exercise – NIH Director's Blog (original) (raw)
To Prevent a Stroke, Household Chores and Leisurely Strolls May Help
Posted on June 21st, 2022 by Lawrence Tabak, D.D.S., Ph.D.
Credit: Shutterstock/Tartila
As we get older, unfortunately our chances of having a stroke rise. While there’s obviously no way to turn back the clock on our age, fortunately there are ways to lower our risk of a stroke and that includes staying physically active. Take walks, ride a bike, play a favorite sport. According to our current exercise guidelines for American adults, the goal is to get in at least two and a half hours each week of moderate-intensity physical activity as well as two days of muscle-strengthening activity [1].
But a new study, published in the journal JAMA Network Open, shows that reducing the chances of a stroke as we get older doesn’t necessarily require heavy aerobic exercise or a sweat suit [2]. For those who are less mobile or less interested in getting out to exercise, the researchers discovered that just spending time doing light-intensity physical activity—such as tending to household chores—“significantly” protects against stroke.
The study also found you don’t have to dedicate whole afternoons to tidying up around the house to protect your health. It helps to just get up out of your chair for five or 10 minutes at a time throughout the day to straighten up a room, sweep the floor, fold the laundry, step outside to water the garden, or just take a leisurely stroll.
That may sound simple, but consider that the average American adult now spends on average six and a half hours per day just sitting [3]. That comes to nearly two days per week on average, much to the detriment of our health and wellbeing. Indeed, the study found that middle-aged and older people who were sedentary for 13 hours or more hours per day had a 44 percent increased risk of stroke.
These latest findings come from Steven Hooker, San Diego State University, CA, and his colleagues on the NIH-supported Reasons for Geographic and Racial Differences in Stroke (REGARDS) study. Launched in 2003, REGARDS continues to follow over time more than 30,000 Black and white participants aged 45 and older.
Hooker and colleagues wanted to know more about the amount and intensity of exercise required to prevent a stroke. Interestingly, the existing data were relatively weak, in part because prior studies looking at the associations between physical activity and stroke risk relied on self-reported data, which don’t allow for precise measures. What’s more, the relationship between time spent sitting and stroke risk also remained unknown.
To get answers, Hooker and team focused on 7,607 adults enrolled in the REGARDS study. Rather than relying on self-reported physical activity data, team members asked participants to wear a hip-mounted accelerometer—a device that records how fast people move—during waking hours for seven days between May 2009 and January 2013.
The average age of participants was 63. Men and women were represented about equally in the study, while about 70 percent of participants were white and 30 percent were Black.
Over the more than seven years of the study, 286 participants suffered a stroke. The researchers then analyzed all the accelerometer data, including the amount and intensity of their physical activity over the course of a normal week. They then related those data to their risk of having a stroke over the course of the study.
The researchers found, as anticipated, that adults who spent the most time doing moderate-to-vigorous intensity physical activity were less likely to have a stroke than those who spent the least time physically active. But those who spent the most time sitting also were at greater stroke risk, whether they got their weekly exercise in or not.
Those who regularly sat still for longer periods—17 minutes or more at a time—had a 54 percent increase in stroke risk compared to those who more often sat still for less than eight minutes. After adjusting for the time participants spent sitting, those who more often had shorter periods of moderate-to-vigorous activity—less than 10 minutes at a time—still had significantly lower stroke risk. But, once the amount of time spent sitting was taken into account, longer periods of more vigorous activity didn’t make a difference.
While high blood pressure, diabetes, and myriad other factors also contribute to a person’s cumulative risk of stroke, the highlighted paper does bring some good actionable news. For each hour spent doing light-intensity physical activity instead of sitting, a person can reduce his or her stroke risk.
The bad news, of course, is that each extra hour spent sitting per day comes with an increased risk for stroke. This bad news shouldn’t be taken lightly. In the U.S., almost 800,000 people have a stroke each year. That’s one person every 40 seconds with, on average, one death every four minutes. Globally, stroke is the second most common cause of death and third most common cause of disability in people, killing more than 6.5 million each year.
If you’re already meeting the current exercise guidelines for adults, keep up the good work. If not, this paper shows you can still do something to lower your stroke risk. Make a habit throughout the day of getting up out of your chair for a mere five or 10 minutes to straighten up a room, sweep the floor, fold the laundry, step outside to water the garden, or take a leisurely stroll. It could make a big difference to your health as you age.
