Why do alcohol and caffeine make us feel worse as we get older?

If your hangovers or coffee jitters are becoming worse as you age, you’re not alone. Here’s why…

When you’re in your 20s, you probably wouldn’t give drinking a few glasses of wine or cups of coffee a second thought. But, as the years roll on, the idea of doing this regularly becomes less attractive. As the effects on the body are felt more keenly.

Why is it that as we age, we feel the negative effects of alcohol and caffeine more? Here’s what the experts say…

Our liver isn’t as good at processing alcohol and caffeine

“Just for the record, drinking excessively, exceeding guidelines and binge drinking are not good at any age!” says dietitian and BDA spokesperson, Clare Thornton-Wood.

“Alcohol and caffeine are metabolised in the liver,” she continues. “As we age our liver becomes less efficient at this, there’s less enzymes and less efficient enzymes to breakdown and metabolise them both.

“So the alcohol is metabolised at a slower rate, therefore spending more time in the body and with more chance of a hangover.

“It’s the same for caffeine it’s not cleared from the bloodstream as quickly as we get older, so its effects – such as being alert will stick around for longer.”

Muscle loss leads to dehydration and hangovers

“Body composition changes as we age,” says Thornton-Wood. “We lose muscle and gain fat – muscle is about 75% water but fat can be as low as 10% water. So the amount of water in the body is less as we get older, which in turn means the alcohol is absorbed more quickly.

“If you have lower water levels to start with, you’re increasing the risk of dehydration, which is also caused by drinking alcohol and causes symptoms such as headaches. A hangover is likely to ensue from a smaller amount of alcohol when older versus younger.”

Alcohol and caffeine affect sleep

Disturbed sleep is an unfortunate side-effect of aging. So, what doesn’t help? Alcohol and coffee, which also disrupt sleep.

“Our REM (rapid eye movement) sleep decreases after drinking - we need adequate REM sleep for good mental health, concentration and memory. As we get older we can experience issues with sleep which are exacerbated by alcohol.”

But what about coffee? “Caffeine is a stimulant so makes you feel more awake and focussed,” adds Thornton-Wood.

“Caffeine blocks adenosine receptors which promote sleep, which then increases production of dopamine, noradrenaline and glutamate - these are all neurotransmitters that play a role in cognitive function. So, you feel more alert and your blood pressure and heart rate increases [when you drink coffee].

“In the right circumstances this can be very useful. However too much and you can feel jittery, have trouble sleeping and feel anxious.”

Both drinks are diuretics too, which means you might be kept up at night with the need to go to the toilet, says Thornton-Wood.

Your stomach’s not quite what it was

Does drinking a few glasses of wine or cups of coffee now lead to acid reflux? It’s not that uncommon.

“If you are predisposed to acid reflux or you’re older then it’s more likely your stomach will be easily irritated when you drink alcohol, with some studies saying it can see you produce more stomach acid.

In addition, “as we age our muscles weaken, this includes the sphincter at the top of the stomach - which if not closed leads to acid flowing back up from the stomach into the oesophagus and causing heartburn.” Alcohol and coffee both relax the sphincter muscle, causing further issues with heartburn.

Genetics

It might not be your age that’s affecting your ability to enjoy coffee but other factors, some which are set in stone and others which change over time.

The University of Bath carried out research investigating how consuming coffee following a night of poor sleep could disrupt your blood sugar levels and impact your metabolism. While age didn’t seem to affect this, lead researcher, Harry Smith, explains some people have a single mutation in one of the genes involved in caffeine metabolism, which could influence how long caffeine stays in your system.

“CYP1A2 is the main enzyme responsible for caffeine clearance that results in ‘fast’ and ‘slow’ metaboliser categories. [A mutation] could be why some people are able to have more than five cups without consequence whereas others can only manage one per day [without side effects].

“The half-life for caffeine clearance can range from 1.5 – 9.5 hours!” says Smith. If you’re at the higher-end of that, then clearly, having a coffee later in the day could cause you problems when trying to sleep or if you’re already feeling anxious.

Other factors

“As with all things metabolism though, I doubt this is the only thing that causes differences in how we tolerate caffeine. Some of the other proposed differences include sex and body composition and there are also behavioural factors that can influence caffeine metabolism like smoking and diet,” says Smith.

“There are also links with bodyweight, heaver people generally tolerate more caffeine,” says Thornton-Wood.

Also, if you’re going through a stressful or anxious period, coffee might not be your best friend, says Thornton-Wood. “If you already suffer with anxiety then caffeine is likely to exacerbate this. In fact, there’s a recognised ‘caffeine induced anxiety’ disorder.” So, if you’re feeling shaky after your usual cup of joe, consider whether you’re stressed.

Drink responsibly

When it comes to alcohol, the NHS advises men and women not to drink more than 14 units per week on a regular basis. These units should be spread over 3 or more days. 14 units is equivalent to 6 pints of average-strength beer or 10 small glasses of lower-strength wine.

Want to keep the effects of alcohol to a minimum without cutting it out completely? “It’s about moderation, know your limits, intersperse with water or have spritzers, lower alcoholic content drinks,” says Thornton-Wood.

When it comes to coffee, the NHS advises that we “drink caffeine in moderation – some people are more sensitive to caffeine than others, depending on how much they drink and how often.” They also advise that people should drink no more than 200mg per day in pregnancy.

In terms of ways to reduce your caffeine intake, here are Thorton-Wood’s suggestions, “Intersperse coffee with water or decaf and leave longer spaces between cups. Consider the caffeine strength too. There are differences between various coffee chains and ground coffee is always higher in caffeine than instant.”

It’s also worth considering how you’re feeling prior to drinking alcohol or caffeine as both could exacerbate existing conditions. “If you already suffer with anxiety then caffeine is likely to exacerbate this. In fact, there’s a recognised ‘caffeine induced anxiety’ disorder,” says Thornton-Wood.

Likewise, alcohol can cause similar issues.

If you are concerned about alcohol addiction, help and support is available.

Originally published August 2024