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.
Fish Oil Supplements Can Be Purer Than Fish
Fish Oil Supplements Can Be Purer Than Fish
University of Southern California School of Pharmacy Detects No PCBs in Fish Oil Supplements in Health Products for Americas Top Retailers.
CARSON, Calif., Jan. 9 — As more Americans eat fish to protect themselves against heart disease and other illnesses, the scientific community debates whether toxins found in fish can do more harm than good. A recent study to be published in the journal Science found that farm raised salmon contained high levels of pollutants like PCBs and pose a health risk to humans. While the debate will continue on acceptable levels of PCB consumption in fish, consumers should understand that fish oil supplements can be purer than fish and are still safe to take.
Recognizing the serious health risks associated with PCBs found in food, Leiner Health Products asked the University of Southern California School of Pharmacy (USC) to test fish oil supplements it sells to the nation’s top retailers. Using analytical procedures approved by the Environmental Protection Agency (EPA), USC randomly analyzed fish oil supplements from 18 different lots. No PCBs, dioxins or heavy metals such as lead, cadium, mercury or arsenic were detected in any of the samples.
“We used EPA’s best method (Gas Chromatography-Electron Capture Detector (GC-ECD) to test Leiner’s fish oil capsules for PCBs. This is a complex, confirmed method of analysis that has been used for over 30 years. Our analysis supports the American Heart Association’s findings of the health benefits from consuming fish oil in the form of dietary supplements. Our research proves that people can take fish oil supplements without risking their health due to possible environmental contaminant intake,” remarked Dr. Roger Clemens, Director of Analytical Research & Services, USC School of Pharmacy.
Additional samples of Leiner’s fish oil capsules were also independently evaluated by Covance Laboratories in Madison, Wisconsin. Those findings were consistent with the USC results.
Some people believe fish oil supplements contain higher concentrations of PCBs than fish but this is not true. In order to produce the purest possible fish oil, Leiner uses a process called molecular distillation to remove pollutants. This process is similar to a water purification process that traps virtually all contaminants, resulting in a “”clean”" oil.
Molecular distillation is an excellent way to rid fish oil of PCBs, other toxins and heavy metals such as mercury, lead, cadium and arsenic to below detectable levels. While it is impossible to remove 100% of all impurities, Leiner fish oil processed using molecular distillation exceeds purity standards set by California’s Proposition 65 requirements and the EPA requirements, which are much more rigorous than FDA.