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
Shaina Willen, MD, of Vanderbilt University Medical Center, presents her poster at the Physiological and Pathophysiological Consequences of Sickle Cell Disease conference.
Sickle cell disease (SCD) is a lifelong disorder of the red blood cells. It’s caused by a mutation in a single gene and affects about 100,000 people in the U.S. Normal red blood cells are round, a shape that helps the cells carry oxygen around the body. But red blood cells in people with SCD can become abnormally shaped like a crescent (sickle), which can cause blood cells to get stuck in blood vessels and interfere with blood flow, leading to severe pain.
Scientists and medical doctors who specialize in SCD gathered last month in Washington, D.C., for the American Physiological Society conference “Physiological and Pathophysiological Consequences of Sickle Cell Disease.” They discussed new research into the causes of the disease and new therapies that can treat and even prevent SCD-related pain episodes. Read on to learn more about their findings.
Certain patients with SCD may have a higher risk than others of developing complications—such as increased pain, stroke, eye problems and kidney disease—but finding out which patients have a higher risk is challenging. New research from Vanderbilt University Medical Center has uncovered a genetic marker that may be able to identify which patients are more likely to have these complications.
Emotional stress is known to trigger or worsen physical symptoms of disease, including some types of pain. A group of researchers from California found that stress and the anticipation of pain causes blood vessels to become narrower (vasoconstriction). In people with SCD, vasoconstriction can be dangerous because abnormally shaped (sickled) cells may be more likely to get stuck in the blood vessels and block blood flow.
A healthy digestive system is typically filled with various types of bacteria that aid in digestion. However, researchers from Howard University found that people with SCD are more likely to have higher levels of one specific bacterium, Veillonella. Veillonella link together to form a film in the digestive tract, which can attract red blood cells. When red blood cells stick to the film, it can block blood flow to the rest of the body, which causes increased pain. This discovery may help scientists find a way to rebalance gut bacteria levels and reduce symptoms.
These studies are just a few examples of the high-caliber SCD research being done. Read more highlights from this year’s conference:
Alzheimer’s drugs may improve red blood cell function and quality of life
Scientists explore ways to create red blood cells outside the body and prevent sickling
– Erica Roth
A typical pregnancy lasts 40 weeks, but about 10 percent of babies in the U.S. are born preterm (before 37 weeks’ gestation) or premature. Less time in the womb means the infants’ organs are immature and not yet ready to function on their own. Generally, the earlier a preterm birth happens, the more likely it is that complications will occur. Most premature infants, or preemies, spend some time in the hospital in a special nursery called the neonatal intensive care unit, or NICU.
Preterm birth has occurred throughout history, but the issue did not catch the public’s attention until the death of President Kennedy’s son in 1963. Baby Kennedy was only 37 weeks’ gestation and died of respiratory distress. This increased focus on prematurity led to more funding to research ways to treat premature infants. Advances in medical treatment have dramatically increased the survival of preemies since the 1960s. By the 1980s, babies as young as 21 weeks’ gestation were surviving to adulthood.
Prematurity affects every organ system. Complications can be treated more successfully now than in the past. Some common issues include:
- Digestive problems: When the cells lining the digestive tract are immature, babies may develop necrotizing enterocolitis (NEC). NEC is inflammation or infection of the intestine that can cause intestinal tissue to die. Doctors recommend breast milk for premature infants because babies who drink breast milk exclusively have a lower risk of NEC.
- Breathing problems: Immature lungs do not produce a substance called surfactant, which helps the air sacs in the lungs stay open. Without surfactant, preemies may struggle to breathe and go into respiratory distress. Doctors first gave surfactant to premature infants in 1980. Death rates from respiratory distress in premature babies have dropped from over 90 percent in the 1950s to less than 5 percent today.
- Vision problems: When a premature infant is born, their eyes are still developing. Blood vessels in the retina—the light-sensitive tissue in the back of the eye—can grow too much and pull it away from the rest of the eye. The detachment can lead to a type of vision impairment called retinopathy of prematurity (ROP). Doctors discovered that decreasing the concentration of supplemental oxygen given to preemies could actually help decrease the chances of developing ROP.
While treatment for premature infants continues to improve, the cause of preterm birth is still unknown. Doctors have identified some risk factors, including:
- age—women over 35 have a higher risk;
- alcohol or drug use;
- intrauterine infection;
- being pregnant with multiples;
- spacing pregnancies very close together;
- having a previous preterm birth; and
Both physicians and patients hope that more research and education will lead to fewer preterm births and improve health outcomes for preemies. November is Prematurity Awareness Month. Read more about ongoing research efforts on the March of Dimes website.
