How Coffee Affects Women’s Health: Key Risks

If you’re a woman who drinks multiple cups of coffee daily—whether for energy, work, or social life—you may want to reconsider. Beyond taste and routine, there’s growing evidence that high coffee consumption carries specific health risks for women, especially in fertility, bone strength, and pregnancy outcomes.

In short: drinking more than one cup of coffee a day can increase your risk of infertility, and having five or more cups daily raises your chance of heart attack by 70%. Long-term high intake is also linked to osteoporosis, pregnancy complications, and higher diabetes risk. Read on for the hard numbers and why they matter.

1. Coffee and Female Infertility

Research shows a clear link between coffee and difficulty conceiving. Women who drink one cup of coffee per day are more likely to experience infertility compared to non-coffee drinkers. One study surveyed 104 coffee-drinking women and found nearly 50 of them had trouble getting pregnant. Experts caution that while some consider this a small-scale study, when no other medical cause for infertility is found, caffeine should be considered a possible contributing factor.

2. Increased Risk of Heart Attack

Drinking large amounts of coffee significantly raises the risk of myocardial infarction (heart attack) in women. A four-year study by Boston University public health researchers tracked 858 women aged 45–69 who experienced their first heart attack and compared them with 858 women who had not. Findings showed that women who drank five or more cups of coffee per day had a 70% higher risk of heart attack—and the risk increased along with coffee consumption.

3. Coffee and Osteoporosis

Long-term coffee intake can weaken bones, particularly in older women. A University of California study of 980 women aged 50–98 found that those who drank more than two cups of coffee daily without consuming milk had reduced bone mineral density in the hips and spine. This bone loss was tied to both the amount of coffee consumed and the duration of the habit. The mechanism? Caffeine binds with free calcium in the body and excretes it through urine. With less free calcium available, the body breaks down stored calcium, leading to osteoporosis over time.

4. Risks During Pregnancy

Pregnant women are advised to avoid coffee. Early studies, including one from the 1980s by U.S. FDA researcher Dr. Koehler, showed that mice given the equivalent of 12–24 cups of strong coffee daily gave birth to offspring with birth defects. While conducted on animals, the findings led to official caution: pregnant women should stop drinking coffee. Human data is limited, but the potential for fetal harm led to strong official advisories.

5. Pregnancy-Induced Hypertension (PIH)

Coffee can raise blood pressure even in small amounts, which is dangerous during pregnancy. A study from Australia found that just a few cups of coffee daily were enough to elevate blood pressure. Since pregnancy-induced hypertension (characterized by swelling, high blood pressure, and protein in urine) can threaten both mother and baby, pregnant women are strongly discouraged from drinking coffee.

6. Potential Link to Diabetes

Countries with the highest coffee consumption—like Finland and the United States—also report the highest rates of diabetes. Finland leads the world in both coffee intake and diabetes cases. In contrast, Japan, with the lowest coffee consumption, also has the lowest diabetes prevalence. Researchers suggest caffeine may affect pancreatic tissues and fetal liver and brain development, possibly increasing diabetes risk in offspring. Though human conclusions are still developing, the correlation across populations is notable.

Other General Health Risks

Beyond gender-specific issues, coffee drinking—regardless of sex—can contribute to heart disease, high blood pressure, and even addiction. These broader risks further support limiting intake, especially among vulnerable groups like pregnant women or those planning to conceive.

Frequently Asked Questions

How many cups of coffee per day are safe for women?

Most risks—especially infertility, heart issues, and pregnancy complications—rise significantly after one cup per day. Drinking five or more cups daily increases heart attack risk by 70%. Health experts suggest women limit intake to one cup or fewer, particularly if pregnant or trying to conceive.

Can coffee really cause osteoporosis in women?

Yes. Studies show women over 50 who drink more than two cups of coffee daily without adequate calcium (such as from milk) have lower bone mineral density in the hips and spine. Caffeine causes the body to excrete free calcium, leading to bone breakdown over time.

Is it safe to drink coffee while pregnant?

No. Research shows even small amounts of coffee can raise blood pressure and may contribute to birth defects or pregnancy complications like hypertension. Most health authorities recommend avoiding coffee entirely during pregnancy.

Does coffee really reduce fertility?

There’s evidence that women who drink even one cup of coffee daily are more likely to face infertility. While not definitive, studies show a clear pattern, and when no other cause is found, caffeine is considered a potential factor.

Why does coffee increase heart attack risk in women?

A long-term study found that women drinking five or more cups daily had a 70% higher risk of myocardial infarction. Caffeine stresses the cardiovascular system, and risk climbs with each additional cup.