Genes may explain why some people turn their noses up at meat

May 2, 2012

If you don't like the taste of pork, the reason may be that your genes cause you to smell the meat more intensely, according to a new study.

Duke University Medical Center scientists, working with colleagues in Norway, found that about 70 percent of people have two functional copies of a gene linked to an odor receptor that detects a compound in male mammals called androstenone, which is common in pork. People with one or no functional copies of the gene can tolerate the scent of androstenone much better than those with two, the researchers said.

Hiroaki Matsunami, Ph.D., a Duke associate professor of and microbiology, had previously discovered and described the genetics of the odor receptor for androstenone (OR7D4). But it wasn't until a group of pork scientists in Norway contacted him that he launched an experiment to learn more precisely at a genetic level how humans perceive the smell of .

The Norwegian team had practical reasons for the study: It was concerned what might happen in Europe if a castration method for swine were outlawed. Currently, female pork meat and castrated male pork meat are sold in Europe. The researchers were curious how consumers might respond to meat from noncastrated males.

The level of androstenone in noncastrated pigs ranges up to 6.4 ppm. In Norway the level of androstenone in immunocastrated (using hormones) pigs is from 0.1 to 0.2 ppm, and in surgically castrated pigs the rate approaches zero.

The findings raise the possibility that more consumers will dislike meat if castration is banned and more meat from noncastrated animals is sold, Matsunami said.

The study was published May 2 online in the PLoS ONE open-access journal.

A total of 23 subjects were recruited: 13 consumers and 10 professional sensory assessors. When all of the subjects were divided into sensitive and insensitive cohorts according to a smell test that was previously devised, all of the androstenone-sensitive subjects had the RT/RT genotype, with two copies of the functional RT gene.

"I was surprised at how cleanly this experiment showed who smelled what," Matsunami said. "The results showed that people with two copies of the functional variant of the gene for that odor receptor thought that the meat smelled worse with higher levels of androstenone added."

For the experiment, the researchers added only biological levels of androstenone to existing pork meat, up to the limit of what might be found in male wild boars.

Matsunami said it would be fascinating to see results done on certain populations, including people in the Middle East, where pork has been omitted from diets for centuries.

"I would also like to know about odor receptor variants in indigenous populations, such as people who live near the Arctic Circle and who never eat these meats. What is their ?" Matsunami said. Vegetarians as a group may also have a genetic predisposition against the smell of meat, but all of these ideas need to be scientifically studied, he said.

Matsunami also speculated whether meat inspectors with both copies of the functional variant, who presumably would be more sensitive to higher levels of androstenone, might make different decisions in their jobs.

The availability of the humane genome has given us the tools for revising sensory and consumer science involving flavor perception, said co-author professor Bjørg Egelandsdal of the Institute of Chemistry, Biotechnology and Food Science at the University of Life Science, in Ås, Norway. "This could be very useful in product development, to learn which flavor sensors are correlated with which flavors. More research is needed, but we may be able to revise the way we recruit consumer groups for evaluating product development."

Another practical solution for meat producers would be to find other compounds that are safe to ingest, but that might block the androstenone receptors to reduce that scent in meat.

Explore further: High levels of MRSA bacteria in retail meat products

Related Stories

High levels of MRSA bacteria in retail meat products

January 20, 2012
Retail pork products in the U.S. have a higher prevalence of methicillin-resistant Staphylococcus aureus bacteria (MRSA) than previously identified, according to new research by the University of Iowa College of Public Health ...

Copper + love chemical = big sulfur stink

February 6, 2012
When Hiroaki Matsunami, Ph.D., at Duke set out to study a chemical in male mouse urine called MTMT that attracts female mice, he didn't think he would stumble into a new field of study.

Denying mental qualities to animals in order to eat them

November 25, 2011
(Medical Xpress) -- New research by Dr Brock Bastian from UQ's School of Psychology highlights the psychological processes that people engage in to reduce their discomfort over eating meat.

Govt proposes clearer labeling of meat additives

July 21, 2011
(AP) -- The Agriculture Department wants consumers to know when there's less chicken in their chicken.

Recommended for you

Scientists identify new way cells turn off genes

July 19, 2017
Cells have more than one trick up their sleeve for controlling certain genes that regulate fetal growth and development.

South Asian genomes could be boon for disease research, scientists say

July 18, 2017
The Indian subcontinent's massive population is nearing 1.5 billion according to recent accounts. But that population is far from monolithic; it's made up of nearly 5,000 well-defined sub-groups, making the region one of ...

Mutant yeast reveals details of the aberrant genomic machinery of children's high-grade gliomas

July 18, 2017
St. Jude Children's Research Hospital biologists have used engineered yeast cells to discover how a mutation that is frequently found in pediatric brain tumor high-grade glioma triggers a cascade of genomic malfunctions.

Late-breaking mutations may play an important role in autism

July 17, 2017
A study of nearly 6,000 families, combining three genetic sequencing technologies, finds that mutations that occur after conception play an important role in autism. A team led by investigators at Boston Children's Hospital ...

Newly discovered gene variants link innate immunity and Alzheimer's disease

July 17, 2017
Three new gene variants, found in a genome wide association study of Alzheimer's disease (AD), point to the brain's immune cells in the onset of the disorder. These genes encode three proteins that are found in microglia, ...

Newly identified genetic marker may help detect high-risk flu patients

July 17, 2017
Researchers have discovered an inherited genetic variation that may help identify patients at elevated risk for severe, potentially fatal influenza infections. The scientists have also linked the gene variant to a mechanism ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

JVK
not rated yet May 02, 2012
"A gene that codes for the mammalian olfactory receptor, OR7D4, links food odors to human hunger, dietary restraint, and adiposity (Choquette et al., 2012). OR7D4 exemplifies a direct link1 from human social odors to their perception (Keller, Zhuang, Chi, Vosshall, & Matsunami, 2007) and to unconscious affects2 on human behavior associated with human olfactory-visual integration (Zhou, Hou, Zhou, & Chen, 2011); human brain activation associated with sexual preferences (Savic, Heden-Blomqvist, & Berglund, 2009), human learned odor hedonics; and motor function (Boulkroune, Wang, March, Walker, & Jacob, 2007). Insect species exemplify one starting point along an evolutionary continuum from microbes to humans that epigenetically links food odors and social odors to multisensory integration and behavior." --http://dx.doi.org...i0.17338

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.