Category: Ageing

New Insights into How Exercise Slows Age-related Cognitive Decline

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New research published in Aging Cell provides insights into how exercise may help to prevent or slow cognitive decline during aging.

For the study, investigators assessed the expression of genes in individual cells in the brains of mice. The team found that exercise has a significant impact on gene expression in microglia, the immune cells of the central nervous system that support brain function. Specifically, the group found that exercise reverts the gene expression patterns of aged microglia to patterns seen in young microglia.

Treatments that depleted microglia revealed that these cells are required for the stimulatory effects of exercise on the formation of new neurons in the brain’s hippocampus, a region involved in memory, learning, and emotion.

The scientists also found that allowing mice access to a running wheel prevented and/or reduced the presence of T cells in the hippocampus during aging. These immune cells are not typically found in the brain during youth, but they increase with age.

“We were both surprised and excited about the extent to which physical activity rejuvenates and transforms the composition of immune cells within the brain, in particular the way in which it was able to reverse the negative impacts of aging,” said co–corresponding author Jana Vukovic, PhD, of The University of Queensland, in Australia. “It highlights the importance of normalising and facilitating access to tailored exercise programs. Our findings should help different industries to design interventions for elderly individuals who are looking to maintain or improve both their physical and mental capabilities.”

Source: Wiley

Increase in Global Life Expectancy of Nearly 5 Years by 2050

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The latest findings from the Global Burden of Disease Study (GBD) 2021, published in The Lancetforecast that global life expectancy will increase by 4.9 years in males and 4.2 years in females between 2022 and 2050.

The largest increases are expected in countries where life expectancy is lower, such as in sub-Saharan Africa, contributing to a convergence of increased life expectancy across geographies. The trend is largely driven by public health measures that have prevented and improved survival rates from cardiovascular diseases, COVID, and a range of communicable, maternal, neonatal, and nutritional diseases (CMNNs).

This study indicates that the ongoing shift in disease burden to non-communicable diseases (NCDs) like cardiovascular diseases and cancer, and exposure to NCD-associated risk factors, such as obesity and smoking, will have the greatest impact on disease burden of the next generation.

Longer lives, but more years of poor health

As the disease burden continues to shift from CMNNs to NCDs and from years of life lost (YLLs) to years lived with disability (YLDs), more people are expected to live longer, but with more years spent in poor health. Global life expectancy is forecasted to increase from 73.6 years of age in 2022 to 78.1 years of age in 2050 (a 4.5-year increase). Global healthy life expectancy (HALE) – the average number of years a person can expect to live in good health – will increase from 64.8 years in 2022 to 67.4 years in 2050 (a 2.6-year increase).

To come to these conclusions, the study forecasts cause-specific mortality; YLLs; YLDs; disability-adjusted life years (DALYs, or lost years of healthy life due to poor health and early death); life expectancy; and HALE from 2022 through 2050 for 204 countries and territories.

“In addition to an increase in life expectancy overall, we have found that the disparity in life expectancy across geographies will lessen,” said Dr Chris Murray, Chair of Health Metrics Sciences at the University of Washington and Director of the Institute for Health Metrics and Evaluation (IHME). “This is an indicator that while health inequalities between the highest- and lowest-income regions will remain, the gaps are shrinking, with the biggest increases anticipated in sub-Saharan Africa.”

Dr Murray added that the biggest opportunity to speed up reductions in the global disease burden is through policy interventions aimed to prevent and mitigate behavioural and metabolic risk factors.

These findings build upon the results of the GBD 2021 risk factors study, also released today in The Lancet. This accompanying study found that the total number of years lost due to poor health and early death (measured in DALYs) attributable to metabolic risk factors has increased by 50% since 2000. Read more on the risk factors report at https://bit.ly/GBDRisks2021.

Alternative scenarios for 2050

The study also puts forth various alternative scenarios to compare the potential health outcomes if different public health interventions could eliminate exposure to several key risk factor groups by 2050.

