Go Ahead, Wear Your Heart on Your Sleeve!

Jousting Competition

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.

audrey-vasauskasAudrey A. Vasauskas, PhD, is an assistant professor of physiology at the Alabama College of Osteopathic Medicine.

Bring on Winter! (But Stay Safe and Healthy)

 

girl playing on a winter walk

Credit: iStock

Winter officially begins next week with the winter solstice—the day of the year with the fewest hours of sunlight—on Dec. 21. With the cold weather and shorter days, you might be tempted to curl up under a blanket until the spring thaw. Whether you plan to hibernate or get outside to enjoy the chill, we’ve got some good reads about how our physiology responds to the cold weather.

Check out these throwback posts featuring cold weather tips to help you stay safe and healthy during the coldest months:

Have fun, be safe and take note of how your body adapts to the season!

Stacy Brooks and Erica Roth

 

 

Can Alcohol Cause Irregular Heartbeat?

red wine

Credit: iStock

Alcohol and heart health have a complicated relationship. Recent research suggests that moderate drinking may reduce your risk of stroke. But for some people, even one or two drinks a day may increase the risk of a form of heart disease called atrial fibrillation (AFib).

AFib is an irregular heartbeat of the two upper chambers of the heart (atria). During an episode of AFib, the atria beat quickly and out of synch with the lower chambers of the heart (ventricles). This irregular pattern can cause blood to clot in the heart, which also increases the risk of stroke.

A recent study published in the Journal of the American Heart Association suggests that over time, moderate alcohol consumption may cause the left atrium to become larger. The enlargement of the heart chamber can lead to AFib in some cases. This is one of the first studies to show in a large population of humans that structural changes in the heart can cause AFib. Previously, AFib had been thought to arise as a result of problems with the electrical impulses in the heart.

For most people who follow a heart-healthy diet, exercise and don’t have high cholesterol or high blood pressure, the occasional drink probably won’t hurt or lead to AFib. However, it’s a good idea to be aware of the alcohol-related heart disease risk as office parties and family gatherings get into full swing this holiday season.

Learn more about atrial fibrillation from the Mayo Clinic.

Erica Roth

Looking for a New Physical Challenge? Try a Mountain Ultra-Marathon

Idyllic Alps Valley

The Aosta Valley in Italy where the Tor des Geants is held. Credit: iStock

Of all the extreme endurance races out there—such as the Ironman triathlon or 50- or 100-mile marathons—the Tor des Géants ultra-mountain marathon may be the most extreme. The course is 205 miles long on the rugged terrain of the Italian Alps with a cumulative elevation gain of 24,000 feet. Participants have 150 hours, little more than six days, to complete the course. These feats of ultra-endurance are fascinating for scientists because they showcase how the heart adapts when pushed to the limit. Previous studies have found that after 3- to 15-hour races like marathons and the Ironman triathlon, the heart doesn’t pump as well, a condition referred to as exercise-induced cardiac fatigue. A group of French researchers looked at what happened to the heart after running for over 100 hours in the Tor des Géants. They were surprised to find that unlike with marathons and triathlons, heart function improved after the ultra-mountain marathon race.

During a heartbeat, the heart fills with blood and then squeezes together to push out the blood. In situations in which the body constantly needs more oxygen, such as with exercise, the amount of blood filling the heart is one signal that tells the heart to keep beating harder. The more the heart fills, the stronger the heart contracts.

This study found that the runners’ hearts filled more during each heartbeat. The researchers think it’s because the amount of plasma, which is the liquid portion of blood, increased, raising the overall amount of blood in the body. But why it increased is not clear. Fluid intake could be one factor, says Michael Joyner, MD, an exercise physiologist not involved in the study, in a podcast. Runners in ultra-long races pay extra attention to staying hydrated and often maintain or gain weight from the extra fluids, he says. Stéphane Nottin, PhD, the lead investigator of the study, wonders if inflammation from the extreme physical stress or greater retention of sodium (the kidneys use sodium to absorb water) is also involved.

