WEDNESDAY, Aug. 27 (HealthDay News) -- People throughout the world have major misconceptions when it comes to what causes cancer, new research suggests.

Results from a survey released Aug. 27 at the International Union Against Cancer's (UICC's) World Cancer Congress in Geneva, found that people tend to inflate the threat from environmental factors and minimize the threat of behaviors that are well-established cancer risk factors.

Researchers interviewed 29,925 people in 29 countries last year to compare data on perceptions about cancer risk factors among high-, middle-, and low-income countries.

Among their findings was the fact that people in high-income countries were least likely to believe that drinking alcohol increases the risk of cancer, when, in fact, cancer risk rises as alcohol intake increases. Specifically, 42 percent of the people in the high-income countries said alcohol does not increase the risk, compared with 26 percent of those in middle-income countries and 15 percent of those in low-income countries.

Another finding was that people in high-income countries felt that not eating enough fruits and vegetables was more risky than drinking alcohol. The truth is that the evidence supporting the protective effect of produce consumption is weaker than the evidence that alcohol intake is harmful.

In addition, people in rich countries thought that stress and air pollution were greater risk factors than alcohol intake, even though stress is not recognized as a cause of cancer and air pollution is a minor contributor compared with alcohol intake.

The people in middle- and low-income countries were more likely than those in high-income countries to say that "not much can be done" to cure cancer or that they didn't know whether anything could be done. And a surprising 75 percent of survey respondents in low-income countries preferred for their doctor to make all their cancer treatment decisions, while 72 percent of the people in high-income countries said that the decisions should be made between the doctor and patient, or by the patient alone.

Finally, people in all countries were more ready to accept that things they could not control (e.g., air pollution) were risk factors than things they could control (e.g., overweight, which is an established cancer risk factor).

The researchers hope that their data will be used to put into action cancer education campaigns that address some of these misconceptions.

"This survey reveals that there are some big unheard messages. These kind of data help us to quantify the differences between countries and to highlight where additional efforts are needed. Some of these countries have rarely had any population survey data to help their programme planning efforts," researcher David Hill, president-elect of UICC and director of the Cancer Council Victoria in Melbourne, Australia, said in a UICC press release.

The survey was conducted by Roy Morgan Research and Gallup International on behalf of the UICC.

More information

The National Cancer Institute has more about cancer.