Crystal Light is the brand name for a series of product lines marketed by Kraft Foods. All Crystal Light products are artificially sweetened; some are powdered for reconstitution with water and others are prepared beverages. Kraft uses three artificial sweeteners for the Crystal Light line: aspartame, sucralose and stevia. Each offers specific beverage-enhancing attributes and its own spectrum of benefits and side effects.
According to a 2002 report from Penn State University, headaches, chronic fatigue syndrome, epilepsy, fibromyalgia and bi-polar disorder have been blamed on aspartame. But well-controlled, clinical research consistently fails to verify these isolated reports. Researchers reporting from the Clinical Research Center at the Massachusetts Institute of Technology in 1998, said that aspartame, a relatively new sweetener to the general public at that time, was safe.
Later claims that aspartame caused brain or any other tumors, were refuted by scientists at The Mayo Clinic in 2008, who also cited agreement by National Cancer Institute scientists. They also cite the U.S. Food and Drug Administration, the FDA, as recommending that safe use of aspartame amounts to 50 mg/kg, of body weight. Safe use is defined as 1/100th of an amount that might cause illness.
Aspartame is not safe for people with a rare genetic disorder called phenylketonuria, or PKU. Any product containing aspartame is required by the FDA to display a PKU warning label.
According to Genevieve Frank, reporting in a 2002 edition of Penn State University's "Undergraduate Research Journal," scientifically documented side effects of Crystal Light's sucralose are unknown. A person would have to drink 450, 12-oz. portions of a sucralose-sweetened beverage in a day to reach a dose equal to amounts previously proven to be non-toxic.
Over 100 human and animal studies conducted in the FDA's food additive approval process detected no risk from sucralose intake up to 16 mg/kg/day, and as high as 1500 mg/kg/day in one study.
If off-flavor is a side effect, sucralose is said to be slightly "dry" tasting and may add a slight sourness to its sweetness.
If you drink sucralose-sweetened beverages to the exclusion of balanced meals, malnutrition may be a side effect of Crystal Light products.
The FDA, as cited by Mayo Clinic nutritionist, Katherine Zeratsky, in 2008, lists stevia in the "generally recognized as safe" category of food additives. Stevia is an herbal, calorie-free sweetener, 300 times as sweet as table sugar, used in some Crystal Light products. However, its physiological effects are unlike sugar and suggest caution and a talk with your doctor before use. Mayo Clinic specialists warn against unpredictable, sometimes dangerously low, blood sugar levels while using stevia, with special caution needed by diabetics. Stevia has also been shown to lower blood pressure. The affect is variable, depending on the amount of the sweetener in a daily diet. This makes blood pressure changes unpredictable and potentially dangerous if you use stevia along with blood pressure medications.