What does alcohol do to your immune system?
Chronic excessive alcohol use weakens your immune system on multiple fronts simultaneously and increases the risk of serious infections. Light to moderate drinking appears less harmful, but offers no demonstrable benefit for your immune system.
Chronic excessive alcohol use impairs multiple layers of your immune defences at the same time. Cells that clear pathogens, such as neutrophils and macrophages, function noticeably less well. At the same time, your T cells and B cells are also affected: the cells responsible for targeted and long-lasting protection. As a result, infections are not only contracted more easily, but also fought off less effectively, and vaccines may have a reduced response.
On top of that, alcohol disrupts the balance of signalling molecules in the body. Pro-inflammatory substances, such as TNF-alpha (involved in liver inflammation), rise. Protective, anti-inflammatory signalling molecules decrease instead. The result is an unfavourable combination: too much inflammation in some places, too little immune defence in others.
The consequences are concretely measurable in disease risk. People who drink chronically and excessively have a demonstrably higher risk of serious bacterial infections such as pneumonia and tuberculosis, and also recover from them less well. An increased risk has also been described for viral infections, including hepatitis and HIV, although the precise causal mechanism has not yet been fully clarified. The lungs are particularly vulnerable: the mucous membranes and local immune defences function less well, making it easier for harmful bacteria to gain a foothold.
Animal research shows that alcohol consumed before a serious trauma makes the inflammatory response more dangerous than trauma or alcohol alone: mortality following infection rose sharply. Whether this works in exactly the same way in humans has not yet been fully investigated, but it is a relevant safety consideration in emergency situations.
A more nuanced picture exists regarding light to moderate drinking. Some studies suggest that moderate consumption, particularly of drinks with a high polyphenol content such as wine, may be less harmful to the immune system than heavy drinking, and may even be associated with somewhat less inflammation. However, this evidence is limited and the mechanisms are poorly understood. It does not justify a recommendation to drink alcohol for the benefit of your immune system.
This answer draws on several reviews that summarise existing research. The evidence on chronic excessive drinking is broadly supported and consistent: multiple independent reviews reach the same conclusions about immune cell dysfunction and infection risk. The section on moderate drinking rests on only two reviews, and the evidence within them is mixed and limited. The section on alcohol in the context of trauma is based primarily on animal experimental research from a single review. The researchers themselves emphasise that drinking pattern, sex, type of drink, and other factors make comparison difficult.
Does too little sleep weaken your immune system?
Yes, too little sleep demonstrably weakens your immune system and increases the risk of infections and chronic inflammatory conditions. Seven to nine hours of sleep is the most commonly cited guideline, and vaccinations also work better when you are well rested.
Does your immune system really weaken as you get older?
Your immune system does indeed weaken as you get older, but how quickly that happens varies considerably from person to person. Lifestyle factors play a role in this, although little has yet been proven specifically for humans.
Does creatine do anything to your immune system?
Creatine affects immune cells, but whether that turns out well or badly depends strongly on the situation. For healthy older adults who also do strength training there is a cautiously positive signal; if you have endometriosis or a certain type of cancer, the context is more complex and consulting your doctor is advisable.
Can air pollution weaken your immune system?
Air pollution disrupts your immune system in several ways at once: a greater chance of allergic reactions, less resistance to viruses. Limit your exposure as much as possible, especially during pregnancy.
What does sleep deprivation do to your immune system?
Sleep deprivation demonstrably weakens your immune system: sleeping fewer than six hours significantly increases your infection risk and impairs your immune cells. Make sure to structurally get seven hours or more, because a single recovery night is not enough to repair the damage.
How do I strengthen my weakening immune system?
You can partly support your immune system by correcting measured deficiencies in vitamins and minerals and by making use of vaccines specifically tailored for older adults. More far-reaching options such as experimental inhibitors are not yet safe enough for daily use outside of studies.