How and why resistance training is imperative for older adults

For many older adults, resistance training may not be part of their daily routine, but a new position statement suggests it is vital to improving their health and longevity.

"When you poll people on if they want to live to 100 years old, few will respond with a 'yes'," says Maren Fragala, Ph.D., director of scientific affairs at Quest Diagnostics and lead author of the position statement.

"The reason mainly being that many people associate advanced age with physical and cognitive decline, loss of independence and poor quality of life," adds Mark Peterson, Ph.D., M.S., FACSM, an associate professor of physical medicine and rehabilitation at Michigan Medicine and one of the senior authors of the statement.

The position statement, published in the Journal of Strength and Conditioning Research, and supported by the National Strength and Conditioning Association, highlights the benefits of strength and resistance training in older adults for healthier aging.

Fragala explains that while aging does take a toll on the body, the statement provides evidence-based recommendations for successful resistance training, or exercise focused on building muscle endurance, programs for older adults.

"Aging, even in the absence of chronic disease, is associated with a variety of biological changes that can contribute to decreases in skeletal muscle mass, strength and function," Fragala says. "Such losses decrease physiologic resilience and increase vulnerability to catastrophic events."

She adds, "The exciting part about this position statement is that it provides evidence-based recommendations for resistance training in older adults to promote health and functional benefits, while preventing and minimizing fears."

Practical applications

The position statement provides 11 practical applications divided into four main components: program design variables, physiological adaptations, functional benefits, and considerations for frailty, sarcopenia and other chronic conditions.

The applications include suggestions on training types and amounts of repetitions and intensities, patient groups that will need adaptations in training models, and how training programs can be adapted for older adults with disabilities or those residing in assisted living and skilled nursing facilities.

"Current research has demonstrated that resistance training is a powerful care model to combat loss of muscle strength and mass in the aging population," says Peterson, a member of the University of Michigan Institute for Healthcare Policy & Innovation and Michigan Center on the Demography of Aging.

"We demonstrate in this position statement just how much resistance training can positively affect physical functioning, mobility, independence, chronic disease management, psychological wellbeing, quality of life and healthy life expectancy. We also provide recommendations for how to optimize resistance training programs to ensure safety and effectiveness."

Fragala adds that the benefits of participating in resistance training as an older adult outweigh the risks.

"The coauthors of this paper and the hundreds of other prolific researchers whose work we synthesized in this position statement have found that in most cases, the vast benefits of resistance training largely outweigh the risks when training is properly implemented," Fragala says.

Empowering healthy aging

The authors are proud to have the support of the National Strength and Condition Association for the statement.

"Too few of older Americans participate in resistance training, largely because of fear, confusion and a lack of consensus to guide implementation," Peterson says. "By having this consensus statement supported by the National Strength and Condition Association, we hope it will have a positive impact on empowering healthier aging."

The full list of authors for the position statement includes: Maren Fragala, Ph.D., Quest Diagnostics; Eduardo Cadore, Ph.D., Federal University of Rio Grande do Sul; Sandor Dorgo, Ph.D., University of Texas at El Paso; Mikel Izquierdo, Ph.D., Public University of Navarre; William Kraemer, Ph.D., The Ohio State University; Mark Peterson, Ph.D., M.S., CSCS*D, FACSM, University of Michigan, Michigan Medicine; Eric Ryan, Ph.D., University of North Carolina -- Chapel Hill.

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Materials provided by Michigan Medicine - University of Michigan. Original written by Kylie Urban. Note: Content may be edited for style and length.

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Journal Reference:

1. Maren S. Fragala, Eduardo L. Cadore, Sandor Dorgo, Mikel Izquierdo, William J. Kraemer, Mark D. Peterson, Eric D. Ryan. Resistance Training for Older Adults. Journal of Strength and Conditioning Research, 2019; 33 (8): 2019 DOI: 10.1519/JSC.0000000000003230

Scientists reverse aging process in rat brain stem cells

New research, published today in Nature, reveals how increasing brain stiffness as we age causes brain stem cell dysfunction, and demonstrates new ways to reverse older stem cells to a younger, healthier state.

