(Press-News.org) DURHAM, N.C. -- Looking around at a 20th high school reunion, you might notice something puzzling about your classmates. Although they were all born within months of each other, these 38-year-olds appear to be aging at different rates.
Indeed they are, say the leaders of a large long-term human health study in New Zealand that has sought clues to the aging process in young adults.
In a paper appearing the week of July 6 in the Proceedings of the National Academy of Sciences, the team from the U.S., UK, Israel and New Zealand introduces a panel of 18 biological measures that may be combined to determine whether people are aging faster or slower than their peers.
The data comes from the Dunedin Study, a landmark longitudinal study that has tracked more than a thousand people born in 1972-73 in the same town from birth to the present. Health measures like blood pressure and liver function have been taken regularly, along with interviews and other assessments.
"We set out to measure aging in these relatively young people," said first author Dan Belsky, an assistant professor of geriatrics in Duke University's Center for Aging. "Most studies of aging look at seniors, but if we want to be able to prevent age-related disease, we're going to have to start studying aging in young people."
Belsky said the progress of aging shows in human organs just as it does in eyes, joints and hair, but sooner. So as part of their regular reassessment of the study population at age 38 in 2011, the team measured the functions of kidneys, liver, lungs, metabolic and immune systems. They also measured HDL cholesterol, cardiorespiratory fitness, lung function and the length of the telomeres -- protective caps at the end of chromosomes that have been found to shorten with age. The study also measures dental health and the condition of the tiny blood vessels at the back of the eyes, which are a proxy for the brain's blood vessels.
Based on a subset of these biomarkers, the research team set a "biological age" for each participant, which ranged from under 30 to nearly 60 in the 38-year-olds.
The researchers then went back into the archival data for each subject and looked at 18 biomarkers that were measured when the participants were age 26, and again when they were 32 and 38. From this, they drew a slope for each variable, and then the 18 slopes were added for each study subject to determine that individual's pace of aging.
Most participants clustered around an aging rate of one year per year, but others were found to be aging as fast as three years per chronological year. Many were aging at zero years per year, in effect staying younger than their age.
As the team expected, those who were biologically older at age 38 also appeared to have been aging at a faster pace. A biological age of 40, for example, meant that person was aging at a rate of 1.2 years per year over the 12 years the study examined.
This paper reports on 954 of the original 1,037 Dunedin study participants. Thirty of them had died by age 38: 12 by illnesses such as cancer and congenital defects, 10 by accidents and eight by suicide or drug overdose. Another 26 did not take part in the study at age 38. Twenty-seven participants had insufficient data to be included.
Most people think of the aging process as something that happens late in life, Belsky said, but signs of aging were already apparent in these tests over the 12 years of young adulthood: from 26 to 38.
Study members who appeared to be more advanced in biological aging also scored worse on tests typically given to people over 60, including tests of balance and coordination and solving unfamiliar problems. The biologically older individuals also reported having more difficulties with physical functioning than their peers, such as walking up stairs.
As an added measure, the researchers asked Duke University undergraduate students to assess facial photos of the study participants taken at age 38 and rate how young or old they appeared. Again, the participants who were biologically older on the inside also appeared older to the college students.
The aging process isn't all genetic. Studies of twins have found that only about 20 percent of aging can be attributed to genes, Belsky said. "There's a great deal of environmental influence," he said.
"That gives us some hope that medicine might be able to slow aging and give people more healthy active years," said senior author Terrie Moffitt, the Nannerl O. Keohane professor of psychology and neuroscience at Duke.
This paper's methods are merely a proof of concept, Belsky said, to show that it's possible to see an aging trajectory by combining multiple measures.
"The time is right for this kind of multi-factorial way of measuring the aging process," he said, but the measures and methods need refinement to be "better, faster and cheaper."
The ultimate goal, of course, is to be able to intervene in the aging process itself, rather than addressing killers like heart disease or cancer in isolation, Belsky said.
"As we get older, our risk grows for all kinds of different diseases," he said. "To prevent multiple diseases simultaneously, aging itself has to be the target. Otherwise, it's a game of whack-a-mole."
INFORMATION:
This research was funded by the New Zealand Health Research Council, U.S. National Institute on Aging, UK Medical Research Council, Jacobs Foundation and the Yad Hanadiv Rothschild Foundation.
CITATION: "Quantification of biological aging in young adults," Daniel Belsky, Avshalom Caspi, et al. PNAS, July 7, 2015. DOI: 10.1073/pnas.1506264112
Madison, Wis. -- In rhesus monkey families - just as in their human cousins - anxious parents are more likely to have anxious offspring.
