Coffee may actually be good for your health, potentially lowering your risk for dementia, stroke and some types of cancer, as well as improving your memory and concentration. It may also affect your metabolism, but it's more likely to increase it than decrease it, especially if you drink caffeinated coffee. However, coffee can have a few downsides if you drink too much or are sensitive to caffeine, so don't overdo it.
Coffee and Metabolism
Beneficial substances called polyphenols in coffee may be helpful for boosting your metabolism, especially fat metabolism. When study participants drank a beverage rich in these polyphenols each day for a week, they experienced greater increases in fat burning than when they drank a control beverage for a week, according to a study published in the Journal of Health Science in 2010. Coffee drinking may help you decrease both your body fat and your weight over time, although the overall effect isn't likely to be very large.
Caffeine and Metabolism
You shouldn't be surprised that caffeine may increase your metabolism; that's why it's often included in weight-loss supplements. Caffeine increases the number of calories you burn each day and also sometimes helps you eat less, according to a review article published in American Journal of Physiology -- Regulatory, Integrative and Comparative Physiology in 2007. This increase in energy expenditure is about 13 percent, and caffeine may also help increase lipid metabolism so your body breaks down more fat, noted a study published in The American Journal of Clinical Nutrition in 2004. Exercise is still a more effective way of increasing the amount of fat your body breaks down and gets rid of, however. Over time, your body may get used to the caffeine, and you may no longer experience as many benefits from consuming coffee or other caffeinated beverages, notes the AJP review article.
Chlorogenic Acid and Metabolism
Coffee contains a substance called chlorogenic acid, or CGA, that may have some health benefits. For example, it may improve your fat and glucose, or sugar, metabolism, according to a review article published in Evidence-Based Complementary and Alternative Medicine in 2013. CGA could help lower your risk for obesity, heart disease, cancer and diabetes. One study included in the review found that CGA helped to increase fat metabolism and inhibit the absorption of fat by your body, thus potentially limiting weight gain.
Potential Coffee Considerations
Getting too much caffeine isn't good for people who suffer from osteoporosis, high blood pressure, heartburn, anxiety, insomnia or diabetes. Caffeine can also interfere with some medications. Excessive amounts can cause side effects, including: vomiting, nausea, depression, anxiety, tremors, increased urination and an increased heart rate. It's best to limit your daily consumption to no more than 300 milligrams, or about three cups of coffee, to limit these risks.
Don't quit drinking caffeinated coffee suddenly, however, as it can cause withdrawal symptoms, such as headaches, drowsiness, irritability, vomiting and nausea. It's better to decrease your coffee consumption gradually.