Resveratrol Helps The Heart Says New University Study
Resveratrol Keeps Hearts Young
June 4, 2008
Resveratrol, A natural compound found in red wine, may protect the heart against the effects of the aging process, researchers said on Tuesday.
In their study, mice were given a diet supplemented with the compound known as resveratrol starting at their equivalent of middle age until old age. These mice experienced changes in their gene activity related to aging in a way very similar to mice that were placed on a so-called calorie restriction diet that slows the aging process by greatly cutting dietary energy intake. Most striking was how the resveratrol, like calorie restriction, blocked the decline in heart function typically associated with aging, according to Tomas Prolla, a University of Wisconsin professor of genetics who helped lead the study. Much as Spaniard Juan Ponce de Leon once searched for the mythical fountain of youth, researchers now are seeking ways to extend the quality and length of human life. In some studies, animals given a diet with greatly reduced caloric intake have lived longer than animals with normal diets. But perpetual hunger is a steep price to pay for greater longevity, some researchers say. Resveratrol, found in abundance in grapes and in red wine, has drawn a lot of interest from scientists and some companies, including GlaxoSmithKline, which in April said it would pay $720 million to buy Sirtris Pharmaceuticals Inc, a company that is developing drugs that mimic the effects of resveratrol. Some studies have shown that in high doses, resveratrol extended the life span of fruit flies and worms and prevented early death in mice fed a high-fat diet. In this study, mice were given relatively low doses compared to the earlier research, and still experienced important aging-related benefits, the researchers said. The researchers began giving the resveratrol diet to the mice when they were 14 months old — their middle age — and followed the animals until they were about 30 months old. The researchers then conducted tests on cardiac function and on gene activity related to aging. “”Resveratrol at low doses can retard some aspects of the aging process, including heart aging, and it may do so by mimicking some of the effects of caloric restriction, which is known to retard aging in several tissues and extend life span,”" added Prolla, whose study was published in the scientific journal PLoS ONE. Using a method that permits simultaneous analysis of thousands of genes at the same time, the researchers found a huge overlap in the genes whose activity were changed by resveratrol and caloric restriction. They looked at the heart, brain and muscles, and said that the effect of resveratrol was strongest in the heart but did prevent some aging-related changes in the other tissues. Just because mice had these benefits does not mean people also would, although Prolla said, “”I think there’s a high likelihood that our findings are applicable to humans.”" He said he expected to see a lot of studies in the coming years on the effects of resveratrol supplementation in people.
Longevity Boost Tied to Specific Nutrients, Not Caloric Restriction
Longevity Boost Tied to Specific Nutrients Cutting fat and protein extends fly lifespan without calorie restriction Cutting fat and protein extends fly lifespan without cutting calories, providing further insight into the effects of diet on longevity.
Caloric restriction is known to extend lifespan in many organisms.
Linda Partridge of University College London and colleagues wanted to determine whether, at least in flies, this is due to a total reduction of calories or a reduction of particular nutrients.
So the researchers varied the nutrients in the fly’s standard lab diet of yeast and sugar.
Both yeast (which contributes protein and fat) and sugar (carbohydrates) have the same calories per gram, allowing the researchers to adjust nutrient composition without affecting the calorie count.
They found that reducing both nutrients increased the flies’ life span, but cutting out the yeast had nearly as great an effect.
Flies on a calorie-restricted diet lived 82% longer than controls, flies on the yeast-restricted diet had a 65% gain and flies on a sugar-restricted diet had just about a 9% gain.
Partridge and colleagues suggest that yeast and sugar trigger different metabolic pathways with different effects on lifespan.
The research is reported in the journal PLoS Biology Read the full text here <a href=”"http://biology.plosjournals.org/perlserv/?request=get-document&doi=10.1371/journal.pbio.0030223″” Nutrients not Caloric Resriction Responsible for Life Extension
Soup Diet Makes Weight Loss Easy
(HealthScoutNews) — Dieting? Here’s a tip from the American Journal of Clinical Nutrition — have a bowl of soup.
