen levels in Asian women. The same was true for black women. For the white women, however, the estrogen levels reduced with the same amount of coffee a day. 

"The results indicate that caffeine consumption among women of child-bearing age influences estrogen levels," shared Enrique Schisterman of the Division of Epidemiology, Statistics and Prevention Research at the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) (via National Institutes of Health). This study also alludes to the fact that genetics play a role in how coffee consumption affects our bodies and how much coffee we can tolerate. 

According to associate professor in the department of preventive medicine at Northwestern University's Feinberg School of Medicine, Marilyn Cornelis, who researched the connection between genes and coffee consumption (via CBC), "As an example, if I have a genetic variant related to higher caffeine metabolism, I generally will consume more dietary caffeine or coffee. We actually see that the genetics alter our behaviours."

According to a 2016 study published in the journal Scientific Reports, there is a reason why some people consume more coffee per day than others. The study compared data collected from 1,200 Italian villagers with that of 1,731 people living in the Netherlands (via Time). Those who had a "greater expression" of a particular gene – PDSS2 — reported requiring fewer cups of this popular pick-me-up beverage than those who didn't.

"The hypothesis is that people with higher levels of this gene are metabolizing caffeine slower, and that's why they're drinking less coffee. They need to drink it less often to still have the positive effects of caffeine, like being awake and feeling less tired," the study's author, Nicola Pirastu of the University of Trieste in Italy told Time. Turns out, the ability to tolerate coffee has a lot more to do than just liking the beverage over other options. Everything from your genes to your sexual orientation might be influencing your choice.