Alcohol and the Liver – Revision

The Liver

The liver is situated above the pancreas, stomach and duodenum, and has the gallbladder near to its central area. The liver is made up of lobules, with hexagonal cells called hepatocytes. These hepatic lobules are supplied with oxygenated blood from the heart through the hepatic artery. Deoxygenated blood goes back to the heart through the hepatic portal vein.

Instead of capillaries, the liver’s circulation relies on the sinusoids or blood channels, which have kupffer cells inside. The kupffer cells eliminate worn out red blood cells and other unwanted debris. The liver has bile channels called canaliculi, which meet to form a common hepatic duct that supplies bile to the gallbladder. The alkaline bile is stored there until chyme (broken up food) enters the duodenum, and then it is used to emulsify the fats and neutralise the acid.

The liver is basically a chemical processing plant…

The liver stores glycogen which can later be turned into glucose through the uptake of insulin. It does this to maintain blood glucose levels. The liver also makes glucose from fructose, galactose and amino acids. It also stores iron and copper, and vitamins A, B12, D, E and K. The liver converts the vitamin D into its active form, so it can assist calcium in being absorbed into the body.

In a high protein diet, the liver will break down the protein into carbohydrates and amino acids. Amino acids are DEAMINATED, or broken down, by the liver. 8 amino acids are acquired through a balanced diet, and the liver makes 12 more using the 8 that are available. Through this process of TRANSAMINATION – the manufacture of amino acids – 20 amino acids are accessed. As the amino acids are deaminated by the liver, nitrogenous waste is made, via ammonia, urea and urine. Ammonia is toxic, and so is changed into urea (less toxic), and then changed into urine and eliminated.

The liver also makes four proteins that circulate in the blood: globulin and albumen are plasma proteins, while prothrombin and fibrinogen are clotting proteins. The clotting factor of a person’s blood is measured using the INR (international Number Ratio).

The liver also makes cholesterol, including HDLs and LDLs. High density lipoproteins contain more protein than fat, and are good cholesterol. Low density lipoproteins contain more fat than protein, and are bad cholesterol.

The liver metabolises, or breaks down, all prescription and recreational drugs, including alcohol. It also changes the bilirubin so it can be excreted in the bile. Bilirubin is the broken down product of the haemoglobin from red blood cells.

Liver Disease

When the liver is damaged, bilirubin will accrue in the body, and the person will develop jaundice, appearing yellow in their skin and the whites of their eyes. The person’s faeces will be pale and clay-like.

The blood will no longer clot easily, and there may be problems with excessive bleeding and bruising. The liver will swell up and cause the abdomen to be bloated. The person will lose weight, and experience nausea, vomiting and tiredness.

Blood tests can reliably diagnose problems with the liver, as enzymes will be raised if liver cells are damaged. ALP, ALT and AST will all be elevated, as will Gamma GT. The latter is more specific to alcohol liver disease, while the others may be more specific to liver diseases, such as Hepatitis A, B and C, and cancer.

The Short Term Effects of Alcohol

Alcohol is a diuretic and can cause dehydration. Alcohol produces a false feeling of bodily warmth and may lead to hypothermia. Alcohol is also a depressant and will exacerbate any underlying anxiety and depression, thus reducing the efficacy of anti-depressant drugs. Unfortunately when depressed, many individuals use alcohol as a negative coping strategy. Alcohol increases the release of dopamine, and triggers the reward areas of the brain, thus making us feel happy and relaxed. This feeling does not last however, and if drinking continues, areas of the brain will be physically depressed, including judgement and reasoning, visual and spatial awareness, the management of emotions and memory impairment. Rash impulsive decisions may be made as a result, and some people may become verbally or physically aggressive, thus getting into trouble, such as fights.

Females may become sexually disinhibited, as their testosterone levels go up, and may thus place themselves in danger. Males, in contrast, tend to lose sexual drive through the reduction of testosterone, and can experience problems with erectile dysfunction.

The brain’s cerebellum will be affected and the person’s balance and gait will become unsteady. The body’s reflex reaction times will significantly slow, and so falling over and sustaining an injury becomes more of a risk.

