Caffeine is found not only in coffee, but also in other foods and drinks, such as chocolate, sodas, tea, energy drinks and certain medications. High caffeine consumption is associated with disorders such as increased anxiety, sleep disorder, hypertension, cardiovascular disease, stroke, fibrocystic breast changes and infertility or pregnancy loss.
How much caffeine is safe?
Scientific studies continue to debate the amount of caffeine that is safe.
- A 1993 study showed that women who consumed more than 300mg of caffeine a day had a 27% lower chance of conception than women who did not.
- A study at Yale, in 1990, showed that the risk of infertility was 55% higher for women who drink 1 cup of coffee a day, and 176% higher if they drank over 3 cups a day.
- Some other studies showed that more than 300mg of caffeine a day increased the risk of miscarriage (possibly doubling the risk).
- A 2011 study performed on mice demonstrated that caffeine impaired the function of the fallopian tube muscle, which is responsible for transporting the egg and the embryo to the uterus. This may be the explanation, even in humans, as to why caffeine can affect fertility.
- On the other hand, a Spanish study did not find any negative correlation unless greater than 500mg of caffeine was consumed per day.
While we may not have exact data on caffeine and fertility risks, to be on the safe side, most medical organizations recommend less than 200-300 mg of caffeine daily when trying to conceive or when pregnant. See the chart below (or better yet, read the caffeine amounts listed on the back of the products you are consuming), to stay below the recommended daily caffeine intake.
Estimated caffeine levels in common sources:
- Coffee, brewed 100-200mg
- Espresso 1 oz 30-90 mg
- Tea 8 oz 40-120 mg
- Soda 12 oz 22-72 mg
- Energy drinks 16 oz 80-260 mg
- Chocolate 1.5 oz 9-31 mg.