Study Finds Obesity Significantly Increases Prostate Cancer Risk in African-American Men

April 16, 2015 

Obesity has a profoundly different effect on prostate cancer risk in African-American as compared to non-Hispanic white men. Obesity in black men substantially increases the risk of low- and high-grade prostate cancer, while obesity in white men moderately reduces the risk of low-grade cancer and only slightly increases the risk of high-grade cancer, according to the first large, prospective study to examine how race and obesity jointly affect prostate cancer risk.

The findings, published April 16 in JAMA Oncology were based on a nationwide study led by researchers at Fred Hutchinson Cancer Research Center and the University of Washington. The research team, led by senior author Alan Kristal Dr.P.H., a member of the Fred Hutch Public Health Sciences Division, and first and corresponding author Wendy Barrington Ph.D. an affiliate public health investigator at Fred Hutch and an assistant professor at the University of Washington School of Nursing, found that black men who are obese (a body-mass index of 35 or higher) had a 122 percent increased risk of low-grade and an 81 percent increased risk of high-grade prostate cancer compared to those who were of normal weight (a BMI of 25 or lower). 

In contrast, among non-Hispanic white men, those who were obese had a 20 percent reduced risk of low-grade and only a 33 percent increased risk of high-grade prostate cancer compared to those of normal weight. 

“For unknown reasons, African-American men have a much higher risk of prostate cancer than non-Hispanic white men. Different effects of obesity might explain at least some of the difference in risk and, more importantly, preventing obesity in African-American men could substantially lower their prostate cancer risk,” Kristal said.

According to the National Cancer Institute, black men have the highest prostate cancer rates of any racial or ethnic group in the U.S., they tend to get more aggressive forms of this cancer and are more than twice as likely to die of the disease as compared to non-Hispanic white men. These elevated risks for African-American men are due to both social disadvantage, such as access to resources, as well as biologic factors, Barrington said.

This study suggests obesity, which is influenced by both social and biologic factors, may play an important role behind what Kristal and Barrington call the “African-American race effect” on disparities in prostate cancer risk. More than a third of the U.S. population is classified as obese, and the prevalence of obesity among African-American men is slightly higher – 37 percent – compared to 32 percent in non-Hispanic white men, Barrington said.

“Given that obesity is more common among African-Americans, [the prostate cancer-obesity connection] is an important question to study, as it may shed light on how to reduce black/white disparities in prostate cancer incidence,” she said.

The study was based on data collected during the Selenium and Vitamin E Cancer Prevention Trial, known as the SELECT Study, an international clinical trial that tested whether supplemental selenium and/or vitamin E could prevent prostate cancer. More than 35,000 men from across the U.S., Canada and Puerto Rico participated.

Study participants, including nearly 3,400 African-American men, were followed carefully for the development of cancer and other diseases, and a single study pathologist examined prostate tissue from the men diagnosed with prostate cancer to determine whether it was low- or high-grade disease. The trial ended early, because after an average of five years there was no evidence that either of the supplements lowered prostate cancer risk.

The study did, however, provide a treasure trove of high-quality data on risk factors such as race, height, weight and family history, as well as the use of prostate-cancer screening. The obesity finding was “serendipitous” and “potentially of enormous importance,” Kristal said. “In an unrelated analysis we wanted to statistically control for effects of obesity. We noticed that the associations of obesity with prostate cancer risk in African-American men were very different than those for non-Hispanic white men.”

What drives the disparity? “There is some evidence that the biological responses to obesity, such as inflammation and glucose tolerance, are more pronounced in African-American men; both inflammation and insulin may promote cancer development,” Kristal said. Obesity might also have an impact on genes that control prostate cancer growth, “but frankly this is just speculation,” he said. “This is the next question for researchers to ask, because the answer will likely tell something very important about prostate cancer development and prevention.”

While the study’s findings concerning obesity and prostate cancer risk in black men are novel and need to be replicated, they underline the ongoing public health toll of the obesity epidemic.

“Obesity prevention and treatment should be a priority for all Americans, but in particular for African-American men,” Barrington said. “Prostate cancer kills 45 out of 100,000 African-Americans and only 19 out of 100,000 white men, and obesity is contributing to this important health disparity. Health care providers need to consider obesity prevention for their African-American male patients as a targeted strategy to reduce prostate cancer disparities.”

How Obesity Has Become a Part of Black Culture

By Dr. Tyeese Gaines Reid

Obesity is a growing epidemic in this country, with Americans eating more and becoming less and less active. Seventy-three percent of adults and 43 percent of all children in the United States are overweight or obese, according to the Centers for Disease Control and Prevention.

Among African-Americans 20 years and older, more than two-thirds are overweight or obese defined as a body mass index (BMI) of 25 pounds or more (h). According to BMI charts, a woman who is 5-feet 5 inches tall and weighs 150 pounds is considered overweight. A man who stands at 5-feet 8 inches is considered overweight once he hits 175 pounds.

What is often considered normal is actually unhealthy. Carrying around those extra pounds increases the likelihood of developing type II diabetes and high blood pressure two diseases that disproportionately affect African-Americans. Being overweight also increases the risk of stroke, heart disease, arthritis and certain cancers.

Obesity could become more dangerous for your health than smoking cigarettes. Yet, in the African-American community, the so-called normal body image is skewed toward the unhealthy. Studies show a strong tendency to deem larger body sizes as acceptable, particularly for women.

"Many African-American women view being obese as part of their culture," says Thaddeus Bell, M.D., a family practitioner in South Carolina, in an online interview for icyou.com.

It is understood within the African-American community that curvy, overweight women are considered more appealing to black men than normal or under-weight women. There is almost a reverse distortion of body image with thicker women fighting weight-loss and slender women wanting to gain weight in order to be accepted.

This may account for the staggering statistic that 4 out of 5 African-American women are overweight or obese. It is even more alarming that some of these women are making a choice to live at an unhealthy weight.

African-American women of all ages report less exercise than their white counterparts. "Many of them feel that it's not feminine or they're afraid to sweat because it will ruin their hairstyle," adds Dr. Bell. Other hindrances include not having child care, not having enough time to be physically active, and not feeling safe being active in their neighborhoods.

African-American men aren't off the hook either. African-American men also exercise less than white women, and have the highest prevalence of obesity among all male ethnic groups.

However, African-American men are more active than their female counterparts, which may be the reason that only 28.8 percent are obese, compared to 50.8 percent of African-American women.

With the head of the African-American family the matriarch more likely to be overweight and sedentary, it is no surprise that many black men and children are also overweight. Regular exercise, portion-control and healthy eating habits are not routinely ingrained into the structure of African-American families.

One in four African-American girls and almost one in five African-American boys are overweight. We are now beginning to see high blood pressure and type II diabetes historically diseases of adulthood in these overweight children.

Seven out of every 10 overweight adolescents will become overweight adults. That number increases to eight if one or more parents is also overweight. Thus, the cycle continues.

The "soul food" tradition adds to the problem in some African-American households. Most of the recipes are passed down from generation to generation, usually from families who originated from the southern states.

There is a strong social component to this style of cooking, centered around family gatherings or opportunities for the family's matriarch to show her love for the family.

However, traditional soul food is often cooked with fat, sugar and unhealthy amounts of salt that contribute to weight gain and high blood pressure. Ironically, soul food is often considered "good food," as compared to fast-food, so the perception of healthy food choices are also skewed.

Even among those families who desire to eat healthier, doing so may not be economically feasible. One in four African-Americans still live in poverty, and there is a strong correlation between low income and obesity.

Many impoverished Black neighborhoods do not even have an accessible grocery store with affordable, healthy options. It's not hard to imagine that tasty, inexpensive fast-food beats out the cost and taste of lean meat, fresh fruits and vegetables.

Fast-food companies also gear marketing efforts toward Black communities. While offhand these ads may appear culturally-sensitive, studies show that ethnic minorities are more responsive to these targeted ads and such marketing is, in fact, manipulative. This poses a dilemma as many of these ads are for less-than-healthy food and beverage options.