References:
[1] How much physical activity do adults need? Centers for Disease Control and Prevention. June 2, 2022.
[2] Association of accelerometer-measured sedentary time and physical activity with risk of stroke among US adults. Hooker SP, Diaz KM, Blair SN, Colabianchi N, Hutto B, McDonnell MN, Vena JE, Howard VJ. JAMA Netw Open. 2022 Jun 1;5(6):e2215385.
[3] Trends in sedentary behavior among the US population, 2001-2016. Yang L, Cao C, Kantor ED, Nguyen LH, Zheng X, Park Y, Giovannucci EL, Matthews CE, Colditz GA, Cao Y. JAMA. 2019 Apr 23;321(16):1587-1597.
Links:
Stroke (National Institute of Neurological Disorders and Stroke/NIH)
REGARDS Study (University of Alabama at Birmingham)
NIH Support: National Institute of Neurological Disorders and Stroke; National Institute on Aging
Posted In: News
Tags: accelerometer, aging, exercise, household chores, light-intensity physical activity, older people, physical activity, prevention, Reasons for Geographic and Racial Differences in Stroke Study, REGARDS Study, sedentary, senior health, sitting, stroke, walking
The People’s Picks for Best Posts
Posted on January 5th, 2021 by Dr. Francis Collins
It’s 2021—Happy New Year! Time sure flies in the blogosphere. It seems like just yesterday that I started the NIH Director’s Blog to highlight recent advances in biology and medicine, many supported by NIH. Yet it turns out that more than eight years have passed since this blog got rolling and we are fast approaching my 1,000th post!
I’m pleased that millions of you have clicked on these posts to check out some very cool science and learn more about NIH and its mission. Thanks to the wonders of social media software, we’ve been able to tally up those views to determine each year’s most-popular post. So, I thought it would be fun to ring in the New Year by looking back at a few of your favorites, sort of a geeky version of a top 10 countdown or the People’s Choice Awards. It was interesting to see what topics generated the greatest interest. Spoiler alert: diet and exercise seemed to matter a lot! So, without further ado, I present the winners:
2013: Fighting Obesity: New Hopes from Brown Fat. Brown fat, one of several types of fat made by our bodies, was long thought to produce body heat rather than store energy. But Shingo Kajimura and his team at the University of California, San Francisco, showed in a study published in the journal Nature, that brown fat does more than that. They discovered a gene that acts as a molecular switch to produce brown fat, then linked mutations in this gene to obesity in humans.
What was also nice about this blog post is that it appeared just after Kajimura had started his own lab. In fact, this was one of the lab’s first publications. One of my goals when starting the blog was to feature young researchers, and this work certainly deserved the attention it got from blog readers. Since highlighting this work, research on brown fat has continued to progress, with new evidence in humans suggesting that brown fat is an effective target to improve glucose homeostasis.
2014: In Memory of Sam Berns. I wrote this blog post as a tribute to someone who will always be very near and dear to me. Sam Berns was born with Hutchinson-Gilford progeria syndrome, one of the rarest of rare diseases. After receiving the sad news that this brave young man had passed away, I wrote: “Sam may have only lived 17 years, but in his short life he taught the rest of us a lot about how to live.”
Affecting approximately 400 people worldwide, progeria causes premature aging. Without treatment, children with progeria, who have completely normal intellectual development, die of atherosclerotic cardiovascular disease, on average in their early teens.
From interactions with Sam and his parents in the early 2000s, I started to study progeria in my NIH lab, eventually identifying the gene responsible for the disorder. My group and others have learned a lot since then. So, it was heartening last November when the Food and Drug Administration approved the first treatment for progeria. It’s an oral medication called Zokinvy (lonafarnib) that helps prevent the buildup of defective protein that has deadly consequences. In clinical trials, the drug increased the average survival time of those with progeria by more than two years. It’s a good beginning, but we have much more work to do in the memory of Sam and to help others with progeria. Watch for more about new developments in applying gene editing to progeria in the next few days.
2015: Cytotoxic T Cells on Patrol. Readers absolutely loved this post. When the American Society of Cell Biology held its first annual video competition, called CellDance, my blog featured some of the winners. Among them was this captivating video from Alex Ritter, then working with cell biologist Jennifer Lippincott-Schwartz of NIH’s Eunice Kennedy Shriver National Institute of Child Health and Human Development. The video stars a roving, specialized component of our immune system called cytotoxic T cells. Their job is to seek out and destroy any foreign or detrimental cells. Here, these T cells literally convince a problem cell to commit suicide, a process that takes about 10 minutes from detection to death.