The results have far reaching implications for how we understand the ageing process, and how we might develop much-needed treatments for age-related brain diseases.

As our bodies age, muscles and joints can become stiff, making everyday movements more difficult. This study shows the same is true in our brains, and that age-related brain stiffening has a significant impact on the function of brain stem cells.

A multi-disciplinary research team, based at the Wellcome-MRC Cambridge Stem Cell Institute (University of Cambridge), studied young and old rat brains to understand the impact of age-related brain stiffening on the function of oligodendrocyte progenitor cells (OPCs).

These cells are a type of brain stem cell important for maintaining normal brain function, and for the regeneration of myelin -- the fatty sheath that surrounds our nerves, which is damaged in multiple sclerosis (MS). The effects of age on these cells contributes to MS, but their function also declines with age in healthy people.

To determine whether the loss of function in aged OPCs was reversible, the researchers transplanted older OPCs from aged rats into the soft, spongy brains of younger animals. Remarkably, the older brain cells were rejuvenated, and began to behave like the younger, more vigorous cells.

To study this further, the researchers developed new materials in the lab with varying degrees of stiffness, and used these to grow and study the rat brain stem cells in a controlled environment. The materials were engineered to have a similar softness to either young or old brains.

To fully understand how brain softness and stiffness influences cell behavior, the researchers investigated Piezo1 -- a protein found on the cell surface, which informs the cell whether the surrounding environment is soft or stiff.

Dr Kevin Chalut, who co-led the research, said: "We were fascinated to see that when we grew young, functioning rat brain stem cells on the stiff material, the cells became dysfunctional and lost their ability to regenerate, and in fact began to function like aged cells. What was especially interesting, however, was that when the old brain cells were grown on the soft material, they began to function like young cells -- in other words, they were rejuvenated."

"When we removed Piezo1 from the surface of aged brain stem cells, we were able to trick the cells into perceiving a soft surrounding environment, even when they were growing on the stiff material," explained Professor Robin Franklin, who co-led the research with Dr Chalut. "What's more, we were able to delete Piezo1 in the OPCs within the aged rat brains, which lead to the cells becoming rejuvenated and once again able to assume their normal regenerative function."

Dr Susan Kohlhaas, Director of Research at the MS Society, who part funded the research, said: "MS is relentless, painful, and disabling, and treatments that can slow and prevent the accumulation of disability over time are desperately needed. The Cambridge team's discoveries on how brain stem cells age and how this process might be reversed have important implications for future treatment, because it gives us a new target to address issues associated with aging and MS, including how to potentially regain lost function in the brain."

This research was supported by the European Research Council, MS Society, Biotechnology and Biological Sciences Research Council, The Adelson Medical Research Foundation, Medical Research Council and Wellcome.

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Materials provided by University of Cambridge. The original story is licensed under a Creative Commons License. Note: Content may be edited for style and length.

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Journal Reference:

1. Michael Segel, Björn Neumann, Myfanwy F. E. Hill, Isabell P. Weber, Carlo Viscomi, Chao Zhao, Adam Young, Chibeza C. Agley, Amelia J. Thompson, Ginez A. Gonzalez, Amar Sharma, Steffan Holmqvist, David H. Rowitch, Kristian Franze, Robin J. M. Franklin, Kevin J. Chalut. Niche stiffness underlies the ageing of central nervous system progenitor cells. Nature, 2019; DOI: 10.1038/s41586-019-1484-9

Good heart health at age 50 linked to lower dementia risk later in life

Good cardiovascular health at age 50 is associated with a lower risk of dementia later in life, finds a study of British adults published by The BMJ today.

The researchers say their findings support public health policies to improve cardiovascular health in middle age to promote later brain health.

Dementia is a progressive disease that can start to develop 15-20 years before any symptoms appear, so identifying factors that might prevent its onset is important.

The American Heart Association's "Life Simple 7" cardiovascular health score, initially designed for cardiovascular disease, has been put forward as a potential tool for preventing dementia.