Rebekah Morrow, PhD, is an assistant professor of immunology and microbiology at the Alabama College of Osteopathic Medicine.
Turkeys are the center of attention at Thanksgiving. But to APS member and Undergraduate Summer Research Fellow Karina Vega, the feathered fowls were the center of a research study that looked at their transition from walking to running. Karina, a biology major at California State University, San Bernardino, studied turkeys while they ran on exercise treadmills in order to study stride frequency and length.
“While running, humans experience an aerial phase, which is when both feet are off the ground at the same time. Turkeys are unique in this aspect in that they instead partake in grounded running, or running without an aerial phase. Turkeys may not seem like the most ideal animal model, but have been proven to be useful for studies that are interested in running mechanics and energetics to define principles that apply to plenty of other animals.” – Karina Vega
As you might imagine, getting a group of turkeys to cooperate is not easy. Read more about Karina’s work, including what she finds most surprising and challenging about the day-to-day life of a scientist, on the APS Undergraduate Researcher blog.
– Erica Roth
The market for electronic cigarettes (e-cigs) and vaping has surged in popularity within the past five years, while traditional cigarette sales have declined. From 2012 to 2013, e-cig sales more than doubled to $1.7 billion. By 2015, sales were estimated at $3.7 billion.
Although manufacturers claim that e-cigs are safer than traditional cigarettes, their use has been associated with clear health risks. E-cigs may seem like they are producing harmless water vapor, but that vapor has been shown to contain a mix of cancer-causing chemicals. Some of the toxin levels are comparable to those in cigarettes.
E-cigs are associated with cellular damage and decreased cough reflex sensitivity after just one use. Cough reflex—triggered by chemical or mechanical irritants—protects the upper respiratory system from infection by getting rid of respiratory secretions (mucus) and foreign material from the lungs. Decreased cough reflex sensitivity may increase the risk of infection because mucus and foreign material aren’t always cleared immediately from the airways. Studies on animals have found that nicotine-containing e-cig fluid may cause changes in the lungs similar to what humans experience with chronic obstructive pulmonary disease (COPD). COPD is a condition often seen in long-term smokers. These changes include narrowing of the airways, more mucus production and increased inflammation. E-cig vapor has also been linked to substantial DNA damage and increased cancer risk and decreased lung function.
More and more research is providing evidence that e-cigs pose serious health risks. One of the greatest concerns is the potential serious long-term consequences in teenagers. Teens are easy targets for tobacco and e-cig advertisers and may also be easily swayed into becoming lifelong tobacco users. Because of the potential health risks of e-cigs, the American Academy of Pediatrics recommends raising the legal purchasing age for both traditional cigarettes and e-cigs from 18 to 21. Marketing strategies of e-cigs try to make e-cigs look socially acceptable to young adults and teens by promoting candy-inspired flavors and vapor tricks on social media. The tendency for the e-cig market to prey on young adult consumers is particularly troubling because the brain is developing critical circuitry that relates to lifelong habits during this time. Users younger than 21 tend to remain nicotine users for life.
The Great American Smokeout sponsored by the American Cancer Society, is November 16. This event is designed to help smokers make a plan to quit, whether it’s traditional tobacco products or e-cigs. Their health depends on it.
Leigh Graziano, MS, is a second-year medical student at the Alabama College of Osteopathic Medicine. She works with Audrey Vasauskas, PhD, on research on pulmonary arterial hypertension, which is high blood pressure in your lungs. In her free time, Leigh enjoys yoga, mountain biking and fishing.
Pleasant View Elementary (Zionsville, Ind.) students learn about the human body during PhUn Week.
Each week on the I Spy Physiology blog, we present examples of physiology in everyday life. This week, the American Physiological Society (APS) is sponsoring an annual event called Physiology Understanding (PhUn) Week. This is the time when scientists and educators take to the streets to spread the word about physiology. APS members have worked with science teachers across the country to plan activities that help explain what physiology is and how it affects the lives of their students.
APS member Mikaela Drake, an assistant professor of health sciences at Butler University in Indiana, participated in her first PhUn Week as a graduate student. “I quickly found myself naturally falling into the role of an educator that day. It was a new sense of satisfaction I hadn’t experienced before, but I knew I wanted more! Not only did my first PhUn Week experience help to inspire those sixth-grade students, unbeknownst to me, it also inspired my future career track,” she said.
