News flashes are posted here frequently to keep you up-to-date with the latest advances in health and longevity. We have an unparalleled track record of breaking stories about life extension advances.
Genetics has less impact on lifespan than once believed
November 12, 2018. The November 2018 issue of Genetics published an article by J. Graham Ruby of Calico Life Sciences and colleagues which concludes that estimates of the heritability of longevity in humans “are substantially inflated.” Heritability is a measure of how much of a variation in a trait can be explained by genetic differences as opposed to lifestyle and other factors.
"We can potentially learn many things about the biology of aging from human genetics, but if the heritability of lifespan is low, it tempers our expectations about what types of things we can learn and how easy it will be," Dr. Ruby commented. "It helps contextualize the questions that scientists studying aging can effectively ask."
Using publicly-available data obtained for over 400 million people from the online genealogy company Ancestry, the team estimated heritability by examining the similarity of life span between relatives. In addition to similar lifespans among blood relatives, similarities were also observed between people who were related only by marriage and did not share households.
The researchers found that heritability of life span was no more than 7%, in contrast with previous estimates of up to 30%. It was determined that past estimates had failed to account for the tendency of humans to select partners with traits that were similar to their own, a process known as assortative mating. "What assortative mating means here is that the factors that are important for life span tend to be very similar between mates," Dr. Ruby explained. “When we failed to take assortative mating into account, our own nominal estimates were similar to those of the literature.”
The finding suggests that if the rate of human aging depends less upon our genes, which we cannot yet change, than upon things that can be modified.
Selenium compound mimics calorie restriction effects
November 9, 2018. An article published on October 24, 2018 in Molecular Medicine Reports reveals improvements in lifespan and aging-associated changes in association with selenocysteine supplementation in the roundworm Caenorhabditis elegans.
“Selenocysteine, a sulfur‑containing amino acid, can modulate cellular oxidative stress defense systems by incorporating into antioxidant enzymes such as glutathione peroxidase and thioredoxin reductase.,” write So-Hyeon Kim and colleagues. “A recent study revealed that dietary supplementation with selenocysteine can increase the resistance of Caenorhabditis elegans to environmental stressors and its lifespan. The objective of the present study was to identify the underlying mechanism involved in the lifespan‑extending effect of selenocysteine and the effect of selenocysteine on age‑associated pathophysiological changes.”
The research involved normal C. elegans worms and genetically modified strains. Supplementation with selenocysteine increased the lifespan of normal worms as well as two of three strains of worms modified to live longer lives. Lack of a significant lifespan increase in association with selenocysteine supplementation in a third worm strain that was a model of dietary restriction suggested that the compound exerts its effects by similar mechanism. It was determined that selenocysteine requires the transcription factor SKN-1 (which is known to regulate responses to dietary restriction-induced lifespan in C. elegans) to extend life.
Further experimentation revealed that selenocysteine decreases the toxicity of amyloid beta, a protein that forms plaques in the brains of Alzheimer’s disease patients. Selenocysteine was also shown to decrease toxicity induced by high levels of glucose and cellular reactive oxygen species.
The research provides evidence for the development of dietary restriction mimetics utilizing selenocysteine. “Further studies focusing on the effect of selenocysteine on age‑related diseases such as Alzheimer’s disease Parkinson's disease, and diabetes mellitus in mammalian disease models and the molecular basis of the effect of selenocysteine are necessary for the understanding of in vivo activity of selenocysteine,” the authors conclude.
Coffee compounds may be protective against Alzheimer’s, Parkinson’s disease
November 7, 2018. On October 12, 2018, the journal Frontiers in Neuroscience reported the finding of the Krembril Research Institute of a potential protective effect for coffee-drinking against Alzheimer’s and Parkinson’s disease.
"Coffee consumption does seem to have some correlation to a decreased risk of developing Alzheimer's disease and Parkinson's disease," noted Dr. Donald Weaver, who is codirector of the Krembil Brain Institute. "But we wanted to investigate why that is--which compounds are involved and how they may impact age-related cognitive decline."
Dr. Weaver, along with Dr. Ross Mancini and Yanfei Wang studied light roast, dark roast, and decaffeinated dark roast coffees. "The caffeinated and decaffeinated dark roast both had identical potencies in our initial experimental tests," Dr. Mancini reported. "So, we observed early on that its protective effect could not be due to caffeine."
