In your 20s, a few glasses of wine or cups of coffee might not give you a second thought. But as you age, those same habits can start to feel less appealing as their effects become more pronounced.
So why do alcohol and caffeine seem to impact us more negatively as we get older? Here’s what the experts have to say:
Liver Efficiency Declines
According to Clare Thornton-Wood, a dietitian and BDA spokesperson, “Drinking excessively, binge drinking, and exceeding guidelines are always harmful, regardless of age.”
She explains, “Both alcohol and caffeine are metabolized in the liver. As we age, our liver becomes less efficient at this process due to a decrease in the number and effectiveness of the enzymes needed to break them down. Consequently, alcohol is metabolized more slowly, remaining in the body longer and increasing the likelihood of a hangover. The same goes for caffeine—it stays in your bloodstream longer, prolonging its stimulating effects.”
Changes in Body Composition
“Body composition changes with age,” Thornton-Wood notes. “We lose muscle mass and gain fat. Muscle tissue is about 75% water, while fat is only about 10% water. This decrease in body water means alcohol is absorbed more quickly. Lower water levels also increase the risk of dehydration, which, when compounded by alcohol consumption, can lead to headaches and more pronounced hangovers.”
Impact on Sleep
Aging often brings sleep disturbances, and both alcohol and caffeine can make things worse. “Alcohol disrupts REM sleep, which is crucial for mental health, concentration, and memory. As we age, sleep issues can be exacerbated by alcohol,” Thornton-Wood explains.
“And caffeine? It’s a stimulant that blocks adenosine receptors responsible for promoting sleep. This increases dopamine and other neurotransmitters, making you feel more alert. But excessive caffeine can lead to jitteriness, anxiety, and trouble sleeping.”
Both alcohol and caffeine are diuretics, potentially causing frequent nighttime bathroom trips, further disrupting your sleep.
Stomach Sensitivity
If you’re noticing more acid reflux or stomach irritation from alcohol or coffee, it might not be a coincidence. “As we age, our stomach lining becomes more sensitive, and alcohol can increase stomach acid production,” Thornton-Wood says. “Additionally, aging weakens the muscles, including the sphincter at the top of the stomach, allowing acid to flow back into the esophagus and cause heartburn. Both alcohol and coffee relax this sphincter muscle, worsening heartburn.”
Genetics
Age isn’t the only factor at play. Genetic differences can influence how we metabolize caffeine. Research from the University of Bath found that variations in the CYP1A2 gene can affect how quickly caffeine is cleared from the body. “Some people are ‘fast’ metabolizers of caffeine, while others are ‘slow’ metabolizers,” explains lead researcher Harry Smith. “Caffeine’s half-life can range from 1.5 to 9.5 hours, so if you’re a slow metabolizer, coffee later in the day could disrupt your sleep or heighten anxiety.”
Other Considerations
Other factors such as sex, body composition, and lifestyle choices like smoking and diet can also affect caffeine metabolism. “Heavier individuals generally tolerate more caffeine,” says Thornton-Wood. “Also, if you’re stressed or anxious, caffeine can exacerbate these feelings, potentially leading to ‘caffeine-induced anxiety.’”
Moderation is Key
To mitigate the effects of alcohol, the NHS recommends that both men and women limit their intake to no more than 14 units per week, spread over three or more days. For alcohol, moderation is essential—consider watering down drinks or opting for lower-alcohol options.
For caffeine, the NHS advises consuming it in moderation, with a maximum of 200mg per day during pregnancy. “Intersperse coffee with water or decaf, and consider the caffeine content, as ground coffee generally contains more caffeine than instant,” suggests Thornton-Wood.
Both alcohol and caffeine can impact existing conditions, so it’s wise to consider how you’re feeling before indulging.
