Thursday, March 31, 2005

Half of Cancer Deaths Could Be Prevented

Lifestyle Changes, More Screening Could Have Big Impact

Yahoo! Health: Cancer News

March 31, 2005 12:00:00 AM PST

At least half of all cancer deaths in the United States could be prevented if Americans adopted a healthier lifestyle and made better use of available screening tests for the disease, a report from the American Cancer Society states.

The information is contained in Cancer Prevention and Early Detection Facts & Figures 2005, an annual ACS report that explores some of the risk factors for cancer that people can control and change.

The report highlights trends in tobacco use, eating habits, exercise patterns, and weight gain among adults and children. The report also discusses cancer screening and ways to help more people take advantage of these potentially life-saving tests that can often find cancer well before there are noticeable symptoms

Steps Forward, and Backward
In some areas, the report shows, the US has made progress in reducing the threat of cancer. For instance, fewer adults and children are smoking now compared to a few years ago. Tobacco use causes about 30% of all cancer deaths in the US, and about 87% of lung cancer deaths, according to the report.

Drops in smoking have been the result of many factors, including higher tobacco taxes, laws limiting smoking in public places, and anti-smoking advertising. But the report warns that many of the state programs that helped lower smoking rates have been drastically scaled back because of budget problems.

A serious and growing problem is weight gain among children and adults. An ACS study published in 2003 showed that excess weight raises the risk of dying from many types of cancer including breast cancer (in certain age groups), the most common cancer in women, and prostate cancer, the most common cancer in men.

About 35% of US adults are overweight and another 30% are considered obese. Nearly 16% of kids 6-19 are too heavy; heavy kids are more likely to become heavy adults with a higher risk of developing cancer and other serious diseases.

The obesity problem stems from a number of factors, according to the report. High-calorie foods are widely available and heavily marketed; Americans rely more than ever on cars to get around; schools have cut physical education programs; many kids favor television, video games, and computers over outdoor activities.

The report makes a number of recommendations for fighting the obesity trend. One of them is to follow ACS guidelines for nutrition and exercise. Others include encouraging restaurants to provide nutrition information so diners can make better food choices, designing communities that encourage exercise with safe sidewalks, bike lanes, and parks, and improving the quality of food served to children at school.

Make Screening a Priority
Lifestyle changes are only part of the cancer equation, though. The report says following screening recommendations is also crucial to reducing the risk of dying from cancer. Screening can find cancers at their earliest stages, when they are easier to treat. In the case of colon cancer, screening can even prevent the disease altogether, by finding polyps so they can be removed before they turn into cancer.

Rates of screening for breast cancer and cervical cancer are generally high, though women without insurance are much less likely to get these important tests. Colon cancer screening, however, remains low. The report says improving insurance coverage of these procedures is key to increasing their use.

Comment: Not only is screening important, but prevention by eating right and taking antioxidants is critical. By the time screenings find the problem, it may also be too late.


DNA damage from micronutrient deficiencies is likely to be a major cause of cancer.
By Bruce N. Ames, professor of molecular and cell biology at UC Berkeley

A deficiency of any of the micronutrients: folic acid, Vitamin B12, Vitamin B6, niacin, Vitamin C, Vitamin E, iron, or zinc, mimics radiation in damaging DNA by causing single- and double-strand breaks, oxidative lesions, or both. For example, the percentage of the US population that has a low intake (<50% of the RDA) for each of these eight micronutrients ranges from 2 to >20%. A level of folate deficiency causing chromosome breaks was present in approximately 10% of the US population, and in a much higher percentage of the poor. Folate deficiency causes extensive incorporation of uracil into human DNA (4 million/cell), leading to chromosomal breaks. This mechanism is the likely cause of the increased colon cancer risk associated with low folate intake. Some evidence, and mechanistic considerations, suggest that Vitamin B12 (14% US elderly) and B6 (10% of US) deficiencies also cause high uracil and chromosome breaks. Micronutrient deficiency may explain, in good part, why the quarter of the population that eats the fewest fruits and vegetables (five portions a day is advised) has about double the cancer rate for most types of cancer when compared to the quarter with the highest intake. For example, 80% of American children and adolescents and 68% of adults do not eat five portions a day. Common micronutrient deficiencies are likely to damage DNA by the same mechanism as radiation and many chemicals, appear to be orders of magnitude more important, and should be compared for perspective. Remedying micronutrient deficiencies should lead to a major improvement in health and an increase in longevity at low cost.