What is methanol? How does it get into drinks and cause harm?

Two Australian teenagers seriously ill in hospital in Thailand after suspected methanol poisoning while traveling in Laos.

According to reports, the couple is, among others, several foreigners become ill after unknowingly consuming alcoholic beverages containing methanol in a Southeast Asian country.

So what is methanol and how does it cause disease?

Methanol versus ethanol

Methanol Is alcohollike a friend ethanol we consume in alcoholic beverages.

Like ethanol, methanol is a colorless, flammable liquid. It also has an ethanol-like odor.

But both have different chemical structure. Methanol consists of only one carbon atom, while ethanol has two.

That one carbon atom makes a difference. This means that methanol is processed differently in our bodies and is much more toxic than ethanol.

Methanol is used in: various industrial and household productssuch as window cleaners, antifreeze and fuel. Not secure for human consumption.

What makes methanol toxic?

The difference lies in the way our bodies metabolize or break down methanol.

Ethanol is metabolized into a chemical called acetaldehyde. Acetaldehyde is toxic, but quickly converts to acetate (also known as acetic acid, found in vinegar). Producing acid may seem bad, but it is actually acetate it produces energy and produces important molecules in the body.

However, methanol is metabolized to formaldehyde (a chemical used in industrial adhesives and, for example, for embalming corpses), and then to formic acid (the chemical found in some ant bites that makes them hurt so much).

Unlike acetate, which the body uses, formic acid poisons mitochondriacell power plants.

As a result, a person exposed to methanol may suffer stern injuries metabolic acidosisthat is, when too much acid accumulates in the body.

Methanol poisoning can cause nausea, vomiting and abdominal pain. Acidosis then causes depression of the central nervous system, which may cause loss of consciousness and coma in people poisoned with methanol, as well as damage to the retina leading to loss of vision. This is because the retinas are full of dynamic mitochondria and are sensitive to their damage.

Death is not inevitable if only a diminutive amount of methanol is ingested, and prompt treatment will greatly reduce the damage.

However, enduring vision damage can occur even with non-lethal doses if treatment is not given promptly.

What is the treatment?

Treatment it mainly involves supportive care such as intubation and mechanical ventilation to lend a hand the patient breathe.

But it can also apply to drugs such as fomepizole (inhibiting the production of toxic formic acid) and dialysis to remove methanol and its metabolites from the body.

How does methanol get into alcoholic beverages?

Methanol can appear in any alcoholic drink, but is most likely to appear in drinks with higher alcohol content, such as spirits, and traditionally brewed drinks, such as fruit wines.

Methanol can enter alcoholic beverages in many ways. Sometimes it is added intentionally and illegally during or after production as a cheaper way to boost the alcohol content of a drink.

Traditional brewing methods it can also unintentionally produce methanol, as well as ethanol and produce toxic levels of methanol depending on the microorganisms and type of plant materials used in the fermentation process.

We don’t yet know how Australian teenagers were poisoned in this tragedy. However, when traveling (especially to areas where fermented beverages are traditionally found, such as Southeast Asia, the Indian subcontinent and parts of Africa), it is always worth exercising caution.

Australian Government Smartraveller website advises that to avoid methanol poisoning, be careful when drinking cocktails and spirits, drink only in reputable, licensed establishments and avoid home-made alcoholic beverages.

Drinking only mass-produced commercial brews may be safer, although understandably people often want to try local brews as part of their adventure.