Are We Aging Slower Than We Think?

Faster increases in life expectancy do not necessarily produce faster population aging, according to new research recently published in the journal PLOS ONE. This counterintuitive finding was the result of applying new measures of aging developed at International Institute for Applied Systems Analysis to future population projections for Europe up to the year 2050.

“Age can be measured as the time already lived or it can be adjusted taking into account the time left to live. If you don’t consider people old just because they reached age 65 but instead take into account how long they have left to live, then the faster the increase in life expectancy, the less aging is actually going on.” says IIASA World Population Program Deputy Director, Sergei Scherbov, who led the study in collaboration with IIASA and Stony Brook University researcher Warren Sanderson.

Stony Brook University Medical Center

Traditional measures of age simply categorize people as “old” at a specific age, often 65. But previous research by Scherbov, Sanderson, and colleagues has shown that the traditional definition puts many people in the category of “old” who have characteristics of much younger people.

“What we think of as old has changed over time, and it will need to continue changing in the future as people live longer, healthier lives,” says Scherbov. “Someone who is 60 years old today, I would argue is middle aged. 200 years ago, a 60-year-old would be a very old person.”

Sanderson explains, “The onset of old age is important because it is often used as an indicator of increased disability and dependence, and decreased labor force participation. Adjusting what we consider to be the onset of old age when we study different countries and time periods is crucial both for the scientific understanding of population aging for the formulation of policies consistent with our current demographic situation.”

In the new study the researchers compared the proportion of the population that was categorized as “old” using the conventional measure that assumes that people become “old” at age 65 and the proportion based on their new measure of age, which incorporates changes in life expectancy.

The study looked at three scenarios for future population aging in Europe, using three different rates of increase for life expectancy, from no increase to an increase of about 1.4 years per decade, the level projected by the Wittgenstein Center’s European Demographic Datasheet. The results show that, as expected, faster increase in life expectancy lead to faster population aging when people are categorized as “old” at age 65 regardless of time or place, but, surprisingly, that they lead to slower population aging when the new measures of age are used.

-MFP News Services
- 9/1/15

Markers on DNA From Fathers’ are Being Linked to Children’s Autism

Baltimore, MD – In a small study, Johns Hopkins researchers found that DNA from the sperm of men whose children had early signs of autism shows distinct patterns of regulatory tags that could contribute to the condition. A detailed report of their findings which was recently published online in the International Journal of Epidemiology.

John Hopkins Bloomberg School of Public Health

Autism spectrum disorder (autism) affects one in 68 children in the U.S. Although studies have identified some culprit genes, most cases remain unexplained. But most experts agree that autism is usually inherited, since the condition tends to run in families. In this study, investigators looked for possible causes for the condition not in genes themselves, but in the “epigenetic tags” that help regulate genes’ activity.

“We wondered if we could learn what happens before someone gets autism,” says Andrew Feinberg, M.D., M.P.H., the King Fahd Professor of Molecular Medicine and director of the Center for Epigenetics at the Johns Hopkins University School of Medicine. “If epigenetic changes are being passed from fathers to their children, we should be able to detect them in sperm,” adds co-lead investigator Daniele Fallin, Ph.D., professor and chair of the Department of Mental Health in the Bloomberg School of Public Health and director of the Wendy Klag Center for Autism and Developmental Disabilities.

In addition to being easier to sample than egg cells from women, sperm are more susceptible to environmental influences that could alter the epigenetic tags on their DNA. Feinberg, Fallin and their team assessed the epigenetic tags on DNA from sperm from 44 dads. The men were part of an ongoing study to assess the factors that influence a child early on, before he or she is diagnosed with autism. The study enrolls pregnant mothers who already have a child with autism and collects information and biological samples from these mothers, the new baby’s father and the babies themselves after birth. Early in the pregnancy, a sperm sample was collected from fathers enrolled in the study. One year after the child was born, he or she was assessed for early signs of autism using the Autism Observation Scale for Infants (AOSI).

The researchers collected DNA from each sperm sample and looked for epigenetic tags at 450,000 different positions throughout the genome. They then compared the likelihood of a tag being in a particular site with the AOSI scores of each child. They found 193 different sites where the presence or absence of a tag was statistically related to the AOSI scores.

When they looked at which genes were near the identified sites, they found that many of them were close to genes involved in developmental processes, especially neural development. Of particular interest was that four of the 10 sites most strongly linked to the AOSI scores were located near genes linked to Prader-Willi syndrome, a genetic disorder that shares some behavioral symptoms with autism. Several of the altered epigenetic patterns were also found in the brains of individuals with autism, giving credence to the idea that they might be related to autism.

The team plans to confirm its results in a study of more families and to look at the occupations and environmental exposures of the dads involved. There is currently no genetic or epigenetic test available to assess autism risk.

-MFP News Services
- 8/31/15

E-cigarettes May Have Content Which Could Be a Cause for Concern

The levels of chemicals used to flavour some brands of e-cigarette fluid exceed recommended exposure limits and could be respiratory irritants, in some cases, suggests research published online in the journal Tobacco Control.

The electronic cigarette market has developed rapidly in recent years, with global sales in 2014 estimated to be in the region of US$7 billion, but the health implications of vaping remain hotly contested.

Artificial and other flavourings in e-cigarettes are mostly the same as those used in food and confectionery manufacture, and are therefore often represented as safe by e-cigarette manufacturers.

But as the US Flavor Extracts Manufacturers Association (FEMA) has pointed out, this safety relates to exposure through eating, and not inhalation. And the ingredients listed on the product labels for e-cigarettes rarely include the chemicals used for flavouring.

The researchers therefore set out to find out the levels and type of chemicals used to flavour e-cigarette fluid in a sample of 30 products.

These included two single use disposable brands in five different flavours of tobacco, menthol, vanilla, cherry and coffee; the same flavours in refill bottles; and additional flavours of chocolate/cocoa, grape, apple, cotton candy and bubble gum in refill bottles.

The flavouring chemicals totalled more than 1% by volume in 13 of the 30 liquids analysed, levels greater than 2% by weight in seven liquids, and levels greater than 3% by weight in two products.

Seventeen of the products contained the same vanillin or ethyl vanillin flavourings, suggesting that a small number of chemicals are particularly popular with manufacturers and users.

And many of the ‘tobacco’ flavoured fluids contained chemicals used to flavour confectionery.

Six of the 24 compounds revealed in the analyses were aldehydes, compounds recognised to be primary respiratory irritants.

Using a consumption rate of around 5 ml/day, as commonly reported on online vaping forums, vapers would be exposed to twice the recommended occupational exposure limits of benzaldehyde and vanillin with the products tested, say the researchers.

“And toxic degradation products may be produced by reaction of the flavour chemicals at the high temperatures present during vaping,” they caution.

They admit that their sample represents a fraction of the e-cigarette products on the market.

But they say: “Nevertheless, the results obtained are likely to be similar to what a broad survey would have revealed, and in any case, suggest that very high levels of some flavour chemicals are undoubtedly present in a great number of the thousands of products currently available.”

Regulations are needed, they argue. These should include compulsory ingredient listing, limiting the levels of certain flavourings, and limiting the total permissible levels of flavourings, particularly as there is some concern that flavoured products might make e-cigarettes more attractive to young people, they suggest.

-MFP News Services
- 8/31/15