“We forecast large differences in global DALY burden between different alternative scenarios to see what is the most impactful on our overall life expectancy data and DALY forecasts,” said Dr Stein Emil Vollset, first author of the study who leads the GBD Collaborating Unit at the Norwegian Institute of Public Health. “Globally, the forecasted effects are strongest for the ‘Improved Behavioural and Metabolic Risks’ scenario, with a 13.3% reduction in disease burden (number of DALYs) in 2050 compared with the ‘Reference’ (most likely) scenario.”

The authors also ran two more scenarios: one focused on safer environments and another on improved childhood nutrition and vaccination.

“Though the largest effects in global DALY burden were seen from the ‘Improved Behavioural and Metabolic Risk’ scenario, we also forecasted reductions in disease burden from the ‘Safer Environment’ and ‘Improved Childhood Nutrition and Vaccination’ scenarios beyond our reference forecast, said Amanda E. Smith, Assistant Director of Forecasting at IHME. “This demonstrates the need for continued progress and resources in these areas and the potential to accelerate progress through 2050.”

“There is immense opportunity ahead for us to influence the future of global health by getting ahead of these rising metabolic and dietary risk factors, particularly those related to behavioural and lifestyle factors like high blood sugar, high body mass index, and high blood pressure,” continued Dr Murray.

Source: Institute for Health Metrics and Evaluation

Age-related Brain Changes Affect Stroke Recovery, Study Finds

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A new study by a global team of researchers has revealed that areas of age-related damage in the brain relate to motor outcomes after a stroke – a potentially under-recognised phenomenon in stroke research. The study was published in Neurology.

A stroke often leads to motor impairment, which is traditionally linked to the extent of damage to the corticospinal tract (CST), a crucial brain pathway for motor control. Signaling along the CST is involved in a variety of movements, including walking, reaching, and fine finger movements like writing and typing. However, stroke recovery outcomes aren’t fully predicted by damage to the CST, suggesting other factors are at play.

The new observational from the Enhancing Neuroimaging Genetics through Meta-Analysis (ENIGMA) Stroke Recovery working group. It examines how one such factor could be white matter hyperintensities (WMHs) – areas of age-related damage in the brain’s white matter, which represent vascular dysfunction and are known to impact cognitive functions. The goal of the ENIGMA Stroke Recovery working group is to understand how changes in the brain after stroke relate to functional outcomes and recovery. ENIGMA Stroke Recovery has data from over 2100 stroke patients collected across 65 research studies and 10 countries, comprising the most extensive multisite retrospective stroke data collaboration to date.

Study leader Sook-Lei Liew, PhD, said: “We are grateful for our many collaborators around the world who lead independent stroke research programs and who are willing to come together and enable large-scale investigations into these critical questions about the role of overall brain health in stroke recovery and rehabilitation.” Dr Liew is an associate professor at the Keck School of Medicine of USC.

The study analysed data from 223 stroke patients across four countries and found that larger WMH volumes were associated with more severe motor impairment after a stroke (e.g., difficulty moving or using their arm for daily tasks), independent of CST damage. WMHs are related to chronic hypertension, diabetes, high cholesterol, and smoking, among other factors and conditions, and have been strongly related to cognitive impairment, but not extensively studied in the context of motor impairment. Interestingly, the relationship between CST damage and motor impairment varied based on WMH severity. Patients with mild WMHs showed a typical relationship between CST damage and motor impairment, while patients with moderate to severe WMHs did not have this relationship. Instead, motor impairment was related to WMH volume, not CST damage.

These findings suggest that WMHs, indicative of cerebrovascular damage from a variety of sources, could provide additional context to understand an individual’s potential for recovery post-stroke. Therefore, assessing WMH volume could improve predictive models for stroke recovery.

