What is alcohol?

Alcohol is created when grains, fruits, or vegetables are fermented. Fermentation is a process that uses yeast or bacteria to change the sugars in the food into alcohol. Fermentation is used to produce many necessary items, everything from cheese to medications. Alcohol has different forms and can be used as a cleaner, an antiseptic, or a sedative, in addition to many types of drinks. Illness from alcohol or related to alcohol costs the NHS 47 billion pounds a year.


What happens when we drink alcohol?

When we drink alcohol, it's absorbed into our bloodstream. From there, it affects the central nervous system (the brain and spinal cord), which controls virtually all body functions. Fifty percent of the alcohol you drink only takes ten minutes to reach the blood stream. After an hour all the alcohol will have been absorbed. On a typical night out you may easily have 200mg/100ml of alcohol in the blood by midnight, which will not be fully flushed out until the following afternoon.

Alcohol is a depressant due to the increased use of the neurotransmitter GABA (Gamma-Amino Butric acid), which means it slows the function of the central nervous system. Alcohol blocks some of the messages trying to get to the brain. This alters a person's perceptions, emotions, movement, vision, and hearing.

In very small amounts, alcohol can help a person feel more relaxed or less anxious. More alcohol causes greater changes in the brain, resulting in intoxication. People who have overused alcohol may stagger, lose their coordination, and slur their speech.

Continuing to drink heavily into adulthood can increase the risk of damage to organs, such as the liver, heart, and brain.

In the liver, alcohol converts to an even more toxic substance, which can cause substantial damage. Not eating when drinking and consuming a variety of different alcoholic beverages are also factors that increase the risk for liver damage.

Alcohol affects your sleep. When we consume alcohol our blood sugar spikes due to the quick absorption of sugar. This excess of sugar sends the body into panic mode, releasing lots of insulin to remove the damaging sugar from the blood. During the night consequently after we have removed the sugar we move into a low blood sugar state. When we have low blood sugar we release adrenalin to stimulate glycogen breakdown.

Heat and cold travel along the same nerve receptors as pain signals, although heat and cold travel faster than pain. If you have an injury it’s sometimes recommended to apply a hot or cold compress as the effects of the heat or cold travel faster through the nerve supplies and can help to reduce the feeling of pain. Alcohol increases blood flow to the extremities and also increases your body temperature, which can subsequently help to numb feelings of pain. We often hear that people drink alcohol to help ‘numb the pain’. Similarly, if you hurt yourself when you’re drunk, it’s never as painful as when you wake up sober the next morning as your body temperature has returned to normal and you therefore feel the pain more.

When to avoid alcohol completely


In certain situations it is advisable to avoid alcohol completely. For example when pregnant or trying to get pregnant. It has been shown that a pregnant woman who consumes more than just one unit of alcohol increases the risk of developing foetal abnormalities. Due to its hormone disrupting effects alcohol should also be avoided if someone is trying to get pregnant.

It is also best to avoid alcohol if you are taking any medications that interact with alcohol, if you suffer from any liver, pancreas or heart conditions or if you have had a haemorrhagic stroke.

Alcohol puts a massive burden on the liver, reducing its ability to detoxify and clean the body of excess hormones, chemicals, medication and toxins. The build-up of these can cause a multitude of health problems.

Guidelines on alcohol units

Official advice on weekly alcohol consumption recommends a maximum of 14 units for both men and women. Prior to 2106 (the last time the guidelines were updated) men had a higher weekly limit of 21 units. The change was due to the carcinogenic properties of alcohol and the associated broad range of different cancers that are attributed to over consumption. The metabolites created in the breakdown of alcohol cause damage to cells. Alcohol increases the hormone oestrogen, which is linked to an increased risk of breast cancer and weight gain, and also decreases the hormone testosterone.

The 14 units per week for both men and women are equivalent to 6 (175ml) glasses of wine at 13% alcohol, 6 pints (568ml) of beer at 4% alcohol, 5 pints (568ml) of cider at 4.5% or 14 (25ml) spirits at 10% alcohol.

One alcohol unit is measured as 10ml or 8g of pure alcohol. This equals one 25ml single measure of whisky, or a third of a pint of beer or half a standard (175ml) glass of red wine.

New studies are now suggesting there is no safe limit to alcohol consumption and it should be avoided completed.

What happens to the alcohol?

The body wants to remove alcohol as quickly as possible. It does this using the enzyme alcohol dehydrogenase (ADH), which is mainly found in the liver, but also in the stomach lining. This enzyme breaks alcohol down to acetaldehyde, which then gets converted to acetate. These alcohol by-products are highly reactive compounds that can cause huge damage to the body, especially the liver. The extra activity required by the liver uses up important nutrients such as B1, B3, B6, Folate, C, A, E and K1. These are all important nutrients needed for energy and the immune system. The liver can only breakdown 1 unit of alcohol per hour regardless of how much you drink.