Designed for "primordial" prevention, where the aim is to prevent the development of risk factors themselves in order to affect risk of disease, it is the sum of four behavioural (smoking, diet, physical activity, body mass index) and three biological (fasting glucose, blood cholesterol, blood pressure) metrics, categorised into poor (scores 0-6), intermediate (7-11), and optimal (12-14) cardiovascular health.

But the evidence remains inconsistent. So to address this uncertainty, an international research project led by Séverine Sabia from the French National Institute of Health and Medical Research and University College London, examined the association between the Life Simple 7 cardiovascular health score at age 50 and risk of dementia over the next 25 years.

Their findings are based on cardiovascular data collected from 7,899 British men and women at age 50 in the Whitehall II Study, which is looking at the impact of social, behavioural, and biological factors on long term health.

Participants were free of cardiovascular disease and dementia at age 50. Dementia cases were identified using hospital, mental health services, and death registers until 2017.

Of the 7,899 participants, 347 cases of dementia were recorded over an average follow-up period of 25 years. Average age at dementia diagnosis was 75 years.

After taking account of potentially influential factors, the researchers found that adherence to the Life Simple 7 cardiovascular health recommendations in midlife was associated with a lower risk of dementia later in life.

Compared with an incidence rate of dementia of 3.2 per 1000 person years among the group with a poor cardiovascular score, those with an intermediate score had an incidence of 1.8 per 1000 person years, while those with an optimal score had an incidence of 1.3 per 1000 person years.

This is an observational study, so can't establish cause, and the researchers point to some limitations, for example relying on self-reported measures and potentially missing cases of dementia in patient records.

However, higher cardiovascular health score at age 50 was also associated with higher whole brain and grey matter volumes in MRI scans 20 years later. And reductions in dementia risk were also evident across the continuum of the cardiovascular score, suggesting that even small improvements in cardiovascular risk factors at age 50 may reduce dementia risk in old age, say the researchers.

"Our findings suggest that the Life's Simple 7, which comprises the cardiovascular health score, at age 50 may shape the risk of dementia in a synergistic manner," they write. "Cardiovascular risk factors are modifiable, making them strategically important prevention targets. This study supports public health policies to improve cardiovascular health as early as age 50 to promote cognitive health," they conclude.

Researchers in a linked editorial agree that the study provides further support for the UK Government's recent policy focus on vascular health in midlife. "However, other evidence makes clear that vascular health at 50 is determined by factors earlier in the life course, including inequality and social and economic determinants," they say.

"Reducing the risk of dementia is a leading concern in aging societies. We know that risk can change across generations, and in the UK the prevalence of dementia has decreased by nearly 25% when standardised for age," they add.

They conclude: "Although the Whitehall study cannot reflect the UK's population, estimates obtained from this cohort reinforce the need for action to shift population risk profiles for cognitive decline and dementia across the life course."

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Materials provided by BMJ. Note: Content may be edited for style and length.

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Journal Reference:

1. Séverine Sabia, Aurore Fayosse, Julien Dumurgier, Alexis Schnitzler, Jean-Philippe Empana, Klaus P Ebmeier, Aline Dugravot, Mika Kivimäki, Archana Singh-Manoux. Association of ideal cardiovascular health at age 50 with incidence of dementia: 25 year follow-up of Whitehall II cohort study. BMJ, 2019; l4414 DOI: 10.1136/bmj.l4414

Abnormal blood pressure in middle and late life influences dementia risk

In a study that spanned two and a half decades and looked at data from more than 4,700 participants, Johns Hopkins researchers have added to evidence that abnormal blood pressure in midlife persisting into late life increases the likelihood of developing dementia. Although not designed to show cause and effect, the study suggests that maintaining a healthy blood pressure throughout life may be one way to help decrease one's risk of losing brain function.

"Our results suggest that one's blood pressure during midlife may influence how blood pressure later in life relates to dementia risk," says Keenan Walker, Ph.D., assistant professor of neurology at the Johns Hopkins University School of Medicine. "We found that individuals with high blood pressure in midlife may benefit from targeting their blood pressure to normal levels in later life, as having blood pressure that is too high or too low in late life may further increase dementia risk."