These cytotoxic T cells are critical players in cancer immunotherapy, in which a patient’s own immune system is enlisted to control and, in some cases, even cure the cancer. Cancer immunotherapy remains a promising area of research that continues to progress, with a lot of attention now being focused on developing immunotherapies for common, solid tumors like breast cancer. Ritter is currently completing a postdoctoral fellowship in the laboratory of Ira Mellman, Genentech, South San Francisco. His focus has shifted to how cancer cells protect themselves from T cells. And video buffs—get this—Ritter says he’s now created even cooler videos that than the one in this post.
2016: Exercise Releases Brain-Healthy Protein. The research literature is pretty clear: exercise is good for the brain. In this very popular post, researchers led by Hyo Youl Moon and Henriette van Praag of NIH’s National Institute on Aging identified a protein secreted by skeletal muscle cells to help explore the muscle-brain connection. In a study in Cell Metabolism, Moon and his team showed that this protein called cathepsin B makes its way into the brain and after a good workout influences the development of new neural connections. This post is also memorable to me for the photo collage that accompanied the original post. Why? If you look closely at the bottom right, you’ll see me exercising—part of my regular morning routine!
2017: Muscle Enzyme Explains Weight Gain in Middle Age. The struggle to maintain a healthy weight is a lifelong challenge for many of us. While several risk factors for weight gain, such as counting calories, are within our control, there’s a major one that isn’t: age. Jay Chung, a researcher with NIH’s National Heart, Lung, and Blood Institute, and his team discovered that the normal aging process causes levels of an enzyme called DNA-PK to rise in animals as they approach middle age. While the enzyme is known for its role in DNA repair, their studies showed it also slows down metabolism, making it more difficult to burn fat.
Since publishing this paper in Cell Metabolism, Chung has been busy trying to understand how aging increases the activity of DNA-PK and its ability to suppress renewal of the cell’s energy-producing mitochondria. Without renewal of damaged mitochondria, excess oxidants accumulate in cells that then activate DNA-PK, which contributed to the damage in the first place. Chung calls it a “vicious cycle” of aging and one that we’ll be learning more about in the future.
2018: Has an Alternative to Table Sugar Contributed to the C. Diff. Epidemic? This impressive bit of microbial detective work had blog readers clicking and commenting for several weeks. So, it’s no surprise that it was the runaway People’s Choice of 2018.
Clostridium difficile (C. diff) is a common bacterium that lives harmlessly in the gut of most people. But taking antibiotics can upset the normal balance of healthy gut microbes, allowing C. diff. to multiply and produce toxins that cause inflammation and diarrhea.
In the 2000s, C. diff. infections became far more serious and common in American hospitals, and Robert Britton, a researcher at Baylor College of Medicine, Houston, wanted to know why. He and his team discovered that two subtypes of C. diff have adapted to feed on the sugar trehalose, which was approved as a food additive in the United States during the early 2000s. The team’s findings, published in the journal Nature, suggested that hospitals and nursing homes battling C. diff. outbreaks may want to take a closer look at the effect of trehalose in the diet of their patients.
2019: Study Finds No Benefit for Dietary Supplements. This post that was another one that sparked a firestorm of comments from readers. A team of NIH-supported researchers, led by Fang Fang Zhang, Tufts University, Boston, found that people who reported taking dietary supplements had about the same risk of dying as those who got their nutrients through food. What’s more, the mortality benefits associated with adequate intake of vitamin A, vitamin K, magnesium, zinc, and copper were limited to amounts that are available from food consumption. The researchers based their conclusion on an analysis of the well-known National Health and Nutrition Examination Survey (NHANES) between 1999-2000 and 2009-2010 survey data. The team, which reported its data in the Annals of Internal Medicine, also uncovered some evidence suggesting that certain supplements might even be harmful to health when taken in excess.
2020: Genes, Blood Type Tied to Risk of Severe COVID-19. Typically, my blog focuses on research involving many different diseases. That changed in 2020 due to the emergence of a formidable public health challenge: the coronavirus disease 2019 (COVID-19) pandemic. Since last March, the blog has featured 85 posts on COVID-19, covering all aspects of the research response and attracting more visitors than ever. And which post got the most views? It was one that highlighted a study, published last June in the New England Journal of Medicine, that suggested the clues to people’s variable responses to COVID-19 may be found in our genes and our blood types.
