“Coffee contains over a thousand chemicals, some of which have antioxidant and antimutagenic activity,” said Mia Hashiba, assistant medical professor at the University of Utah and lead investigator of the study, Life's Little Mysteries. "We need more research to identify which ingredients in coffee are responsible for the results we observed in our study.”

Scientists are still trying to determine what exactly gives coffee its disease-fighting properties, but recent research is getting closer to discovering the mysterious power behind the energy drink.

Your brain when you drink coffee

Coffee may also be good for the brain. Earlier this year a study was conducted by neuroscientists at the University of Lisbon, it showed that drinking coffee may help prevent neuronal degeneration associated with brain disorders and aging. The scientists found that drinking four cups of coffee a day over a long period of time actually prevented memory deterioration.

Other research has shown that coffee is good for the cardiovascular system. Women who drank one to three cups of coffee a day reduced their risk of cardiovascular disease by 24 percent, according to Women's Health Study from Iowa, who monitored 27,000 women for 15 years, although it was noted that this benefit diminished when the amount exceeded three cups of coffee.

Although coffee has had a bad reputation for allegedly increasing the risk of strokes and coronary heart disease, scientific studies have shown the opposite. Drinking coffee reduces the risk of stroke by 19 percent among women, according to a 2009 study conducted by the Faculty of Medicine of the University of Harvard, who kept a record of coffee drinking habits and the incidence of stroke among 83 000 American women for nearly a quarter century.

The risk of some cancers may be lowered by drinking coffee. Research presented at the Conference on Research Frontiers in Cancer Prevention, of the American Association for Cancer Research, showed that coffee reduced the risk of aggressive prostate cancer by 60 percent, based on a study conducted on 50,000 men during 20 years.

 People who drink coffee can reduce their risk of developing liver cancer by 41% compared with people who never drink coffee, according to a study published called Hepatology. The researchers speculated that the compounds found in coffee may block the action of enzymes involved in detoxifying carcinogenic compounds that could lead to liver cancer, the third leading cause of cancer death worldwide after stomach and lung cancers.

Other recent studies have shown that coffee protects against certain brain tumors, endometrial cancer and advanced prostate cancer, said Hashiba.

While it is true that some of the chemicals in a cup of coffee may irritate the gastrointestinal organs, coffee is not such a large cause of heartburn and reflux as previously thought. Scientists have actually identified a chemical in coffee called N-methyl pyridine, which inhibits acid production. The compound is most common in French roast beans, according to the Research Platform for Molecular Food Science at the University of Vienna.

Chemical combination of coffee

But not all the chemicals found in coffee are good for you. The drink has been attacked for containing pesticides and hazardous chemicals.

A typical cup of coffee contains about 10 milligrams of known carcinogens like benzene and formaldehyde, according to chemistry professor Joe Schwarcz of McGill University, who writes in the book "The Fly in the Ointment: 70 Fascinating Commentaries on the Science of Everyday Life "(ECW Press, 2004). However, other experts argue that trace amounts of these substances are too small to pose a serious risk of cancer, and point to studies showing that coffee reduces the risk of several cancers.

 In fact, for most adults, coffee is the main source of antioxidants, according to a study funded by the American Cocoa Research.

"Americans get more antioxidants from coffee than any other dietary source," reported Joe Vinson, lead author of a study on antioxidants produced by the University of Scranton in Pennsylvania. "Nothing else comes close."

Although antioxidants help reduce cell damage and aging, scientists have yet to determine if these compounds are responsible for the rare-but-wonderful benefits of coffee for health.

There are many organic and inorganic compounds in a regular cup of coffee, among which are chemicals called phenolic compounds, Melanoides and diterpenes. It is believed that some of these chemicals are beneficial, such as chlorogenic acid, a natural compound found in coffee beans and other plants. It is also an antioxidant that is believed to aid in digestion, according to the American Journal of Clinical Nutrition.

"Coffee is a very complex blend of different chemicals," said Hashiba. Researchers are still trying to identify exactly what makes coffee so mysteriously beneficial, but their antioxidant components might be part of their protective effects against cancer.

Potential disadvantage

But because coffee contains caffeine, which is a stimulant, drinking too much could lead to headaches, nervousness and rapid heartbeat. Even decaffeinated coffee contains traces of the substance, because the decaffeination process can not completely eliminate caffeine.

A safe dose of caffeine a day is 300 milligrams for adults and 35 to 40 milligrams a day for children, according to Department of Health and Human Services. Although it was once thought dangerous for women to consume caffeine during pregnancy, the HHS has determined that mothers who drink less than 300 milligrams of caffeine per day were not putting their baby in danger.

However, the HHS warns that women who drink or consume more than 300 milligrams of caffeine per day may have trouble getting pregnant, and a study from the Research Division of Kaiser found that a high dose of caffeine a day -two or more cups of regular coffee or five 12-ounce cans of soda with caffeine- during pregnancy may increase the risk of abortion.

"Each individual metabolizes caffeine and other components of coffee in a different way," said Hashiba, so it is not possible to have a general recommendation for all audiences. Coffee can increase heart rate, blood pressure and affect sleep, but these effects are felt differently in different people.