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Some people are programmed to be chocoholics

Mali, a one-month-old, endangered bonobo, is fed last week by caretakers at the San Diego Zoo. Born on Sept. 4 in critical condition, the baby bonobo, an ape related to chimpanzees, is reportedly progressing nicely - growing, eating, and gaining weight. Mali, a one-month-old, endangered bonobo, is fed last week by caretakers at the San Diego Zoo. Born on Sept. 4 in critical condition, the baby bonobo, an ape related to chimpanzees, is reportedly progressing nicely - growing, eating, and gaining weight. (Ken Bohn/Zoological Society of San Diego)

METABOLISM

Whether you love chocolate or not may be programmed into your metabolism, a new study finds. People respond differently to different foods and drugs, and determining their metabolic types or "metabotypes" is a rapidly emerging field. Sunil Kochhar of the Nestle Research Center in Switzerland and colleagues recently looked at whether preference for a specific food, chocolate in this case, was linked to the metabolic type of the person. Kochhar and colleagues enlisted 22 men of approximately the same age and weight - 11 claimed to be "chocolate lovers," and 11 said they were indifferent to chocolate. The subjects were all put on the same diet for five days, and all ate chocolate or bread for the duration of the study. Researchers found that the "chocolate lovers" had lower LDL-cholesterol and higher albumin levels in their urine and blood, even on days when they didn't consume chocolate. This meant that there were certain metabolic "markers" or "imprints" in chocolate lovers, in this case the lower cholesterol and higher albumin, that distinguished them from the group indifferent to chocolate. Researchers think that based on their cholesterol and albumin levels people can, therefore, be grouped as the "chocolate-loving metabotype" and "chocolate-indifferent metabotype." "We don't know what creates what - whether metabolic type determines food preferences or whether food preferences change metabolic type," said Kochhar. BOTTOM LINE: "The study helps to look at the metabolic consequences of our relationship with food," said Kochhar. Knowing how different people react to different foods can help determine the optimum diet and nutrition for everyone. WHAT'S NEXT: The study looked at only males and researchers now want to repeat the study with women.
CAUTIONS: This small study was funded by the chocolate industry. More and larger studies are needed to confirm the findings.
WHERE TO FIND IT: American Chemical Society's Journal of Proteome Research online, Oct. 2.

SENA DESAI GOPAL

Hearing

Little-known structure in the ear may be key to understanding sound


When a word is spoken into the ear, the sound wave moves a small, delicate structure called the basilar membrane, much like the wind might rustle a leaf. The brain then interprets this rustling in the form of electronic signals - and so we hear. There is also another small, delicate structure in the ear, called the tectorial membrane, but its role in hearing was unknown. A new study from the Harvard-MIT Division of Health Sciences and Technology provides this long-sought mechanical data, potentially changing our understanding of how hearing works. In the study, led by Roozbeh Ghaffari, researchers first removed the tiny, transparent tectorial membrane from the ears of mice. They then suspended it, much like a bridge and examined its motion in response to different sound waves that a human ear might experience. Using advanced optical equipment, the researchers were able to see that the membrane was able to carry a wave down its free-hanging portion, suggesting that the tectorial membrane may be a key player in hearing. "We show that a second wave mechanism may exist in the human ear," Ghaffari says, reshaping our understanding of how we might process such complex sounds as human language or a concerto, while also potentially refining future technologies in helping those with hearing difficulty to hear again.
BOTTOM LINE: Boston-based researchers have found that a little-known structure in the ear may be crucial to hearing, providing new possibilities for treating hearing impairments.
CAUTIONS: The experiment was performed while looking at the tectorial membrane outside of the ear - the ideal scenario would be to repeat this experiment with the membrane in its usual environment.
WHAT'S NEXT: Researchers plan to repeat this experimental in mice with different hearing mutations to determine whether motion of the tectorial membrane in response to sound waves is affected.
WHERE TO FIND IT: Proceedings of the National Academy of Science, advance online, Oct. 9.

SUSHRUT JANGI

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