High Carb Diet Linked to Prostate

Tumor Growth

ScienceDaily (Nov. 28, 2007) — A diet high in refined carbohydrates, like white rice or white bread, is associated with increased prostate tumor growth in mice.

Having too much insulin in the blood, a condition called hyperinsulinemia, is associated with poorer outcomes in patients with prostate cancer. Vasundara Venkateswaran, Ph.D., of Sunnybrook Health Sciences Centre in Toronto and colleagues investigated whether high insulin levels caused by eating a diet high in refined carbohydrates would lead to more rapid growth of prostate tumors in mice.

Forty mice were randomly assigned to either a high carbohydrate-high fat diet or a low carbohydrate-high fat one for nine weeks. The researchers measured the animals’ weight, tumor size, and insulin levels weekly. Mice on the high carbohydrate diet gained more weight, had faster growing tumors, and had higher insulin levels than mice on the low carbohydrate diet.

“Our results provide support for the concept that diets associated with a reduction in insulin level may have benefits for prostate cancer patients, particularly for the subset of patients who are hyperinsulinemic,” the authors write.

Sourced and published by Henry Sapiecha 19th April 2010

High-Altitude Metabolism Lets Mice

Stay Slim and Healthy

on a High-Fat Diet

ScienceDaily (Apr. 16, 2010) — Mice that are missing a protein involved in the response to low oxygen stay lean and healthy, even on a high-fat diet, a new study has found.

“They process fat differently,” said Randall Johnson, professor of biology at the University of California, San Diego, who directed the research, which is published in the April 15 issue of the journal Cell Metabolism. While their normal littermates gain weight, develop fatty livers and become resistant to insulin on a high fat diet, just like overweight humans do, the mutant mice suffered none of these ill effects.

The protein, an enzyme called FIH, plays a key role in the physiological response to low levels of oxygen and could be a new target for drugs to help people who struggle with weight gain. “The enzyme is easily inhibited by drugs,” Johnson said.

Because the protein influences a wide range of genes involved in development, the scientists were surprised that its deletion improved health.

“We expected them to die as embryos,” said Na Zhang, a graduate student in Johnson’s lab and lead author of the study. “Then we saw they can survive for a long time.”

“From the beginning I noticed that these mice are smaller, but not sick. These mice seem to be healthy,” Zhang said. The lean mice have a high metabolism, and a common check for insulin resistance, a symptom of diabetes, revealed a super sensitivity to insulin.

“We fed the mice with a very high fat diet — 60 percent fat — just to see how they would respond,” Zhang said. “Mutants can eat a lot, but they didn’t gain a lot of weight. They are less fatty around their middles compared with their littermates.”

Obese people develop a “fatty liver,” and so did the wild type littermates. The fat mice also developed high blood cholesterol with elevated levels of the “bad” type, LDL. In lean mutants, LDL increased much less.

“All of these observations support that the modified mice have better metabolic profiles,” Zhang said.

The genetic manipulations disabled the FIH gene entirely. “In every tissue, in every cell, the protein is gone,” Zhang said. But the scientists wanted to know what part of the mouse physiology was responsible for the changes, so they created new mice in which the FIH protein was deleted only in specific tissues: the nervous system or the liver.

Mice that were missing FIH only from their nervous system showed most of the same effects. “But if it was only deleted in the liver, then no.” Zhang said.

Though smaller, the mutant mice eat and drink 30 to 40 percent more than wild-type mice.

“Where do those calories go? To heat generation and an increased heart rate.” Johnson said. They also breathe heavily compared with normal mice, taking in 20 to 40% more air. “This deep breathing is like exercise for them.”

The FIH protein is part of a wide system that responds to low levels of oxygen. The mice behave as if they are breathing thin air. When people travel to higher altitudes, they breathe heavily for a few days, then adjust by producing more oxygen-carrying blood cells. “These mice never adjust to the apparent low oxygen,” Johnson said. “They stay in this acute phase of hypoxic response their whole lives.”

Sourced and published by Henry Sapiecha 19th April 2010

Chocolate may cure coughs


Go on, have another bite (Image: iStockphoto)

An ingredient in chocolate could be used to stop persistent coughs and lead to more effective medicines, say U.K. researchers.

Their small study found that theobromine, found in cocoa, was nearly a third more effective in stopping persistent coughs than codeine, currently considered the best cough medicine.

The Imperial College London researchers, who published their results online in the FASEB Journal, said the discovery could lead to more effective cough treatments.