The researchers found that gene variants in two regions of the human genome are associated with severe COVID-19 and correspondingly carry a greater risk of COVID-19-related death. The two stretches of DNA implicated as harboring risks for severe COVID-19 are known to carry some intriguing genes, including one that determines blood type and others that play various roles in the immune system.
In fact, the findings suggest that people with blood type A face a 50 percent greater risk of needing oxygen support or a ventilator should they become infected with the novel coronavirus. In contrast, people with blood type O appear to have about a 50 percent reduced risk of severe COVID-19.
That’s it for the blog’s year-by-year Top Hits. But wait! I’d also like to give shout outs to the People’s Choice winners in two other important categories—history and cool science images.
Top History Post: HeLa Cells: A New Chapter in An Enduring Story. Published in August 2013, this post remains one of the blog’s greatest hits with readers. The post highlights science’s use of cancer cells taken in the 1950s from a young Black woman named Henrietta Lacks. These “HeLa” cells had an amazing property not seen before: they could be grown continuously in laboratory conditions. The “new chapter” featured in this post is an agreement with the Lacks family that gives researchers access to the HeLa genome data, while still protecting the family’s privacy and recognizing their enormous contribution to medical research. And the acknowledgments rightfully keep coming from those who know this remarkable story, which has been chronicled in both book and film. Recently, the U.S. Senate and House of Representatives passed the Henrietta Lacks Enhancing Cancer Research Act to honor her extraordinary life and examine access to government-funded cancer clinical trials for traditionally underrepresented groups.
Top Snapshots of Life: A Close-up of COVID-19 in Lung Cells. My blog posts come in several categories. One that you may have noticed is “Snapshots of Life,” which provides a showcase for cool images that appear in scientific journals and often dominate Science as Art contests. My blog has published dozens of these eye-catching images, representing a broad spectrum of the biomedical sciences. But the blog People’s Choice goes to a very recent addition that reveals exactly what happens to cells in the human airway when they are infected with the coronavirus responsible for COVID-19. This vivid image, published in the New England Journal of Medicine, comes from the lab of pediatric pulmonologist Camille Ehre, University of North Carolina at Chapel Hill. This image squeezed in just ahead of another highly popular post from Steve Ramirez, Boston University, in 2019 that showed “What a Memory Looks Like.”
As we look ahead to 2021, I want to thank each of my blog’s readers for your views and comments over the last eight years. I love to hear from you, so keep on clicking! I’m confident that 2021 will generate a lot more amazing and bloggable science, including even more progress toward ending the COVID-19 pandemic that made our past year so very challenging.
Posted In: Generic
Tags: aging, blood type, brown fat, C. diff, cancer, cancer immunotherapy, cathepsin, cathepsin B, Clostridium difficile, coronavirus, COVID-19, cytotoxic T cells, diet, dietary supplements, DNA-PK, exercise, FDA, genes, HeLa cells, Henrietta Lacks, Henrietta Lacks Enhancing Cancer Research Act, Hutchinson-Gilford progeria syndrome, Ira Mellman, Jennifer Lippincott-Schwartz, lonafarnib, lung cells, memory, mitochondria, muscle, obesity, progeria, sam berns, T cells, trehalose, weight gain, Zokinvy
Panel Finds Exercise May Lower Cancer Risk, Improve Outcomes
Posted on October 16th, 2019 by Dr. Francis Collins
Credit: gettyimages/vgajic
Exercise can work wonders for your health, including strengthening muscles and bones, and boosting metabolism, mood, and memory skills. Now comes word that staying active may also help to lower your odds of developing cancer.
After reviewing the scientific evidence, a panel of experts recently concluded that physical activity is associated with reduced risks for seven common types of cancer: colon, breast, kidney, endometrial, bladder, stomach, and esophageal adenocarcinoma. What’s more, the experts found that exercise—both before and after a cancer diagnosis—was linked to improved survival among people with breast, colorectal, or prostate cancers.
About a decade ago, the American College of Sports Medicine (ACSM) convened its first panel of experts to review the evidence on the role of exercise in cancer. At the time, there was limited evidence to suggest a connection between exercise and a reduced risk for breast, colon, and perhaps a few other cancer types. There also were some hints that exercise might help to improve survival among people with a diagnosis of cancer.
