For many years, coffee lovers the world over have reached for a cup without thinking of the possible health benefits (or risks) associated with their favorite beverage. That all changed in 1991. The World Health Organization (WHO) categorized coffee together with other ingredients as possible carcinogens (cancer-causing agents). Thus, the future of coffee looked very bleak. But 25 years later, a new study turned the WHO’s list of carcinogens on its head.

A recent study found that, contrary to what was previously thought, coffee doesn’t actually increase your risk of getting cancer, but instead actually decreases it! It seems as though the initial results were misinterpreted because the consumers’ smoking history was not taken into account. In other words, smoking history was a confounding factor. When this smoking history was properly accounted for, coffee’s name was cleared.

Coffee is rich in caffeine, vitamin B2 (riboflavin), magnesium, and polyphenols (plant compounds said to have antioxidant properties). One standard cup or brewed coffee contains about 95 mg of caffeine, and according to most health organizations, 400 mg (about 3 to 5 cups per day) is considered safe for most adults. But what effect does it have on your health?

1. Cancer

Coffee stimulates your colon muscles, speeding up digestion. This means that coffee can actually decrease the amount of time your colon is exposed to possible carcinogens. In animal studies, polyphenols (also found in red wine and chocolate) have been shown to have a preventative effect against cancer growth. Coffee is also associated with a lower estrogen level, a hormone that has been linked to various cancer types.

2. Diabetes

Drinking coffee can lead to short-term increased blood sugar, but over a longer period, it appears as though regular coffee drinkers are at a lower risk of developing type 2 diabetes. This is attributed to the polyphenol and magnesium content which helps the body to better metabolize glucose.

3. Heart disease

Certain coffee preparations (like espresso or French press coffee) contain a moderate to high amount of diterpenes, compounds that can actually increase your bad (or LDL) cholesterol (filter and drip-brewed coffee contain insignificant amounts of these compounds). Despite this, studies are showing that coffee consumption is associated with a lower risk of stroke and cardiovascular disease.

4. Other diseases

Coffee seems to have a protective effect against certain neurogenerative diseases. It protects brain cells that produce dopamine, and in doing so, lowers your risk of developing Parkinson’s disease. Although some studies suggest coffee may be associated with a decreased risk of Alzheimer’s, results are still somewhat inconclusive due to a limited number of studies.

There seems to be a fine line between what is good or bad and this varies from one individual to the next (depending on your caffeine tolerance). For some, three cups would be enough to give them energy, alertness, and increased concentration. For another, three cups might give them heart palpitations, anxiety, or restlessness. The best is to experiment and see what is your ‘acceptable’ level of coffee. If you feel alert, that’s great. If you feel like a bouncy ball, you might want to reduce your consumption with a cup or two.