Mikaela discusses the experiments—including working with 3D anatomy puzzles and a red blood cell activity—and individuals who made PhUn Week so exciting for her as a student and now as a faculty member on the PhUn Week blog.
– Erica Roth
It’s Halloween and the number of vampire attacks in your neighborhood may be on the rise! What would happen to your body if you were unlucky enough to be the victim of a blood-sucking vampire?
The average adult has about 1 to 1.5 gallons of blood circulating in their body. Maintaining this amount of blood is very important—proper blood volume helps keep your blood pressure at a steady level and moves the right amount of blood around your body. As your heart pumps blood through your blood vessels, the blood carries nutrients and oxygen to your organs so that they have energy to do their jobs. The blood also takes away the waste that your organs produce.
When you lose a large amount of blood very rapidly (such as during a vampire attack) your blood pressure drops quickly. This is similar to having a punctured bicycle tire. As the air escapes through the hole, there is less pressure in your tire. During an episode of significant blood loss, your body starts to take action to increase blood volume and blood pressure:
- Sensors called baroreceptors detect the decrease in blood pressure and cause your heart to pump faster and your blood vessels to narrow (constrict).
- Your body releases chemicals called catecholamines, which also cause your heart to pump faster and your blood vessels to constrict.
- Your pituitary gland releases a chemical called vasopressin. Vasopressin constricts blood vessels and helps your body hold on to as much water as possible by decreasing the amount of urine you produce.
When blood vessels constrict, the blood inside the vessels push against the sides of the vessel more, causing blood pressure to increase. Increased blood pressure reduces the amount of blood needed to fill your vessels.
If these actions are unable to restore your blood pressure, you can go into shock. Shock occurs when your blood pressure is so low that not enough blood is getting to your organs. In a state of shock, your heart, liver, kidneys and brain can’t function properly and they start to die from lack of oxygen and nutrients. You’ll eventually lose consciousness if you don’t get urgent medical attention—typically with intravenous fluids—to raise your blood pressure and increase circulation.
If you choose to trick or treat this Halloween, stay safe. Carry some garlic with you to ward off those pesky vampires and dial 911 ASAP if you have a run-in with a fanged stranger.
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.
A year ago, I went to California to participate in a scientific conference. After a couple of days, my mentor and I started to have trouble breathing. As two healthy adults, we wondered why this was happening. I did not know the answer at that time, but I did notice a pattern: Other female colleagues, especially those with asthma, were also struggling to breathe, but not many men were. Our symptoms got better once we left the conference. A research study we later performed in our lab helped us understand what had happened. We discovered some differences in lung function among male and female mice exposed to ozone and other air pollutants, and we learned that females had worse symptoms than males. So something in the air caused our breathing problems.
In the past decade, air pollution has become the world’s single biggest environmental health risk, causing about 7 million deaths—nearly one of every eight—worldwide each year. According to the Air Quality-Life Index, increased air pollution concentration levels may shorten your lifespan by one month if you live in New York and by up to eight months if you live in California. Exposure to pollutants such as ozone, biomass fuels, and fine particles like soot and smoke has been strongly associated with increased mortality from lung disease. As the evidence piles up, we are starting to realize what a big problem these little molecules create—and that what you can’t see can kill you.
Researchers have shown that women are more susceptible to the negative effects of air pollution than men are. The exact reason remains unclear, but we know that men have more relative fat mass, which gives them a larger distribution volume for chemical particles in the environment. Women’s bodies also metabolize pollutants more quickly than men’s, resulting in higher toxicity. A recent study in the American Journal of Physiology—Lung Cellular and Molecular Physiology has shown that sex steroid hormones are somewhat responsible for the male and female differences, indicating that both sex and air pollution may alter the effectiveness of lung immunity.
The American Lung Association offers these and other tips to help protect you from unhealthy air:
- Check daily air pollution forecasts.
- Avoid exercising outdoors when pollution levels are high.
- Avoid exercising near high-traffic areas.
- Use less energy in your home.
- Explore other alternatives to driving your car (bike, walk).
- Don’t burn wood or trash.
- Don’t allow anyone to smoke indoors.
October 22–28 is Respiratory Care Week. Let’s help the world breathe better. Your life and the lives of your loved ones may depend on it.
