3 reasons that Caffeine affects Women more than Men……..


I am a woman. And I drink caffeine. I am also the Mama of Mama Tea, therefore I drink a LOT of Mama Tea herbal tea. Accordingly, my caffeine intake has gone down substantially, however I now experience more noticeable effects of drinking my regular Starbucks/Costa/Caffe Nero coffee. I get flushed, hot, clammy, and my heart races. I suffer headaches and feel a bit jittery. As a result, I only drink one cup of coffee a day. However, I thought it would be interesting to look at a few of the facts about caffeine and women.

Caffeine affects women more than men.

Wow – really?? I hear you ask. Well, you might be surprised to find out that “roughly, 75% of the human research into caffeine has been conducted on men”  – {p225 – “Caffeine Blues” by Stephen Cherniske}.

Research shows that caffeine affects women much more than men. Why?

Reason 1 – Slower detoxification

Women detoxify caffeine much slower than men per se. However due to the fluctuations of hormones during a woman’s cycle, the “HALF-LIFE” of coffee (i.e. the time it takes the body to eliminate one half-dose of a dose of coffee) can change, varying from 5.5 hours to 7 hours depending on the stage of the cycle {M.J.Arnauld. “Metabolism of Caffeine and Other Components of Coffee” in “Caffeine, Coffee & Health”}. 

All of this means that by the time you are hitting your second or third cup, your body still has not recovered from the first cup. if you want to detox, try cutting down your coffees as the first step!

Reason 2 – Caffeine zaps your iron levels

Caffeine reduces your iron levels. The reason why this is so important for women is that women often suffer from iron malnourishment. Up to 30% of women will suffer anemia until they stop menstruating, just because it is so difficult to get iron from food. {L. Hallberg, “Iron” in “Present Knowledge in Nutrition”, 5th ed.}.

“Depending on the composition of a meal, a caffeinated beverage can reduce iron availability by a whopping 50 percent” {p235 “Caffeine Blues by Stephen Cherniske}. 

That’s a lot!

Reason 3 – Caffeine makes you stressed

Stress generally affects women much more than men – women’s stress hormones increase more rapidly than men’s when faced with conflict. {J. Ferri, “Under Pressure”} 

What does caffeine have to do with this? Well, caffeine increases the “Stress Response”. Caffeine has numerous effects on the body. One of these is is that it disrupts the function of the “ADENOSINE RECEPTORS”. 

What on earth does this mean? Well, Stephen Cherniske sums it up better than I could:

“Have you ever inserted the wrong key in a door and found that the key fits just fine but it wouldn’t unlock the door? That’s what caffeine does in a adenosine receptor. It fits, but does not perform the adenosine function……when caffeine plugs an adenosine receptor, an important biochemical message that was supposed to be sent to the cell is not delivered…….When caffeine inactivates this control mechanism, your neurone circuits keep firing, and you feel alert. The problem is, your circuits keep firing, and firing, and firing……”

This uncontrolled neuron firing creates an EMERGENCY RESPONSE in the brain – it activates the whole flight-or-fight flight stress reaction, flooding the brain with the stress hormones. And it keeps on doing it, over and over!

Combine this with the fact that women suffer stress more acutely and you can see that this fact alone is a reason for women to wean themselves off more than your one cappuccino a day!


How much Caffeine is in your Coffee?

Do you know how much caffeine is in your coffee? Did you know that it varies wildly depending which coffee shop you go to? Scientists at Glasgow University carried out a snap shot study of caffeine levels in espressos sold in high street coffee shops in Glasgow. The wide variety of levels gives an indication that as a consumer we have no way of knowing how much caffeine we are consuming when we purchase one of these drinks.

Espresso Dual-Wall Glass - 75ml

The Figures

Here’s a list of five of the better known coffee shops where samples were taken and the caffeine levels found in a single shot of espresso;

The study identifies factors that could have an effect on the level of caffeine in the coffee such as the quantity of ground coffee used for making the espresso, the grind, the temperature of the water and the beans.

These results are for a single shot of espresso, many coffees we buy from high street coffee shops will be made with two, three or even four shots of espresso. Starbucks have recently announced their intention to start putting a double shot of espresso in tall lattes and cappucinos, the customer will now be getting over 100mg of caffeine in a standard drink.

Other Drinks

So what are the caffeine levels in other beverages?

  • Current guidelines suggest that in a 225ml mug of instant coffee there is 60-85mg
  • A standard can of Coca Cola has 35mg and Diet Coke 45mg
  • 225ml mug of decaf filter coffee has about 6mg
  • Red Bull has 80mg and other energy drinks go as high as 300mg per can/bottle

These figures are all taken from www.energyfiend.com. There are many factors influencing the caffeine content of tea, including brew time and temperature of water, making it difficult to put a figure on the caffeine levels.

 The Conclusion

The reality is most of us have no idea how much caffeine we are consuming and the wide variety of caffeine levels in drinks purchased from coffee shops make it very difficult to even try and monitor our intake. So whilst you may think you’re only drinking one or two cups of coffee a day, depending where you buy it, how it is made and size, your one cup could be equivalent to another person’s four cups in terms of caffeine.