Not Horsing Around: Therapeutic Effects of Horseback Riding

Anne with students and Paralympians

Anne R. Crecelius, PhD, and students visit with La Roja Paralimpica athletes in Chile.

Choosing your favorite part of a trip can be a difficult decision for travelers. I had countless unforgettable and unique experiences during a recent four-week trip to Chile. One excursion that stands above the rest was a weekend trip to San Pedro de Atacama in Northern Chile.

I was studying with a group of students who had booked a horseback riding tour through the oasis of Sequitor. With the Andes Mountains as our backdrop, we spent two hours enjoying the perfect blue sky, warm sun and crisp air. This small agricultural region is in what is often called the driest desert in the world.

I had never been horseback riding and did not realize how much coordination, strength

Processed with VSCO with c1 preset

Molly Gearin tries her hand at horseback riding.

and physical and mental stamina it required. I later learned that horseback riding is a type of rehabilitative treatment—called hippotherapy—that may improve coordination, balance and strength in people with physical disabilities, including cerebral palsy (CP).

CP is a neurological disorder that affects body movement and coordination. Studies have shown that hippotherapy can improve joint stability, balance and painful muscle contractions in people with CP. Children with CP may especially benefit from hippotherapy. Therapeutic riding can change how the abdominal and lower back (core) muscles respond to different movements. These physiological benefits can improve posture and the overall quality of life in some children, particularly among those who have the ability to walk, run and jump.

Researching hippotherapy was not the first time I thought about people with CP on our trip to Chile. Another favorite activity was our opportunity to watch La Roja Paralimpica, the Chilean Paralympic Fútbol 7-a-side team, practice. This sport is adapted from traditional fútbol (soccer) to accommodate athletes with disabilities. The modified rules allow Paralympic athletes to enjoy a sport that is at the heart of Chilean culture.

As a future physical therapist, I enjoyed observing elite athletes at work and learning about hippotherapy, an activity that could be of benefit to people with CP.

– Molly Gearin (Anne Crecelius contributed to this post)

Molly Gearin is a pre-physical therapy major at the University of Dayton. Anne R. Crecelius, PhD, is an assistant professor in the Health and Sport Science Department at the University of Dayton. They spent four weeks in Chile as part of a study abroad program in partnership with the Universidad de los Andes studying nutrition, sports and research in the context of the Chilean culture. This is the first in a three-part series that spies physiology in this dynamic South American country.

 

 

The Brain in Your Gut

Relation of human brain and guts, second brain

Credit: iStock

Did you know your gut has a brain of its own? It’s called the enteric nervous system. The brain in your gut is embedded in the wall of the digestive tract. Together with your “big brain,” the enteric nervous system helps control gastrointestinal function, including the mixing and grinding of food in the stomach and absorption of nutrients in the intestines.

An adult’s enteric nervous system is made up of 200 to 600 million nerve cells (neurons). That’s as many neurons as are in a cat’s brain or even your spinal cord! The neurons in the enteric nervous system interact with smooth muscle to move food through the digestive system. The brain in your gut also plays an important role in regulating your immune system. It attacks bacteria and viruses (pathogens) that invade the digestive tract by releasing protective substances called peptides that make it harder for pathogens to do harm.

Although the brain in your gut functions independently from the “big brain”—and is the only organ in your body that can do so—normal digestive function requires communication between the enteric nervous system and the brain. The enteric nervous system provides sensory information to the brain to help you decide what, when and how much you eat. When you’re hungry or see something you’re craving (like a piece of chocolate cake or a juicy burger), your brain tells your gut to start the digestion process by producing gastric secretions in the stomach.

Problems with the enteric nervous system can lead to different digestive diseases such as irritable bowel syndrome and functional constipation. Studies have demonstrated that losing some of the neurons in the gut can be a cause of these conditions. Understanding how and why these neurons die is an important topic of research that could result in finding new treatments for digestive diseases.

To learn more about digestive disease, visit the National Institute of Diabetes and Digestive and Kidney Diseases website.

 

Ninotchska DelvalleNinotchska Delvalle is a doctoral candidate in the neuroscience program at Michigan State University. Her research focuses on how specialized cells of the enteric nervous system (enteric glia) contribute to the development of gastrointestinal disease.

