The Way of Science

Laetrile

Like most humans, Americans have a fascination with quick and easy solutions. This is particularly apparent in medical fields, where patent medicines, bizarre machines, quacks and charlatans abound. The popularity of "alternative medicine" is a continuation of this tendency. The pseudoscience of homeopathy is undergoing a rebirth, and one can still find examples of extreme pseudoscientific claims made by some chiropractors. Many of these early quackeries were worse than useless; they were dangerous. The abuses of uncontrolled medicines and adulterated products led Congress to establish a series of regulatory laws and enforcement agencies. The final version of this decades-long sequence appears in the 1940s, with the centralization of the FDA (Food and Drug Administration) in Washington, DC. It is much reviled by groups such as the tobacco industry, the "health food" lobby, and others who oppose regulation of their products. The "Committee for Freedom of Choice in Cancer Therapy," for example, states that "¼cancer patients should have access to any drug, regardless of the FDA." However, the job of the FDA, as specified by Congress, is logical and necessary. This agency must verify both the efficacy and the safety of drugs.

Let us now turn to an example of politics and public opinion over-riding science in the US. Laetrile, widely used here as a supposed cancer "cure," began its life in the 1920s, as a crude extract of apricot pits (it's "natural"!). The seeds of many trees contain this or similar compounds, which can be cyanogenic: the acidity of a mammal's stomach causes the molecule to break down, and liberate small quantities of cyanide. Death has resulted in humans from eating too many apple seeds at once, and peach pits and bitter almonds can be dangerous for the same reason.

Laetrile, in its purified form, was used extensively in Mexican clinics as a cancer treatment. Many Americans, desperate for help, traveled to Mexico, where the drug was legal. Some came back with cancer remission, and - convinced that laetrile was responsible - spread the word. By the 1970s, the FDA was under heavy pressure from Congress and the public to legalize laetrile.

Testing of cancer drugs usually follows a standard pattern. Initial screening of new compounds is commonly done in vitro (literally, "in glass."). Cultures of cancer cells are treated with drugs as a fast and reliable way of separating the few good candidate molecules from the mass of ineffective ones. If a molecule or extract shows anti-cancer activity in vitro, the much more time-consuming and expensive trials on non-human animals may be done. If these studies continue to support efficacy and safety, clinical trials on humans would be the next step.

Initial tests by a major biomedical institute (Sloane-Kettering Cancer Center) showed no efficacy. Normally, laetrile's story would have ended here. However, public pressures continued, and a way was found to bypass the FDA. By 1978, 17 state legislatures, acceding to public demands, had legalized laetrile for use within the states. One cancer specialist commented on that dismal state of affairs by saying that it is "...appalling that scientific knowledge has been negated by the political process..."