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.
Scientists Learning More Why Aging Cells Fail to Repair Themselves
Why Aging Cells Lose Ability to Repair Themselves Study finds defect that could lead to new treatments for disease
FRIDAY, Sept. 5 (HealthWire) — A defect in the body’s self-defense mechanism against age-related genetic mutations has been identified by researchers at the University of Texas Medical Branch at Galveston.
The finding may help explain why the aging human body can’t defend itself against DNA damage in the mitochondria, the power plants that fuel the growth and activity of cells.
Finding ways to help aging cells repair their own damaged DNA could possibly lead to ways to prevent or treat cancer, Alzheimer’s disease, Parkinson’s disease and other health problems caused by genetic defects.
As cells age, they experience continuous genetic mutations, some of which are caused by the harmful byproducts of the oxygen we inhale. But the body’s repair mechanism is constantly at work fixing this DNA damage. However, this repair activity becomes less efficient as cells age.
In this study, the researchers analyzed why this DNA repair activity becomes less effective in the mitochondria as cells age. They found a biochemical “”roadblock”" that prevents much of the repair enzyme activity from reaching the site of the DNA damage in the mitochondria of aging cells.
In old cells, about half of the repair enzyme activity can’t reach the mitochondria DNA to repair it.
The study was published online this week in the Proceedings of the National Academy of Sciences.
Science Begins to Add Weight to CLA
The flurry of activity in CLA applications is being backed by a growing body of research to support the ingredient, particularly for its effects on weight loss. A review published in this month’s Journal of Nutrition supports conjugated linoleic acid’s action on weight management, concluding that it is at least in part due to regulation of glucose and fatty acid uptake and metabolism.
Conjugated linoleic acid is the common name of a group of fatty acids found in dairy products and meat. CLA isomers have been studied for their action on an impressive range of diseases, including cancer, atherosclerosis, obesity, and immune function. However as scientists begin to reveal their effects on reduction of body fat, food makers are increasingly looking at the ingredient for the valuable slimming market.
In Canada, where many of the patents for CLA are held, the dairy industry has long been studying the production of high-CLA milk. In Europe, a research centre in Ireland is studying the compound which could add significant value to its dairy industry, while in Italy, Techno Foods introduced a strawberry flavoured yoghurt naturally rich in CLA (conjugated linoleic acid) and omega-3 fatty acids this summer.
Specific CLA isomers have been shown to prevent the development of obesity in certain rodent and pig models and this has been attributed mainly to trans-10, cis-12 CLA, both in vivo and in vitro, write the University of North Carolina researchers in the review. However, CLA’s ability to modulate human obesity remains controversial because data from clinical trials using mixed isomers are conflicting.
In vitro studies by the team demonstrated that while trans-10, cis-12 CLA prevents triglyceride accumulation in human cells, cis-9, trans-11 CLA increases triglyceride content. The team concluded that the isomers’ regulation of glucose and metabolism must partly explain its mechanism on human fat.
The news is also good for supplement marketers who recently learned of research carried out by Cognis backing the long-term safety of its Tonalin CLA.
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.