Nathalie Fuentes is a PhD candidate in the biomedical sciences program at Penn State College of Medicine. Her studies in Dr. Patricia Silveyra’s lab include the development of sex-specific therapies to treat lung diseases, sex differences in asthma-related lung inflammation triggered by ground-level ozone and the role of male and female sex hormones in lung disease. Nathalie is originally from Caguas, Puerto Rico.
When your body gets overheated, it responds in several ways as it races to cool you back down and prevent serious health problems. Heat stress is when your internal body temperature rises above the normal range of 97 to 99 degrees Fahrenheit. This triggers physiological responses geared toward maintaining normal body temperature. Our internal body temperature is so tightly regulated that an increase of less than 1 degree activates functions such as sweating to cool our body and restore balance. Heat stress can put strain on many areas of the body, including the kidneys. The kidneys transport nutrients throughout and remove waste from your body.
A review published in Comprehensive Physiology evaluated how the cardiovascular system and kidneys respond to heat stress. When your body overheats, your heart pumps more blood, the blood vessels in your organs narrow, and the blood vessels in your skin widen to help decrease the excess heat. While this redistribution of blood to the skin is a positive response to help cool you down, it also decreases blood flow and volume to the kidneys by up to 30 percent. Restricted blood flow reduces the amount of oxygen and nutrients that is delivered to the kidneys. Prolonged exposure to heat stress and decreased blood flow to the kidneys can lead to kidney damage and even kidney failure.
Heat stress can be life-threatening to people who have medical problems that affect body temperature regulation or are otherwise vulnerable to overheating. Seniors, children, people who work outdoors (including military personnel and firefighters) and those who live in parts of the world where it is extremely hot may have an increased risk of heat stress. Some common signs of heat stress include muscle cramps and dehydration. People suffering from heat stress may also experience symptoms of heat exhaustion (pale skin, extreme fatigue, dizziness, heavy sweating, headache and blurred vision) and heat stroke (high body temperature, convulsions, confusion and even unconsciousness). It is important to recognize these signs and get medical help as soon as possible.
The next time you’re out in the hot weather, stay hydrated. Drink water often—even before you get thirsty. The Occupational Safety and Health Administration suggests that outdoor workers drink water every 15 minutes. Finally, limit your sun exposure by taking frequent rest breaks under the shade or inside an air-conditioned building in order to protect your kidneys.
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.
“That day, for no particular reason, I decided to go for a little run. … For no particular reason I just kept on going. I ran clear to the ocean. And when I got there, I figured, since I’d gone this far, I might as well turn around, just keep on going.” – Forrest Gump
The feats of ultra-endurance athletes are remarkable and sometimes incomprehensible. There are few published data on how the body deals with the stresses of an ultra-endurance event because the fieldwork is difficult to perform without interfering with the athlete’s performance. A new study published in the Journal of Applied Physiology explores how muscle deals with prolonged exercise performed in an “unfriendly” environment (high mileage at high altitude). The primary question these researchers wanted to know: In an event that requires a lot of energy, would the muscles have enough energy to rebuild and adapt to the stress?
The researchers studied a single cyclist during a mountain bike race that spanned 497 miles from Denver to Durango, Colorado, along the high-altitude Colorado Trail. The participant rode 19 to 20 hours each day for five days. The investigators took muscle and blood samples at the beginning and end of the race and compared the changes to a period of normal exercise training.
They found that during the race, the muscles were able to make mitochondria—which are responsible for producing energy in the cells—at an extremely high rate. In addition, the mitochondria increased their ability to use fat energy sources, an important adaptation for long-term exercise. The proteins that contract the muscle also continued to build, but not at a rate fast enough to maintain the muscle’s size, which led to the muscle shrinking in size. In addition, there was significant muscle damage and inflammation. The blood samples also showed evidence of significant stress with changes that were consistent with impaired kidney and liver function.
Overall, this study suggests that when the body is performing an exceptionally, energetically challenging activity, muscle is able to rebuild at an extremely high rate, although maybe not enough, to try to adapt to its new demands. In this case, the extreme stress of the race caused significant muscle damage and organ dysfunction. Scientists hope to continue to find new approaches to study the demands of ultra-endurance athletes to better understand the limits of human performance.
Benjamin Miller, PhD, is an associate professor in the department of Health and Exercise Science at Colorado State University. He co-directs the Translational Research in Aging and Chronic Disease (TRACD) Laboratory with Karyn Hamilton, PhD.