Myasthenia Gravis May Be (Literally) All Greek to You

neuron

Myasthenia gravis is a disease that affects the way that muscles receive signals from nerves. Myasthenia is Greek for “muscle weakness,” which is a good description of this disease’s symptoms. Muscle weakness, which worsens after physical activity but gets better with rest, is the primary symptom of the condition.

Weakness may occur in any skeletal muscle, but smaller muscles in the face are commonly affected. This leads to symptoms that may include:

  • difficulty chewing or swallowing,
  • speech impairment,
  • altered facial expression,
  • drooping eyelids, and
  • blurred vision.

Weakness in the limbs is often a symptom when larger muscles are affected. One of the most serious consequences of myasthenia gravis is a myasthenic crisis, which occurs when the respiratory muscles that allow us to breathe are affected. Someone in myasthenic crisis may need a machine (ventilator) to help them breathe if they have trouble on their own.

An understanding of how nerves work with muscles is important to understanding the effects of myasthenia gravis. The brain sends signals through the nerves, telling them which direct body parts to move. The signals travel down nerves to nerve endings, which are located very close to—but not touching—muscle fibers. Nerves release chemicals called neurotransmitters to send signals that bridge the gap between the nerves and muscles. Neurotransmitters bind to molecules on the surface of the muscle cells (receptors) that send a signal inside the cell. Acetylcholine is a neurotransmitter that causes muscle movement when it binds to its receptor. The normal interaction between a neurotransmitter and receptor doesn’t always work as smoothly as it should. In some cases, the immune system interferes, producing proteins called antibodies that are meant to protect the body from substances that might harm it. In the case of myasthenia gravis, the immune system makes antibodies that bind to acetylcholine receptors, which prevents the interaction between the neurotransmitters and receptors.

The disease typically occurs in women under 40 and men over 60, but it can develop at any age. Myasthenia gravis may be debilitating, but the good news is that symptoms can usually be controlled with medication. Steroids can help limit the production of antibodies that target acetylcholine receptors. Drugs called acetylcholinesterase inhibitors increase muscle strength by slowing the breakdown of acetylcholine. When neurotransmitters remain for longer periods of time, signals to the muscles are more likely to go through.

As you enjoy the outdoors and weather during Myasthenia Gravis Awareness Month, keep in mind all the things your muscles and nerves are doing without you even thinking about it.

 

Rebekah Morrow 3Rebekah Morrow, PhD, is an assistant professor of immunology and microbiology at the Alabama College of Osteopathic Medicine.

Like Father, Like Son (and Daughter): How Your Dad’s Past Affects Your Future

Happy daughter playing with dad

Credit: iStock

What makes your father the best dad in the world? Maybe it’s his sense of humor or the times he has taken you to the movies or played catch in the yard. Or maybe it’s the fact that he made healthy lifestyle choices before you were born. Recent research suggests that your father’s health before you were conceived (preconception) may change the way your genes behave to affect your future health. It almost sounds like something out of a science fiction movie, but it’s real.

Studies tend to focus on the mother’s preconception health and the risks her baby might face later in life if she’s overweight. But a dad’s weight and early eating habits can also play a role, according to research published in the American Journal of Stem Cells. Researchers found that offspring of men who were obese before reproducing were more likely to have diabetes and be overweight. On the other hand, the researchers also found that fathers who had limited food resources in their early life caused genetic changes that protected their children—and even grandchildren—against cardiovascular disease.

Most people know that exercise is one of the healthiest lifestyle choices you can make to maintain your weight and keep your heart and even your brain healthy. However, research presented at the APS Integrative Biology of Exercise 7 meeting showed that offspring of men who exercised long term before conceiving had a higher likelihood of being obese and developing diabetes. This result was a huge surprise to the research team, but is it a reason to stop exercising? Not really. The study focused on how efficiently the body used energy on a high-fat diet. Limiting dietary fat and being active is still the way to go for most people.

Keeping stress levels low is also a good plan for dads-to-be. One study suggests that a man’s preconception stress may program his kids for mood disorders. Researchers found a pathway in the brain that transmits signals about stress hormones, and it may be passed down to the next generation.  If the signal is passed on to you, then your father’s stress levels could affect your predisposition for anxiety and depression.

These studies represent clues to learning how genetic material is transformed as it passes through generations. It’s also a reminder that following a healthy diet, staying active and maintaining mental health is important for everyone at every age.