Alcohol is absorbed into the bloodstream through the stomach and small intestines. Having food in the stomach helps to slow this process. When there is food in the stomach alcohol is held there for longer allowing it to be acted upon by enzymes and broken down. Men naturally tend to have more of the enzyme alcohol dehydrogenase than women in the stomach lining.

The kidneys are also put under extra pressure when you drink alcohol due to the release of the anti-diuretic hormone, increasing urination and subsequently the loss of important minerals and electrolytes, especially selenium, calcium, magnesium, copper and manganese.

It seems that alcohol detoxifies best between 1 and 3am in the morning, however it does this best when you have stopped drinking and are lying down!

Alcohol is a diuretic that causes the body to excrete important vitamins and minerals, including a lot of the B vitamins, which are essential for the nervous system, hormone production and nail and hair repair

The more water you have in your body the more you can dilute the alcohol. Muscle contains water, fat contains less, so the more muscle mass a person has the more they can tolerate alcohol.

We often hear that alcohol contains polyphenols and antioxidants (resveratrol in this case). Polyphenols are chemicals that display protective qualities and anti-aging properties like antioxidants, which protect cells from free radical damage. However, alcohol is very low in nutrients and resveratrol is actually found in grapes, not alcohol. The same protective polyphenols are found in hazelnuts, blueberries, apples and almonds to name a few, so it’s not really a great argument for alcohol consumption!

Alcohol and fat loss

Alcohol has a massive affect on the body and can be the difference between getting results with your training and not.

Firstly alcohol is full of empty calories, and not really any useful nutrients. Some might argue the antioxidant resveratrol in red wine is useful but it can be found in grape juice. Six 175ml glasses of wine per week (which is the recommended upper limit) at 160 calories per glass, equates to over 3,800 calories per month, from alcohol alone. When we know that 3,500 calories equals 1 pound of fat, avoiding alcohol could be the equivalent to loosing 12 pounds, nearly a stone of fat in a year without any other changes. And this is only 14 units a week remember, most people drink much more than this. It is worth noting that every gram of alcohol is about 7 calories.

Secondly alcohol spikes blood sugar, and like any high glycemic carbohydrate (sugar) it causes a blood sugar drop. A blood sugar drop will subsequently cause food cravings, normally from high fat, sugary sources.

Thirdly the body treats alcohol as a poison, while it is in your system more energy is directed to liver function and fat storage is increased. It is also thought that you burn 75% less fat while alcohol is in your system, as your body chooses to use the highly reactive breakdown products (acetaldehyde, and acetate) as fuel. Very little of the alcohol that you consume will be stored as fat, but because the body will be using the by-products as fuel a majority of the food you eat over the 24 hours after drinking alcohol will be stored as fat.

Lastly alcohol increases the hormone cortisol, which not only has the affect of slowing down your metabolism but also decreasing the important fat burning hormone testosterone (which is important for women as well as men). There is also an increase in the enzyme aromatase, which converts testosterone to the fat storage hormone oestrogen. It is easy to see that while on any fat loss plan it would be prudent to avoid alcohol.

A few things to avoid when drinking alcohol

  • Grapefruit juice – this will increase the toxicity of the alcohol.

  • Fatty foods – these put extra strain on the liver slowing its function, creating a build-up of toxic alcohol and further increasing liver damage.

  • Coffee - when you have been drinking avoid coffee. It is not only a diuretic (depleting body fluid) that will subsequently increase the alcohol concentration, it also speeds up phase one liver function detoxification which causes a build-up of the more toxic alcohol metabolites as phase 2 detox can’t keep up.

A few things that may help following alcohol consumption

  • Fruits & vegetables – it’s a good idea to eat lots of colorful fruits and vegetables as they are full of antioxidants, minerals and vitamins that are needed for proper liver function. See our liver article for more detailed information on this.

  • Soluble fibre – consuming soluble fibre from foods such as flax seeds, oat bran and porridge helps to aid toxin removal.

  • Water – it’s important to drink plenty of water to counter the effects of alcohol. See our hydration guide for more information.

  • Milk thistle – this is a great herb to aid liver function. If you are taking any prescribed medications you should speak to your doctor before taking any herbs or supplements to check for contraindications.

  • Multivitamins - a good quality multivitamin is always a good idea if you feel you are not getting sufficient nutrients in your diet, although real food is always the best option if possible.

According to the Office of National Statistics more people in the UK are turning away from alcohol. We have certainly seen an increase in national campaigns such as ‘dry January’ and ‘Stobtober’ that encourage us to take an extended break from alcohol. As outlined earlier in this piece, for some people alcohol really should be avoided altogether, but for others there may be minimal harm in enjoying a few drinks providing that you are aware of the impact and risks.

This article has
been written by
Terry Fairclough