Health Effects From Diet Cola

Diet colas are popular sugar-free beverages. Although they don't have the sugar and calories that regular soft drinks do, diet colas do contain artificial sweeteners, caffeine and chemicals that can affect how your body functions. Depending on your overall health, drinking an occasional diet cola probably won't hurt you, as long as you make healthy choices otherwise and don't make drinking it a daily habit.

Phenylalanine

Diet sodas to which the artificial sweetener aspartame has been added contain phenylalanine, an essential amino acid naturally found in most foods that contain protein. If you suffer from a rare metabolic disorder known as phenylketonuria or PKU, your body is missing the enzyme it needs to process phenylalanine. High levels of phenylalanine can lead to seizures and brain damage. Phenylalanine can cause severe mental retardation in infants with PKU. Aspartame in diet sodas can cause levels of phenylalanine in the brain to increase rapidly. Katherine Zeratsky, a nutritionist at Mayo Clinic, advises using caution when consuming products that contain aspartame if you have a sleep or anxiety disorder, suffer from the neurological syndrome tardive dyskinesia or take certain medications. These include anti-psychotic drugs and tranquilizers, antidepressant drugs in the monoamine oxidase inhibitor category or medications containing levodopa used to treat Parkinson's disease.

Caffeine

Most soft drinks contain some amount of caffeine, even sodas like root beer and cream soda that aren't colas. Find out how much caffeine your favorite diet cola contains by reading the label. Although caffeine only takes about 15 minutes to hit your bloodstream, you can continue to feel the effects for up to 10 hours, according to Beth Czerwony, a registered dietitian at Cleveland Clinic. Some of the adverse side effects of caffeine include irritability, feeling jittery, headaches, heart palpitations, sleeplessness and dehydration.

Weight Gain or Loss

Diet colas contain no calories so you may actually be tempted to eat more foods high in fat and sugar. People often think that by drinking diet soda they save calories, which allows them to eat more of the foods they like. But this can lead to overeating and weight gain. If you drink diet colas as a way to cut back on your total number of calories, you still need to pay attention to the calorie content of all the other foods and beverages you consume. Drinking diet colas won't make you fat as long as you limit the volume of food you eat and include plenty of less calorie-dense foods like vegetables and fruits in your daily diet. While diet colas might not necessarily harm your health, they contain no healthy nutrients.

Preventing Kidney Stone

A study reported in the April 2009 supplement issue of the "Journal of Urology" suggests drinking diet sodas that contain modest amounts of citrate and malate might be helpful to individuals suffering from calcium nephrolithiasis -- a medical condition more commonly known as kidney stones. Citrate works to prevent the formation of calcium stones, therefore, people who have a low amount of citrate in their urine are at higher risk of forming kidney stones. If you have trouble with kidney stones, drink enough fluids throughout the day to produce at least two quarts of urine, recommends the National Institute of Diabetes and Digestive and Kidney Diseases. Drinking water is best for preventing kidney stones.