Today, the evidence linking exercise and cancer has grown considerably. That’s why the ACSM last year convened a group of 40 experts to perform a comprehensive review of the research literature and summarize the level of the evidence. The team, including Charles Matthews and Frank Perna with the NIH’s National Cancer Institute, reported its findings and associated guidelines and recommendations in three papers just published in Medicine & Science in Sports & Exercise and CA: A Cancer Journal for Clinicians [1,2,3].
Here are some additional highlights from the papers:
There’s moderate evidence to support an association between exercise and reduced risk for some other cancer types, including cancers of the lung and liver.
While the optimal amount of exercise needed to reduce cancer risk is still unclear, being physically active is clearly one of the most important steps in general that people of all ages and abilities can take.
Is sitting the new smoking? Reducing the amount of time spent sitting also may help to lower the risk of some cancers, including endometrial, colon, and lung cancers. However, there’s not enough evidence to draw clear conclusions yet.
Every cancer survivor should, within reason, “avoid inactivity.” There’s plenty of evidence to show that aerobic and resistance exercise training improves many cancer-related health outcomes, reducing anxiety, depression, and fatigue while improving physical functioning and quality of life.
Physical activity before and after a diagnosis of cancer also may help to improve survival in some cancers, with perhaps the greatest benefits coming from exercise during and/or after cancer treatment.
Based on the evidence, the panel recommends that cancer survivors engage in moderate-intensity exercise, including aerobic and resistance training, at least two to three times a week. They should exercise for about 30 minutes per session.
The recommendation is based on added confirmation that exercise is generally safe for cancer survivors. The data indicate exercise can lead to improvements in anxiety, depression, fatigue, overall quality of life, and in some cases survival.
The panel also recommends that treatment teams and fitness professionals more systematically incorporate “exercise prescriptions” into cancer care. They should develop the resources to design exercise prescriptions that deliver the right amount of exercise to meet the specific needs, preferences, and abilities of people with cancer.
The ACSM has launched the “Moving Through Cancer” initiative. This initiative will help raise awareness about the importance of exercise during cancer treatment and help support doctors in advising their patients on those benefits.
It’s worth noting that there are still many fascinating questions to explore. While exercise is known to support better health in a variety of ways, correlation is not the same as causation. Questions remain about the underlying mechanisms that may help to explain the observed associations between physical activity, lowered cancer risk, and improved cancer survival.
An intensive NIH research effort, called the Molecular Transducers of Physical Activity Consortium (MoTrPAC), is underway to identify molecular mechanisms that might explain the wide-ranging benefits of physical exercise. It might well shed light on cancer, too.
As that evidence continues to come in, the findings are yet another reminder of the importance of exercise to our health. Everybody—people who are healthy, those with cancer, and cancer survivors alike—should make an extra effort to remain as physically active as our ages, abilities, and current health will allow. If I needed any more motivation to keep up my program of vigorous exercise twice a week, guided by an experienced trainer, here it is!
References:
[1] Exercise Is Medicine in Oncology: Engaging Clinicians to Help Patients Move Through Cancer. Schmitz KH, Campbell AM, Stuiver MM, Pinto BM, Schwartz AL, Morris GS, Ligibel JA, Cheville A, Galvão, DA, Alfano CM, Patel AV, Hue T, Gerber LH, Sallis R, Gusani NJ, Stout NL, Chan L, Flowers F, Doyle C, Helmrich S, Bain W, Sokolof J, Winters-Stone KM, Campbell KL, Matthews CE. CA Cancer J Clin. 2019 Oct 16 [Epub ahead of publication]
[2] American College of Sports Medicine Roundtable Report on Physical Activity, Sedentary Behavior, and Cancer Prevention and Control. Patel AV, Friedenreich CM, Moore SC, Hayes SC, Silver JK, Campbell KL, Gerber LH, George SM, Fulton JE, Denlinger C, Morris GS, Hue T, Schmitz KH, Matthews CE. Med Sci Sports Exerc. 2019 Oct 16. [Epub ahead of publication]
[3] Exercise Guidelines for Cancer Survivors: Consensus Statement from International Multidisciplinary Roundtable. Campbell KL, Winters-Stone KM, Wiskemann J, May AM, Schwartz AL, Courneya KS, Zucker DS, Matthews CE, Ligibel JA, Gerber LH, Morris GS, Patel AV, Hue TF, Perna FM, Schmitz KH. Med Sci Sports Exerc. 2019 Oct 16. [Epub ahead of publication]
Links:
Physical Activity and Cancer (National Cancer Institute/NIH)
