n active brain stimulant, which produces sleeplessness, hence its great value in narcotic poisoning, in acute cases is injected into the rectum. Very valuable in cases of snake-bite, helping to ward off the terrible coma. It also exerts a soothing action on the vascular system, preventing a too rapid wasting of the tissues of the body; these effects are not only due to the volatile oil but to the caffeine it contains. Caffeine is valuable for heart disease, ascites and pleuritic effusion and combines well with digitalis; also valuable in cases of inebrity; is a powerful diuretic, but loses its effect with use.
Coffee consumption has generally been shown to have little or no impact on cancer development.
Coffee consumption reduces the risk of prostate cancer, Alzheimer's disease, dementia, Parkinson's disease, heart disease, diabetes mellitus type 2, non-alcoholic fatty liver disease, cirrhosis, and gout. It may increase the risk of acid reflux and associated diseases.
The fact that decaffeinated coffee also exhibits preventative effects against diseases such as prostate cancer and type 2 diabetes suggests that coffee's health benefits are not solely a product of its caffeine content. Specifically, the antidiabetic effect of caffeine has been attributed to caffeic acid and chlorogenic acid.
The presence of antioxidants in coffee has been shown to prevent free radicals from causing cell damage. Evidence suggests that roasted coffee has a stronger antioxidant effect than green coffee.
Coffee is no longer thought to be a risk factor for coronary heart disease.
Caffeine acts as an acute antidepressant. A review published in 2004 indicated a negative correlation between suicide rates and coffee consumption. It was suggested that the action of caffeine in blocking the inhibitory effects of adenosine on dopamine nerves in the brain reduced feelings of depression.
Excessive amounts of coffee can cause very unpleasant and even life-threatening adverse effects. Coffee's adverse effects are generally more common when taken in excess. Many of coffee's health risks are due to its caffeine content and can therefore be avoided by drinking decaffeinated coffee.
Oily components called diterpenes are present in unfiltered coffee and coffee brewed using metal filters, but not in coffee brewed using paper filters. The two diterpenes present in coffee, kahweol and cafestol, have been associated with increased risk of coronary heart disease via elevation of low-density lipoprotein (LDL) levels in blood.
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Overview of effects of moderate consumption of caffeine, a main active component of coffee Elderly individuals with a depleted enzymatic system do not tolerate coffee with caffeine well. They may also react poorly to decaffeinated coffee because it can cause heartburn. Moderate amounts of coffee (50–100 mg of caffeine or 5–10 g of coffee powder a day) are well tolerated by most elderly people.
Coffee consumption can lead to iron deficiency anemia by interfering with iron absorption, especially in mothers and infants.
Coffee's interference with iron absorption is due to the polyphenols it contains. However, excess iron is carcinogenic to the liver. Therefore, coffee consumption's negative correlation with the development of liver cancer is also attributed to polyphenols.
Although some chemicals in coffee are carcinogens in rodents at very high doses, research suggests that they are not dangerous at the levels consumed by humans. Instant coffee has a much greater amount of acrylamide than brewed coffee. Research suggests that drinking caffeinated coffee can cause a temporary stiffening of arterial walls. Coffee may aggravate pre-existing conditions such as gastroesophageal reflux disease, migraines, arrhythmias, and cause sleep disturbances.
Caffeine can cause anxiety, especially in high doses and in those with pre-existing anxiety disorders.
Some research suggests that a minority of moderate regular caffeine consumers experience some amount of depression, anxiety,
low vigor, or fatigue when discontinuing their caffeine use. However, the methodology of the these studies has been criticized. Withdrawal effects are more common and better documented in heavy caffeine users.
About 15% of the U.S. general population reports having stopped drinking coffee altogether, citing concerns about their health and the unpleasant side effects of caffeine.