Hangovers are usually caused by alcohol consumption, but other components of alcoholic beverages might contribute to hangover symptoms or make a hangover worse.
Pathophysiology as a result of the accumulation of
acetaldehyde, the first
metabolite of alcohol After being ingested, the ethanol in
alcoholic beverages is first converted to
acetaldehyde by the enzyme
alcohol dehydrogenase and then to
acetic acid by oxidation and the egestion process. These reactions also convert
nicotinamide adenine dinucleotide (NAD+) to its reduced form NADH in a
redox reaction. By causing an imbalance of the NAD+/NADH redox system, alcoholic beverages make normal bodily functions more difficult. Consequences of the alcohol induced redox changes in the human body include increased
triglyceride production, increased
amino acid catabolism, inhibition of the
citric acid cycle,
lactic acidosis,
ketoacidosis,
hyperuricemia, disturbance in
cortisol and
androgen metabolism and increased
fibrogenesis. The metabolism of
glucose and
insulin are also influenced. However, recent studies showed no
significant correlation between hangover severity and the concentrations of various
hormones,
electrolytes,
free fatty acids,
triglycerides, lactate,
ketone bodies, cortisol, and glucose in blood and urine samples. Alcohol also induces the
CYP2E1 enzyme, which metabolizes ethanol and other substances into more reactive toxins. In particular, in
binge drinking the enzyme is activated and plays a role in creating a harmful condition known as
oxidative stress, which can lead to cell death.
Acetaldehyde Acetaldehyde, the first by-product of ethanol, is between 10 and 30 times more toxic than
alcohol itself and can remain at an elevated plateau for many hours after initial ethanol consumption. In addition, certain genetic factors can amplify the negative effects of acetaldehyde. For example, some people (predominantly
East Asians) have a
mutation in their
alcohol dehydrogenase gene that makes this enzyme unusually fast at converting ethanol to acetaldehyde. In addition, about half of all East Asians convert acetaldehyde to acetic acid more slowly (via
acetaldehyde dehydrogenase), causing a higher buildup of acetaldehyde than normally seen in other groups. The high concentration of acetaldehyde causes the
alcohol flush reaction, colloquially known as the "Asian Flush". Since the alcohol flush reaction is highly uncomfortable and the possibility of hangovers is immediate and severe, people with this gene variant are less likely to become
alcoholics. Acetaldehyde may also influence
glutathione peroxidase, a key
antioxidant enzyme, and increases the susceptibility to
oxidative stress.
Congeners In addition to ethanol and water, most alcoholic drinks also contain
congeners, either as flavoring or as a by-product of
fermentation and the
wine aging process. While ethanol is by itself sufficient to produce most hangover effects, congeners may potentially aggravate hangover and other residual effects to some extent. Congeners include substances such as
amines,
amides,
acetones, acetaldehydes,
polyphenols, methanol,
histamines,
fusel oil,
esters,
furfural, and
tannins, many but not all of which are toxic. while some whiskey congeners such as
butanol protect the stomach against gastric mucosal damage in the rat. Different types of alcoholic beverages contain different amounts of congeners. In general, dark liquors have a higher concentration while clear liquors have a lower concentration. Whereas
vodka has virtually no more congeners than pure ethanol,
bourbon has a total congener content 37 times higher than that found in vodka. All four studies concluded that darker liquors, which have higher congeners, produced worse hangovers. One even showed that hangovers were worse
and more frequent with darker liquors. Since methanol metabolism is effectively inhibited by consumption of alcohol, methanol accumulates during drinking and only begins to be metabolized once ethanol has been cleared. This delayed action makes it an attractive candidate explanation for delayed post-intoxication symptoms and correlations between methanol concentrations and the presence of hangover symptoms that have been found in studies. and electrolytes. Furthermore, alcohol is a
diuretic, causing excretion of electrolytes through urination. After a night of drinking, the resulting lack of key B and C vitamins, as well as potassium, magnesium, and zinc may cause fatigue, aching and other hangover-like symptoms.
Dehydration Ethanol has a
dehydrating effect by causing increased urine production (diuresis), which could cause thirst, dry mouth,
dizziness, and may lead to an
electrolyte imbalance. Studies suggest that electrolyte changes play only a minor role in the genesis of the alcohol hangover and are caused by dehydration effects. Drinking water may help relieve symptoms as a result of dehydration, but it is unlikely that rehydration significantly reduces the presence and severity of alcohol hangover.
Immune system In current research, the significant relationship between immune factors and hangover severity is the most convincing among all factors so far studied. Some pharmacological studies such as on
tolfenamic acid and
Opuntia ficus-indica (OFI) have also indicated an involvement of the immune system. These studies suggest that the presence and severity of hangover symptoms can probably be reduced by administration of a
cyclooxygenase inhibitor such as
aspirin or
ibuprofen. • Cigarette smoking: acetaldehyde, which is absorbed from cigarette smoking during alcohol consumption, is regarded as a contributor to alcohol hangover symptoms. ==Management==