Moving Through Cancer (American College of Sports Medicine, Indianapolis, IN)
American College of Sports Medicine
Charles Matthews (NCI)
Frank Perna (NCI)
NIH Support: National Cancer Institute
Posted In: News
Tags: ACSM, American College of Sports Medicine, bladder cancer, breast cancer, cancer, cancer prevention, cancer survivor, colon cancer, endometrial cancer, esophageal cancer, exercise, exercise guidelines, kidney cancer, liver cancer, lung cancer, Molecular Transducers of Physical Activity Consortium, MoTrPAC, Moving Through Cancer, physical activity, physical fitness, stomach cancer
On Your Marks, Get Set
Posted on September 20th, 2019 by Dr. Francis Collins
It was my job to blow the whistle starting the 36th Annual NIH Institute Challenge Relay on September 18,2019. The relay race involved registered teams of five runners from many NIH institutes, centers, and offices. Each runner completed the same half-mile loop on the NIH campus and then passed the baton to the next team member. All teams included male and female runners with at least two team members of the same sex. It’s always a fun event and an annual reminder of the importance of exercise and staying fit. The race is sponsored by the NIH Recreation and Welfare Association. Credit: NIH
‘Exercise Hormone’ Tied to Bone-Strengthening Benefits
Posted on December 18th, 2018 by Dr. Francis Collins
Credit: gettyimages/kali9
There’s no doubt that exercise is good for us—strengthening our muscles, helping us maintain a healthy weight, maybe even boosting our moods and memories. There’s also been intriguing evidence that exercise may help build strong bones.
Now, an NIH-funded study is shedding light on the mechanism behind exercise’s bone-strengthening benefits [1]. The new work—which may lead to new approaches for treating osteoporosis, a disease that increases the risk of bone fracture—centers on a hormone called irisin that is secreted by muscles during exercise.
In a series of mouse experiments, the researchers found that irisin works directly on a common type of bone cell, stimulating the cells to produce a protein that encourages bones to thin. However, this chain of molecular events ultimately takes a turn for the better and reverses bone loss.
Bruce Spiegelman’s lab at the Dana-Farber Cancer Institute and Harvard University Medical School, Boston, first discovered the irisin hormone in 2012 [2]. In the years since, evidence has accumulated suggesting a connection between irisin and many of the benefits that come with regular workouts. For example, delivering low doses of irisin—sometimes called “the exercise hormone”—increase bone density and strength in mice.
But how does irisin act on bones? The answer hasn’t been at all clear. A major reason is the protein receptor on our cells that binds and responds to irisin wasn’t known.
In the new study reported in the journal Cell, Spiegelman’s team has now identified irisin’s protein receptor, called αVβ5 integrin. Those receptors are present on the surface of osteocytes, the most common cell type found in mature bone tissue.
The researchers went on to show that irisin helps osteocytes to live longer. It also leads the bone cells to begin secreting a protein called sclerostin, known for its role in preparing bones for remodeling and rebuilding by first breaking them down. Interestingly, previous studies also showed sclerostin levels increase in response to the mechanical stresses that come with exercise.
To further explore the role of irisin in mouse studies, the researchers gave the animals the hormone for six days. And indeed, after the treatment, the animals showed higher levels of sclerostin in their blood.
The findings suggest that irisin could form the basis of a new treatment for osteoporosis, a condition responsible for almost nine million fractures around the world each year. While it might seem strange that a treatment intended to strengthen bone would first encourage them to break down, this may be similar to the steps you have to follow when fixing up a house that has weakened timbers. And Spiegelman notes that there’s precedent for such a phenomenon in bone remodeling—treatment for osteoporosis, parathyroid hormone, also works by thinning bones before they are rebuilt.
That said, it’s not yet clear how best to target irisin for strengthening bone. In fact, locking in on the target could be a little complicated. The Speigelman lab found, for example, that mice prone to osteoporosis following the removal of their ovaries were paradoxically protected from weakening bones by the inability to produce irisin.
This new study fits right in with other promising NIH-funded efforts to explore the benefits of exercise. One that I’m particularly excited about is the Molecular Transducers of Physical Activity Consortium (MoTrPAC), which aims to develop a comprehensive map of the molecular changes that arise with physical activity, leading to a range of benefits for body and mind.
