The following statements are taken from the article at http://www.bbc.co.uk/news/health-15114325
Why alcohol has this negative effect on all elements of our health could be down to acetaldehyde - the product alcohol is broken down into in the body.
Acetaldehyde is toxic and has been shown to damage DNA.
Alcohol is a well-established cancer causing agent, he says.
"We need to be very careful when suggesting there is a 'safe' level of drinking for the population. Rather, we need to explain that there are risks associated with alcohol consumption, and that the less you drink the lower your risk is of developing health problems.
Dr Sheron agrees: "There is no such thing as a safe level, but the government has got to draw a line somewhere. It's a balance.
Also, this URL discusses recent research results showing that heavy drinking actually rewires the brain: