Navigation Links
Blacks Have Less 'Bad Fat' Than Whites
Date:12/18/2009

It's a puzzle, because less visceral fat should mean less obesity-linked disease, experts say

FRIDAY, Dec. 18 (HealthDay News) -- Blacks tend to carry around less of a particularly unhealthy type of abdominal fat than whites, even though they suffer more from obesity-linked illness, researchers report.

The new finding suggests that body-mass index (BMI) guidelines may need to be tailored to specific racial groups to better reflect risk, experts say.

"The study clearly shows we have these racial differences in body fat, not just in the type of body fat but where the fat is stored, and these are important differences," said study author Peter Katzmarzyk, a professor of population science at Pennington Biomedical Research Center in Baton Rouge, La.

Adipose (fat) tissue is found throughout the body. Subcutaneous adipose tissue is found just under the skin, while visceral adipose tissue is found in the abdominal cavity around the organs.

Fat settling around the organs has been linked to development of obesity-related diseases such as cardiovascular disease and type 2 diabetes, according to background information in the article.

But you can't tell just by looking at someone how much visceral fat someone has. Even a pot belly won't tell you for sure because visceral fat is deep within the body cavity, Katzmarzyk said.

In the study, researchers used computer tomography (CT scans) and dual- energy X-ray absorptiometry (DXA) to measure visceral fat in about 1,400 white men and women and 570 black men and women aged 18 to 84. Participants' height, weight, BMI and total body fat composition were also measured.

At a given body fat percentage, black men and women had lower visceral fat than white men and women. Conversely, blacks also tended to have higher subcutaneous fat than whites. Researchers controlled for age and smoking status, among other variables.

The study appears in the January issue of The American Journal of Clinical Nutrition.

Despite the tendency to have less visceral fat, black Americans are still at higher risk of dying from obesity-related diseases such as diabetes and cardiovascular disease. One explanation for this is that blacks have higher overall obesity rates overall, Katzmarzyk said.

About 31 percent of white adults and 45 percent of black adults are obese, according to the study.

"It's a paradox," Katzmarzyk said. "The fact that white individuals have more visceral adipose tissue and also have lower rates of obesity-related disease is probably because African-Americans have higher rates of obesity overall."

The findings also bring up the issue of whether the "one-size-fits-all" BMI guidelines apply equally to all races, Katzmarzyk said.

BMI is a calculation based on height and weight. While a high BMI tends to mean you also have a lot of body fat, BMI is not a direct measurement of fat composition. A very muscular person, for example, may have a high BMI but low body fat composition.

A BMI of 30 or above is considered obese, while a BMI of 25 or above is overweight.

Yet previous research has suggested there may be racial variations in what constitutes a healthy BMI. Diabetes risk for Asians start to rise at a BMI of about 23, for example. An optimal BMI for blacks may also vary somewhat, Katzmarzyk said.

"BMI may mean different things for different people," he said. "The study suggests we may need to think about ethnic-specific thresholds to identify obesity-related health risks."

Eric Bailey, a professor of anthropology and public health at East Carolina University and author of Food Choice and Obesity in Black America: Creating a New Cultural Diet, said BMI recommendations were developed using too little data on black Americans or other racial and ethnic groups.

"We are using BMI as a 'gold standard,' but it needs to be reassessed," Bailey said. "It does not necessarily apply to each and every population in the same way. Our biology and genetic makeup is slightly different. African-Americans may be healthier at a different BMI compared to a European population."

Biology aside, Bailey added, there is no question that obesity remains a serious issue in the black community. Poverty can make affording fresh fruits and vegetables and the healthiest cuts of meat more difficult, while unsafe neighborhoods discourages getting adequate exercise.

"Many times, sociological, behavioral and cultural issues overrides the biological," Bailey said. "One-third of African Americans are still in poverty, and that influences the types of foods you are able to eat."

In another study from the same issue, researchers found that gene variants that have been implicated in a tendency toward obesity played only a small role in a person's BMI.

Previous research in twins has suggested as much as 40 percent to 85 percent of obesity can be blamed on the genes, but the new research shows the influence of genetic variants may be much smaller.

Researchers at the University of Cambridge looked for 12 genetic markers for obesity in more than 20,000 participants from the United Kingdom. Those with at least one gene marker were 3 percent to 14 percent more likely to be obese than those without the marker, while each additional genetic marker raised the risk of obesity by nearly 11 percent.

But taken together, the genetic variations accounted for only about a one percent variation in BMI -- meaning the currently known markers are poor predictors of who is at risk for obesity, according to the study.

Researchers said it's possible that other, more important obesity-related gene variants have yet to be identified.

More information

There's a personal BMI calculator at the U.S. National Heart, Lung and Blood Institute.



SOURCES: Peter Katzmarzyk, Ph.D., professor, population science, Pennington Biomedical Research Center, Baton Rouge, La.; Eric Bailey, Ph.D., MPH, professor, anthropology and public health, East Carolina University, Greenville, N.C.; January 2010 The American Journal of Clinical Nutrition


'/>"/>
Copyright©2009 ScoutNews,LLC.
All rights reserved

Related medicine news :

1. Blacks at Greater Risk for Colorectal Cancer
2. Glaucoma Tied to Gene Variants in Blacks
3. Blacks Fare Worse After Cardiac Arrest
4. Lupus Worse in Blacks, Hispanics Than in Whites, Study Finds
5. Pancreatic Cancer Deaths Higher for Blacks
6. Lilly Named Best Company for Blacks in Technology
7. Women, blacks, Medicare recipients less likely to be evaluated for liver transplantation
8. Obesity increases risk of prostate cancer recurrence for both blacks and whites
9. Low prevalence of HPV infection may be tied to poor prognosis for blacks with head and neck cancer
10. Blacks Have Highest Obesity Rates in U.S.
11. Cancer Gap Between Whites, Blacks May Be Biological in Part
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:12/7/2016)... ... December 07, 2016 , ... The Honolulu ... fully redesigned website, which launched October 17, 2016, features comprehensive information regarding a ... easy-to-navigate layout. Visitors and patients can discover the latest clinical dermatology treatments for ...
(Date:12/7/2016)... ... 07, 2016 , ... The medical profession is well aware that heart attacks ... study analyzing heart attacks among 138,602 people recorded a 35% higher number of heart ... all agree of course–no time of year is a good time for a heart ...
(Date:12/7/2016)... ... December 07, 2016 , ... “The Road To Restoration”: an informative ... a one hour a week showing of hands. “The Road To Restoration” is the ... you are familiar with the brass ring that you could reach out for, and ...
(Date:12/7/2016)... ... 2016 , ... The Business Architecture Guild is ... on March 21-22, 2017. This premier event features business practitioners and experts from ... of industries such as financial services, insurance, healthcare, manufacturing, transportation, retail, and utilities. ...
(Date:12/6/2016)... ... December 06, 2016 , ... The International Vaccine ... a vaccine against the Middle East Respiratory Syndrome Coronavirus (MERS-CoV). The collaboration will ... Korea for emergency deployment in the event of a future outbreak. , IVI ...
Breaking Medicine News(10 mins):
(Date:12/6/2016)... Anaplastic Oligoastrocytoma - Pipeline Review, H2 ... Pharmaceutical and Healthcare disease pipeline guide Anaplastic Oligoastrocytoma ... of the Anaplastic Oligoastrocytoma (Oncology) pipeline landscape. ... when two types of cells in the brain, ... to form a mass. These brain cells are ...
(Date:12/6/2016)... -- Human Vaccines Market: Scope and Methodology ... wise analysis of the human vaccines market. Stakeholders ... products, raw material suppliers, vaccine processing companies, and ... The report provides qualitative and quantitative analysis of ... market dynamics, trends, product overview, and country-level market ...
(Date:12/6/2016)... , Dec. 6, 2016 Eurofins ... accreditation from the College of American Pathologists (CAP) ... (CLIA) for its new laboratory in ... moved its North American headquarters. "Our ... sequencing -- which is still considered the ,Gold ...
Breaking Medicine Technology: