Each year, scientists who study physiology and other biomedical research fields—including anatomy, biochemistry, pathology and pharmacology—gather at the Experimental Biology (EB) meeting. Scientific meetings such as EB provide a platform to present and learn about new and cutting-edge research and form collaborations with colleagues that can lead to advances in science and medicine. This year’s EB meeting in San Diego featured studies ranging in topics from nutrition and exercise to mental well-being and women’s health. Read on to learn more about the relationship between mind and body.
When you’re physically tired, you may feel like your entire body slows down. You might have trouble keeping your eyes open or putting one foot in front of the other. However, science says something different: In older adults, it’s mental fatigue, not physical energy, that affects walking ability. Researchers from Clarkson University in Potsdam, N.Y. asked a group of seniors to perform a timed walking test that tired them out physically and then gave them math problems to sap their mental energy. They found that the more mentally—not physically—tired the volunteers were, the more their walking speed and stride length decreased.
Mindfulness meditation can help calm your mind and body. As it turns out, the practice of focusing on your breathing and thoughts may reduce your risk of heart disease after one 60-minute session. Researchers from Michigan Technological University tested the blood pressure, heart rate and artery stiffness of people with anxiety after an hour-long meditation class. All of these factors improved after a single meditation session. That’s reason enough to get your Zen on.
“Summertime and the livin’ is easy”… or so you thought. However, a study from Poznan University of Medical Sciences in Poland finds that for some medical students, stress hormones rise in the summer when compared to the colder, darker winter season.
Interested in learning about more research presented at the meeting? Check out these studies focused on women’s health and exercise:
Black moms may burn calories slower than white moms to keep more baby weight
Zinc deficiency before conception may make it harder to conceive
Regular soaks in a hot tub may improve insulin resistance and reduce inflammation in obese women
Drinking water may help exercising seniors stay mentally sharp
Exercising after concussion may help teens recover
– Erica Roth
About 35 million adults in the U.S. may develop high blood pressure because of negative events that happened to them during childhood. Researchers are exploring how an event you experience when you’re a kid can cause high blood pressure as an adult.
About 35 million children in the U.S. experience early-life stress (ELS). ELS is any traumatic event that occurs for an extended period of time to a child younger than 10. These experiences may range from emotional, sexual or physical abuse to parental divorce or growing up in a low-income household. ELS often has negative health effects—including high blood pressure—throughout a person’s adult life.
High blood pressure occurs when the force of the blood passing through the blood vessels remains higher than normal. If the pressure is not controlled, the blood vessels become stiff over time, which reduces blood flow and oxygen to the heart and increases the risk of heart failure or heart attack. High blood pressure can also cause severe damage to blood vessels in the kidneys and may eventually lead to chronic kidney disease, a condition in which the kidneys are no longer able to filter blood to remove toxic waste from the body. People with severe chronic kidney disease require a treatment called dialysis to keep them alive. During dialysis, a machine removes waste and excess water from the blood, effectively acting as an artificial kidney outside the body.
Because of these potential complications, it’s important to understand how ELS puts people at risk for high blood pressure. Numerous studies have shown that activation of immune cells can make high blood pressure worse. A recent study explored how ELS affects the immune system in rat kidneys, the organs responsible for long-term blood pressure control. The study found that rats exposed to ELS had higher numbers of immune cell markers and more immune cell activation in their adult life. Prolonged immune cell activation can prevent the kidneys from working properly, which may cause high blood pressure later on.
Interestingly, the study also found that when the immune cells in the kidneys of ELS rats were stimulated they showed that the immune cells were overactive. This finding is important because it shows researchers are starting to understand more about the link between ELS and high blood pressure. However, more research is needed to fully establish a connection between childhood trauma, the immune response of the kidneys and high blood pressure in adulthood.
Ijeoma Obi, MS, is a PhD candidate in the University of Alabama at Birmingham’s Department of Medicine, Nephrology Division, Section of Cardio-Renal Physiology and Medicine.
If getting more exercise is one of your New Year’s resolutions, here is another reason to stick with it: daily exercise—which is known to lower blood pressure—has also been shown to reduce stress and anxiety. I am not the first to notice that physical activity improves my ability to respond to stressful situations, but as a physiologist, I naturally wonder about the biological basis of this observation.
The hippocampus—one of the brain regions that regulates anxiety levels—becomes activated during both exercise and stress. Research suggests that exercise can calm some of the nerve cells in the hippocampus that become overstimulated during times of stress. While we don’t fully understand the mechanisms, we do know that certain chemical signals in the brain inhibit nerve cell activity, and some of these signals are likely responsible for the observed reduction in stress and anxiety.
Reduced anxiety and stress immediately after physical activity is not the only benefit of exercise. Blood pressure also declines to healthier levels within minutes after exercising. Studies suggest that exercise causes vasodilation, or widening of the blood vessels. When blood vessels open wider, it allows the blood to flow more easily, thereby lowering the pressure of the blood inside the vessels. Activation of histamine receptors is one mechanism that contributes to the reduction in blood pressure following exercise.