“While persistent coughing is not necessarily harmful it can have a major impact on quality of life, and this discovery could be a huge step forward in treating this problem,” said Professor Peter Barnes of Imperial College and Royal Brompton Hospital.

Ten healthy volunteers were given theobromine, codeine or a dummy pill during the trial.

Neither the volunteers nor the researchers knew who received which pill.

The researchers then measured levels of capsaicin, which is used in research to cause coughing and as an indicator for how well the medicines are suppressing coughs.

The team found when the volunteers were given theobromine, the concentration of capsaicin needed to produce a cough was around a third higher than in the placebo group.

When they were given codeine they needed only marginally higher levels of capsaicin to cause a cough compared with the placebo.

The researchers said that theobromine worked by suppressing vagus nerve activity, which is responsible for causing coughing.

They also found that unlike some standard cough treatments, theobromine caused no adverse effects on the cardiovascular or central nervous systems, such as drowsiness.

Dry coughs

The type of cough medicine someone takes depends on the type of cough they have.

Productive coughs, or coughs associated with phlegm, are treated with expectorants, drugs that help the body expel mucus from the respiratory tract.

But dry coughs are treated with antitussives, medicines that suppress the body’s urge to cough. And it is the antitussive class of cough medicines that the U.K. researchers looked at.

Antitussives can work centrally, via the brain, or peripherally, via the respiratory tract.

Codeine is one of the antitussives that acts centrally. But the researchers think that theobromine acts on the peripheral nervous system.

Theobromine is also a stimulant and belongs to the same class of molecule as caffeine.

While their chemical structures are similar, they have very different effects on the body. Theobromine is a mild, lasting stimulant that improves your mood while caffeine is stronger and acts very quickly to increase alertness.

Sourced and published by Henry Sapiecha 13th May 2009


White tea may fight obesity


BEIJING (UPI) — A study funded by a German health food company suggests Chinese white tea may fight obesity by reducing fat cells.

The study by Beiersdorf AG, published in the journal Nutrition and Metabolism, said extracts of white tea reduced fat levels on laboratory-grown human fat cells, The Daily Telegraph reported Friday.

Nutritionist Marc Winnefeld said the white tea extract induced a decrease in the expression of genes associated with the growth of new fat cells and prompted existing adipocytes to break down the fat they contain, the British newspaper reported.
White tea is named for the white downy fur that covers the unopened bud of the tea leaf. During manufacturing, the buds are lightly steamed instead of being rolled and fermented, the report said.

Copyright 2009 by United Press International

Sourced and published by Henry Sapiecha 4th May 2009

Phthalates found in obese children


NEW YORK (UPI) — A U.S. study suggests endocrine disruptors such as phthalates may play a role in childhood obesity, the Mount Sinai School of Medicine said.

Researchers found children in New York’s East Harlem are three times more likely than other children in the United States to be overweight.
The study determined neighborhood characteristics — including availability of convenience foods — likely play a strong role in the number of obese children. Eighty percent of the children in the study reported purchasing food items from convenience stores at least one time per week, the hospital said in a report released Thursday.

High levels of phthalates and Bisphenol A found in the children’s urine may play a role in obesity by disrupting hormones that regulate growth and development, researchers said. Higher levels of three endocrine disruptors — 2,5 DCP, MBP and MEHHP — were also found.
The levels of DCP, formed in the body from the chemical DCB, were three to 10 times higher than those found in a national sample of children the same age, the report said. The chemical is common in mothballs, room deodorizers and toilet bowl deodorizer cakes.

Sourced and published by Henry Sapiecha 22nd April 2009

Factors other than genes may cause obesity


WEST LAFAYETTE, Ind. (UPI) — Purdue University scientists say factors other than genetics may be involved in the development of obesity.

The researchers said they have uncovered evidence that genetically identical cells store widely differing amounts of fat, depending on subtle variations in how the cells process insulin. They said identifying the precise mechanism responsible for fat storage in cells could lead to methods for controlling obesity in humans.

“Insights from our study also will be important for understanding the precise roles of insulin in obesity or Type II diabetes and to the design of effective intervention strategies,” said Assistant Professor Ji-Xin Cheng, who said the findings indicate the faster a cell processes insulin, the more fat it stores.

Although other studies have suggested certain “fat genes” might be associated with excessive fat storage in cells, the Purdue researchers confirmed such genes are expressed, or activated, in all of the cells. Yet those cells varied drastically — from nearly zero in some cases to pervasive in others — in how much fat they stored.

The study is reported in the online journal PLoS One.

Copyright 2009 by United Press International

Sourced and published by Henry Sapiecha 20th April 2009