Benefits and Risks of Drinking Coffee for Health

If you’ve ever felt jittery after one cup of instant coffee or struggled to sleep at night, you’re not alone. Many coffee drinkers wonder: when does coffee help, and when does it hurt? The answers aren’t always straightforward—but research offers clear numbers and timing advice for different health conditions.

The key number: just one cup of instant coffee—about 2 to 3 teaspoons of coffee powder—can cause a rapid heartbeat in healthy individuals. Drinking it at night often leads to insomnia. For people with certain cardiovascular diseases, the same amount can trigger high blood pressure. And for those with stomach or duodenal ulcers, coffee increases gastric acid, irritating the stomach lining and hindering healing.

What Is the Best Time to Drink Coffee?

According to overseas health recommendations, the optimal time to consume coffee is between 4 and 6 p.m. in summer and autumn, or between 3 and 5 p.m. in winter and spring. These are the periods when most people feel most fatigued. A cup of coffee at these times not only provides a nutritional boost but also helps increase alertness and improve work performance.

Coffee and Cancer Risk

Research from France has found that coffee consumption may significantly increase the risk of pancreatic cancer. Their survey showed that people who drank 60,000 cups of coffee over their lifetime had twice the risk of developing pancreatic tumors compared to non-coffee drinkers. In 1981, Greek cancer researchers reported that women who drank coffee had double the risk of ovarian cancer compared to those who did not. Coffee has also been linked to breast cysts in women. Although not cancerous, these cysts can potentially develop into cancer. Reports indicate that women with breast cysts are four times more likely to develop breast cancer than those without.

Coffee and Premenstrual Syndrome (PMS)

Premenstrual syndrome refers to a range of symptoms that occur in women before menstruation, including mood swings, irritability, anxiety, difficulty concentrating, insomnia, headaches, and breast tenderness. According to a report in the American Journal of Public Health, women who consume caffeinated beverages are more prone to PMS. Therefore, women who experience PMS or regularly consume caffeine are advised to avoid caffeinated drinks like coffee and tea, especially strong coffee and tea, in the days leading up to their period.

Coffee and Coronary Heart Disease

Researchers from the Johns Hopkins University School of Medicine and other institutions conducted a long-term study on 1,130 male medical students to examine the relationship between coffee consumption and coronary heart disease. Over a follow-up period of 19 to 35 years, the study found that men who drank five or more cups of coffee per day had a relative risk of coronary heart disease that was 2.8 times higher than that of non-coffee drinkers. Even after adjusting for other risk factors such as age, smoking, high blood pressure, and serum cholesterol levels, the relative risk remained 2.49 times higher. Experts concluded that higher coffee intake—specifically five or more cups daily—is associated with an increased risk of coronary heart disease, approximately 2 to 3 times greater than for non-drinkers.

Frequently Asked Questions

How many cups of coffee can cause a rapid heartbeat in healthy people?

One cup of instant coffee, which is roughly equivalent to 2 to 3 teaspoons of coffee powder, can cause a rapid heartbeat in healthy individuals.

Is it bad to drink coffee at night?

Yes, drinking coffee at night can lead to insomnia for many people due to its stimulating effects.

Does coffee increase the risk of pancreatic cancer?

Some French research suggests that lifetime consumption of around 60,000 cups of coffee may double the risk of pancreatic tumors, though this is based on extreme consumption levels.

Are women who drink coffee more likely to develop ovarian or breast cysts?

Greek research from 1981 found that coffee-drinking women had double the risk of ovarian cancer. Additionally, coffee has been linked to breast cysts, which may further raise breast cancer risk in affected women.

Can caffeine make premenstrual syndrome worse?

Yes, according to the American Journal of Public Health, caffeine intake is associated with increased prevalence of PMS symptoms, and women prone to PMS are advised to avoid caffeinated drinks before their period.

How much coffee raises the risk of coronary heart disease?

Drinking five or more cups of coffee per day has been linked to a 2.8 times higher risk of coronary heart disease, which remains elevated at 2.49 times even after adjusting for other risk factors.

Recommended FrontStreet Coffee for Health-Conscious Sipping

For coffee lovers watching their health, try FrontStreet Coffee’s washed Yirgacheffe for a bright, citrus-forward cup with gentle acidity—ideal in moderation. Their balanced Brazil Queen Manor offers nutty sweetness and low bitterness, great for steady energy. Both beans highlight clean, low-intervention processing to support a cleaner caffeine experience. Freshly roasted within 5 days · Orders placed before 17:00 ship the same day · Next-day delivery across most of Guangdong Province.