Indeed, the therapeutic potential for irisin doesn’t end with bone. In healthy people, irisin circulates throughout the body. In addition to being produced in muscle, its protein precursor is produced in the heart and brain.
The hormone also has been shown to transform energy-storing white fat into calorie-burning brown fat. In the new study, Spiegelman’s team confirms that this effect on fat also depends on the very same integrin receptors present in bone. So, these new findings will no doubt accelerate additional study in Speigelman’s lab and others to explore the many other benefits of irisin—and of exercise—including its potential to improve our moods, memory, and metabolism.
References:
[1] Irisin Mediates Effects on Bone and Fat via αV Integrin Receptors. Kim H, Wrann CD, Jedrychowski M, Vidoni S, Kitase Y, Nagano K, Zhou C, Chou J, Parkman VA, Novick SJ, Strutzenberg TS, Pascal BD, Le PT, Brooks DJ, Roche AM, Gerber KK, Mattheis L, Chen W, Tu H, Bouxsein ML, Griffin PR, Baron R, Rosen CJ, Bonewald LF, Spiegelman BM. Cell. 2018 Dec 13;175(7):1756-1768.
[2] A PGC1-α-dependent myokine that drives brown-fat-like development of white fat and thermogenesis. Boström P, Wu J, Jedrychowski MP, Korde A, Ye L, Lo JC, Rasbach KA, Boström EA, Choi JH, Long JZ, Kajimura S, Zingaretti MC, Vind BF, Tu H, Cinti S, Højlund K, Gygi SP, Spiegelman BM. Nature. 2012 Jan 11;481(7382):463-8.
Links:
Posted In: News
Tags: aging, Bone, bone remodeling, exercise, exercise hormone, fat, irisin, memory, metabolism, Molecular Tranducers of Physical Activity Consortium, mood, MoTrPAC, muscle, osteocyte, osteoporosis, sclerostin, thinning bones
Study Suggests Light Exercise Helps Memory
Posted on October 2nd, 2018 by Dr. Francis Collins
Credit: iStock/Wavebreakmedia
How much exercise does it take to boost your memory skills? Possibly a lot less than you’d think, according to the results of a new study that examined the impact of light exercise on memory.
In their study of 36 healthy young adults, researchers found surprisingly immediate improvements in memory after just 10 minutes of low-intensity pedaling on a stationary bike [1]. Further testing by the international research team reported that the quick, light workout—which they liken in intensity to a short yoga or tai chi session—was associated with heightened activity in the brain’s hippocampus. That’s noteworthy because the hippocampus is known for its involvement in remembering facts and events.
Posted In: News
Tags: brain, brain connectivity, brain imaging, brain scans, cerebral cortex, exercise, fMRI, hippocampus, light exercise, memory, memory improvement, Molecular Tranducers of Physical Activity Consortium, MoTrPAC, physical activity, spatial memory, tai chi, yoga
Snapshots of Life: Building Muscle in a Dish
Posted on March 29th, 2018 by Dr. Francis Collins
Credit: Kevin Murach, Charlotte Peterson, and John McCarthy, University of Kentucky, Lexington
As many of us know from hard experience, tearing a muscle while exercising can be a real pain. The good news is that injured muscle will usually heal quickly for many of us with the help of satellite cells. Never heard of them? They are the adult stem cells in our skeletal muscles long recognized for their capacity to make new muscle fibers called myotubes.
This striking image shows what happens when satellite cells from mice are cultured in a lab dish. With small adjustments to the lab dish’s growth media, those cells fuse to form myotubes. Here, you see the striated myotubes (red) with multiple cell nuclei (blue) characteristic of mature muscle fibers. The researchers also used a virus to genetically engineer some of the muscle to express a fluorescent protein (green).
Tags: aging, exercise, FASEB Bioart 2017, fluorescence microscopy, muscle, muscle fibers, myotubes, satellite cells, senior health, skeletal muscle
Creative Minds: Designing Personalized Clinical Trials
Posted on December 14th, 2017 by Dr. Francis Collins
Karina Davidson/Credit: Jörg Meyer
It might have been 25 years ago, but Karina Davidson remembers that day like yesterday. She was an intern in clinical psychology, and two concerned parents walked into the hospital with their troubled, seven-year-old son. The boy was severely underweight at just 37 pounds and had been acting out violently toward himself and others. It seemed as though Ritalin, a drug commonly prescribed for Attention Deficit Disorder, might help. But would it?