There are, however, national efforts to reverse these unhealthy perceptions and traditions. The "Black Women DO Workout" website and organizations such as the National Black Marathoners' Association are encouraging African-Americans to pursue healthier lifestyles.

With luck, African-American families can begin passing down the traditions of family fitness and health, rather than obesity and preventable diseases.

Poverty And Obesity Related Diseases

Mark Hyman

Not having enough food to eat may cause obesity, diabetes, high blood pressure, and heart disease. Most of us think the chronic disease epidemic is fueled by abundance, but it may be fueled as much by food scarcity and insecurity as it is by excess. And, right now, America is suffering from the highest levels of poverty and food insecurity that it has seen in more than a decade.

In 2008 49 million Americans--including 16.7 million children--lived in a home at risk of not having enough food on the table every day. After working in Haiti, the poorest country in the Western hemisphere, I learned that one in two Haitians wake up every day not knowing where their next meal will come from. But right here in the wealthiest nation in the world, one in five children live in poverty, one in four children live on food stamps, and one in 10 people don't know where their next meal will come from.

A new report released by Bread for the World shows that not all families in the United States are feeling the burden of food scarcity equally. Analyzing the country's most recent poverty and hunger statistics, the report found that one in four African-American households struggles to put food on the table on a regular basis, compared with about one in seven households nationally.

This news comes on the heels of recent estimates by researchers at Washington University in St. Louis that suggest 90 percent of African American children will receive food stamp benefits by the time they turn 20 - a claim this report found to be true.

It seems clear that the drastic disparity in unemployment rates between African Americans and the general population is fueling high rates of hunger. Bread for World's report cites unemployment numbers from January 2010 that show 16.8 percent of African Americans were unemployed last month while only 9.7 percent of the general population was out of work.

Naming the current economic crisis as a driving factor behind these figures, Bishop Don Williams of Bread for the World goes as far as to say that "an entire generation of African American children is at risk of being set back due to the current recession."

The Census Bureau recently reported that the nation's poverty rate increased to 14.3 percent in 2009--the highest level we've seen since 1994. 43.6 million Americans lived below the poverty line in 2009, earning less than $21,954 per year for a family of four or $10,956 for an individual; for African-Americans 1 in 4 are poor (25%) and nearly 40% of Black children live in poverty. We now have the highest number of people living on the threshold of poverty in the history of government record keeping.

The poorest areas of the country are also the sickest and have the highest rates of obesity, diabetes, and premature death. These people are dying younger, and life expectancy is plummeting in the poorest states. These states also happen to be the fattest. For example, Mississippi the poorest state in the union has poverty rates over 20 percent, obesity rates over 33 percent, and extremely high childhood obesity rates. This is no coincidence.

How does not having enough to eat cause obesity, diabetes, heart disease, cancer, and early death? Let's investigate.

Food Insecurity: The Root of Obesity and Disease

The Life Sciences Research Office says food insecurity exists "whenever the availability of nutritionally adequate and safe foods or the ability to acquire acceptable foods in socially acceptable ways (e.g., without resorting to emergency food supplies, scavenging, stealing, or other coping strategies) is limited or uncertain." This may mean going hungry for some. But for a large portion of Americans floating on or sinking beneath the poverty line this means bingeing on cheap, sugary, starchy, fatty calories in order to avoid hunger.

Many poor people in this country are consuming an excess of nutritionally-depleted, cheap calories from sodas, processed foods, and junk food. These folks scarcely eat whole, fresh foods at all, and for good reason: We have made calories cheap, but real food expensive.

Almost $300 billion of government subsidies support an agriculture industry that focuses on quantity not quality, on producing cheap sugar and fats from corn and soy that fuel both hunger and obesity.

These calorie-rich, sugary, processed foods are what most people buy if they don't have enough money. You can fill up on 1200 calories of cookies or potato chips for $1, but you'll only get 250 calories from carrots for that same $1. If you were hungry, what would you buy?