Happy Father’s Day!

– Erica Roth

Putting Out Fires Hurts Firefighters’ Hearts

Credit: IStock

As the temperature outside rises, our bodies make adjustments to keep our internal temperature constant to prevent us from overheating through a process called thermoregulation. This includes bodily functions such as sweating and widening of the blood vessels (vasodilation). When we sweat, perspiration evaporates from our skin to cool us down. When the blood vessels under our skin widen, our heart pumps more blood to our skin, which releases more heat from our inner body.

Our bodies are constantly working to hold a steady core temperature around 98-100 degrees Fahrenheit (F). This allows our organs to function properly. But when the temperature outside is extremely hot, our temperature can start to rise. A person with a body temperature above 104 degrees can develop heat stroke. This can cause dizziness, difficulty breathing, confusion, seizures or loss of consciousness. Brain and heart damage—sometimes permanent—can occur when body temperature climbs above 107 degrees F.

Too much summer heat can be unhealthy for everyone, but it can be especially dangerous to firefighters. The incidence of fires increases in the U. S. during the summer months. Firefighters fight almost twice as many fires in the summer compared to the rest of the year. On top of dealing with the extreme heat (sometimes over 700 degrees F!), these first responders face extreme physical exertion, mental stress and smoke inhalation on the job. All of these factors together can place firefighters in immediate danger of heat exhaustion, heatstroke and heart problems. In fact, firefighters are up to 136 times more likely to die from coronary artery or heart disease during or soon after they suppress a fire.

In a study published in Circulation last month, researchers may have uncovered several reasons why putting out fires puts firefighters at risk for heart disease. They discovered that a single, 20-minute session of fire simulation training—where healthy firefighters were exposed to physical activity in the extreme heat (about 755 degrees F)—was enough to injure their blood vessels, even though the firefighters’ core body temperature never reached above 101 degrees F. The problem: Although the firefighters’ bodies did keep their core temperature within a healthy range, their blood vessels did not relax properly immediately after the training. Also, as a result of the training, the firefighters’ blood clotted more easily. Damaged blood vessels and increased clotting of the blood can be very harmful to the heart and sometimes can lead to a heart attack.

This research shows us that even when we are able to keep our body temperature from getting too high, there are hidden dangers of being physically active in extremely hot temperatures. So keep your heart healthy this summer and don’t overexert yourself while outdoors!

Dao Ho, PhD

Dao H. Ho, PhD, is a biomedical research physiologist at Tripler Army Medical Center. The views expressed in this blog post are those of the author and do not reflect the official policy or position of the U.S. Department of the Army, U.S. Department of Defense or the U.S. government.

Is Running Barefoot Better than Wearing Shoes?

woman's feet running on gravel road

Credit: iStock

Visit any sporting goods store today, and you’ll see a wall display full of running shoes for all types of runner, from sprinters to marathoners and everything in between. Before the 1970s, however, specialized running shoes weren’t readily available, and most runners ran with minimally supportive shoes or without any shoes at all.

It is easy to imagine how people could run shoeless along unpaved roads a hundred years ago, but on U.S. streets today? That’s a bit harder to picture. Still, barefoot running has grown in popularity over the past two decades. The question remains why a runner would want to strike hard ground with the tender sole of his or her foot instead of a cushioned running shoe. The answer may be that barefoot runners have fewer impact-related injuries.

Researchers set out to determine if there was a difference in the way barefoot runners’ feet strike the ground and if this decreased the force the runners felt in their joints. The research team studied three groups: U.S. runners who always ran in shoes, Kenyan runners who grew up running barefoot but now run in shoes and U.S. runners who started their running careers wearing shoes but now run barefoot. They found that athletes who have always worn shoes tended to land heel first and then roll up onto their toes, unlike barefoot runners who tended to land toe first. The Kenyan runners—who came late to the practice of running with shoes—also landed toe first, suggesting that early barefoot running can influence foot landing even when the runner starts wearing shoes.

Running is a high-impact activity that generates large forces when the feet strike the ground. This impact often causes injuries, particularly in high-mileage athletes, who are prone to repetitive motion injuries. When the researchers examined the force of foot-strikes, barefoot runners struck the ground with much lower forces than those wearing shoes. The lower strike force seems to be directly linked to landing toe first instead of heel first. Barefoot runners also lower their center of gravity more than runners who wear shoes. This decreases the stress on their legs during a foot strike and allows for more “give” in their stride. The lower impact of barefoot running is interesting because running shoes are designed to cushion the foot and protect against forceful impact.

