What Effect Does Caffeine & Alcohol Have On The Urinary System?

Caffeine is a stimulant that increases alertness, while alcohol is a central nervous system depressant, notes the National Institute on Drug Abuse. Despite their opposing functions in the body, both caffeine and urine affect the urinary system similarly, causing an increase in urine production and a need to visit the bathroom frequently. Alcohol has a more negative effect on the urinary system, however. Excessive alcohol consumption can impair kidney function, according to research by nephrologist Dr. Murray Epstein, as reported in "Alcohol Health & Research World."

Urinary System

The National Kidney & Urological Diseases Information Clearinghouse, or NKUDIC, describes the urinary system as consisting of organs, tubes, muscles and nerves that create, store and carry urine. It includes the kidneys, bladder, sphincter muscles and urethra. The kidneys filter water and waste from the blood, which forms urine. From the kidneys, urine moves through tiny tubes called ureters to the bladder, where it is eliminated from the body. A healthy urinary system can hold up to two cups of urine comfortably for two to five hours, reports NKUDIC. Drinking alcohol and caffeine cause more frequent urination, however, because they act as diuretics, leading to increased urine elimination.

Caffeine's Effect

Caffeine is a stimulant found in coffee, tea, chocolate and some colas. After consuming these caffeinated foods or beverages, caffeine is passed quickly to the brain and does not collect in the bloodstream or get stored in the body, reports MedlinePlus, a service of the National Institutes of Health. The caffeine exits your body several hours later in your urine. Because caffeine is a diuretic, it can lead to dehydration. Caffeine can also cause temporary urinary incontinence, or the involuntary leakage of urine, notes the MayoClinic.com website. Coffee, tea and carbonated drinks, either caffeinated or decaffeinated, can also aggravate the bladder.

Alcohol's Effect

Unlike caffeine, alcohol collects in the bloodstream and affects the urinary system in multiple ways, including causing changes in the structure and function of the kidneys and impairment in their ability to regulate the volume and composition of fluids and electrolytes. Alcohol can promote urination within 20 minutes of consumption, according to Dr. Epstein. Drinking too much alcohol can cause failure of bladder nerves, keeping them from signaling to the brain when the bladder is full. This can lead to urinary incontinence. Finally, long-term excessive alcohol consumption can result in kidney failure by causing liver disease.

Solution

If caffeine is causing bladder control problems, NKUDIC recommends choosing decaffeinated coffee, tea and colas. Drink most of your fluids during the day and limit drinking after dinner to reduce nighttime urination problems. MayoClinic.com advises cutting back gradually by having one less can of soda or a smaller cup of coffee each day, or brewing tea for less time to reduce caffeine. Reduce alcohol consumption by setting a drinking goal, such as no more than two alcoholic drinks a day, drinking slowly with at least an hour break between drinks, and eating while drinking to slow the alcohol absorption in your bloodstream, recommends the National Institute on Alcohol Abuse and Alcoholism. If you suspect you may have a drinking problem, talk to your doctor about enrolling in an alcohol treatment program.