The guidelines that follow should help facilitate a discriminating search for correct health information.

Avoid Jumping to Conclusions

Most health misinformation is actually based on facts, not lies. The problem is that facts get exaggerated and sometimes lead people to wrong conclusions. The phrase "risk factor" is a good example. Numerous studies report that certain habits increase the risk of getting certain diseases. This might be helpful information but by itself doesn't mean much. If you were told that the risk of death from bungee jumping increased 100% last year, whereas deaths caused by driving to school increased by 25%, you would likely, and incorrectly, conclude that bungee jumping is four times more risky. What is missing is information about actual baseline risk. If the baseline risk of death from bungee jumping is 1 in 1000, a 100% increase would raise it to 2 in 1000. On the other hand if the baseline risk for driving to school is 400 in 1000, then a 25% increase would increase the risk of death by 100 cases, to 500 in 1000. Although this example is hypothetical, it serves as a reminder of the importance of inquiring about the chances of getting a disease in the first place before drawing conclusions regarding risk factors, diseases, and death.

Much health literature is based on research involving statistical relationships, or associations among two or more events. Relationships are helpful clues to health, but they cannot and do not establish cause-and-effect relationships. The mistake many people make is to read or hear about a new health finding and erroneously conclude that one event causes the other. One of the areas most commonly abused by reference to cause-and-effect relationships is cancer.

A good example is tea, the most widely consumed beverage in the world after water. Researchers are interested in tea because an increase in tea consumption has been associated with a decrease in cancer and heart disease. Supposedly something in tea interferes with the ability of cancer-causing substances to bind to DNA. That's important because DNA is where cancer cell initiation begins. Also, tea contains antioxidants. Population studies of the Japanese, who smoke nearly twice as many cigarettes as Americans but far surpass Americans in tea consumption, have only about one-half as much lung cancer. The question is: does tea consumption actually cause a change in cell physiology that prevents cancer. So far, cause and effect have not been demonstrated. The 100 studies that show an association between tea consumption and lower cancer rates are epidemiological studies. Epidemiological studies are population studies (rather than scientifically controlled experimental studies of individuals) that observe large numbers of people to see if there is a link between lifestyle habits and disease. Because the studies observe people's behavior, it's always possible that unknown factors can influence findings. For example, people might not accurately remember or report their tea consumption over decades. Even if they do, it still doesn't prove that tea rather than something else about their lifestyles affected their risk of cancer. Because epidemiological studies don't establish cause and effect, researchers turn to experimental studies with animals or humans to build a stronger case.

Relationships are based on statistical procedures. Although these relationships may provide a basis for better understanding health concerns, they usually fall short of supporting many of the sweeping generalizations and conclusions that make headlines.