That advice comes by way of a study from the nutrition department at Pennsylvania State University. Researchers already knew that watered-down foods with a “”low caloric density”" could fill you up just as well as foods that had more calories in every spoonful.
But what if the food and water were consumed separately? To test the notion, one group of people ate a bowl of soup, and another group ate a casserole made with the same ingredients as the soup, then drank a glass of water.
The results: people who ate the soup were full after 1,209 calories. The people who had the casserole with the water on the side kept going until they had reached 1,657 calories.
PSA Test
PSA Test a Thing of the Past? MONDAY, May 10 (HealthDayNews) — The PSA test, long the gold standard for deciding who should have a biopsy for prostate cancer, may have outlived its usefulness for the most part.
Stanford University researchers say PSA (prostate specific antigen) levels bear little relationship to the severity of a cancer these days. They presented their finding May 9 at the American Urology Association’s annual meeting in San Francisco.
“”We need to recognize that PSA is no longer a marker for prostate cancer,”" said study author Dr. Thomas A. Stamey, a professor of urology at Stanford University School of Medicine. “”We urgently need to find a new marker for prostate cancer, and that marker must be proportional to how much cancer you have.”"
“”We have been so thorough and effective in screening for prostate cancer over this 20-year period that PSA no longer has a relationship to prostate cancer,”" Stamey said. “”Because we all develop the cancer, we’re now removing prostates from men whose cancer is so small that they do not need the procedure. We’re finding all these little cancers that are never going to be a danger to the patient.”"
“”In smaller cancers, the PSA test is not relevant anymore,”" Stamey explained. “”You might as well biopsy a man because he has blue eyes.”"
PSA is a protein produced by the cells of the prostate gland. Because blood levels of the antigen tend to rise as the gland enlarges, it has been used for years as a test of whether a person needs a biopsy for cancer. The test, however, is not foolproof.
“”People’s perceptions [are] that if your PSA is a certain level, you’re very likely or you do have prostate cancer, and that is incorrect,”" said Dr. Mark Soloway, chairman of the department of urology at the University of Miami School of Medicine.
“”The PSA test is a very good test. It’s not a perfect test, especially in younger men,”" added Dr. Jay Brooks, chief of hematology/oncology at the Ochsner Clinic Foundation in New Orleans.
To see how the efficacy of the PSA test might have waned, researchers in Stamey’s lab reexamined every prostate that had been removed since 1983 (1,317 of them) and compared the size of the cancer with blood PSA levels. None of the cancers had been treated with chemotherapy, radiation, or hormones before surgery.
Each cancer was rated on eight or 10 different parameters thought to indicate how aggressive the cancer was, including the size of the tumor and its grade.
Stamey then divided the samples into four five-year periods to see what had happened to the qualities of the cancers over time.
“”What we showed was that in the first five years, the cancers were related to the level of serum PSA,”" Stamey said. “”Then in the next five years, they were still bad but not as bad as the first five years. Then in the third five-year period, they were better and better. And in the last five years ending Jan. 1 of this year, the cancers were so small they had no relationship to serum PSA.”"
Twenty years ago, 80 percent of cancers were detected by digital rectal examination; only 20 percent of cancers are now detected that way, Stamey explained.
Instead, PSA levels today are driven by benign enlargement of the prostate, a condition that does not usually require surgery.
The concept that the PSA test is not foolproof is not an entirely new one. “”The point is well taken that in microscopic disease, the volume of cancer is clearly overshadowed by the volume of noncancer, so that the cancer cannot be the cause of the elevated PSA,”" said Dr. John Phillips, physician-in-charge of urologic oncology at Beth Israel Medical Center in New York City.
The question now is what can replace it. “”People are trying to find other ways of finding cancer,”" Phillips added.
As a matter of fact, University of Pittsburgh researchers who presented at the same conference reported that additional testing for a protein called early prostate cancer antigen (EPCA) might mean prostate cancer could be detected as many as five years earlier than with just the PSA test.
