Long-term effects of alcohol
[22][23][24][25] Nonetheless, some authors remain suspicious that the apparent health benefits of light alcohol use are in large part due to various selection biases and competing risks.
The variance in alcohol consumption that is explained by genetics is small, requiring large sample sizes and potentially violating assumptions of the analysis.
[27] As one reviewer noted, "Despite the wealth of observational data, it is not absolutely clear that alcohol reduces risk, because no randomized controlled trials have been performed.
[31] In 2013, Norwegian psychiatrist Hans Olav Fekjær compared the situation to those of hormone replacement therapy (HRT), vitamin E, and β-carotene; similarly to alcohol, observational studies for each of these treatments showed significantly reduced risk of coronary heart disease, but initial randomized trials of these treatments failed to replicate the effect.
[56] The landmark INTERHEART Study has revealed that alcohol consumption in South Asians was not protective against CAD in sharp contrast to other populations who benefit from it.
[78] A prospective study published in 1997 found "moderate alcohol consumption appears to decrease the risk of PAD in apparently healthy men.
"[79] In a large population-based study, moderate alcohol consumption was inversely associated with peripheral arterial disease in women but not in men.
The study concluded "an inverse association between alcohol consumption and peripheral arterial disease was found in nonsmoking men and women.
[86] At present there have been no randomised trials to confirm the evidence which suggests a protective role of low doses of alcohol against heart attacks.
[88] A systematic review reported that reducing alcohol intake lowers blood pressure in a dose-dependent manner in heavy drinkers.
At present, due to poor study design and methodology, the literature is inconclusive on whether moderate alcohol consumption increases the risk of dementia or decreases it.
Epidemiological studies of middle-aged populations generally find the relationship between alcohol intake and the risk of stroke to be either U- or J-shaped.
This impaired cognitive ability leads to increased failure to carry out an intended task at a later date, for example, forgetting to lock the door or to post a letter on time.
Wernicke's encephalopathy is the acute presentation of the syndrome and is characterised by a confusional state while Korsakoff's psychosis main symptoms are amnesia and executive dysfunction.
[120] Ethanol is known to activate aminobutyric acid type A (GABAA) and inhibit N-methyl-D-aspartate (NMDA) glutamate receptors, which are both implicated in essential tremor pathology[121] and could underlie the ameliorative effects.
[133] Evidence that the mental health disorders are often induced by alcohol misuse via distortion of brain neurochemistry is indicated by the improvement or disappearance of symptoms that occurs after prolonged abstinence, although problems may worsen in early withdrawal and recovery periods.
It is possible in some cases that excessive alcohol use, via a kindling mechanism, can cause the development of a chronic substance-induced psychotic disorder, i.e. schizophrenia.
A diagnosis of major depression at entry into an inpatient treatment for alcohol dependence showed shorter times to first drink and also relapse in both women and men.
A national survey (NHANES) conducted in the U.S. concluded, "Mild to moderate alcohol consumption is associated with a lower prevalence of the metabolic syndrome, with a favorable influence on lipids, waist circumference, and fasting insulin.
Many theories have become apparent in research, including alcohol being responsible for high estrogen and androgen levels, specifically in women, which may facilitate the alcohol-related immunodeficiency and/or immunosuppression that causes carcinogenesis.
[168] In contrast to these findings, a large prospective study has shown a protective effect of moderate alcohol consumption on respiratory mortality.
Several reviews and meta-analyses of existing literature show that low to moderate alcohol consumption significantly decrease erectile dysfunction risk.
[citation needed] A twenty-year twin study from Finland reported that moderate alcohol consumption may reduce the risk of type 2 diabetes in men and women.
Some of the biological mechanisms by which ethanol reduces the risk of destructive arthritis and prevents the loss of bone mineral density (BMD), which is part of the disease process.
[206][207] Chronic excessive alcohol use is associated with a wide range of skin disorders including urticaria, porphyria cutanea tarda, flushing, cutaneous stigmata of cirrhosis, psoriasis, pruritus, seborrheic dermatitis, and rosacea.
Heavy drinkers who are exposed to high acetaldehyde levels due to a genetic defect in alcohol dehydrogenase have been found to be at greater risk of developing cancers of the upper gastrointestinal tract and liver.
[224] Alcohol crosses the placental barrier and can stunt fetal growth or weight, create distinctive facial stigmata, damaged neurons and brain structures, and cause other physical, mental, or behavioural problems.
[227] Feelings of depression and antisocial behaviors experienced in early childhood frequently contribute to marital conflict and domestic violence.
In another study conducted with data from eight European countries,[235] 77% of alcohol dependent patients had psychiatric and somatic co-morbidity, which in turn increased systematic healthcare and economic cost.
[240] The wide range is due to inconsistency in measurement of economic burden, as researchers in some studies attributed possible positive effects from long term alcohol consumption.
