A Myth - alcohol kills brain cells - Article in The Conversation

Do you ever wake up with a raging hangover and picture the row of brain cells that you suspect have have started to decay? Or wonder whether that final glass of wine was too much for those tiny cells, and pushed you over the line?

Well, it’s true that alcohol can indeed harm the brain in many ways. But directly killing off brain cells isn’t one of them.

The brain is made up of nerve cells (neurons) and glial cells. These cells communicate with each other, sending signals from one part of the brain to the other, telling your body what to do. Brain cells enable us to learn, imagine, experience sensation, feel emotion and control our body’s movement.

Alcohol’s effects can be seen on our brain even after a few drinks, causing us to feel tipsy. But these symptoms are temporary and reversible. The available evidence suggests alcohol doesn’t kill brain cells directly.

There is some evidence that moderate drinking is linked to improved mental function. A 2005 Australian study of 7,500 people in three age cohorts (early 20s, early 40s and early 60s) found moderate drinkers (up to 14 drinks for men and seven drinks for women per week) had better cognitive functioning than non-drinkers, occasional drinkers and heavy drinkers.

But there is also evidence that even moderate drinking may impair brain plasticity and cell production. Researchers in the United States gave rats alcohol over a two-week period, to raise their alcohol blood concentration to about 0.08. While this level did not impair the rats’ motor skills or short-term learning, it impacted the brain’s ability to produce and retain new cells, reducing new brain cell production by almost 40%. Therefore, we need to protect our brains as best we can.


Even moderate drinking may impair brain plasticity. Image from shutterstock.com
Excessive alcohol undoubtedly damages brain cells and brain function. Heavy consumption over long periods can damage the connections between brain cells, even if the cells are not killed. It can also affect the way your body functions. Long-term drinking can cause brain atrophy or shrinkage, as seen in brain diseases such as stroke and Alzheimer’s disease.

There is debate about whether permanent brain damage is caused directly or indirectly.

We know, for example, that severe alcoholic liver disease has an indirect effect on the brain. When the liver is damaged, it’s no longer effective at processing toxins to make them harmless. As a result, poisonous toxins reach the brain, and may cause hepatic encephalopathy (decline in brain function). This can result in changes to cognition and personality, sleep disruption and even coma and death.

Alcoholism is also associated with nutritional and absorptive deficiencies. A lack of Vitamin B1 (thiamine) causes brain disorders called Wernicke’s ncephalopathy (which manifests in confusion, unsteadiness, paralysis of eye movements) and Korsakoff’s syndrome (where patients lose their short-term memory and coordination).

So, how much alcohol is okay?

To reduce the lifetime risk of harm from alcohol-related disease or injury, the National Health and Medical Research Council recommends healthy adults drink no more than two standard drinks on any day. Drinking less frequently (such as weekly rather than daily) and drinking less on each occasion will reduce your lifetime risk.


Health guidelines suggest men and women drink no more than two standard drinks a day.
To avoid alcohol-related injuries, adults shouldn’t drink more than four standard drinks on a single occasion. This applies to both sexes because while women become intoxicated with less alcohol, men tend to take more risks and experience more harmful effects.

For pregnant women and young people under the age of 18, the guidelines say not drinking is the safest option.

So while alcohol may not kill brain cells, if this myth encourages us to rethink that third beer or glass of wine, I won’t mind if it hangs around.


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Source: The Conversation
http://theconversation.edu.au/mondays-medical-myth-alcohol-kills-brain-cells-12666

Global poverty is shrinking: study - Article in Conversation

Global poverty is declining and may be eradicated altogether in some countries in the next 20 years, a new study by the University of Oxford has found.

The Oxford Poverty and Human Development Initiative analysed 22 countries using a Multidimensional Poverty Index, a collection of factors such as number of years of schooling, child mortality, nutrition, electricity and drinking water access, living standards, housing and asset ownership.

The findings showed poverty levels had significantly dropped in 18 out of 22 countries.

Bangaldesh, Rwanda and Nepal were the top performing countries, with the largest reductions in absolute poverty.

“If the current pace of poverty reduction continues to the end, then half of the countries would eradicate [multidimensional] poverty within 20 years, 18 of the 22 within 41 years and the remaining four countries within 95 years,” according to the report.

The study showed that a total of 1.6 billion people are living in multidimensional poverty – which looks at a range of factors driving poverty, rather than just income – and that 51% of the world’s poorest live in South Asia.

Dr Paul Burke, an economic and development expert from the Arndt-Corden Department of Economics at Australian National University, said the study will “help us better understand the global poverty picture – where poverty is located, and in what form impoverishment takes.”

“While income-based measures pick up a lot of what we need to know, when it comes to something as serious as poverty, more data is normally better,” he said.

“The data allow countries and regions within countries to be benchmarked against one another over a number of criteria. If a country is struggling in one particular dimension of poverty, the country’s government and international donors might be able to better target this area,” said Dr Burke, who noted that the data released did not include countries from the Australia Pacific region.

“The data complement what’s available from the World Bank, United Nations, and other sources. The provision of sub-national data is particularly useful, as differences within countries can be just as large as differences between countries.”

But some experts have expressed concerns with the use of an aggregated multidimensional index to compare levels of poverty and development.

“I am quite against the idea of constructing a single MPI index that collapses all dimensions of human development with equal weight or some arbitrary weighting schemes,” said Dr Sommarat Chantarat, from the Crawford School of Public Policy at the Australian National University.

“As a development economist, we all realise that poverty is multifaceted, but it is unclear what we could learn and what policy implications might be from looking (and comparing) an aggregated MPI index.”

Dr Chantarat said studies that compare MPIs across countries and regions could fail to indicate “the varying impacts of growth on households' productive investment and the varying impacts of looming stochastic shocks (economics, climate, manmade and natural disasters) that could prevent some subpopulation from gaining from growth.”

Dr Daniel Suryadarma, a development economics expert from the Arndt-Corden Department of Economics at the Australian National University’s Crawford School of Public Policy, also expressed concerns with the methodology of the study.

“First, the number of dimensions included and the weight assigned to each dimension depend on the judgement of the researcher,” he said.

“So, while they usually claim that their measure is more comprehensive than studies using a single measure of poverty – for example consumption poverty – the potential for researcher subjectivity to "pollute” the results is actually higher."

“Second, the factor analysis basically produces a single measure of poverty and, from experience, I understand that the resulting measure is usually very highly correlated with consumption. Therefore, the advantage of calculating multidimensional poverty over consumption poverty is negligible.”

Dr Suryadarma said while he had concerns for the study’s methodology, economic development may have reduced poverty in many areas.

“I believe the results that poverty – however measured – has generally fallen in most countries,” he said. “The explanation is simple: economic growth, which is the most powerful poverty reduction tool.”

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http://theconversation.edu.au/global-poverty-is-shrinking-study-12877