Toxins

Virtually all food contains an appreciable level of toxicity, which does not pose a substantial threat to a robust individual, either because of low concentration, or because the individual can readily eliminate it. See excretion. At increasingly high toxin concentrations, otherwise-edible material can no longer be called "food". See poison, contamination.

Food additives

Some people claim that food additives, such as artificial sweeteners, colorants, preserving agents, and flavourants may cause health problems even though they were extensively tested before being allowed into the market. For example, artificial colorants are claimed to cause hyperactivity in susceptible children. As another example, people on calorie restricted diets often choose to buy products advertised as "reduced calorie" or "no sugar added". These products contain artificial sweeteners. These are safe to consume in small quantities, and are of low toxicity. Safety studies may well show some advantage in substitutions, product by product. Over a period of time, many different products are approved for sale, each one relying on a study done in isolation, and each one suggesting the artificially sweetened product has fewer associated health problems than equivalent all-natural products. When dieters buy reduced-calorie soft drinks, biscuits, cakes, flavoured water, yogurt, and so on, all may contain combinations of the leading artificial sweeteners aspartame, acesulfame potassium or sucralose. Cumulative doses are at higher levels than those on which the safety studies were based.

The issue of sweetening is just one example. Other taste-enhancing additives (e.g. salt substitutes) or flavourants are also hidden in processed foods and drink, as are colourants. Mandatory food labelling is one attempt to overcome the problem. This invites the consumer to check the ingredients of their foods before consumption. However, the average person has no training in organic chemistry and its nutritional effects. Neither is it practical for individuals to manage score cards recording all the nutrients they consume.

Some would assert that research into the toxicity of many varied artificial ingredients has been inconclusive. The USA's Food and Drug Administration has very stringent requirements for the introduction of new food ingredients, and this includes rigorous testing on animals, where the animals are given exorbitant amounts of these chemicals - far more than humans ever would be likely to consume.

Studies often attempt to determine whether an artificially-produced food additive is potentially carcinogenic, conduicive to heart disease, or possessing of other malicious properties.

A good rule of thumb to remember when reading the results of these studies is that the more widespead a food additive is in existing packaged food, the more likely the studies will conclude said additive to be benign.