Scientific Research

Take Care of Yourself while You Take Care of Your Garden

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Springtime signals warmer weather and, for many people, more time outside. A garden can be a great place to get sunlight (to support vitamin D production), physical activity and delicious fresh fruits and veggies. When you go out to plant, water and weed your garden this year, keep an eye on how well-watered you are to prevent yourself from getting dehydrated.

Gardening is a hidden form of exercise because you squat, bend and stand without even thinking about it. But the constant changing of positions requires your body to perform a complex balancing act. Every time you stand up, your blood vessels coordinate a rapid sequence of expansion (dilation) and narrowing (constriction) to keep the blood pumping around your body and to your head. The body uses a feedback system called the baroreflex to prevent your blood pressure from getting too high or too low. However, dehydration makes it more difficult for our baroreflex to regulate blood pressure.

Gravity pulls blood from your head toward your feet to regulate blood pressure, making standing up a challenge to the cardiovascular system even in moderate temperatures. It becomes more difficult— particularly for older adults—to be out in the hot sun without drinking enough fluids. When you do not drink enough water, there is less fluid moving through your bloodstream. This can cause blood pressure to dip too low. Blood pressure needs to be high enough to keep your blood flowing to the head to prevent dizziness and fainting.

To avoid passing out when you are picking flowers or tomatoes, keep water nearby to drink. Don’t wait until you feel thirsty to drink—you can lose up to 10 percent of your blood volume before you feel thirsty. Drink water before going outside, sip a cold beverage frequently while you’re out in the heat and continue “watering” yourself after you come inside.

Enjoy the outdoors and the (literal) fruits of your labor this spring, but do so with a water bottle in hand.

Joseph WatsoJoseph C. Watso is a doctoral research fellow in the department of kinesiology and applied physiology at the University of Delaware. Watso is interested in studying the role of lifestyle habits, such as diet and exercise, in maintaining heart and blood vessel health throughout aging. 

 

 

 

Food, Friend or Foe: How Our Gut Recognizes Good from Bad

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Knight Riding to the Castle Gate

Your gut is like a well-fortified Medieval castle. Credit: IStock

Think about the last time you ate an apple—from the apple’s perspective. Pulverized in your mouth and dunked in a cauldron of stomach acid, the fruit slowly passed through the intestine before its final, unceremonious exit. Digestion is a wild, wacky journey.

Scientists study how the body can both absorb life-sustaining nutrients and keep out harmful invaders. Understanding this balance—and how it can get thrown out of whack—could lead to better treatments for digestive diseases.

Most of the nutrients from food we eat get absorbed in the intestine, which is home to a vast population of bacteria known as the microbiome. These bacteria help break down complex particles that we can’t, such as the fiber in fruits and vegetables. But some gut bacteria, known as pathogens, cause disease. The immune system’s job is daunting: It must protect us from pathogens without targeting healthy gut bacteria or food particles.

The first line of defense is the barrier of cells that line the intestine. These immune cells allow only small particles to pass through, making the intestine a bit like a medieval castle: A small rat can slip through the walls, but people have to get past the guards. This castle has a moat, too: a slippery layer of mucus that keeps organisms from getting too close. And no castle is complete without archers staffing the walls. Immune cells fire off proteins called antibodies that stick to gut bacteria to prevent them from attacking the body.

The immune system also learns to tolerate common foods and gut bacteria so it can recognize them as harmless and unlikely to cause disease. Researchers are studying exactly how this works, but they think that the intestine is naturally wired to permit most foods and beneficial bacteria.

Sometimes, however, the immune system commits friendly fire and attacks the body when it shouldn’t. Two common examples are celiac disease, an immune response to gluten, and inflammatory bowel disease, a response to the microbiome in the gut. Scientists are not sure why people get these diseases, although some studies suggest that specific genes may be involved. But it’s clear that more research is needed to reveal the secret of how the immune system distinguishes food and friend from foe.

Jonathan Wosen 2Jonathan Wosen is a PhD candidate in immunology at Stanford University, where he studies how the cells that line the intestines communicate with the surrounding immune system. Wosen was the 2017 American Physiological Society-sponsored AAAS Mass Media Science and Engineering Fellow at STAT News, a national science news publication based in Boston.

Curcumin, the Golden Spice

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Growing up, I enjoyed spending time in my grandmother’s kitchen. Her cooking usually involved an array of colorful spices, including a generous mix of curry powder in nearly every Indian recipe. You can’t mistake the tantalizing smell—cooking with this yellow-tinted powder can fill a room quite quickly. But it appears that there is much more to the aromatic spice than first meets the nose. It may help maintain heart health, too.