Driving a car is definitely to be avoided, although many people over-estimate their abilities when under the influence of alcohol. The reality of course, is that their reaction times behind the wheel will be much slower, and so last minute braking is virtually impossible. Speeds and distances will be extremely hard to judge. It is always best to avoid drinking altogether when planning to drive, as just one unit of alcohol takes approximately one hour to be metabolised by the body.

When drinking lots of alcohol, many people experience an increase in their appetite and often will order late-night takeaways. People drinking at home may be more tempted to cook something independently, and there have been many instances in which individuals have set their homes on fire, through oil in chip pans catching fire, because they had gone to sleep.

Exceeding sensible alcohol limits can be a high risk behaviour. It is best to avoid alcoholic binges, and to drink responsibly and safely, perhaps enjoying alcohol with a meal. Drinking alcohol with food reduces its absorption, as well as being pleasant and adding a sense of occasion.

 

Alcoholic Drinks: Friend or Foe?

The drinking of alcohol is often viewed as a normal social activity and part of everyday life. Many adults will relax and unwind with a glass or two of their favourite alcoholic beverage, either after work in the evenings, or on the weekends. It is often viewed as a small personal reward for working hard, and a pleasant way to achieve a feeling of relaxation. As along as sensible levels of consumption are observed and respected, drinking alcohol is perfectly acceptable and enjoyable.

Daily guideline amounts, as recommended by the National Health Service, are 3-4 units per day for a man and 2-3 units per day for a woman. To illustrate what this might represent, one unit is equal to: half a pint of regular beer, lager or cider; one small glass (125ml) of wine; or 1 single measure (25ml) of spirits. It must be noted however, that stronger beers and wines are going to be worth additional units; for example, a 440ml can of super strength lager is equivalent to four units, which is the maximum level for a male. To consume a bottle of wine, depending on the strength, you are looking at about 9 units.

In comparison to Public Houses, alcohol is relatively cheap to buy at the supermarket or local off-licences, and so many people now choose to drink at home instead. The generosity of drink measures, however, can easily be over-estimated at home. Domestic glassware measures may not be obvious and easy to monitor, and there is also a tendency to be a little more lavish when you know that the alcohol represents good value for money. The resulting outcome is that many people will unwittingly exceed their daily guideline units, or may even go further, and finish the bottle or the last can, just because it is not really worth leaving.

According to the Department of Health (2007), 24% of people in the UK are drinking heavily, either through regular drinking or binge drinking. As these people are not addicted to alcohol, they will probably not be concerned about their drinking levels, when actually they probably should be. Their short term risks may include loss of consciousness, accidents or injuries, or alcohol poisoning (potentially fatal); while their long term risks may include cancers, heart disease, liver disease or brain damage, such as memory loss or dementia.

Heavy drinkers may also start to put on weight, as alcohol is very calorific. They may also start to age prematurely, as alcohol is not good for the skin, as it dehydrates the body; and alcohol will affect the quality of a person’s sleep, with them often missing out on the deep REM stages of the sleep cycle. Coupled with a smoking habit, which is often a common accompaniment to a heavy drinking habit, the effects upon health and personal appearance are going to be even worse.  

Alcohol is a depressant, and so heavy alcohol consumption is often linked to poor mental health. A depressed person who drinks will initially feel elated, but afterwards they will feel more depressed than before. To feel better again, they are likely to reach for another drink, and so the vicious cycle will negatively repeat itself. If a person is suffering with depression, it really is advisable to avoid alcoholic drinks altogether, as they are not going to aid with recovery.

It is worth knowing that one unit of alcohol will take roughly one hour to be metabolised by the body, and so after a heavy night’s drinking, many people will still be over the drink-drive limit in the morning. Driving when over the limit may cost you your licence and your job. In extreme circumstances, it may even cost your life or someone else’s.

This all seems really negative, but this is precisely why daily guideline unit recommendations were initially formulated. To enjoy alcohol safely, take note of the guideline amounts, the size of drinks and their alcohol content. It is always best to eat when drinking, or at least to eat prior to drinking. It is sensible practice to alternate alcoholic drinks with water or a soft drink, as this helps to prevent dehydration and to limit consumption.

For further information, some good sites are:

Drink Aware, the Facts

http://www.drinkaware.co.uk

NHS Choices, Drinking and Alcohol

http://www.nhs.uk/Livewell/alcohol/Pages/Alcoholhome.aspx