Processed foods have become cheaper as real food grows more expensive. The U.S. Department of Agriculture (USDA) reported that between 1985 and 2000 the retail price of carbonated soft drinks rose by 20 percent, fats and oils by 35 percent, and sugars and sweets by 46 percent.

Compare that to the 118 percent increase in the retail price of fresh fruits and vegetables. In fifteen years the price of vegetables ballooned six times as fast as the cost of sugary, calorie-rich, nutrient-poor sodas.

This is further compounded by the fact that in some communities in America, the only place to buy food is a local convenience store where fruits, vegetables, or other whole, fresh, real foods cannot be found. Without a car in an urban setting you may have to walk miles to find anything resembling real food.

Social factors like these set the stage for the epidemics of obesity and disease we are facing. This in combination with the nature of human metabolism put our nation's poor in a trap from which it is very difficult to escape.

How the Biology of Starvation Contributes to Disease

What often happens in poverty-stricken families is a hunger-bingeing cycle that follows the economic conditions in the household. When resources come in, people buy cheap, abundant calories in the form of junk and processed foods that fill them up and stave off hunger leading to rapid fat storage, a common biological effect after a period of lower calorie intake or hunger. This is simply how human metabolism works.

When calories are scarce metabolism slows down and muscle is lost. As a result the blood sugar imbalances that drive the process of insulin resistance and lead to pre-diabetes and diabetes worsens, and soon people are caught in a recurrent pattern of bingeing on nutrient-poor calories once resources are again available.

Certainly people can learn to eat better for less as I pointed out in my recent blog on the topic, and doing so is an essential part of what needs to happen to break out of this cycle of poverty and disease as I will discuss more below. That said, breaking the hunger-binge cycle is easier said than done.

Bingeing after food scarcity and the increased fat accumulation and insulin resistance that come along with it are hard-wired biological mechanisms to prevent us from starvation. Once you have diabetes, engaging in this cycle makes blood sugar control that much more difficult and leads to the swings of high and low sugar that drive health problems and their related costs.

Diabetics without access to adequate food have fives times as many doctor visits as diabetics who have enough to eat on a regular basis. The burden this creates in families already struggling to stay afloat is unspeakable. It's like they are caught in a Grecian hell--pushing the boulder of economic burden up a hill they will never see the top of, reaching for fruit that grows ever further from their reach.

We need to rethink how and what we feed our nation or the epidemics of disease and obesity will consume us. In Haiti, one in two people worry about where their next meal will come from. In America it is one in 10. In order to shift this we need a bold new vision and initiatives that can change our food culture and food availability.

Here are a few initiatives and ideas that may help shift this frightening tide of poverty and disease:

1. Stop or reduce subsidies of agriculture products that allow for the glut of cheap, high-calorie, nutrient-poor sugars and fats from corn and soy into the marketplace.
2. Consider taxing sugar and processed food to support national food programs and community projects, and help cover the hundreds of billions of dollars of health care costs from increasing obesity, diabetes, and heart disease.
3. Fund community-based initiatives to support healthy eating including community kitchens, gardens, and cooking classes that teach how to make good food cheaply. This is part of the new health care bill, and on the agenda of the new Council on Prevention, Health Promotion, and Public Health.
4. Make school lunches healthy by providing only real food and modeling healthy eating. Food can be both fun for you and good for you. Create national standards based on sound 21st century nutritional science and common sense. Most schools have only a microwave or deep fryer, hardly the tools needed to feed our children real, fresh food.
5. Expand the Supplemental Nutrition Assistance Program (formerly the Food Stamp Program). Increasing eligibility, helping those who are not aware they are eligible enroll, and creating new programs that support consumption of more healthful foods could shift the tide of the widening socioeconomic disparities in chronic disease.

You should not be able to buy chips and soda with food stamps.Everyone reading could also sign up for Jamie Oliver's Food Revolution and learn a recipe using inexpensive, fresh, whole food to create a delicious meal and teach that recipe to three people. They, in turn, could teach three more people. After just a few rounds of that, all of America would learn how to feed themselves again.