Turmeric, one of the spices that make up curry powder, contains curcumin. Evidence suggests that consuming curcumin has a wide range of physiological effects that may be beneficial to health. Curcumin is rich in antioxidants and acts as an anti-inflammatory, which may help explain its ability to promote nitric oxide (NO) availability. NO is a key compound in maintaining the health of our blood vessels. Scientists think that the body makes less NO and more becomes inactive as we age. Consequently, there is less available as we get older.

Also as we age, our blood vessels aren’t able to expand (dilate) as well. They become stiffer and less flexible and more likely to become clogged. Older people have a greater risk for developing high blood pressure due to the increased stiffness and reduced flexibility of the blood vessels. This process is called vascular aging. Women appear to experience vascular aging more quickly after menopause when the hormone estrogen is no longer produced.

A study of healthy middle-aged and older women in Japan found that taking curcumin supplements for eight weeks improved the blood vessels’ ability to dilate and reduced stiffening of the carotid artery in the neck. A recent study in the Journal of Applied Physiology found that exercise training alone does not protect against blood vessel stiffening in postmenopausal women. Therefore, combining exercise training with curcumin may be a promising way for women to slow down the steep decline in vascular health after menopause.

Another study of healthy middle-aged and older adults found that 12 weeks of curcumin supplementation improved NO availability and reduced oxidative stress (a type of cell damage) to improve blood vessel function.

These studies show promise for curcumin as a preventive therapy to lower heart disease risk in both men and women.

It seems that this golden spice really is a spice for life and may help prevent cardiovascular disease—the leading cause of death in the United States and worldwide—in older people.

March is National Nutrition Month. Learn more about how eating a balanced diet can improve your health at the Academy of Nutrition and Dietetics website.

Yasina Somani cropYasina Somani, MS, is a PhD student in the Cardiovascular Aging and Exercise Lab at Penn State. She is interested in studying the effects of novel exercise and nutritional therapies on cardiovascular outcomes in both healthy and clinical populations.

In Heart Disease, Women and Men Are Not Created Equal

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It may seem as if heart disease affects mostly men, but in fact it’s the No. 1 cause of death for both genders—more people die from heart disease than all cancers combined. Perhaps even more surprising is that more women than men will develop heart failure or die within a year of a heart attack.

Medical professionals don’t completely understand why women have worse outcomes than men when it comes to heart disease. One factor, however, is that heart attack symptoms are often very different in women and in some cases aren’t as obvious. Like men, women may experience classic chest pain, but they may also have a variety of more general symptoms, including:

  • nausea or vomiting,
  • indigestion,
  • shortness of breath,
  • pain in the upper back or arm,
  • neck and jaw pain, or
  • unusual fatigue.

Sometimes these symptoms may fade and reappear.

Men and women often have different types of artery disease. This may be a key to why symptoms are not the same. Men are more likely to have significant blockage of a major artery whereas many women have no evidence of arterial blockage. Women are more likely to have microvascular disease, which affects the heart’s smaller blood vessels.

Because many people believe that women are less likely to have a heart attack—combined with the differences in symptoms—may be why women don’t always realize they are having one. As a result, they may not seek treatment immediately. In one study, women did not get medical treatment for an average of 50 hours, compared to fewer than 16 hours for men. A delay in treatment contributes to a greater chance of dying from a heart attack.

In the emergency room, the lack of classic heart attack symptoms can lead to misdiagnosis, resulting in a delay in treatment. Studies show that women are less likely to receive appropriate treatment for heart attack compared to men. Even when they are treated appropriately, women often experience a higher risk of complications.

Although there have been tremendous improvements in the treatment of heart disease in women, more still needs to be done. Increased education and improved training will help the general public and medical professionals recognize the differences between men’s and women’s symptoms. In addition, more clinical research is needed to understand the reason for these gender-related differences and to better personalize the management of heart disease in women.

February is American Heart Month. Visit the American Heart Association’s website to learn more about heart disease in women.

 

John ChathamJohn Chatham, DPhil, is a professor of pathology and director of the Division of Molecular and Cellular Pathology at the University of Alabama at Birmingham.

 

Why Marriage Is Good for Your Heart

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Loving tourists in Cartagena

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Valentine’s Day is a time when many of us reflect on the importance of our closest relationships. Whether they include family, friends or a significant other, science is not silent on the impact these relationships have on our health. A review of 148 studies reveals that strong social relationships are associated with a 50 percent increased likelihood of survival, regardless of medical condition. Other studies link low social support to an increased risk and incidence of heart disease. The newest research, however, explores the effect our most intimate relationships—with a romantic partner—have on heart health.

