Q: I’ve been gaining weight in recent years. But as long as my doctor doesn’t tell me I need to lose weight, can I assume it’s not really a health issue?
A: Not necessarily. According to a recent federal health survey, doctors don’t always talk to their overweight patients about weight. These results are similar to results from earlier studies. In the government survey, more than 70 percent of people classified as overweight and almost 30 percent of those classified as obese said their health care professional never told them they were overweight. This can happen for a variety of reasons. But it’s a problem, because in the same survey, nearly a quarter of women and nearly half of men who were overweight identified their weight as being appropriate. And weight alone does not identify all people with excess body fat.
That’s the reason health experts now recommend checking your waist size, too. It’s clear that health-related risks are greatest at highest levels of obesity. However, even moderate overweight poses some increased risk of cancer and other health problems by promoting inflammation and unhealthy levels of certain hormones. For example, even weight gains of 15 pounds or so over adult life carries some increased risk of postmenopausal breast cancer. If your doctor hasn’t brought up your weight gain, at the very beginning of your next appointment bring it up as something you want to discuss.
Q: Does eating more fiber lower risk of other cancers, too, or only colon cancer?
A: According to the most recent report from the American Institute for Cancer Research and World Cancer Research Fund on how diet may reduce cancer risk, the cancer most clearly related to fiber is colorectal. There is now convincing evidence that eating relatively high amounts of dietary fiber lowers risk. However, fiber could lower risk of other cancers, too. A recent analysis of 10 population studies, involving more than 712,000 women, linked higher consumption of dietary fiber with lower risk of breast cancer. Overall, the women who consumed the most fiber were 11 percent less likely to develop breast cancer than those who consumed the least. In this analysis, the women in the highest fiber group generally ate at least 26 grams of fiber per day, which is the minimum recommendation for good health. Women consuming the least amount of fiber generally took in about 12 to 16 grams per day, comparable to average U.S. adult fiber consumption. Population studies like this one don’t explain how fiber might provide protection, but other types of research suggest that fiber could act from within the gut to bind estrogen and reduce amounts of estrogen circulating in the blood.
Fiber could also act by reducing levels of insulin, which seems to act as a growth factor promoting development of breast cancer. This analysis also does not tell us whether some high-fiber foods might offer more protection than others. Vegetables, fruits, whole grains and beans all offer a variety of natural plant compounds that seem to put the brakes on at several different points in the process of cancer development. Some studies also link higher consumption of foods providing dietary fiber with reduced risk of other cancers, but there is much less data on this and, again, it’s hard to separate lower risk due to fiber consumption from protective benefits of other components in vegetables, fruits, whole grains and beans. Eating enough high-fiber foods is clearly smart for overall health, whether it’s due to the fiber or not.
Karen Collins is a registered dietician and certified diabetes nutritionist with the American Institute for Cancer Research, the cancer charity that fosters research on the relationship of nutrition, physical activity and weight management to cancer risk.