Food Additive Sensitivities – Aspartame and Caffeine


Aspartame is an artificial, low-calorie sweetener made of aspartic acid and phenylalanine, two amino acids, and methanol. It is found in a variety of foods and beverages including diet sodas and other beverages, yogurt, pudding, gelatin desserts, and chewing gum. It’s also sold as the tabletop sweeteners NutraSweet and Equal.

Aspartame is 200 times sweeter than sucrose (a simple sugar) and is used in such small amounts in foods that it’s virtually calorie free. It was first approved by the FDA for use in low-calorie tabletop sweeteners and powdered mixes in 1981, and in all foods and beverages since 1996.

Despite aspartame’s approval by the FDA, some people have reported a wide range of symptoms associated with consumption of aspartame-containing foods and beverages, such as headaches, dizziness, mood changes, vomiting, nausea, and many others. Despite this, the FDA deems aspartame safe for use by the general public, including those with diabetes, pregnant and nursing women, and children. This conclusion is consistent with that of several other organizations that have also reviewed extensive research on aspartame, including the American Medical Association, the American Diabetes Association, and the American Dietetic Association.

The acceptable daily intake (ADI) for aspartame, set by the FDA, is 50 milligrams per kilogram (mg/kg) of body weight. To reach the ADI, an adult would need to consume any of the following on a typical day (in approximate amounts):

• 20 cans of diet soda
• 42 servings of sugar-free gelatin
• 97 packets of low-calorie tabletop sweeteners

Despite its safety for most people, some people are unable to properly metabolize phenylalanine, an essential amino acid. This can lead to an unhealthy buildup of the amino acid in the body. People who need to severely restrict their intake of aspartame (which contains phenylalanine) include

• Those with phenylketonuria (PKU), a rare inherited disease
• Pregnant women with hyperphenylalanine (high levels of phenylalanine in their blood)

Products made with aspartame are required by law to have a warning label that says they contain phenylalanine to alert those with PKU who need to avoid the substance.


Caffeine is a bitter substance found naturally in the leaves, seeds, and fruits of plants. It is naturally found in coffee, tea, cocoa and cocoa products, and some flavorings. It’s also added to a variety of foods including carbonated beverages, energy drinks, chocolate-flavored milks, yogurts, frozen desserts, and even some medicines such as over-the-counter pain-relievers.

Up to 300 milligrams a day (the amount of caffeine in about three cups of brewed coffee) is considered safe for most people. Although caffeine is classified as GRAS by the FDA, some people can be sensitive to its effects. Symptoms include

• Insomnia
• Headaches
• Irritability
• Nervousness
• Migraine headaches

The effects of caffeine intake on individuals can vary and depend on many factors, such as body weight, how much is consumed, how often is consumed, and overall health status. Children, for example, tend to be a lot more sensitive to the effects of caffeine than adults. Those who experience symptoms should limit or avoid caffeine, as should the following:

• Those with heartburn
• Those who have peptic ulcers
• Those who suffer from anxiety or panic attacks
• Those with a history of depression or who take antidepressant medications

Because caffeine content is not required to be listed on food and beverage packages, calling the manufacturer is the best way to determine how much caffeine a product contains.

Generally recognized as safe (GRAS) is a term created by the FDA that indicates a chemical or substance added to food is considered safe under conditions of its intended use.

Hydrolyzed proteins are proteins that have been chemically broken down in the body into amino acids. When these proteins are broken down, glutamate is formed and joins with free sodium to form MSG.

A preservative helps maintain the freshness of food; protects against spoilage by organisms such as bacteria, molds, fungi, and yeasts; and slows or prevents changes in color, flavor, and textures of food.

Acceptable daily intake (ADI) is an estimate of how much of a substance can be consumed over a lifetime without significant health risk. It is often used for food additives.

Phenylketonuria (PKU) is an inherited condition in which the body cannot process phenylalanine, an essential amino acid, because it lacks or does not have enough of the enzyme called PKU which, if left untreated, can cause irreversible mental retardation, small head size, epilepsy, or behavioral problems.

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