Health Scan: Not just what you eat
Jerusalem Post (Israel)
Nutrition is not the only factor driving obesity, which has grown to epidemic proportions in the Western world. New Tel Aviv University research has shown that fat mass in cells expands with disuse, and that the mechanics of "cellular expansion" plays a primary role in fat production. The research was published in
To understand how obesity develops, Prof.
With a better understanding of the process, the researchers are now creating a platform to develop new therapies and technologies to prevent or even reverse fat gain.
Two years ago, the researchers were awarded a grant from the
"Contrary to muscle and bone tissue, which get mechanically weaker with disuse, fat deposits in fat cells expanded when they experienced sustained loading, by as much as 50 percent. This was a substantial discovery."
The researchers discovered that, once it accumulated lipid droplets, the structure of a cell and its mechanics changed dramatically.
Using a cutting-edge atomic force microscope and other microscopy technologies, they were able to observe the material composition of the transforming fat cell, which became stiffer as it expanded. This stiffness alters the environment of surrounding cells by physically deforming them, pushing them to change their own shape and composition.
"When they gain mass and change their composition, expanding cells deform neighboring cells, forcing them to differentiate and expand," said Gefen.
"This proves that you're not just what you eat. You're also what you feel – and what you're feeling is the pressure of increased weight and the sustained loading in the tissues of the buttocks of the couch potato."
"If we understand the etiology of getting fatter, of how cells in fat tissues synthesize nutritional components under a given mechanical loading environment, we can think about different practical solutions to obesity," Gefen said. "If you can learn to control the mechanical environment of cells, you can then determine how to modulate the fat cells to produce less fat."
VITAMIN D HELPS BREAST CANCER PATIENTS
Breast cancer patients with high levels of vitamin D in their blood are twice as likely to survive the disease as women with low levels of the vitamin,
In previous studies, family medicine specialist Prof.
That finding, he said, prompted him to question the relationship between 25-hydroxyvitamin D – a metabolite produced by the body from the ingestion of vitamin D – and breast cancer survival rates.
Garland and colleagues performed a statistical analysis of five studies, including nearly 4,500 breast cancer patients, of 25-hydroxyvitamin D obtained at the time of patient diagnosis and their follow-up for an average of nine years.
"Vitamin D metabolites increase communication between cells by switching on a protein that blocks aggressive cell division," said Garland. "As long as vitamin D receptors are present, tumor growth is prevented and kept from expanding its blood supply. The vitamin receptors are not lost until a tumor is very advanced. This is the reason for better survival in patients whose vitamin D blood levels are high."
"The study has implications for including vitamin D as an adjuvant to conventional breast cancer therapy," said co-author and colleague Prof.
Garland recommended randomized controlled clinical trials to confirm the findings but suggested physicians consider adding vitamin D into a breast cancer patient's standard care now and then closely monitoring the patient.
"There is no compelling reason to wait for further studies to incorporate vitamin D supplements into standard care regimens, since a safe dose of vitamin D needed to achieve high serum levels, above 30 nanograms per milliliter, has already been established," said Garland.
According to the
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