wine and grapes

1) Alcohol Impacts on Our Nutrient Absorption

Drinking alcohol reduces our digestive enzymes, without which we cannot properly digest our food and absorb nutrients.  It may increase this problem by damaging cells in our gut too.  However, the problem isn’t just a direct effect – nutrients work together to keep us healthy so having low levels of one may reduce our ability to absorb another, or reduce the ability of others to work properly:

  • Calcium may be depleted due to problems absorbing fat.
  • Magnesium is most likely depleted due to a reduced intake when an individual is a heavy drinker (alcohol may replace nourishing foods), or increased excretion.
  • It is thought that alcohol may interfere with zinc transportation within the body, which may also contribute to increased gut permeability.  This increases our risk of chronic inflammation and associated health conditions.
  • Vitamins A, D, E and K are fat-soluble vitamins therefore, alcohol’s effect on fat absorption can increase the risk of depletion of these nutrients. It is possible that depletion of vitamins A and E may contribute to liver damage in heavy drinkers.
  • Vitamin B9 (folate). Alcohol disrupts the mechanisms that enable us to absorb folic acid and can increase the amount removed by the kidneys.
  • Vitamin B1 (thiamine) is important for brain function but is often found to be deficient in individuals with alcohol abuse problems. This may lead to impaired movement and memory.
  • Vitamin C absorption can be reduced by the effect of chronic drinking on the pancreas, where the nutrient is usually absorbed. Research has found that both heavy and moderate drinkers excrete an increased level of vitamin C in their urine.  Furthermore, alcohol may also reduce the ability of the liver to utilise the nutrient.

Mild and moderate drinking has been found to increase the amount of iron our bodies store, but it is most notable in individuals with alcoholic liver disease.  Despite its importance to our health, excessive iron levels can be toxic and may contribute to liver damage.  Therefore individuals with genetic haemochromatosis may need to be particularly careful with alcohol.  The increase in iron levels may be due to changes in intestinal permeability meaning that more iron is absorbed.  However, there is also a theory that alcohol reduces our synthesis of hepcidin which helps regulate iron levels.  Hepcidin is a protein made in the liver and when levels our low, we are at an increased risk of iron overload.

Chronic, heavy drinking is particularly problematic for our nutrient absorption.

2) Disruption to Protein Metabolism

Muscle protein is not only used to create the muscle and make it functional, it is a store for the amino acids (protein building blocks) that support energy in the cells of other tissues.  Studies suggest that alcohol interferes with our ability to make this protein and the functioning of existing protein molecules.  Part of the problem is that alcohol interferes with the release of hormones that send the messages for protein to be made (testosterone and human growth hormone).  In terms of digestion, alcohol is thought to reduce our ability to process amino acids in the liver and small intestine, and the liver’s ability to release amino acids (important for us to make the proteins we need – the protein we eat is broken down and then rebuilt according to our needs).  It is possible that a low protein diet and poor protein digestion, may contribute to the problem of pancreatitis in heavy drinkers.

In fact, alcohol may also cause our muscle protein to breakdown.  Double-whammy!

It is possible that this does not just occur with chronic alcohol use, but also binge drinking and may continue after alcohol has been cleared from our circulation.  This damage can occur independently of other possible alcohol-related health issues.

3) Poor Quality Diet Choices

For anyone who has seen (or joined) the queues outside kebab shops when the pubs close will not be surprised by this!  When we have been drinking we typically make less healthful food choices, which will not help our weight management or nutrient intake.  One study found that drinking wine with lunch resulted in an intake of an additional 200 calories per day, and this wasn’t just from the wine!

Not only can alcohol trigger hunger by interfering with our insulin, it can also reduce the effects of leptin (a hormone that suppresses our appetite when we have eaten), and the hormone that inhibits our food intake (GLP-1).  It is possible that alcohol also stimulates nerves in the brain that increase appetite.  No wonder we start to feel hungry!  Unfortunately when we are under the influence of alcohol we are less likely to think about our choices and simply grab whatever is near and easy – crisps, biscuits, or takeaway (these are the typically the types of shops that are open, not the greengrocer’s!).  Admittedly, these foods are probably safer than trying to cook for ourselves in a drunken state.  However, these foods tend to be low in beneficial nutrients compounding the problems that alcohol can cause to our nutrient absorption.  Poor dietary choices also affect our energy intake (which can contribute to weight gain), and typically contain high levels of unhealthy fats and sugar.

4) Blood Sugar Management

We do not appear to metabolise the sugar from alcohol in the same way as sugar (carbohydrate) from food.  And the energy from alcohol may have less impact on our body weight than the energy we obtain from food.  The mechanism is not fully understood.  However, it is known that alcohol can disrupt our ability to control the level of sugar in our blood.  Overtime, alcohol may result in a reduced insulin secretion which contributes to high levels of blood sugar.  Yet, in the short term drinking alcohol may increase our insulin secretion and if there is insufficient food to digest we may deplete our blood sugars and end up with them being too low.  Furthermore, the products we produce while processing alcohol may prevent us using other nutrients, such as proteins, for energy.  This combination may contribute to the feelings of hunger people often get when, or after, drinking alcohol.

Individuals with diabetes or taking medication that affects blood sugar balance, should take extra care when consuming alcohol or abstain completely.  If you are concerned or require further advice, contact your medical team.

5) Lower Metabolic Rate Affects Our Ability to Reduce Body Fat

For those of us who have concerns about body fat, a lower metabolic rate makes it harder for us to reduce body fat.  This is because instead of burning calories, our bodies focus on removing the alcohol, which it considers to be a toxin.  We therefore don’t burn stored energy (body fat), particularly that around our waists which is most associated with health risks.

Interestingly, one study found that older women who drank moderately gained less weight than the women who abstained from alcohol.  However, these women may have adjusted their energy intake and exercise levels to off-set the alcohol on the days they drank.

References/Further Reading