“WMHs are related to overall cardiovascular and brain health as we age. By integrating assessments of age-related brain health, we may be better able to predict stroke recovery and tailor rehabilitation to individual needs. This personalised approach could open avenues to improve outcomes after stroke,” says lead author Jennifer K. Ferris, PhD, of Simon Fraser University.

The researchers’ next step is to pursue longitudinal studies to confirm their findings. This insight lays the groundwork for developing more accurate markers for recovery, which could transform post-stroke care and rehabilitation.

Source: Keck School of Medicine of USC

Staying or Getting Active Pays off for Middle-aged Women, Study Finds

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Consistent adherence to physical activity guidelines throughout middle-age is associated with a higher health-related quality of life in women, according to a new study publishing May 2nd in the open-access journal PLOS Medicine by Binh Nguyen of University of Sydney, Australia, and colleagues.

The evidence for an association between physical activity and health-related quality of life has been based primarily on cross-sectional studies and short-term randomised controlled trials. Few longitudinal studies have measured physical activity at more than one time point and examined the long-term causal effects of exercise.

In the new study, researchers used data collected at three-year intervals beginning in 1996 from 11 336 participants in the Australian Longitudinal Study on Women’s Health. Women were born in 1946 through 1951, making them 47 to 52 years old at the study outset. Participants were classified as either meeting WHO physical activity guidelines – of 150 minutes of activity a week – consistently throughout the fifteen-year exposure period, not initially meeting the guidelines but starting to meet them at age 55, 60 or 65, or never meeting the guidelines. Health-related quality of life was assessed using the physical health composite score (PCS) and mental health composite score (MCS) from the Short Form 36 Health Survey, which includes 36 questions about functional health and well-being.

On average, people who consistently met physical activity guidelines and those who first started to meet guidelines at age 55 had a three-point higher PCS (46.93 [95% CI 46.32 to 47.54] and 46.96 [95% CI 45.53 to 48.40], respectively), compared to those that did not meet physical activity guidelines (43.90 [95% CI 42.79 to 45.01]). The effect of physical activity on the PSC was significant even after controlling for socioeconomic factors and pre-existing health diagnoses. However, there was no significant association between physical activity and MCS.

“Combined with existing evidence, this study contributes to growing evidence of the benefits of maintaining or adopting an active lifestyle in mid-age,” the authors say. “An important public health message is that being active for as many years as possible, even if women start to meet physical activity guidelines in their mid-50s, could have important health benefits in terms of physical health, especially in physical functioning.”

The authors add, “Our study shows that it’s important for women to be active throughout mid-age to gain the most benefits for physical health in later life. Ideally, women should increase their activity levels to meet the guidelines by age 55.”

Provided by PLOS

Trial with Warning Letters on Antipsychotic’s Risks Safely Cut Prescribing

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Warning letters from Medicare can safely cut prescribing of a powerful but risky antipsychotic, according to a new study published in JAMA Network Open. Researchers used data from Medicare, the U.S. public health insurance system for over 65s, to study the effects of the letters on hundreds of thousands of older adults with dementia. The study, by Columbia University Mailman School of Public Health, found a significant and lasting reduction in prescribing but no signs of adverse effects on patient health.

“Our study shows that low-cost letter interventions can safely reduce antipsychotic prescribing to patients with dementia,” said Adam Sacarny, PhD, assistant professor of Health Policy and Management at Columbia Mailman School. The work was conducted with researchers at the London School of Economics, Harvard T.H. Chan School of Public Health and Johns Hopkins University.

The researchers evaluated a large trial in which Medicare sent warning letters to high prescribers of quetiapine, the most popular antipsychotic in the U.S. Antipsychotics are frequently prescribed to people with dementia, but can cause numerous harms in this group. Researchers therefore studied the hundreds of thousands of older adults with dementia who were treated by the prescribers in the trial. Most previous studies on reducing prescribing in dementia care consisted of small trials or observational analyses, with limited evidence from large-scale randomised studies.

The results were striking. “People with dementia living in nursing homes and in the community were prescribed less and we did not detect negative health impacts for these groups,” said Michelle Harnisch, research student at the London School of Economics and first author of the study.

The findings are important because antipsychotics, such as quetiapine, are often used in dementia care to address behavioural symptoms. About 1 in 7 nursing home residents receives an antipsychotic every quarter. However, the drugs have a number of well-known risks. These include weight gain, cognitive decline, falls, and death. In turn, physician specialty societies, government regulators, and policymakers have aimed to reduce prescribing of these medications to people with dementia.

To test whether the warning letters reduced prescribing safely, the researchers used administrative data from Medicare to link the 5055 physicians in the original trial to the Medicare records of their patients with dementia. They ultimately analysed 84 881 patients in nursing homes and 261,288 patients living in the community.

The intervention reduced quetiapine use among nursing home patients by 7% and community-dwelling patients by 15%. The researchers did not find adverse effects across numerous health outcomes, including cognitive function, behavioural symptoms, depression, or metabolic outcomes like diabetes. There were signs of improved mental health outcomes, and the risk of death for patients living in the community fell slightly.

This research follows up on the original evaluation of the warning letters. In that study, members of the same research team also showed that the letters reduced prescribing. However, they focused on a considerably smaller sample of patients and studied a limited set of health outcomes. In contrast, the new research evaluates a number of key health indicators for dementia care and substantially expands the patient sample with a focus on dementia.

“These results show that this intervention and others like it could be leveraged to make prescribing safer and improve dementia care” noted Sacarny. “Similar interventions could also be adapted to other contexts to promote high-quality care.”

Source: Columbia University’s Mailman School of Public Health

New Study Explains Why we Move More Slowly with Age

It’s one of the inescapable realities of aging: The older we get, the slower we tend to move – whether we’re walking around the block or just reaching for the remote control. A new study led by CU Boulder engineers helps explain why.

The research is one of the first studies to experimentally tease apart the competing reasons why people over age 65 might not be as quick on their feet as they used to be. The group reported that older adults may move slower, at least in part, because it costs them more energy than younger people – perhaps not too shocking for anyone who’s woken up tired the morning after an active day.

The findings could one day give doctors new tools for diagnosing a range of illnesses, including Parkinson’s disease, multiple sclerosis and even depression and schizophrenia, said study co-author Alaa Ahmed. 

“Why we move the way we do, from eye movements to reaching, walking and talking, is a window into aging and Parkinson’s,” said Ahmed, professor in the Paul M. Rady Department of Mechanical Engineering. “We’re trying to understand the neural basis of that.”

She and her colleagues published their findings this month in the journal JNeurosci.

For the study, the group asked subjects age 18 to 35 and 66 to 87 to complete a deceptively simple task: to reach for a target on a screen, akin to playing a video game on a Nintendo Wii. By analysing patterns of these reaches, the researchers discovered that older adults seemed to modify their motions under certain circumstances to conserve their more limited supplies of energy. 

“All of us, whether young or old, are inherently driven to get the most reward out of our environment while minimising the amount of effort to do so,” said Erik Summerside, a co-lead author of the new study who earned his doctorate in integrative physiology from CU Boulder in 2018.

Using engineering to understand the brain

Ahmed added that researchers have long known that older adults tend to be slower because their movements are less stable and accurate. But other factors could also play a role in this fundamental part of growing up.

According to one hypothesis, the muscles in older adults may work less efficiently, meaning that they burn more calories while completing the same tasks as younger adults – like running a marathon or getting up to grab a soda from the refrigerator.

Alternatively, aging might also alter the reward circuitry in the human brain. Ahmed explained that as people age, their bodies produce less dopamine, a brain chemical responsible for giving you a sense of satisfaction after a job well done. If you don’t feel that reward as strongly, the thinking goes, you may be less likely to move to get it. People with Parkinson’s disease experience an even sharper decline in dopamine production.