Barefoot running seems to be easier on the body and results in fewer injuries. National Go Barefoot Day is June 1, and Global Running Day is June 7, so get out there and try a short barefoot run!

 

Jessica Taylor 2017

Jessica C. Taylor, PhD, is a physiologist, medical educator and exercise enthusiast.  She was previously the executive director of the Mississippi Osteopathic Medical Association and will be joining the APS staff as the Senior Manager of Higher Education Programs this summer.

A Healthy Diet: A Prescription for a Healthy Life!

food pyramid pie chart

Credit: iStock

We have all heard the phrase “You are what you eat.” Not only is there a lot of truth in that little saying, it is also a great reminder for us to be aware of everything we put into our bodies. Everything we eat and drink has an effect on our being and our physical and mental health depends on proper nutrition.

Most people know that nutrition means getting the right amount of nutrients to fuel our bodies and brains. But the difference between the types of nutrients can be less clear.

Nutrients are divided into three categories: micronutrients, macronutrients and water.

Micronutrients are vitamins, minerals and substances such as sodium and potassium called electrolytes. They are essential for growth, development and normal cellular activities. A wide variety of fruits, vegetables and animal products such as meat and dairy are rich in micronutrients.

Macronutrients include carbohydrates (sugar and starches), protein and fats. Macronutrients are extremely important because they give us the calories we need to produce energy. Each person needs a different amount of macronutrients depending on their body size, body composition and level of physical activity. This last point—activity level—is key. We often eat and drink far too many calories for our body’s needs and store the extra calories as fat. The excess fat can become a big problem, causing inflammation, problems with metabolism and cardiovascular issues.

Water is important for maintaining your body’s fluid balance and for functions such as digestion, circulation and body temperature. We also need water to carry nutrients throughout our body and to energize our muscles.

The lack of proper nutrition is still an issue in areas of the U.S. and other Western countries. However, consuming too many calories without enough nutrients is also a critical health problem in the developed world. In fact, the definition of “malnutrition” has been updated to include overnutrition. The expanded definition of malnutrition highlights the serious threat that overnutrition and obesity have on human health.

If you want to learn more about how to fit better nutrition into your life, visit the U.S. Department of Agriculture’s Choose My Plate website. This tool can help jump-start your nutrition knowledge and get you on your way to feeling great.

Audrey Vasauskas

 

In May, Take Steps to Prevent Melanoma

melanoma

Credit: iStock

With the weather getting warmer, you may be tempted to bare more skin in the coming months. However, sunnier days can increase your risk of skin cancer if you don’t protect yourself. May is Melanoma/Skin Cancer Detection and Prevention Month. Read on to learn more about your body’s largest organ and how melanoma grows.

Your skin is composed of three main layers: the layer that you see (epidermis), the layer directly beneath the epidermis (dermis) and the deepest, innermost layer (hypodermis). Melanoma, the most dangerous form of skin cancer, starts with an abnormal growth of cells at the bottom of the epidermis layer of the skin. These cells, called melanocytes, produce melanin to give skin its color.

Exposure to the sun’s ultraviolet (UV) rays is a major risk factor for developing melanoma. Even just a handful of blistering sunburns during childhood or adolescence can double your risk of developing melanoma later in your life. UV exposure can damage and cause mistakes (mutations) in the DNA of the melanocytes. UV-related mutations that occur in molecules important for controlling cell growth can lead to skin cancer.

Although only about 5 percent of all skin-related cancers are melanoma, it’s the deadliest form, causing approximately 10,000 deaths per year in the U.S. People with melanoma that is confined to a small area (primary melanoma) have close to a 90 percent survival rate. However, the recovery rate is significantly lower in melanoma that starts in the skin and spreads to other parts of the body (metastatic melanoma).

Metastatic melanoma most commonly spreads to the liver, lungs, bones and brain. This is troublesome for several reasons. Once cancer has spread, it is extremely difficult to determine the original cancer type, making treatment problematic. Also, cancer cells compete with normal cells for nutrients. Because cancer cells grow quickly, the body often ends up sending more nutrients (sometimes unintentionally) to the cancer, allowing its size to further increase. Early detection of melanoma is extremely important, giving you the best chance for treatment and survival.

