Coffee

How does Coffee work?

Coffee contains caffeine. Caffeine works by stimulating the central nervous system (CNS), heart, and muscles.

Are there safety concerns?

Coffee is safe for most adults. Drinking more than 6 cups/day might cause "caffeinism" and cause symptoms such as anxiety or agitation.

Coffee containing caffeine can cause insomnia, nervousness and restlessness, stomach upset, nausea and vomiting, increased heart and breathing rate, and other side effects. Consuming large amounts of coffee might also cause headache, anxiety, agitation, ringing in the ears, and irregular heartbeats.

Drinking unfiltered coffee can increase total cholesterol, low-density lipoprotein (LDL), and triglyceride levels, which might increase the risk of heart disease. Using coffee filters helps to reduce these effects on cholesterol.

There is some concern that consuming more than 5 cups/day of coffee might not be safe for people with heart disease. But for people who don't have heart disease, consuming several cups daily does not seem to increase the change of developing a heart problem.

There is also concern that occasional coffee drinking might trigger a heart attack in some people. People who usually don't consume more than a cup of coffee daily and also have multiple risk factors for heart disease seem to have an increased risk for heart attack within an hour after drinking coffee. But people who regularly consume greater amounts do not seem to have this risk.

Coffee containing caffeine is probably safe for pregnant women in amounts of 2 cups/day or less. This amount of coffee provides about 200 mg of caffeine. However, consuming more than this amount has been linked to an increased risk of miscarriage and other negative effects.

Avoid excessive amounts of caffeinated coffee if:

• You are pregnant or breast-feeding.
• You have a heart condition.
• You have diabetes.
• You have high blood pressure. Small amounts of coffee taken regularly do not seem to raise blood pressure, but the caffeine in coffee can affect blood pressure in someone who consumes caffeinated drinks infrequently.
• You have osteoporosis.
• You have high cholesterol.
• You have glaucoma.
• You have a bleeding disorder.
• You have anxiety.