In the study, the researchers asked more than 80 people to sit down and grab the handle of a robotic arm, which, in turn, operated the cursor on a computer screen. The subjects reached forward, moving the cursor toward a target. If they succeeded, they received a reward – not a big one, but still enough to make their brains happy.

“Sometimes, the targets exploded, and they would get point rewards,” Ahmed said. “It would also make a ‘bing bing’ sound.”

Moving slower but smarter

That’s when a contrast between the two groups of people began to emerge.

Both the 18 to 35-year-olds and 66 to 87-year-olds arrived at their targets sooner when they knew they would hear that ‘bing bing’ – roughly 4% to 5% sooner over trials without the reward. But they also achieved that goal in different ways.

The younger adults, by and large, moved their arms faster toward the reward. The older adults, in contrast, mainly improved their reaction times, beginning their reaches about 17 milliseconds sooner on average.

When the team added an 8-pound (3.6kg) weight to the robotic arm for the younger subjects, those differences vanished.

“The brain seems to be able to detect very small changes in how much energy the body is using and adjusts our movements accordingly,” said Robert Courter, a co-lead author of the study who earned his doctorate in integrative physiology from CU Boulder in 2023. “Even when moving with just a few extra pounds, reacting quicker became the energetically cheaper option to get to the reward, so the young adults imitated the older adults and did just that.”

The research seems to paint a clear picture, Ahmed said. Both the younger and older adults didn’t seem to have trouble perceiving rewards, even small ones. But their brains slowed down their movements under tiring circumstances.

“Putting it all together, our results suggest that the effort costs of reaching seem to be determining what’s slowing the movement of older adults,” Ahmed said.

The experiment can’t completely rule out the brain’s reward centres as a culprit behind why we slow down when we age. But, Ahmed noted, if scientists can tease out where and how these changes emerge from the body, they may be able to develop treatments to reduce the toll of aging and disease.

Source: University of Colorado Boulder

Essential Tremor Increases Cognitive Impairment Risks over Time

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Essential tremor, a nervous system disorder that causes rhythmic shaking, is one of the most common movement disorders. A new study published in the Annals of Neurology reveals details on the increased risk of mild cognitive impairment (MCI) and dementia that individuals with essential tremor may face.

The research represents the longest available longitudinal prospective study of rates of MCI and dementia in people with essential tremor. The study enrolled 222 patients, 177 of whom participated in periodic evaluations over an average follow-up of 5 years.

Investigators observed a cumulative prevalence of 26.6% and 18.5% for MCI and dementia, respectively. They also noted a cumulative incidence of 18.2% and 11.2% for MCI and dementia, respectively. Each year, 3.9% of patients with normal cognition “converted” to having MCI, and 12.2% of those with MCI “converted” to having dementia.

“We know from related research that the presence of cognitive impairment in patients with essential tremor has meaningful clinical consequences. For example, patients with essential tremor who are diagnosed with dementia are more likely to need to use a walker or wheelchair, to employ a home health aide, and to reside in non-independent living arrangements than are patients with essential tremor without dementia,” said corresponding author Elan D. Louis, MD, MS, of the University of Texas Southwestern Medical Center. “With this in mind, the findings of the present study highlight the importance of cognitive screening and monitoring in patients with essential tremor. Early detection of impairment may provide opportunities for interventions that may slow further cognitive decline and improve the quality of life of patients and their families.”

Source: Wiley

Do More Mentally Challenging Jobs Protect against Cognitive Decline?

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The harder your brain works at your job, the less likely you may be to have memory and thinking problems later in life, according to a new study published in Neurology®, the medical journal of the American Academy of Neurology. This study does not prove that stimulating work prevents mild cognitive impairment. It only shows an association.

“We examined the demands of various jobs and found that cognitive stimulation at work during different stages in life – during your 30s, 40s, 50s and 60s – was linked to a reduced risk of mild cognitive impairment after the age of 70,” said study author Trine Holt Edwin, MD, PhD, of Oslo University Hospital in Norway.

