Wednesday, October 19, 2011

The Mystery of Epigenetic Heredity, and Its Possible Impact on Longevity

The basic mechanisms of life and inheritance function much the same in worms, fruit flies, mice, and humans. That is one reason why lower life forms are used so often in longevity research. Much shorter lifespans is another reason. A recent Stanford study on worms provides a hint at an epigenetic method of inheritance which may eventually prove useful for extending lifespans in human offspring.
The study used Caenorhabditis elegans worms with very low levels of the SET-2 enzyme. The SET-2 enzyme normally adds methyl molecules onto DNA's protein packaging material. In doing so, the enzyme opens up the packaging material, allowing the genes to be copied and expressed. Some of those genes appear to be pro-aging genes, says Brunet. Her team knocked out SET-2 by removing genes that code for it. This had the effect of significantly lengthening the worms' lifespan, presumably because those pro-aging genes were no longer expressed.

Next, the long-lived, enzyme-lacking worms mated with normal worms. The offspring had the regular genes for making SET-2, and even expressed normal amounts of the enzyme, but they lived significantly longer than control worms whose parents both had regular lifespans. The life-extending effect carried over into the third generation, but returned to normal by the fourth generation (in the great-grandchildren of the original mutant worms). For the first few generations, having a long-lived ancestor increased life expectancy from 20 days to 25, extending a worm's life by 25 to 30 percent on average.

Brunet and her team haven't yet determined the exact mechanism for the lifetime extension, or which molecules are at work. This is one of the study's imperfections, says David Katz, who researches epigenetic transcriptional memory at Emory University. Regardless, "the effect is clearly epigenetic," he says, "and it's probably one of the most complicated traits that has been linked to epigenetic inheritance."

...The results, published October 19 in Nature (Scientific American is part of Nature Publishing Group), provide the first evidence that some aspects of lifespan length can be passed from parent to offspring, independent of the direct influence DNA. _SciAm
Contrary to what Dr. Katz asserts above, the fact that the research team hasn't determined the exact mechanism for the lifetime extension is one of the study's great promises.

Remember, it is often the questions that a study raises which causes the study to become frequently cited, and immortalised -- not necessarily the questions the study answers. Studies that raise good questions often act as springboards for entire new developments in science. Such may be the case here.


Sunday, October 09, 2011

What Supplements Should Be Taken to Preserve the Brain?

A recent study published in the Journal of Intelligence looked at the effects on IQ of a proprietary combination of nutritional supplements, called Ceretrophin, vs. placebo. The combination is made up of Huperzine A, Vinpocetine, Acetyl-l-carnitine, R. Rosea and Alpha-lipoic acid, all readily available over the counter in the US. The researchers tested the subjects on Ravens Advanced Progressive Matrices (APM) prior to treatment and after 4 weeks of treatment or placebo.
A significant study visit (time) treatment condition interaction was found: F (1, 57) = 7.279, p = 0.009, partial 2 = .113, with paired samples t-tests revealing a significant improvement in mean APM score from baseline to retest (week 4) (t(34) = 4.045, p < .001) for the Ceretrophin group. Improvements in APM scores could be attributed to the active intervention over the placebo, indicating that the treatment improved general intelligence. Implications for improving our understanding of the biological basis of intelligence and pharmacologically improving human cognition are discussed. _Intelligence_via_Inductivist
Ron Guhname at the Inductivist blog suggests that this improvement in Ravens APM scores represents an increase in IQ score of 6 points (see comment at link).

The assortment of supplements included in "Ceretrophin" provides a wide spectrum of effects on neural tissues, including anti-inflammatory, stimulant, vascular, and neuroreceptor effects.

In addition to the supplements listed, there are a number of others which should be considered, including curcumin and omega 3 fatty acids. It would be easy to go overboard on taking supplements, so make sure that you find a good justification for each supplement that you choose to take. Also keep in mind possible interactions between supplements, between supplements and any drugs you may take, an any potential of supplements to exacerbate a pre-existing condition you may have.

In general, the doses of supplements and herbs available OTC in pills and capsules in western nations, should not represent significant risk to most individuals.

Al Fin gerontologists and cognitive scientists do not dispute the findings in the study, although they feel the sample size was too small for definitive conclusions. Nevertheless, the study suggests that similar research with larger sample sizes and a variety of supplement combinations could be justified.


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