In their study, they found that those people with the high blood pressure condition hypertension during middle age and during late life were 49% more likely to develop dementia than those with normal blood pressure at both times. But, putting one at even greater risk was having hypertension in middle age and then having low blood pressure in late life, which increased one's dementia risk by 62%. The findings were published Aug. 13 in JAMA.

High blood pressure was considered any measurement more than 140/90 millimeters of mercury, whereas low blood pressure was defined as less than 90/60 millimeters of mercury. A cognitive exam, caregiver reports, hospitalization discharge codes and death certificates were used to classify participant brain function and determine cognitive impairment.

High blood pressure can be genetic, but can also be the result of not enough exercise and poor diet. As people age, the top blood pressure number (systolic) oftentimes increases while the bottom number (diastolic) can decrease due to structural changes in the blood vessels. Walker says dementia itself may lead to a lowering of blood pressure, as it may disrupt the brain's autonomic nervous system. Stiffening of the arteries from disease and physical frailty can also lead to low blood pressure in late life.

According to the Centers for Disease Control and Prevention, 75 million people in the U.S. have high blood pressure, and high blood pressure can raise the risk for heart disease, as well as other health conditions.

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Materials provided by Johns Hopkins Medicine. Note: Content may be edited for style and length.

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Journal Reference:

1. Keenan A. Walker, A. Richey Sharrett, Aozhou Wu, Andrea L. C. Schneider, Marilyn Albert, Pamela L. Lutsey, Karen Bandeen-Roche, Josef Coresh, Alden L. Gross, B. Gwen Windham, David S. Knopman, Melinda C. Power, Andreea M. Rawlings, Thomas H. Mosley, Rebecca F. Gottesman. Association of Midlife to Late-Life Blood Pressure Patterns With Incident Dementia. JAMA, 2019; 322 (6): 535 DOI: 10.1001/jama.2019.10575

Diet change needed to save vast areas of tropics

One quarter of the world's tropical land could disappear by the end of the century unless meat and dairy consumption falls, researchers have warned.

If the global demand for animal products continues to grow, large swathes of natural land will vanish potentially leading to widespread loss of species and their habitats.

Some nine per cent of natural land -- 95 per cent of which is in the tropics -- could go within 80 years unless global dietary habits change, the scientists say.

Researchers at the University of Edinburgh and Karlsruhe Institute of Technology studied the impact of consumption trends on biodiverse regions -- areas that have a wealth of mammals, birds, amphibians and plant life.

They found that rapid increases in meat and milk production result in sharp rises in land clearing in tropical regions that harbour high levels of biodiversity.

As incomes increase across the globe, consumption has shifted from staples such as starchy roots and pulses to meat, milk, and refined sugars.

Meat and dairy production is associated with higher land and water use and higher greenhouse gas emissions than any other foods.

By replacing animal products with plant-based alternatives, they predict that the global demand for agricultural land could be reduced by 11 per cent.

Researchers also found that industrial feed systems reduce agricultural expansion but may increase environmental degradation due to agricultural pollutants such as fertiliser.

The study comes after the Intergovernmental Panel on Climate Change last week published a special report that identified reducing meat consumption as an important focus for climate change mitigation.

Lead author Dr Roslyn Henry, said, "Reducing meat and dairy consumption will have positive effects on greenhouse gas emissions and human health. It will also help biodiversity, which must be conserved to ensure the world's growing population is fed. Changing our diets will lead to a more sustainable future and complement food security goals while addressing global food inequalities."

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Materials provided by University of Edinburgh. Note: Content may be edited for style and length.

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Journal Reference:

1. Roslyn C. Henry, Peter Alexander, Sam Rabin, Peter Anthoni, Mark D.A. Rounsevell, Almut Arneth. The role of global dietary transitions for safeguarding biodiversity. Global Environmental Change, 2019; 58: 101956 DOI: 10.1016/j.gloenvcha.2019.101956

C-DIFF Diarrhea-causing bacteria adapted to spread in hospitals

Scientists have discovered that the gut-infecting bacterium Clostridium difficile is evolving into two separate species, with one group highly adapted to spread in hospitals. Researchers at the Wellcome Sanger Institute, London School of Hygiene & Tropical Medicine and collaborators identified genetic changes in the newly-emerging species that allow it to thrive on the Western sugar-rich diet, evade common hospital disinfectants and spread easily. Able to cause debilitating diarrhea, they estimated this emerging species started to appear thousands of years ago, and accounts for over two thirds of healthcare C. difficile infections.