While there are many other benefits to regular exercise, the reductions in stress and blood pressure occur immediately and last for many hours. So, consider engaging in a physically active lifestyle that includes daily exercise, and encourage family and friends to join in. The result could be less stress, less anxiety, and lower blood pressure. What better way to start 2018?
William B. Farquhar, PhD, is a professor in the department of kinesiology and applied physiology at the University of Delaware. In addition to being a member of the American Physiological Society, he is a Fellow of the American College of Sports Medicine.
If you tend to see the proverbial glass as half empty instead of half full, you may want to rethink your position. Looking on the bright side and expecting good things to happen may have a positive effect on your physical health. An optimistic outlook on life may reduce your cardiovascular disease risk, lower blood pressure and improve overall health and longevity. It can also reduce sensitivity to pain and may help people manage chronic pain more easily.
You may be skeptical or cautiously optimistic about this. How can simple optimism lead to good health? The answer is still not entirely clear, but scientists are slowly uncovering the biological details. They’ve learned that the body’s response to stress may be an important factor.
When the body is stressed, it sends biological messengers called stress hormones into the bloodstream to tell different organs to respond in various ways. One of the major stress hormones is cortisol. When cortisol is high, the body responds by making unhealthy amounts of certain substances (such as cholesterol) that can harm the heart. These substances may damage and cause inflammation in the blood vessels. Inflammation may also lead to more damage in the circulatory system. This unfavorable chain of events may increase the risk of heart disease.
People who look on the bright side may be more likely to have markers of good health—including lower stress hormone levels—even when they face stressful situations. One study found rats with pessimistic behavior traits had more inflammation than their optimistic counterparts. Lower cortisol and inflammation levels may be due to decreased activity of the fight-or-flight nervous response, although more research is needed.
Motivation may also play a role in boosting the health of optimists. People who think positively may be more motivated and tend to make more of an effort in social interactions than those who are pessimistic. This can lead to healthier social connections and an increase in beneficial behaviors such as exercising regularly and following a healthy diet. The motivational aspects of optimism (or pessimism) may also affect a person’s behavioral response to stress.
December 21 is “Look on the bright side” day. Try a visualization exercise to boost your optimism. It may have a positive effect on your overall health.
– Audrey Vasauskas
“I’m not flexible enough to do yoga!” In my 12 years as a yoga instructor, this is the excuse I have heard most often for why people aren’t practicing yoga. My initial response is usually, “That’s exactly why you should be practicing yoga!” However, I am also an assistant professor of physiology, and I know that the benefits of yoga go far beyond flexibility. Participating in yoga regularly imparts a number of benefits— from weight management to stress reduction—to our physical and mental health.
One very important side benefit of yoga that is linked to both physical and mental health is breath control. Slow, deep, conscious abdominal (belly) breathing, especially during difficult poses, trains us to use the same type of breathing in challenging scenarios off the mat, such as giving a presentation, taking an exam or performing a difficult task.
Why do deep, yogic belly breaths help us through stressful situations? Recent studies suggest that this type of breathing can decrease firing of the sympathetic nervous system while increasing activity of the parasympathetic nervous system. The spike in heart rate and blood pressure, sweaty palms and voice tremors you might experience when you speak in front of an audience, for example, are due to activation of your sympathetic nervous system—the “fight-or-flight” response. This nervous response is great if you are running from a bear in the woods. But in real life these changes can lead to short-term memory problems and high anxiety levels that may interfere with giving a presentation or taking a test.
If you approach stressful situations with abdominal breaths, however, you help shut down the fight-or-flight reaction and increase the parasympathetic nervous response. Called a relaxation response, your heart rate slows down and your blood pressure returns to normal. Once you’re relaxed, you can approach the task at hand in a calm, collected way.
Many types of yoga incorporate physical movements with deep abdominal breathing. The physical demands of these movements have the potential to cause the fight-or-flight response, but by combining these poses with yogic breathing, we learn how to control our breath in seemingly stressful situations. So the next time someone tells me they are not flexible enough to do yoga I will ask them if they can take a deep breath. If they say yes, then I know they are ready to go!
September is National Yoga Month. Check out a yoga class or festival near you.
While walking through Santiago, Chile, you are likely to come across at least one of the countless wandering dogs that live on the busy streets. Homeless dogs are a normal part of Santiago’s culture. They are quick to make friends with anyone who offers a welcoming hand or food. They are not quick, however, to forget their friends. If you make a canine companion in this city, as my classmates and I did, it will probably remember you the next time you come down the street.
The feeling of attachment between the dogs and people of Santiago reminded me of the way a mother and her infant gaze into each other’s eyes. This simple, mutual act of love causes an automatic reaction in both the mom and baby, which increases the levels of oxytocin in the body. Oxytocin is a hormone that plays a major role in social bonding between mothers and infants and between romantic partners. The release of oxytocin promotes a feeling of social well-being and may prevent stress. Interacting with the local dogs in Chile made me wonder if this same sense of happiness and bonding occurs between dogs and people.