We need to reclaim our food supply and revive traditional ways of eating. As Michael Pollan says, "If 'food' was made in a plant, don't eat it. If it grows on a plant, then enjoy!"

Stress And Black Obesity

The main cause of obesity is overeating. However, not many people know the causes of overeating; one major cause is ‘socioeconomic stress’. Blacks are the most stressed population in the U.S. Just living under the stressor of racism alone takes a tremendous psychological toll on so many Black people.

In her book, ‘Environmental Stress and African-Americans’, author Grace Carroll states that race is brought to the consciousness of African Americans every day through interaction with employers, service providers, landlords, the police, and the media.

She says the stress experienced by Blacks merely as a result of being African American causes micro-aggressions that include experiences such as being denied service, being falsely accused, being negatively singled out on account of one's race.

Carroll labels the stress that results from such micro-aggressions as Mundane Extreme Environmental Stress (MEES) - which she says is a daily experience, has a significant impact on one's psychological well being and world view, is environmentally induced, and is detracting and energy consuming.

Arline Geronimus a professor of health behavior and health education at the University of Michigan echoes Carroll by stating the stress of living and working in a race conscious society slowly wears down Black people from all walks of life.

From Geronimus perspective racist stress, coupled with poverty, eventually erodes Blacks mental and physical health, a gradual process that she calls ‘weathering’. This daily weathering results in depression, substance abuse, suicide, strained relationships, and frustration that leads to misplaced Black-on-Black violence.

Living under much strain Blacks tend to eat comfort foods high in fats and sugars to ease the pain of stress. Black obesity is driven by stressful emotion based reactive eating and an addiction to comfort foods. Stress can make you feel hungry even though you just ate. Because of this reason Blacks tend to eat more portions and obesity continues to rise.

More Than 1 in 3 Blacks Are Obese

by Robert Higgs

Nearly 36 percent of black Americans are obese -- much more than other major racial or ethnic groups -- and that gap exists in most states, a new federal study finds. About 29 percent of Hispanics and 24 percent of whites are obese, the Centers for Disease Control and Prevention reported.

Racial differences in obesity rates have been reported before, and health officials were not surprised to see larger proportions of blacks tipping the scales. But the new CDC report is the first to look at the gap on a state-by-state level, finding blacks had much higher obesity rates in 17 states, and had rates about as high or higher than other groups in an additional two dozen more states.

Health officials believe there are several reasons for the differences. People with lower incomes often have less access to medical care, exercise facilities and more expensive, healthier food. In many places, minorities are disproportionately poor.

But attitudes about weight also are believed to be a factor, said Dr. Liping Pan, a CDC epidemiologist. "Black and Hispanics are more accepting of high weight," she said, adding that heavy people who are satisfied with their size are not likely to diet or exercise.

Obesity is based on the body mass index, a calculation using height and weight. A 5-foot, 9-inch (1.75-meter) adult who weighs 203 pounds (92 kilograms) would have a BMI of 30, which is considered the threshold for obesity.

The data comes from national telephone surveys of hundreds of thousands of Americans in the years 2006 through 2008

Black Americans Less Likely to Recognize Obesity

by Gary G. Bennett, PhD

Overweight black Americans are two to three times more likely than heavy white Americans to say they are of average weight — even after being diagnosed as overweight or obese by their doctors, according to a new study led by Dana-Farber Cancer Institute researchers.

Weight "misperception" was most common among black men and women, and also was found among Hispanic men (but not women) compared to their white counterparts. The findings, which appear in the current online issue of the International Journal of Behavioral Nutrition and Physical Activity, are significant as excess body weight is a known risk factor for diabetes, heart disease, many forms of cancer, and premature death.

Growing concern over the national obesity epidemic in recent years apparently has not significantly increased overweight blacks' recognition of their excess pounds, said Gary G. Bennett, PhD, of Dana-Farber's Center for Community-Based Research and Harvard School of Public Health in Boston, lead author of the study.

The report by Bennett and Kathleen Y. Wolin, ScD, of Northwestern University is based on an analysis of data collected in the National Health and Nutritional Examination Survey (NHANES), a government-sponsored research study begun in the 1960s. It includes both interviews and physical examinations carried out by mobile units across the country.

