From The Desk Of Clarence Bass
Preventable Cancer Risks
Poor Diet on Par with Alcohol, Obesity, and Physical Inactivity
I’ve had quite a lot to say about the role of lifestyle in cardiovascular disease, but relatively little about cancer. A study published May 22, 2019, in JNCI Cancer Spectrum and featured in the April, 2020, Tufts Health & Nutrition Letter is a good place to start. Study author Fang Fang Zhang, MD, PhD, a cancer epidemiologist at the Friedman School of Nutrition and Science at Tufts University, and a stellar team of researchers including Darius Mozaffarian, MD, DrPH, Dean of the Friedman School and Editor-in-Chief of the Tufts Letter, are among the first to focus on diet as a significant risk factor in cancer.
(Discussion in the Tufts Letter, wide-ranging and easy to understand, is heavily relied on here.)
Role of Diet
Zhang et al emphasize that diet is a major cancer risk factor that can be remedied. “Our study estimated that more than 80,000 new cancer cases among U.S. adults in 2015 could be attributable to suboptimal diet.” This is comparable to the cancer burden associated with alcohol, excessive body weight, and physical inactivity—all lifestyle factors subject to self-help.
The study found that low consumption of whole grains contributed to the largest number of diet-associated cancer cases, followed by low consumption of dairy foods. Low consumption of vegetables and fruits were also among the seven dietary factors uncovered in the study.
High intake of processed meats also contributed to the highest burden.
Noting that not all research findings about milk-and-dairy consumption is positive, the Tufts Letter observes that “much antidairy information is based on limited or misinterpreted science.”
“We’re learning that the health effects of different dairy foods are tremendously complex,” Dr. Mozaffarian adds. “We’re just beginning to scratch the surface. Dairy foods represent a meaningful proportion of calories and nutrients for many around the world, creating an urgent need for additional careful research on dairy foods, their different characteristics, and effects on health.”
For Dr. Mozaffarian’s continuum of foods from “benefit” to “harm” see Milk in the Middle:
The Letter also observes that sugar-sweetened beverages are strongly associated with obesity, another factor associated with cancer. Approximately 16 percent of diet associated cancers were attributed to obesity.
“Aside from smoking, staying a healthy weight throughout life is the single most important way to protect against cancer,” the Tufts Letter tells us. “Research has found a strong link between excess body fat and increased risk for cancers of [practically every organ in the body].”
Healthy eating is, of course, a key factor in maintaining a healthy body weight.
Dr. Zhang and her colleagues break down the cancer burden attributable to poor diet by cancer type. They also chart the connection between cancer type and dietary factors from low whole grains to high sugar-sweetened beverages. (See link below)
Colorectal cancer had the highest proportion of diet-related cases, with 38% of all cases associated with poor diet.
The Tufts Letter explains that body fat is a metabolically active organ. Fat cells produce estrogen, high levels of which are linked to cancer risk. They also produce a variety of proteins that can increase levels of insulin and other hormones, which spur cancer cell growth. Other substances produced by fat cells can cause chronic inflammation, which is associated with increased cancer risk. (See below)
The visceral fat concentrated in the waist region is the most metabolically active type of fat tissue. “It churns out growth stimulants that encourage cell division—and the more often cells divide, the more opportunity there is for a cancerous mutation to occur.”
The inflammation-cancer connection is well established. Joel B. Mason, MD, a professor at the Friedman School and director of the Carcinogenesis Laboratory, and colleagues recently published a study that found elevated levels of inflammatory markers in the colons of 26 obese individuals but not in 16 of their lean peers. Concentration of two major inflammatory proteins rose as body mass (BMI) rose. “We have known for a couple of decades that obesity creates a state of low-grade chronic inflammation in the blood stream and fat tissue,” Mason told the Tufts Letter. “This study supports our findings in mice that inflammation also exists within the lining of the colon of individuals with obesity.”
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“Our findings underscore the need for reducing cancer burden and disparity in the United States by improving the intake of key food groups and nutrients of Americans,” Dr. Zhang et al concluded.
You can read the entire study online:
This study makes perfect sense. A balanced diet of whole foods lowers cancer risk. It’s the diet that has kept me lean and healthy.
This casual photo of me at 70 is one of a series taken by Laszlo with natural lighting.
Whole grains, dairy and other unprocessed foods fill you up without overshooting your calorie needs. They also aid bowel function. It 's logical that they would lower the risk of colorectal cancer—and cancer burden in general.
Understanding the difference between processed and unprocessed foods goes a long way toward setting the stage for this common sense diet—connecting the dots between food, weight control, and health.
Here's the key to distinguishing between the two forms of food:
Food processing is any procedure that alters food from its natural state. Some processing is, of course, necessary to make foods edible. That kind of processing is perfectly fine and desirable. The kind of processing that's a concern is the kind that reduces volume and concentrates calories. Highly processed foods are usually no longer recognizable as their original plant or animal sources. It makes food go down quick and easy--with minimal preparation and little chewing. Examples are white bread, hot dogs, baked goods, ice cream, and candies.
A gym owner friend of mine used to call hot dogs "mystery meat." That says it all, doesn't it?
You’ll find more details in my FAQ: (scroll down)
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The connection between healthy eating and cancer risk is one more example of self-help—the amazing power we have to keep ourselves lean and healthy.
August 1, 2020
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