Alcohol is unhealthy because it does damage to our bodies.

The argument

Long term alcohol use has been shown to cause damage to the liver, brain, and heart, and cause cancer. The argument's structure is cumulative: rather than resting on a single serious harm, it traces a separate mechanism through each of several organ systems, so the case does not depend on any one of them being decisive on its own. The cardiovascular route comes first. Alcohol can narrow the blood vessels and weaken the heart, leading to high blood pressure and increased risk for stroke or other heart issues, which is a weakened pump working through narrower channels. The neurological route is direct rather than mediated: drinking can damage nerve cells and brain tissue, leading to problems with cognition and memory, so the harm shows up as a loss of function rather than only as a finding on a scan. The liver's involvement follows from the job it is given. The liver is responsible for breaking down the toxins contained in alcohol, and can be damaged in this process, which means the organ is harmed precisely by doing what the body requires of it, and the more there is to process, the greater the exposure. This can lead to liver problems such as hepatitis (inflammation of the liver) and cirrhosis (liver scarring), which can lead to serious health issues and death. Cancer is attributed to two distinct pathways. Alcohol can damage cells, which increases the chance of DNA mutations (and therefore cancer) during reparation, since a cell rebuilding itself is a cell that may rebuild itself wrongly. It can also be converted to acetaldehyde while the body processes it, which is a chemical shown to cause cancer. Alcohol has been shown to increase the chance of liver, colon, mouth, and breast cancer. The acute risk completes the picture: consumption of too much alcohol all at once, known as an alcohol overdose, can lead to brain damage and death.

Premises

Counter-arguments

-Alcohol only causes health damage when consumed in excess.

Rejecting the premises

[Rejecting P1] The premise describes long-term use without specifying a quantity, so it establishes that heavy or sustained drinking damages the cardiovascular system rather than that drinking as such does; the strength of the case turns on dose, which the premise leaves out. [Rejecting P2] Hepatitis and cirrhosis are outcomes associated with prolonged heavy drinking rather than with any consumption, so citing them supports a conclusion about a pattern of drinking rather than about the drink. [Rejecting P3] Raising the risk of a disease is not the same as causing it, and no magnitudes are given — without them a reader cannot tell whether the increase holds at every level of consumption or only at high ones.