Analyses of NHANES data collected in 1988-98 and 2001-02 show that the prevalence of misperception actually has increased among blacks. "During this period weve seen rapid gains in obesity," said Bennett. "We think it's a considerable problem that this is still not resonating among blacks and other minorities," he added.

Although the prevalence of overweight and obesity is even higher among blacks (estimated at over 75 percent) than the national average, Bennett said less pressure exists in the black community for people to lose weight through diet and exercise because of a cultural acceptance of higher body weights and heavier body shapes.

"We think that misperception can be very useful when it comes to protecting people against overly stringent body image ideals and eating disorders," said Bennett, who is black. "But it's a problem when people fail to realize the health consequences associated with obesity."

The researchers analyzed data on 6,552 overweight and obese men and women who participated in the 1999-2002 NHANES surveys. Included in the analyses were data on height, weight, body mass index, whether they had received a diagnosis of overweight from a doctor, and responses to the question, "Do you consider yourself now to be overweight, underweight, or about the right weight?" Since all the participants were overweight or obese by standard health guidelines, all answers of "about the right weight" were categorized as "inaccurate" or a "misperception" by the researchers. The study was not designed to determine whether the inaccurate statements were intentional or not.

The study found that men were more likely than women to misperceive their weight. Among women, the prevalence of misperception was highest among overweight black women (40.9 percent, compared to 20.6 percent in overweight white women) and men (66.4 percent, compared to 43.2 percent in overweight white men). It was lowest among obese white women (3.1 percent, compared with 11.2 percent in obese black women) and men (8.9 percent, compared to 26.2 of obese black men.)

Altogether, overweight black men and women were twice as likely as whites to make inaccurate body weight perceptions, and obese black adults were even more likely to exhibit weight status misperceptions, according to the report.

Unrealistic assessments of body weight were just as common in people who were relatively financially well off as in poorer people, and in those who had been told by their doctors that they were overweight or obese.

One lesson from the findings, Bennett said, is that "it is probably not sufficient for physicians to simply tell a person that he or she is overweight; doctors should do much more intensive counseling regarding the health consequence of being overweight."

The message is complicated, he added, by research findings showing that blacks generally don't experience life-shortening health effects until they are more obese compared to whites. "Obesity-associated mortality occurs at a higher BMI (body mass index) among blacks than it does for whites," probably for biological reasons, said Bennett. Yet some of the health effects associated with excess weight, such as diabetes, high cholesterol and hypertension, can be causing harm in blacks long before they result in death.

"The tendency to dramatically underestimate the degree of their overweight should be a clarion call to blacks," Bennett said. "We hope that people will increasingly recognize the health consequences associated with excess weight."

Fast Food and Black Neighborhoods

Fast Food Joints More Common in Poor, Black Neighborhoods. The high density of fast food outlets in low-income, majority black neighborhoods may contribute to the obesity epidemic, say Tulane University researchers.

“Where people live and the kinds of food available close to them is likely to affect their ability to have a healthy diet,” says senior author Karen DeSalvo, chief of general internal medicine at the Tulane University School of Medicine. “We found that high-income and mostly white neighborhoods have fewer fast food outlets per square mile than lower income or mostly black neighborhoods.”

Researchers used computer software to analyze the placement of fast food restaurants in Orleans Parish. The team found that predominantly black neighborhoods had 2.4 such eateries per square mile, while white neighborhoods only had 1.5, says lead author Jason Block, who is now an internal medicine physician at Brigham and Women's Hospital in Boston, Mass.

“We know that when people eat fast food, they often have larger portions with higher calorie counts than they do if they cook fresh food at home,” Block says. “We also know that obesity is increasingly a problem for low-income and black individuals.”

Access and the cost of food items do have an impact on what people eat, the authors wrote. DeSalvo and Block agree that more research is needed to examine the role of fast food in the obesity of low income and black populations.

The study is published in a recent issue of the American Journal of Preventive Medicine.