And a new study in an extended family of monkeys provides important insights into how the risk of developing anxiety and depression is passed from parents to children.
The study from the Department of Psychiatry and the Health Emotions Research Institute at the University of Wisconsin-Madison shows how an over-active brain circuit involving three brain areas inherited from generation to generation may set the stage for developing ...
Across the entire world, women can expect to live longer than men. But why does this occur, and was this always the case?
According to a new study led by University of Southern California Leonard Davis School of Gerontology researchers, significant differences in life expectancies between the sexes first emerged as recently as the turn of the 20th century. As infectious disease prevention, improved diets and other positive health behaviors were adopted by people born during the 1800s and early 1900s, death rates plummeted, but women began reaping the longevity benefits ...
PITTSBURGH, July 6, 2015 - University of Pittsburgh Cancer Institute (UPCI) scientists recently led a panel of experts in revising national guidelines for thyroid cancer testing to reflect newly available tests that better incorporate personalized medicine into diagnosing the condition.
Their clinical explanation for when to use and how to interpret thyroid cancer tests is published in the July issue of the scientific journal Thyroid. The American Thyroid Association is revising its 2015 Guidelines for Thyroid Nodule and Thyroid Cancer Management to direct doctors to ...
Alexandria, VA - With the Internet, science and a little imagination, scientists are able to bring remote worlds to life. Dinologue.com brings the Mesozoic to life, and EARTH Magazine reviews it in the July 2015 issue.
The website was created through a partnership between Parallax Film Productions and popular science writer, and amateur paleontologist, Brian Switek. The Dinologue portal is filled with captivating articles and adventurous videos to help bring science and paleontology to the masses. Get the geoscientist's perspective of Dinologue in EARTH Magazine: http://bit.ly/1JJDy7r.
The ...
Researchers have provided a new roadmap for tackling future agricultural production issues by using solutions that involve crassulacean acid metabolism (CAM), a specialized type of photosynthesis that enhances the efficiency by which plants use water.
Plants that use CAM, which include cacti and agave, are typically found in dry environments. Increasing agricultural production to accommodate society's growing population might be achieved by developing CAM crops as new sources for food, feed, fiber, and bioenergy or by engineering non-CAM crops to use CAM strategies to ...
Putnam Valley, N.Y. (July 6, 2015) - Peripheral nerve injuries often are caused by trauma or surgical complications and can result in considerable disabilities. Regeneration of peripheral nerves can be accomplished effectively using autologous (self-donated) nerve grafts, but that procedure may sacrifice a functional nerve and cause loss of sensation in another part of the patient's body.
Searching for an alternative to autologous nerve grafts (autografts), researchers in Japan transplanted mobilized dental pulp stem cells (MDPSCs) into laboratory rats with sciatic nerve ...
By studying climate data in the British-Irish Isles over a 142-year period, researchers have confirmed the important role of cyclones. Seasonal precipitation totals were strongly related to cyclone frequency, especially during summer.
The researchers found that relative to the 1961-1990 period, summers have become much wetter and more cyclonic. The move towards wetter summers in recent years is more of a re-establishment of conditions typical of the earlier half of the 20th Century rather than being unusual in the long term.
Recent years have seen three of the stormiest ...
For the first time, researchers have used a simplified technique derived from a defense mechanism evolved by bacteria and other single-celled organisms to successfully insert a large DNA sequence into a predetermined genomic site in mammalian cells.
The methods used may help investigators genetically engineer cells to produce high levels of certain proteins--for example by placing the DNA sequence of a particular protein at the site of a highly active gene.
"The CRISPR-Cas system has been previously used to insert a foreign DNA sequence into a targeted genomic site ...
Since Ebola was first described in 1976, there have been several outbreaks, but all have been self-limiting. In a new Journal of Internal Medicine review, Dr. Ali Mirazimi of the Karolinska Institutet considers why the latest outbreak occurred and discusses the factors that contributed to making it the largest, most sustained, and most widespread outbreak of Ebola. He also notes that several potential treatments are now undergoing clinical trials and have shown initial promising results.
"Emerging and re-emerging infectious diseases will continue to challenge both human ...
Researchers have developed a non-invasive technique that allows clinicians to accurately detect various forms of skin cancer.
The current clinical "gold standard" non-invasive technique, called dermoscopy, is a highly subjective method. But by using what's called Raman spectroscopy, investigators found that malignant melanoma could be detected with an accuracy of 91% and non-melanoma skin cancers could be detected with accuracy between 73% and 85%.
"The non-invasive and label-free nature of Raman spectroscopy enables the application in various medical fields. The method ...