A study that looked at more than 6,000 people reports that being single is associated with heart disease. Specifically, people who were single had a 45 percent higher rate of death from heart disease than those who were married. A striking finding in this study was that even though the reason for being unmarried varied among the participants—some people had never married, others were divorced, separated or widowed—the risks were consistently lower in married people. From these results, the overall benefit of the spousal relationship on heart health seems clear.

Many factors may account for the positive effect of marriage on heart health, including:

  • improved social support,
  • a less sedentary lifestyle, and
  • increased motivation to make healthy lifestyle changes.

The quality of marital relationships over time also influences heart disease risk factors. Men who described their relationships as “improving” had a lowering of risk factors compared to those in marriages categorized as “consistently good” or “deteriorating.”

In other words, marriage is generally good for your heart health and even better when you work to improve that relationship over time. So as you think about those closest to your heart on Valentine’s Day, do your heart a favor and take your sweetheart on a date.

Shawn Bender, PhD

Shawn Bender, PhD, is an assistant professor at the University of Missouri and a research health scientist at the Harry S. Truman Memorial Veterans’ Hospital.

Why Does Muscle Matter?

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When young people think about their muscles, they often focus on enhancing their muscle size and strength for cosmetic or athletic reasons. Those older than 50, however, need to be more concerned with just keeping the muscle they have. On average, people over the age of 50 lose 1 to 2 percent of their muscle mass each year, and after age 60, this number increases to 3 percent. Bed rest, lack of exercise and sedentary behavior in the elderly can speed up this gradual loss over time. Why is maintaining muscle so important for the elderly?

The simplest reason is that muscle is essential for all kinds of movement. Mobility is a crucial component of maintaining independence as we age. Adequate muscle mass and strength allow seniors to continue performing simple daily activities—things like bathing, getting dressed and preparing food—without assistance. Another less obvious reason is that muscle burns a large percentage of the energy that we get from the foods we eat. Losing muscle mass means that we do not use the energy from food as effectively, which can lead to chronic health conditions. In fact, loss of muscle mass is a major contributor to the increased rates of type 2 diabetes in older adults.

Current research has revealed, however, that muscle size is not the only, or even best measure of muscle health. Scientists have traditionally used the term “sarcopenia” to refer to aged-related loss of muscle mass, but many scientists are now focusing more on “dynapenia,” which indicates the loss of muscle function due to aging. New research is showing that how well muscle works can be just as important as how much muscle mass remains. In fact, a person with a smaller amount of muscle mass whose muscle function is good may be stronger and healthier than someone with more muscle mass but poor muscle function. This realization has led to new strategies for promoting muscle health in aging. Although maintaining muscle mass is still important, new approaches are targeting improvement in muscle function. These strategies go beyond simply lifting weights and look at ways to make the inner machinery of the muscle work better. Although nothing can completely stop the loss of muscle function with age, promising new nutritional and exercise therapies are emerging to substantially slow the decline, helping seniors stay active and independent for as long as possible.

Ben MillerBenjamin 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.

Relieve Stress and Anxiety with Exercise in the New Year

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Group of Young People Exercising in a Gym

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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-farquharWilliam 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.

 

Keeping the Juices Flowing with Beets

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Beetroot Juice

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With the new year upon us, many people are setting new goals for themselves related to improving their health or focusing on career-related goals. If establishing better exercise and nutrition habits are part of your quest to attain optimal health and productivity in 2018, you are not alone. New gym memberships are likely to rise in the coming months, and some may try nutritional products such as fruit and vegetable juice concoctions touted to enhance performance and overall health. The global juicing industry has gained a lot of traction in the last several years due to a wider health awareness among consumers. Emerging evidence suggests that casting beets in the starring role of your juice habit—along with aerobic exercise—may be one potential route to improving your cardiovascular health, and more recently shown, brain health.

Beets are a good source of antioxidants, minerals and nitrates. The nitrate-rich properties of beets have caught the attention of researchers, particularly those in the field of vascular medicine. Nitrates in food are converted to nitric oxide in the body. Nitric oxide relaxes the walls of the arteries, lowering blood pressure and increasing blood flow to muscles. That is one of the reasons why the nitrates in beetroot juice have been shown to enhance exercise performance in high-performing athletes, as well as in less elite exercisers.