“Our findings highlight the value of having a job that requires more complex thinking as a way to possibly maintain memory and thinking in old age.”

The study looked at 7000 people and 305 occupations in Norway. Researchers measured the degree of cognitive stimulation that participants experienced while on the job. They measured the degree of routine manual, routine cognitive, non-routine analytical, and non-routine interpersonal tasks, which are skill sets that different jobs demand.

Routine manual tasks demand speed, control over equipment, and often involve repetitive motions, typical of factory work. Routine cognitive tasks demand precision and accuracy of repetitive tasks, such as in bookkeeping and filing.

Non-routine analytical tasks involve analysing information, engaging in creative thinking and interpreting information for others. Non-routine interpersonal tasks include establishing and maintaining personal relationships, motivating others and coaching. Non-routine cognitive jobs include public relations and computer programming.

Researchers divided participants into four groups based on the degree of cognitive stimulation that they experienced in their jobs. The most common job for the group with the highest cognitive demands was teaching. The most common jobs for the group with the lowest cognitive demands were mail carriers and custodians.

After age 70, participants completed memory and thinking tests to assess whether they had mild cognitive impairment. Of those with the lowest cognitive demands, 42% were diagnosed with mild cognitive impairment, compared to 27% for those with the highest cognitive demands.

After adjustment for age, sex, education, income and lifestyle factors, the group with the lowest cognitive demands at work had a 66% higher risk of mild cognitive impairment compared to the group with the highest cognitive demands at work.

“These results indicate that both education and doing work that challenges your brain during your career play a crucial role in lowering the risk of cognitive impairment later in life,” Edwin said. “Further research is required to pinpoint the specific cognitively challenging occupational tasks that are most beneficial for maintaining thinking and memory skills.”

A limitation of the study was that even within identical job titles, individuals might perform different tasks and experience different cognitive demands.

Source: American Academy of Neurology

Genetic Predisposition for Muscle Strength may Predict Longer Lifespan

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A study conducted at the University of Jyväskylä showed that a genetic predisposition for higher muscle strength predicts a longer lifespan and a lower risk for developing common diseases. This study, published in The Journals of Gerontology: Series A, is the most comprehensive international study to date on hereditary muscle strength and its relationship to morbidity. The genome and health data of more than 340 000 Finns was used in the research.

Muscle strength, especially hand grip strength, can indicate an individual’s physiological resources to protect against age-related diseases and disabilities, as well as their ability to cope with them. Age-related loss of muscle strength is individual and influenced not only by lifestyle but also by genetics.

The study revealed that individuals with a genetic predisposition for higher muscle strength have a slightly lower risk for common noncommunicable diseases and premature mortality. It did not however predict better survival after acute adverse health events compared to the time before illness onset.  

“It seems that a genetic predisposition for higher muscle strength reflects more on an individual’s intrinsic ability to resist and protect oneself against pathological changes that occur during aging than the ability to recover or completely bounce back after severe adversity,” says doctoral researcher Päivi Herranen from the Faculty of Sport and Health Sciences. 

A unique study population  

Muscle strength is a multifactorial trait influenced by lifestyle and environmental factors but also by numerous genetic variants, each with a very small effect on muscle strength. In this study, the genetic predisposition for muscle strength was defined by constructing a polygenic score for muscle strength, which summarises the effects of hundreds of thousands of genetic variants into a single score. The polygenic score makes it possible to compare participants with an exceptionally high or low genetic predisposition for muscle strength, and to investigate associations with inherited muscle strength and other phenotypes, in this case, common diseases.  

“In this study, we were able to utilise both genetic information and health outcomes from over 340 000 Finnish men and women,” Herranen explains. “To our knowledge, this is the first study to investigate the association between a genetic predisposition for muscle strength and various diseases on this scale.” 