The team identified phenylindanes, a group of compounds produced in coffee as a result of the roasting process, as able to inhibit the clumping of protein fragments known as tau and amyloid beta. Clumping of these substances can occur in the brains of both Alzheimer’s disease and Parkinson’s disease patients. "So phenylindanes are a dual-inhibitor,” Dr. Weaver observed.
Since roasting increases phenylindane content, dark roast coffee may have more potent effects than light roast.
"It's the first time anybody's investigated how phenylindanes interact with the proteins that are responsible for Alzheimer's and Parkinson's," Dr. Mancini announced. "The next step would be to investigate how beneficial these compounds are, and whether they have the ability to enter the bloodstream or cross the blood-brain barrier."
"What this study does is take the epidemiological evidence and try to refine it and to demonstrate that there are indeed components within coffee that are beneficial to warding off cognitive decline," Dr. Weaver concluded.
Zinc plus plant phenol protects against oxidative stress
November 5, 2018. Research reported on October 1, 2018 in Nature Chemistry has revealed that a combination of hydroquinone with the trace mineral zinc combats the superoxide radical, a cause of oxidative stress associated with aging and decreased life expectancy. Hydroquinone is a phenol occurring in polyphenols that are found in such foods as coffee, tea and chocolate.
Superoxide is a reactive oxygen species thought to have a role in the aging process and adverse health conditions. Not only can superoxide damage the body’s proteins and lipids, but it can also harm the cells’ DNA. Damage caused by the superoxide radical has been associated with inflammation, neurodegenerative diseases and cancer. Superoxide is quenched by an antioxidant enzyme produced in the body known as superoxide dismutase (SOD), yet the body’s production of SOD may be insufficient.
“Reactive oxygen species are integral to many physiological processes,” Meghan B. Ward and her associates write. “Although their roles are still being elucidated, they seem to be linked to a variety of disorders and may represent promising drug targets.”
By itself, hydroquinone is incapable of breakdown superoxide. The research team, led by Professor Ivana Ivanovi-Burmazovi of Friedrich-Alexander-Universität Erlangen-Nürnberg in Germany, along with Dr Christian R. Goldsmith of Auburn University, discovered that zinc activates hydroquinone, thereby protecting against harmful superoxide radicals formed during human cell respiration. The addition of hydroquinone to zinc results in a metal complex that imitates SOD. This avoids the potential problems associated with SOD mimetics which have utilized other minerals that have a greater potential for toxicity.
'It is certainly possible that wine, coffee, tea or chocolate may well become be available in future with added zinc,” predicted Professor Ivanovi-Burmazovi. “However, any alcohol content whatsoever would destroy the positive effects of this combination.”
Higher vitamin D levels linked to better cardiorespiratory fitness
November 2, 2018. An article published on October 30, 2018 in the European Journal of Preventive Cardiologyreported an association between higher serum vitamin D and a greater level of cardiorespiratory fitness, which is considered to be an indicator of physical fitness.
Amr Marawan and colleagues analyzed data that included serum 25-hydroxyvitamin D levels and maximal oxygen consumption during exercise (VO2 max) obtained from the 2001-2004 National Health and Nutrition Survey (NHANES). Among 1,995 participants, those whose vitamin D levels were among the top 25% had more than four times greater cardiorespiratory fitness (as assessed by VO2 max) in comparison with participants whose levels were among the lowest 25%. For each 10 nanomole increase in vitamin D there was associated a 0.78 milliliter/kilogram/minute increase in VO2 max. "This suggests that there is a dose response relationship, with each rise in vitamin D associated with a rise in exercise capacity," Dr Marawan explained. "The relationship between higher vitamin D levels and better exercise capacity holds in men and women, across the young and middle age groups, across ethnicities, regardless of body mass index or smoking status, and whether or not participants have hypertension or diabetes.”
"Our study shows that higher levels of vitamin D are associated with better exercise capacity," Dr Marawan concluded. "We also know from previous research that vitamin D has positive effects on the heart and bones. Make sure your vitamin D levels are normal to high. You can do this with diet, supplements, and a sensible amount of sun exposure."
"We know the optimum vitamin D levels for healthy bones, but studies are required to determine how much the heart needs to function at its best,” he added. “Randomized controlled trials should be conducted to examine the impact of differing amounts of vitamin D supplements on cardiorespiratory fitness."