In addition to the cardiovascular and performance benefits of consuming beets, recent studies suggest that the root vegetable may also be linked to brain health. One study found that older adults who performed aerobic exercise for six weeks and drank beetroot juice daily had greater improvements in brain activity related to movement than the participants who exercised without drinking beetroot juice. The brain networks of the juicing group more closely resembled the brains of younger adults, suggesting that when combined with exercise, beets can enhance the brain’s ability to make new connections between brain cells. Another study showed that young adults who drank a single dose of beetroot juice had increased blood flow to the area of the brain involved in higher-order thinking. The study participants also fared better in cognitive tasks such as basic math.

So, before you lace up your running shoes or settle back into your office chair, consider topping off with a dose of beetroot to keep the juices flowing.

 

Yasina Somani cropYasina Somani, MS, is a PhD student in the Cardiovascular Aging and Exercise Lab at Penn State. She is interested in studying the effects of novel exercise and nutritional therapies on cardiovascular outcomes in both healthy and clinical populations.

 

Taking Ibuprofen during Exercise May Cause More Harm than Good

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Every January gym memberships spike and the wait to get on the treadmill gets longer. This happens because about 40 percent of Americans make New Year’s resolutions, the most common of which are exercising more and improving fitness. Some people may believe in the concept of “no pain no gain,” but it’s a common misconception that if your muscles don’t feel sore then you are not working out hard enough. Many athletes reach for nonsteroidal anti-inflammatory drugs (NSAIDs) to ease the aches and pains of a hard workout. Naproxen and ibuprofen are two commonly used NSAIDs that are available over the counter. Studies estimate that up to 75 percent of long-distance runners take NSAIDs before, after or during training.

Microscopic tears in the muscles cause soreness following strenuous exercise. In response to injury, the body produces compounds called prostaglandins, which play an important role in healing. NSAIDs reduce pain by slowing the production of prostaglandins, which reduces inflammation. The problem is that inflammation also plays an important role in healing damaged muscle as well as helping the muscle growth that occurs with regular exercise. In other words, taking NSAIDs after a workout may not necessarily be a good thing.

A recent study in mice found that levels of a specific prostaglandin increased after minor muscle injury. This particular prostaglandin stimulated regeneration of new muscle stem cells to repair the damage. But when the mice were given NSAIDs their bodies produced fewer active stem cells, leading to weaker muscles even after the injuries had healed.

Other negative effects, such as kidney injury, have been associated with NSAIDs. In one study, elite athletes took either 400 milligrams of ibuprofen or a placebo every four hours during a 50-mile race. At the end of the race, more than 40 percent of the runners tested high for creatinine, a marker of kidney injury. Runners who took ibuprofen instead of the placebo were more likely to develop kidney injury and their degree of injury tended to be worse. The study did not explain why ibuprofen may cause kidney injury in elite athletes, and it’s not clear whether the risks are similar in people participating in less-intense workouts. More studies are needed to examine the effects of ibuprofen following different types of exercise.

If exercising is one of your New Year’s resolutions, start off slow to avoid muscle pain. If you do overdo it, try easing your aches with a warm heating pad before reaching for the ibuprofen.

John ChathamJohn Chatham, DPhil, is a professor of pathology and director of the Division of Molecular and Cellular Pathology at the University of Alabama at Birmingham.

2017’s 10 Most-read Posts

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Using technology to take brainstorming to the next level

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Another physiology-filled year on the I Spy Physiology blog is almost over. This year, we’ve explored dozens of topics, ranging from skin cancer, gut health and spinal cord injury to the mystery of how hibernating animals’ muscles remain strong. We’ve celebrated women in science and smiled at the thought of turkeys running on treadmills. Today, we’re highlighting the 10 most-read posts of 2017.

Scholarly articles highlight the need for more research about women’s responses to illness and disease risk. In that vein, our most popular post this year looked at the relationship between sex-specific hormones and asthma. Posts about the danger of e-cigs—especially in the under-21 set—and how muscle rebuilds during the daunting feat of cycling the 500-mile Colorado Trail rounded out the top three. Take a look at this year’s top 10:

  1. When Hormones Take Your Breath Away
  2. The Trouble with E-Cigs: Why They May Pose More Harm than Good
  3. Muscle Rebuilding on the Colorado Trail
  4. Beer Does a Body Good?
  5. Meet Karyn Hamilton, Health and Exercise Science Professor
  6. Dog Gazing: Bond between Hound and Human
  7. Why Does Air Pollution Affect More Women than Men?
  8. When Vampires Attack: How Your Body Reacts to Extreme Blood Loss
  9. Microvesicles and Blood Vessels and Exercise, Oh My!
  10. The Hispanic Paradox: Why Are Some Ethnic Groups Living Longer than Others?

We’d love to hear what you’d like us to feature next year. Share your thoughts in the comments or send us an email. And don’t forget to follow our blog in 2018.

– Erica Roth