Further research on the effects of lifestyles is still needed 

Information about the genetic predisposition for muscle strength could be used alongside traditional risk assessment in identifying individuals who are at particularly high risk of common diseases and health adversities. However, further research on the topic is still needed. 

“Based on these results, we cannot say how lifestyle factors, such as physical activity, modify an individual’s intrinsic ability to resist diseases and whether their impact on health differs among individuals due to genetics,” Herranen notes. 

The study utilised the internationally unique FinnGen dataset, compiled through the collaboration of Finnish biobanks. The dataset consisted of 342 443 Finns who had given their consent and provided a biobank sample. The participants were aged 40 to 108 years, and 53% of them were women. The diagnoses selected for the study were based on the leading causes of death and the most significant noncommunicable diseases in Finland. Selected diagnoses included the most common cardiometabolic and pulmonary diseases, musculoskeletal and connective tissue diseases, falls and fractures, mental health and cognitive disorders, cancers, as well as overall mortality and mortality from cardiovascular diseases. 

Source: University of Jyväskylä

Pregnancy may Add Months to a Woman’s Biological Age

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Pregnancy may carry a cost, according to a new study involving 1735 young people in the Philippines, and shows that women who reported having been pregnant looked biologically older than women who had never been pregnant, and women who had been pregnant more often looked biologically older than those who reported fewer pregnancies.

Notably, the number of pregnancies fathered was not associated with biological aging among same-aged cohort men, which implies that it is something about pregnancy or breastfeeding specifically that accelerates biological aging. The findings are published in the Proceedings of National Academy of Sciences.
 
This study, from the Columbia University Mailman School of Public Health, builds on epidemiological findings that high fertility can have negative side effects on women’s health and longevity. What was unknown, however, was whether the costs of reproduction were present earlier in life, before disease and age-related decline start to become apparent. Until now, one of the challenges has been quantifying biological aging among the young. This challenge was overcome by using a collection of new tools that use DNA methylation (DNAm) to study different facets of cellular aging, health, and mortality risk. These tools, called ‘epigenetic clocks’ allow researchers to study aging earlier in life, filling a key gap in the study of biological aging.
 
“Epigenetic clocks have revolutionised how we study biological aging across the lifecourse and open up new opportunities to study how and when long-term health costs of reproduction and other life events take hold”, said Calen Ryan, PhD, associate research scientist in the Columbia Aging Center, and lead author.
 
“Our findings suggest that pregnancy speeds up biological aging, and that these effects are apparent in young, high-fertility women,” said Ryan. “Our results are also the first to follow the same women through time, linking changes in each woman’s pregnancy number to changes in her biological age.”
 
The relationship between pregnancy history and biological age persisted even after taking into account various other factors tied to biological aging, such as socioeconomic status, smoking, and genetic variation, but were not present among men from the same sample. This finding, noted Ryan, points to some aspect of bearing children – rather than sociocultural factors associated with early fertility or sexual activity – as a driver of biological aging.
 
Despite the striking nature of the findings, Ryan encourages readers to remember the context: “Many of the reported pregnancies in our baseline measure occurred during late adolescence, when women are still growing. We expect this kind of pregnancy to be particularly challenging for a growing mother, especially if her access to healthcare, resources, or other forms of support is limited.”
 
Ryan also acknowledged that there is more work to do, “We still have a lot to learn about the role of pregnancy and other aspects of reproduction in the aging process. We also do not know the extent to which accelerated epigenetic aging in these particular individuals will manifest as poor health or mortality decades later in life.”
 
Ryan said that our current understanding of epigenetic clocks and how they predict health and mortality comes largely from North America and Europe, but that the aging process can take slightly different forms in the Philippines and other places around the world.

“Ultimately I think our findings highlight the potential long-term impacts of pregnancy on women’s health, and the importance of taking care of new parents, especially young mothers.”

Source: Columbia University’s Mailman School of Public Health