Visit the Skin Cancer Foundation to learn how to reduce your risk of developing skin cancer.

 

Adam Morrow

Adam Morrow, PhD, is an assistant professor of biochemistry at the Alabama College of Osteopathic Medicine.

Walking and the Brain, Aromatherapy for Horses and a Whole Lot More!

Physiology, the study of function from microscopic cells to complete organ systems, encompasses a wide range of fascinating topics. The annual Experimental Biology (EB) meeting is a showcase for thousands of researchers studying humans and animals alike. Check out some of the research presented at last month’s meeting in Chicago:

Close up shot of runner's shoes

Credit: iStock

Most people know that walking is good for heart health, weight management and flexibility. New research from New Mexico Highlands University reveals how your brain also benefits from walking. Each step you take sends pressure waves through your arteries and increases blood flow—and oxygen—to the brain. The researchers found that running also had a beneficial effect on blood flow, while sports like cycling that don’t involve foot impact were less likely to make a significant difference.

Dressage test

Credit: iStock

Do you like the calming scent of lavender when the pressure’s turned up? Turns out, you’re not alone. Research out of Albion College studied the effects of aromatherapy on horses. Much like people, competition horses get stressed out when they’re transported from their home to an unfamiliar venue. Stress reduction therapies are highly regulated in competition horses, and non-medicinal treatments could go a long way to calm the animals before they perform. The researcher found that stress hormone levels dropped significantly among trailered horses that were exposed to lavender aromatherapy when compared to distilled water mist.

Two women rowing on a lake

Credit: iStock

Olympic-caliber athletes appear to be the picture of strength and power. But new research suggests that high-intensity workouts without a proper recovery period could interfere with optimum bone health. A study of female Olympic rowers from Canada’s Brock University showed that the levels of a protein that stops bone mineral loss dropped during extended periods of heavy training. Bone mineral loss weakens the bones and increases the risk of stress fractures and osteoporosis.

These studies just scratched the surface of all the top-notch physiology research presented at EB. Read more highlights from this year’s meeting:

Why vitamin A and a high-fat diet don’t mix

The role of immune cells in the cause—and treatment of—preeclampsia

How an ice bag on the face can help treat severe blood loss

An “exercise pill” may be in our future

How orange essential oil reduces PTSD symptoms

 

Erica Roth

April Showers Bring May Flowers—and Sneezes

Allergy Sufferers

Credit: iStock

There are plenty of things to love about spring. It’s warmer and daylight lasts longer, so you can spend more time outdoors. It’s the end of cold and flu season, so you may be feeling better than you did over the winter. And it seems that everything is in bloom. However, those beautiful spring flowers and trees can cause their own problems in the form of seasonal allergies.

Pollen is the cause of most seasonal allergies. Pollen counts increase in the spring as trees and plants wake from winter dormancy. Trees and other plants release pollen into the air as a method of fertilization (pollination) to produce seeds and fruit.  Pollen travels as tiny particles (particulates) similar to dust. Every time you inhale, you breathe in a lot of particulates. Most of them are not harmful, but if you have seasonal allergies, your immune system reacts to pollen and makes an immune response against it. This immune response happens because your body—rightly so—thinks of pollen particulates as invaders. To fight these invaders, your body makes an inflammatory substance called histamine, which causes the itchy and watering eyes, sneezing and runny nose that are the hallmark symptoms of seasonal allergies. Your body is trying to keep you safe, but ends up making you miserable.

Many anti-allergy medications can help reduce allergy symptoms. Most of them do this by limiting the release of histamine from the immune cells inside your body. You can also reduce your symptoms by:

  • steering clear of outdoor activities as much as possible when pollen counts are high,
  • wearing sunglasses outdoors to help keep pollen out of your eyes,
  • changing your clothes after being outdoors, and
  • keeping the windows and doors closed in your home to limit the amount of pollen coming in and spreading around inside.

The best thing about seasonal allergies is that they are time-limited. Most plants have limited blooming seasons. As soon as the pollen counts drop, you can breathe easy and enjoy spring outdoors again.

 

Rebekah Morrow 3Rebekah Morrow, PhD, is an assistant professor of immunology and microbiology at the Alabama College of Osteopathic Medicine