Tuesday, November 30, 2010

Diabetes And Cancer

Interesting stuff:

"Diabetes and cancer are common diseases that have a tremendous impact on health worldwide. Epidemiologic evidence suggests that people with diabetes are at a significantly higher risk of many forms of cancer. Type 2 diabetes and cancer share many risk factors, but to our knowledge, potential biologic links between the 2 diseases are incompletely understood....

"The association between weight loss and subsequent cancer risk is less clear. Most evidence has been derived from breast cancer studies, in which weak or null associations were observed. Because the weight loss definition and the referent groups differed across studies, these studies are difficult to compare. Weight loss categories tend to have small numbers, and many women who do lose weight do not maintain their weight loss beyond 1 year. In the Nurses' Health Study, a statistically significant inverse association between adult weight loss and postmenopausal breast cancer was found only when the weight loss had been maintained for 2 survey cycles, or 4 years."

So you'd better keep the weight off...  I was happy to see this (emphases mine):

"Diet

"A majority of studies (despite different study designs and differing study populations) suggest that diets low in red and processed meats and higher in vegetables, fruits, and whole grains are associated with a lower risk of many types of cancer. Diets that are low in red and processed meat but high in monounsaturated fatty acids, fruits, vegetables, whole-grain cereals, and dietary fiber may protect against type 2 diabetes, possibly through improving insulin sensitivity. Low-carbohydrate diets (which often include a greater consumption of red meats and fat) have also been associated with weight loss and improvements in insulin sensitivity and glycemic control. However, to the best of our knowledge, randomized controlled trial evidence of dietary interventions and diabetes prevention exists only for low-fat, low-calorie, plus/minus high-fiber diets.

"Several studies have suggested that diets high in foods with a high glycemic index or load are associated with an increased risk of type 2 diabetes. However, evidence of their associations with cancer risk is mixed. Regardless, to the extent that energy-dense and sugary foods contribute to overweight and obesity, the American Cancer Society, the World Cancer Research Fund, and the American Institute for Cancer Research recommend limiting consumption of these foods. "

Given where the science is on this, I would say this is a totally fair summary.  Kudos to the researchers for giving the low-carb option fair mention.

Of course the NY Times buries any mention of the dietary options:

"People with Type 2 diabetes tend to have a higher risk of getting certain cancers. And preliminary evidence suggests that metformin, the most widely used diabetes pill, might be effective in treating or preventing cancer.

"It is still not clear if high blood glucose is the reason diabetics have a higher cancer risk. A more likely explanation is that people with Type 2 diabetes have high levels of insulin, a hormone that is known to promote growth of certain tumors, according to the consensus statement.

"Similarly, metformin might fight cancer by lowering insulin levels, not blood sugar levels. But there is some evidence that the drug works in part by inhibiting glucose metabolism in cancer cells.

"Even if blood sugar levels fuel tumor growth, however, experts say that trying to lower the body’s overall level of blood sugar — like by starving oneself — would probably not be effective. That is because, at least for people without diabetes, the body is very good at maintaining a certain blood glucose level despite fluctuations in diet."

So keep piggin' out until the Doctor gives you a pill. This message brought to you by Big Pharm.

Given what I've read about diabetes and cancer and the emergence of both as widespread diseases since the adoption of the Modern American Diet, I'd run screaming away from the Modern American Diet ASAP.  Oh, wait, I already have...

Unfortunately the phrase "linoleic acid" does not appear in the link above.

While you're pondering all this, go for a run:

"Physical Activity

"Evidence from observational epidemiologic studies consistently demonstrates that higher levels of physical activity are associated with a lower risk of colon, postmenopausal breast, and endometrial cancer. Physical activity may also help prevent other cancers, including lung and aggressive prostate cancer, but a clear link has not been established to date. Some evidence also suggests that physical activity after diagnosis may improve survival for some cancers, including those of the breast and colorectum.

A protective role for increased physical activity in diabetes metabolism and outcomes has been demonstrated. Data from observational and randomized trials suggest that approximately 30 minutes of moderate-intensity physical activity, such as walking, at least 5 days per week substantially reduces (approximately 25-36%) the risk of developing type 2 diabetes. Analyses of the effects of different components of the intensive lifestyle intervention in the Diabetes Prevention Program have suggested that those who did not reach weight loss goals still significantly reduced their risk of diabetes if they achieved the physical activity goals, although weight loss was the only component found to be independently associated with diabetes prevention on multivariate analyses.