“”We would like a perfect test that would only find biologically significant cancers,”" Soloway said. “”Today we can’t distinguish between those with indolent cancer and those whose cancers threaten their life. We need another way. That’s going to be a difficult task.”"
In the meantime, the American Urological Association issued a statement that, for the time being, the PSA test in combination with a digital rectal exam and a full medical history is the best way to determine when a biopsy might be necessary
Brain Cell Growth Boosted By DHEA Supplements
‘Anti-aging’ hormone DHEA Found to Boost Brain Cell Growth August 24, 2004
Human neural stem cells, exposed in a lab dish to the steroid DHEA, exhibit a remarkable uptick in growth rates, suggesting that the hormone may play a role in helping the brain produce new cells, according to a new study published this week in the online edition of the Proceedings of the National Academy of Sciences (PNAS).
The new work, conducted by a team of scientists at the University of Wisconsin-Madison, provides some of the first direct evidence of the biological effects of DHEA on the human nervous system, according to Clive Svendsen, the study’s senior author and an authority on brain stem cells at UW-Madison’s Waisman Center.
“What we saw was that DHEA significantly increased the division of the cells,” said Svendsen, a UW-Madison professor of anatomy and neurology. “It also increased the number of neurons produced by the stem cells, prompting increased neurogenesis of cells in culture.”
DHEA or dehydroepiandrosterone is among the most abundant naturally occurring steroids in the blood of young humans, but levels decline with age and its physiological effects are poorly understood.
A synthetic form of the hormone is sold over-the-counter as a dietary supplement in the US, thought to have anti-aging properties and to offer prevention against cancer and heart disease, Alzheimer’s and other diseases. But scientists know relatively little about the drug and its basic biological effects on humans.
“We don’t know much about DHEA, but this new work adds a piece to the puzzle,” said Svendsen, who conducted the study with colleagues Masatoshi Suzuki, Lynda S. Wright, Padma Marwah and Henry A. Lardy, all of UW-Madison. “This is the first real evidence of DHEA’s effects on human neural cells.”
Svendsen and Suzuki carried out the experiments by growing human fetal neural stem cells in culture. The cells form aggregates known as ‘neurospheres,’ which were exposed to a cocktail of DHEA and growth and inhibitory factors, and observed a 29 per cent increase in new brain cells compared to cells grown in a medium with the same factors, but without DHEA.
“We saw such a pure effect of DHEA,” Svendsen said.
“It’s the only steroid we tested that had such a direct effect on stem cell growth and new neuron formation,” according to Suzuki.
The new work is important because it provides a direct window to the controversial hormone’s effects on critical human cells. Similar studies have been conducted in mice and rats, but those models have shortcomings that are difficult to address, Svendsen notes.
“There are previous studies in rats that suggest DHEA is neuroprotective, but the problem with DHEA in rats is that it is not a major metabolite in that animal so its effects may not be the same as those seen in humans,” he said. According to Lardy, metabolic products of DHEA hormone have also been shown to aid memory retention in old mice.
Despite hints from the studies in rodents that DHEA may play a role in enhancing the brain and memory, the new findings reported in the PNAS article were a surprise, he said.
“We assumed the compounds we were testing would be more active than DHEA in brain stem cells,” Lardy explains. In previous studies, Lardy, with Wisconsin biochemistry colleagues James Ntambi and Brian Fox, showed that DHEA blocked a step in fat synthesis.
“The effects of DHEA on brain stem cells is a completely new finding,” said Lardy. “The problem of whether DHEA itself is having this effect, or if there’s another metabolite of the hormone involved, still exists.”
One of the intriguing aspects of the new work, according to Svendsen, is the possibility that DHEA could have some positive effects on the adult human brain.
It is known that DHEA amounts fall progressively during aging, and reduced levels of DHEA have been reported in both adolescents and adults with major depressive disorders. And given the fact that adult humans have neural stem cells that continue to make new neurons in some parts of the brain, there is a possibility that DHEA could play a role in moderating the genesis of new brain cells.