A research study looking at the bond between humans and dogs found a similar release—and increase—of oxytocin during social interactions, such as gazing, in both the animals and people. The dogs’ hormone levels also increased when people talked to and petted them. Scientists think this looped interaction reaction (bonding in both directions between pooch and person) may be a reason that humans were able to domesticate wild dogs in the first place. Dogs are one of the only animals known to fully recognize human facial features and expressions. This ability likely helps dogs and people communicate, love and take comfort in one another’s presence.
This mutual interaction is likely the cause of a quick, yet memorable, friendship between humans and dogs both at home and in places like the streets of Santiago. So next time you see a dog in passing, don’t be afraid to gaze into its eyes and form a quick friendship.
Logan Goff is an exercise physiology 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 final installment in a three-part series (read part one and part two) that spies physiology in this dynamic South American country.
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:
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.
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.
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
A jousting knight wears his heart on his sleeve. Credit: iStock
In medieval times, a jousting knight would wear the colors of the lady he was courting tied around his arm. Hence, the phrase “Wear your heart on your sleeve” was born. Today, we use this romantic phrase to describe someone who expresses their emotions openly. How applicable that ancient phrase really is to maintaining a healthy heart!
In a landmark paper, a group of scientists discussed how stress and social interactions with others affected the health of the heart. It is well-known that stress is a major factor in the development of heart disease. This is because stress is a double whammy: It activates the “fight-or-flight” nervous response, and it causes inflammation in the cells that line blood vessels. Both of these events can damage blood vessels in the heart.
Research shows that positive social interaction expressing emotion is important for heart health. Support from a spouse or partner, friends or other groups can reduce stress and help you stick to a healthy diet and exercise program to minimize your risks.
Heart disease is the leading cause of death worldwide, with annual deaths creeping up to 24 million. Reducing stress and anxiety is an important aspect of keeping your heart healthy. Exercise, yoga, meditation and even deep breathing can promote a sense of calm when tensions mount. Try running or yoga with a friend or join an exercise class to keep you on track for a healthy heart. Go ahead, wear your heart on your sleeve—it’s good for you!
February is American Heart Month. You can find more information about keeping your ticker ticking on the American Heart Association’s website.
During American Diabetes Month in November, you may notice more people are talking about diabetes, a disease that affects 29 million Americans. It’s a great time to learn more about diabetes and the ways that you can decrease or manage your risk of developing the disease.
Diabetes mellitus is a problem with how your body handles blood glucose (sugar). People who have type 2 diabetes aren’t able to use the hormone insulin properly to remove glucose from the bloodstream for use in the fat and muscle cells. Ultimately, this causes people with type 2 diabetes to have higher than normal levels of glucose in their blood.
You may have heard that someone who is overweight and has a large, apple-shaped body is more likely to develop metabolic syndrome—a group of health conditions such as elevated blood pressure, blood sugar and cholesterol levels—which may increase the risk of developing diabetes. However, there are a number of less well known risk factors for type 2 diabetes including:
Some research even links non-health-related factors such as job security to an increased diabetes risk. A recent study published in the Canadian Medical Association Journal analyzed data from 19 different studies including almost 141,000 participants which suggested that job insecurity was associated with a modest increased risk of diabetes. Job insecurity has also been associated with weight gain (a diabetes risk factor) and coronary artery disease (a complication of diabetes).
Recognizing risk factors for diabetes and dealing with them, if possible, is important for both children and adults. Consuming a healthy, nutrient-rich diet and staying physically active can help maintain weight, manage stress and avoid type 2 diabetes and its many related complications. To learn more about ways to prevent diabetes, visit the American Diabetes Association website.
Barb Goodman, PhD, is a professor of physiology at the University of South Dakota.
With Halloween next week, you may be planning to head to a haunted house or cozy up on the couch with popcorn and a horror flick. Either way, you’re probably hoping for a good scare.
Enjoying the thrill of a scary movie or riding a rollercoaster isn’t the same as a real life-threatening situation, but your body doesn’t always know the difference. This is because the same senses are triggered when you’re startled in a safe environment as when there’s a genuinely fearful situation. Whether the fear is real or fake, your body leaps into action to prepare for whatever is going to unfold:
- Your cardiovascular system pumps more blood and your heart beats faster.
- Your brain sends adrenaline to your skeletal muscles, getting ready to move.
- Your pupils dilate so you can see better.
- Your digestive system slows down until the threat has passed.
Referred to as the “fight or flight” response, the human body functions similarly to how it would have thousands of years ago when faced literally with these two options: fight (for food or for your life, for example) or flight (run away).
During the physiological reaction to fear, scientists believe the brain stimulates the production of dopamine, a chemical that activates the pleasure center of the brain. Many people enjoy the feeling of a good scare and pursue other thrill-seeking behaviors to get the same “high.” Research suggests that thrill-seekers may have different brain chemistry than those who don’t enjoy a heart-pounding experience. If you don’t like to be scared, skip the tricks, enjoy the treats and remember to breathe deeply during this spooky season.
No matter where you fall on the scare scale, be safe this Halloween!
– Erica Roth