To find out, the clinical team did something unconventional: they designed for the boy a clinical trial to test the benefit of Ritalin versus a placebo. The boy was randomly assigned to take either the drug or placebo each day for four weeks. As a controlled study, neither clinical staff nor the family knew whether he was taking the drug or placebo at any given time. The result: Ritalin wasn’t the answer. The boy was spared any side effects from long term administration of a medication that wouldn’t help him, and his doctors could turn to other potentially more beneficial approaches to his treatment.
Davidson, now an established clinical psychologist at the Columbia University Irving Medical Center, New York, wants to take the unconventional approach that helped this boy and make it more of the norm in medicine. With support from a 2017 NIH Director’s Transformative Research Award, she and her colleagues will develop three pilot computer applications—or digital platforms—to help doctors conduct one-person studies in their offices.
Posted In: Health, Science, technology
Tags: 2017 NIH Director’s Transformative Research Award, All of Us, clinical trials, diabetes, digital platform, exercise, high blood pressure, light therapy, melatonin, N-of-1 trials, pain, personalized medicine, precision medicine, standard care, weight loss
NIH Family Members Giving Back: Toben Nelson
Posted on August 29th, 2017 by Dr. Francis Collins
Caption: Toben Nelson (back row, far left) celebrates with his Roseville Raiders after winning Gopher State Tournament of Champions.
Caption: Heather Hammond Nelson
What was Toben Nelson, a University of Minnesota epidemiologist who studies the health risks of alcohol abuse and obesity, doing this summer lugging around a heavy equipment bag after work? Giving back to his community. Nelson volunteered as a coach for the Roseville Raiders, a 13-year-old-and-under traveling baseball team that just wrapped up its season by winning the prestigious Gopher State Tournament of Champions in their age group.
In the fall, Nelson will gear up for hoops as the volunteer president of the Roseville Youth Basketball Association, which provides an opportunity for kids in this Minneapolis-St. Paul suburb to take part in organized sports. Nelson says volunteering grounds him as a scientist. It reminds him every single day that his NIH-supported research back at the office affects real lives and benefits real communities like his own.
Posted In: Health, Science, Tribute
Tags: adolescents, alcohol, alcohol abuse, athletics, baseball, basketball, childhood obesity, epidemiology, exercise, Gopher State Tournament of Champions, Mike Muscala Basketball Camp, Minnesota, NBA, obesity, sports, teens, volunteerism, volunteers, young adults, youth sports
Widening Gap in U.S. Life Expectancy
Posted on May 16th, 2017 by Dr. Francis Collins
Caption: Life expectancy at birth by county, 2014. Life expectancy into 80s (blue), 70s (green, yellow, orange), 60s (red).
Americans are living longer than ever before, thanks in large part to NIH-supported research. But a new, heavily publicized study shows that recent gains in longevity aren’t being enjoyed equally in all corners of the United States. In fact, depending on where you live in this great country, life expectancy can vary more than 20 years—a surprisingly wide gap that has widened significantly in recent decades.
Researchers attribute this disturbing gap to a variety of social and economic influences, as well as differences in modifiable behavioral and lifestyle factors, such as obesity, inactivity, and tobacco use. The findings serve as a sobering reminder that, despite the considerable progress made possible by biomedical science, more research is needed to figure out better ways of addressing health disparities and improving life expectancy for all Americans.
In the new study published in JAMA Internal Medicine, a research team, partially funded by NIH, found that the average American baby born in 2014 can expect to live to about age 79 [1]. That’s up from a national average of about 73 in 1980 and around 68 in 1950. However, babies born in 2014 in remote Oglala Lakota County, SD, home to the Pine Ridge Indian Reservation, can expect to live only about 66 years. That’s in stark contrast to a child born about 400 miles away in Summit County, CO, where life expectancy at birth now exceeds age 86.
Tags: Alabama, alcohol, behavior, childhood mortality, Colorado, epidemiology, exercise, geographical disparities, health, health disparities, health metrics, inequalities, Kentucky, life expectancy, lifestyle, longevity, Mississippi, Native American Indian, North Dakota, obesity, Oglala Lakota County, Pine Ridge Indian Reservation, smoking, socioeconomics, South Dakota, Summit County, U.S. counties, West Virginia