Tell me about alcohol abuse

Some studies have suggested that in moderation, alcohol consumption has significant health benefits. These include a lower risk of heart attack,[7] lower risk of diabetes,[8] lower risk of Alzheimer's disease,[9] reduced risk of stroke,[10] and an increase in overall longevity.[11] One study found that a person fifty-five or older who consumed 1-3 drinks daily was half as likely to develop dementia linked to poor oxygen to the brain as a person who did not. Additionally, because alcohol increases 'good' cholesterol and decreases the 'bad' cholesterol, there are indications that frequent doses in moderation reduce the risk of blood clots and stroke. These benefits are all counteracted by excessive consumption.[12] The health benefits of moderate use have been disputed with researchers claiming that earlier studies that seemed to show such benefits were flawed. It is claimed that health benefits are only gained with heavy drinking where the harm outweighs the benefits.[13] A 2001 report estimates that medium and high consumption of alcohol led to 75,754 deaths in the USA. Low consumption has some beneficial effects so a net 59,180 deaths were attributed to alcohol.[14]

Alcohol intoxication affects the brain, causing slurred speech, clumsiness, and delayed reflexes. The condition is called alcohol intoxication or drunkenness, and eventually subsides. Alcohol stimulates insulin production, which speeds up the glucose metabolism and can result in low blood sugar, causing irritability. In excess, the poisoning can be severe, even lethal. A blood-alcohol content of .45% represents the LD50, or the amount which would prove fatal in 50% of test subjects. This is about six times the level of intoxication (0.08%), but vomiting and/or unconsciousness are triggered much sooner in people with a low tolerance, among whom such high levels are rarely reached unless a large amount of alcohol is consumed very quickly.[12] However, chronic heavy drinkers' high tolerance may allow some of them to remain conscious at levels above .4%, despite the serious health dangers.

Chronic effects of alcohol consumption include effects of its metabolism in the liver, its carcinogenity, its effects on the brain, and effects of addiction (alcoholism). For example, cirrhosis is stereotypically found in heavy drinkers. The consumption of alcohol does not kill brain cells but rather damages dendrites, the branched ends of nerve cells that bring messages into the cell. Alcohol dilates the channels in the cellular structure that regulate the flow of calcium, causing excess calcium to flow into the cells and stimulating increased activity. This does not kill the whole cell, but causes a loss of the end segments, leading to the loss of incoming signals and therefore a change in brain function. Most of this damage is temporary, but the recovery process changes nerve-cell structure permanently.[15] Some forms of cancer have been linked to excessive consumption of alcohol. "3.6% of all cancer cases worldwide are related to alcohol drinking, resulting in 3.5% of all cancer deaths" (see Alcohol and cancer for details).[16]

Alcohol is also a potentially addictive substance, with numerous health effects, and potentially lethal effects of withdrawal. Alcoholism has more and more serious effects on health than moderate drinking. Alcoholism is a major concern for public health; like other kinds of addiction, it is also viewed as a form of immorality. Propensity to alcoholism is partially genetic; individuals with such propensity may have a different biochemical response to alcohol. Alcohol addiction can also lead to malnutrition because it can alter digestion and metabolism of most nutrients. Severe thiamine deficiency is common due to deficiency of folate, riboflavin, vitamin B6 and selenium. Muscle cramps, nausea, appetite loss, nerve disorders and depression are some common symptoms. It can also lead to osteoporosis and bone fractures due to vitamin D deficiency (vitamin D helps in calcium absorption).