 source NewScientist
by John Pickrell
People have been using substances to lift their spirits for millennia.
Techniques for fermenting beer and related tipples are known from Egypt
and Sumeria 4000 years ago, and they soon spread across the inhabited
world. Coca leaves (the source of cocaine), tobacco, and caffeine were also popular with ancient cultures.
Humans may
even have an evolutionary pre-disposition to seek out narcotics, even
though they can be addictive and damaging. Some people may have genes
which make them more genetically prone to drug addiction than others.
Even some animals - jaguars, lemurs and bees, for example - have a
habit of getting high.
There is an enormous amount of research on drug taking, examining both legal highs, such as alcohol, nicotine and caffeine, and illegal stimulants, such as marijuana, LSD, cocaine, ecstasy, amphetamines, heroin and magic mushroomsrohypnol and GHB. and the so-called date-rape drugs
Alcohol - Some experts believe that the world's first impromptu breweriesimpairs their judgement, affects sexual desire and performance, creates beer bellies and leads to hangovers (and dubious cures).
might have been created when grain stores became drenched with rain and
warmed in the sun. Ever since, humans have discovered that alcohol
reduces their inhibitions,
Binge drinking is an ever-increasing health concern, and when not consumed in moderation, alcohol can lead to liver problems, brain damage and infertility. Drinking whilst pregnant can also damage the unborn child. It is not all bad news though: studies show that some types of booze, such as red wine, are rich in antioxidant polyphenols which can help prevent heart disease and cancer.
Marijuana,
once the preserve of hippies, is now regularly smoked by millions of
people in the US and UK. Around 14.6 million Americans have used
marijuana in the last 30 days. Though still controversial, support for controlled legalisation of this most common illegal drug is growing.
That support is bolstered by research showing that cannabis (and psychoactive extracts such as THC or cannabinoids) can provide relief for sufferers of multiple sclerosis, Alzheimer's disease and epilepsy. Cannabis can also help to improve appetite and decrease weight loss in AIDS victims and may be able to slow the growth of cancerous tumours.
However, detractors argue that the long-term effects of smoking dope on the brain are unclear, that it decreases fertility, damages the unborn foetus, can contribute to cot death in babies born to dope-smoking parents, and may lead to memory loss, schizophrenia, depression and other illnesses.
Ecstasy, or MDMA,
was allegedly first prescribed as an anti-depressant. It was also used
by American marriage counsellors and psychotherapists in the 1970s. The
drug made patients feel less anxious and more open, accepting and
empathic. But notoriety for the drug in the UK did not come until it
was popularised by the rave dance scene
in fields and warehouses in the late 1980s. Use of the drug is now
common in main stream clubs and 2 million or more British youngsters
pop the tablets at weekends. Clubbers enjoy the feelings of emotional
closeness, rushes of energy, increased stamina heightened sense of
touch and other effects.
Critics say that regular ecstasy use is a recipe for causing memory loss and lasting damage to the brain's serotonin-producing neurons. Users can die from fatal overheating or a dangerous build-up of water on the brain. Ecstasy causes other problems such as stifling sex drive and damaging babies in the womb.
Tablets contaminated with other compounds are part of the problem and many tests have been developed to check for purity. Controversial research found evidence of a link between ecstasy and Parkinson's disease in 2002, though the finding was later retracted. Other animal studies conversely hinted that ecstasy might actually help treat the symptoms of Parkinson's disease.
Some experts point to the fact that despite the drug's massive
popularity, ecstasy deaths remain extremely rare: downhill skiing kills
more people. Controversial medical trials are testing the use of MDMA to treat post-traumatic stress disorder in victims of rape and violent crime.
Cocaine comes from the coca plant,
the leaves of which have been used by Native South Americans for 3000
years as a mild stimulant. Cocaine itself was first developed as a local anaesthetic,
but has been a popular street drug since the 1970s. Today it is used by
millions of people in the US alone and up to 150,000 end up in
emergency rooms with heart attacks or other side effects. It acts on the brain's dopamine system, and is thought to mimic the thrill of desire and anticipation.
Cocaine is highly addictive - many users become dependent after a year or two, and some research suggests that
just a single dose could get you hooked. Use of the drug is linked to high blood pressure, deadly heart conditions and violent behaviour. Therapies to help addicts conquer their dependence include vaccines and related methods, which use antibodies to bind cocaine and stop it reaching its target in the brain. Other drugs can block cocaine cravings.
Nicotine comes from the leaves of the tobacco
plant and was first cultivated and used by Native Americans 8000 years
ago. Early European settlers in the Americas cultivated it as a cash
crop for export, and smoking became popular back home in Europe during
the 1600s. These days, an estimated 46 million Americans smoke 420 billion cigarettes per year. Smoking was thought to have few ill effects until researchers noticed that lung cancer prevalence rose enormously, along with the popularity of cigarette smoking in the twentieth century.
Today the 40-plus known carcinogenic chemicals in tobacco smoke are linked to cancers
including those of the stomach, lung, pancreas, cervix and kidney.
Research has also shown that nicotine or other tobacco chemicals can increase the speed of growth of tumours, cause cot death in the children of smokers, kill brain cells and lead to heart disease, strokes, emphysema and even mental illness.
Passive smoking is also widely thought to be dangerous activity and has been linked to an increase in cancers, heart disease and stroke, as well as lower than average IQ levels in children. Some people may be genetically-prone to nicotine addiction, and teenagers are more likely to become addicted than adults. Scientists are developing a controversial vaccine which could be used to protect young people against cigarette addiction.
Caffeine is found in around 60 known plant species, is a key ingredient of coffee, tea and chocolate,
and is the world's most popular stimulant. Tea has been popular in
China for at least 3000 years, but possibly for much longer. Caffeine
is used by billions of people to boost alertness.
The
drug increases blood pressure and stimulates the heart lungs and other
organs. There have been few verifiable links between caffeine and serious health problems, though research has shown it can increase sensitivity to pain, cause panic attacksplay havoc with sleep cycles.
Some role in heart disease and cancer has been suggested, but not
proven. Research has hinted that caffeine perhaps offers some unusual
benefits by protecting against diabetes and radiation poisoning. Critics argue that addictive caffeine - supposedly a flavouring - is used by soft drink manufacturers to keep punters coming back for more.
source NewScientist
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