Vet Blog

07/29/09

Yet Another Article Shows That Calorie-Restricted Diets Increase Life Span. Too Bad Nobody Ever Will Follow the Program!
Dr. Eric Barchas, DVM

hungry-the_lentil_eater_is_hungryWhen I was reviewing the Health and Science section of the July 31, 2009 issue of The Week for Monday’s article about cats purring, another blurb caught my eye. It’s totally off topic, but I can’t resist commenting. I’ll return to juicy veterinary topics tomorrow.

The content in the short article has been published thousands (or perhaps hundreds of thousands) of times over the last ten years. It keeps being repackaged as a new story and sold to the public as a revolutionary discovery–even though it is old, old news. I guess the editors believe that the human quest to live forever will make us forget that this story was published in one form or another last year, and the year before, and the year before, and . . .

Living longer by going hungry

If we eat a lot less, will we live longer? It works for monkeys, says The New York Times. After studying a group of rhesus monkeys for 20 years, scientists found that those that were fed one-third less food aged much more slowly than their peers, which were allowed to eat as much as they wanted. The calorie-restricted monkeys also showed less deterioration of muscle and brain matter, conditions that typically come with aging, and appeared to be on course to live up to 20 percent longer than the norm. For humans, that might mean extending life spans by seven to 15 years. “We were frankly blown away by these findings,” says lead research Richard Weindruch, of the University of Wisconsin School of Medicine and Public Health.

Dr. Weindruch, were you set up to look silly in that quote? Surely a researcher in your field is aware of the dozens of studies and countless (dare I say mercilessly incessant stream of) news articles documenting this completely unsurprising fact in basically every species imaginable–except humans (more on that soon). You could not plausibly have been “blown away” by this new set of results.

The article continues . . .

The results dovetail with other research indicating that caloric restriction can extend the lives of mice, dogs, yeast, fruit flies, and worms.

You don’t say?

I remember a decade or so ago when the first study showed that calorie restriction increased life span in rodents. I realized that I might be able extend my life span significantly, if only someone would lock me in a cage and starve me.

No study of this matter has been performed in humans, because almost nobody willingly starves him- or herself. In fact, people who voluntarily refuse to eat are considered to suffer from pathology: anorexia nervosa.

The hope of these types of studies is that chronic starvation activates genes that extend life span. Ideally, some day we will be able to activate these genes without having to go hungry. Then we can all live to be 130, and collect Social Security for half of our lives. (My apologies to the youthful Americans who will be stuck paying for this. One day you also will have the opportunity to stick it to a younger generation.)

Meanwhile, I’m going to start my day with an omelette.

Photo: say goodbye to longevity! By Mattia Luigi Nappi.

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07/27/09

Researcher Concludes Cats Can Manipulate People
Dr. Eric Barchas, DVM

peeshyI’m going to file this one under “science adds insight into what we already knew”. I see pets (both cats and dogs) who have owners wrapped around their phalanges on a daily basis!

From the July 31, 2009 issue of The Week.

What ‘meow’ really means

Cats are known to be manipulative, and a new study of their purring confirms just how clever they can be. Karen McComb, an animal-communication researcher at the University of Sussex in the U.K., analyzed the purrs of house cats as they begged their owners for food. She found that when cats were hungry, they altered their purring so that it was eerily similar to the cry of an infant. When McComb played back these cat cries to human listeners, people found them almost impossible to ignore. The mixture of frequencies in the sounds “subliminally triggers a sense of urgency,” McComb tells ABCnews.com. She suspects that this human-like vocalization is natural to cats, but that they learn to exaggerate it to get what they want from us.

Photo: Peeshy knows you will obey. Who could say no to her?

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06/01/09

Cancer Linked to Clinical Depression in Rats
Dr. Eric Barchas, DVM

knockout_ratI always am saddened when I diagnose cancer in a patient. However, the remorse I feel when making the diagnosis generally has been tempered by a small silver lining. Most of the cancer patients I treat do not seem to realize that they are sick. Although humans with cancer often suffer profound psychological effects from the diagnosis, most pets behave as if they feel fine until the disease causes serious complications.

Or so I had thought.

A brief article in the June 5, 2009 issue of The Week has given me a reason to look harder at the quality of life of my cancer patients. It also has given me another reason to hate cancer–as if I needed one.

Tumors are doubly depressing

A diagnosis of cancer is obviously a good reason to be depressed. But new research finds that the feeling isn’t just psychological: Tumors produce high levels of a chemical that can effect [sic] mood and make people feel down. Behavioral neuroscientists at the University of Chicago compared depression and anxiety rates in groups of rats with and without tumors. Since rats have no awareness that they have cancer, Dr. Brian Pendergast tells BBCnews.com, “their behavioral changes were likely the result of purely biological factors.” He found that rats with cancer exhibited signs of depression and anxiety, floating passively when placed in water while cancer-free rats swam for safety. The tumor-ridden rats also hoarded and buried objects they were given, and lost interest in eating sweets. The scientists believe that the anxious and depressive behavior is connected to levels of chemicals called cytokines, which are produced by tumors and also by the immune system when it’s battling cancer. Rats with tumors had double the normal level of cytokines, which have a direct, depressing effect on emotional centers in the brain.

Note that this study does not say anything specifically about dogs or cats. But it does give me an additional reason to hope that some major breakthroughs in cancer research will come soon. For the record, I think they will.

Also, be aware that a great deal of research currently is directed towards understanding and modifying cytokines (cytokines are linked to pain and a number of other physiological responses that might be modifiable through pharmaceuticals). However, in the case of cancer, there is no doubt that the best approach is not to target cytokines. The best tactic is to cure the disease.

Photo: Transposagenbio. License: CC.

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05/16/09

$12 Million Study Discovers Unusual Flavor in Wine
Dr. Eric Barchas, DVM

From the May 22, 2009 issue of The Week:

(It was a good week for) nuance, after a six-year, $12 million scientific study identified the flavors in New Zealand’s signature Sauvignon Blanc as a combination of passion fruit, asparagus, and cat’s pee. “If you had a whole lot of cat’s pee it obviously wouldn’t be great,” said researcher Sue Blackmore. “It’s amazing what a little can do.”

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