Published in Nature Genetics today (12 August), the largest ever genomic study of C. difficile shows how bacteria can evolve into a new species, and demonstrates that C. difficile is continuing to evolve in response to human behaviour. The results could help inform patient diet and infection control in hospitals.

C. difficile bacteria can infect the gut and are the leading cause of antibiotic-associated diarrhea worldwide. While someone is healthy and not taking antibiotics, millions of 'good' bacteria in the gut keep the C. difficile under control. However, antibiotics wipe out the normal gut bacteria, leaving the patient vulnerable to C. difficile infection in the gut. This is then difficult to treat and can cause bowel inflammation and severe diarrhea.

Often found in hospital environments, C. difficile forms resistant spores that allow it to remain on surfaces and spread easily between people, making it a significant burden on the healthcare system.

To understand how this bacterium is evolving, researchers collected and cultured 906 strains of C. difficile isolated from humans, animals, such as dogs, pigs and horses, and the environment. By sequencing the DNA of each strain, and comparing and analysing all the genomes, the researchers discovered that C. difficile is currently evolving into two separate species.

Dr Nitin Kumar, joint first author from the Wellcome Sanger Institute, said: "Our large-scale genetic analysis allowed us to discover that C. difficile is currently forming a new species with one group specialised to spread in hospital environments. This emerging species has existed for thousands of years, but this is the first time anyone has studied C. difficile genomes in this way to identify it. This particular bacteria was primed to take advantage of modern healthcare practices and human diets, before hospitals even existed."

The researchers found that this emerging species, named C. difficile clade A, made up approximately 70 per cent of the samples from hospital patients. It had changes in genes that metabolise simple sugars, so the researchers then studied C. difficile in mice, and found that the newly emerging strains colonised mice better when their diet was enriched with sugar. It had also evolved differences in the genes involved in forming spores, giving much greater resistance to common hospital disinfectants. These changes allow it to spread more easily in healthcare environments.

Dating analysis revealed that while C. difficile Clade A first appeared about 76,000 years ago, the number of different strains of this started to increase at the end of the 16th Century, before the founding of modern hospitals. This group has since thrived in hospital settings with many strains that keep adapting and evolving.

Dr Trevor Lawley, the senior author from the Wellcome Sanger Institute, said: "Our study provides genome and laboratory based evidence that human lifestyles can drive bacteria to form new species so they can spread more effectively. We show that strains of C. difficile bacteria have continued to evolve in response to modern diets and healthcare systems and reveal that focusing on diet and looking for new disinfectants could help in the fight against this bacteria."

Prof Brendan Wren, an author from the London School of Hygiene & Tropical Medicine, said: "This largest ever collection and analysis of C. difficile whole genomes, from 33 countries worldwide, gives us a whole new understanding of bacterial evolution. It reveals the importance of genomic surveillance of bacteria. Ultimately, this could help understand how other dangerous pathogens evolve by adapting to changes in human lifestyles and healthcare regimes which could then inform healthcare policies."

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Story Source:

Materials provided by Wellcome Trust Sanger Institute. Note: Content may be edited for style and length.

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Journal Reference:

1. Nitin Kumar, Hilary P. Browne, Elisa Viciani, Samuel C. Forster, Simon Clare, Katherine Harcourt, Mark D. Stares, Gordon Dougan, Derek J. Fairley, Paul Roberts, Munir Pirmohamed, Martha R. J. Clokie, Mie Birgitte Frid Jensen, Katherine R. Hargreaves, Margaret Ip, Lothar H. Wieler, Christian Seyboldt, Torbjörn Norén, Thomas V. Riley, Ed J. Kuijper, Brendan W. Wren, Trevor D. Lawley. Adaptation of host transmission cycle during Clostridium difficile speciation. Nature Genetics, 2019; DOI: 10.1038/s41588-019-0478-8