“Physiology has a long history of expedition-led investigations—whether it’s high altitude, desert—and this paper follows in that wonderful tradition,” Joyner says. Other current ongoing studies in this spirit include a Mount Everest climb to examine cognitive decline at low oxygen levels and a study on the heart of a swimmer swimming across the Pacific.

Maggie Kuo

The Anti-Aging Cure May Be in Your Medicine Cabinet

Older dog - Younger dog

Credit: iStock/Getty Images

Rapamycin, a drug used to prevent organ transplant rejection, may also turn back time—in dogs at least. A study is underway to see if rapamycin can delay aging in dogs, and the puppy-like energy of one canine participant, eight-year-old Bela, gives some hope that the drug might work. Rapamycin is one of several drugs prescribed to treat other conditions that are being studied for their potential to help humans grow old without the health problems of aging. These drugs are particularly promising because they are already being used by people and are well-tolerated by the body. Other drugs being investigated include:

  • Metformin: Metformin is a commonly prescribed treatment for type 2 diabetes. The specifics of how it counteracts aging are still being debated, but the scientific community generally agrees that small doses of metformin can improve metabolic health, reduce cancer risk and lengthen lifespan. The Targeting/Taming Aging with Metformin study is currently underway to test if metformin has anti-aging effects in people, as it did in mice.
  • Aspirin: Constant low-level inflammation is considered a hallmark sign of aging, so researchers wonder if anti-inflammatory drugs such as aspirin can help. Studies have found that lifelong use of aspirin lengthens the average lifespan of male mice but does not increase maximum lifespan. No effects have been seen in female mice. Other studies in mice have shown that aspirin can improve immune, metabolic and cardiovascular health. However, aspirin also prevents blood from clotting and irritates the intestines, which can increase the risk of internal bleeding.

Researchers are also looking at lifestyle choices for their fountain-of-youth benefits, including:

  • Vegan diet: A vegan diet reduces the consumption of methionine, a nutrient abundant in eggs and meat. Eating less methionine has been shown to increase the lifespan of yeast, worms, flies and rodents. However, methionine is an essential nutrient for the body, so its anti-aging properties may be counteracted by the health effects of not having enough of it.
  • Calorie restriction: Reduced-calorie diets are a well-established method for extending the lifespan in various species, including certain strains of mice. However, in other mice strains, calorie restriction dramatically shortens the lifespan.

This detrimental effect in mice demonstrates a primary concern for testing anti-aging treatments in humans: A drug or lifestyle switch might shorten a healthy participant’s life. While it will take many years to find out if a treatment can truly increase longevity, we already know that wisdom only comes with time—and age.

Maggie Kuo

Don’t Be Cold-Hearted: Understand and Protect Yourself from the Cardiovascular Risks of Cold Weather

Shoveling Snow

Credit: Getty Images

Winter storms, like those that hit the East Coast in January, are often followed by sad reports of deaths from heart attacks related to winter weather. These reports often seem to be isolated incidents, but emerging evidence reveals a clear association between winter temperatures and heart attacks, particularly severe heart attacks. Recent research demonstrated that for every 18-degree drop in outdoor temperature below 86 degrees Fahrenheit, the risk for a severe heart attack increased by 7 percent. That means the risk of a heart attack is 28 percent higher at freezing temperatures. What accounts for the increased risk with cold weather?

There are a number of factors that raise a person’s chance of having a heart attack, but many heart attacks ultimately arise from an inability to provide enough oxygen to the heart. This can cause permanent damage to the heart and, if severe enough, can lead to death. In response to cold temperatures, the heart begins to pump more blood with every heart beat, and blood vessels in the limbs narrow (constrict). These physiological responses coupled with cold weather-associated activities such as shoveling snow increase the heart’s demand for oxygen-rich blood. In healthy individuals, this demand is readily met by increasing blood flow to the heart, but this increase is often blunted in individuals with cardiovascular disease or risk factors. Men older than 55 are twice as likely as women to experience snow-related heart problems, especially if they have a family or personal history of cardiovascular disease.

How can we use this information to protect ourselves? Some practical tips:

  • Understand your own cardiovascular risk and family history.
  • Maintain your preventive health care throughout the year by staying physically active, eating a balanced diet and having annual check-ups with your doctor.
  • Dress appropriately for work and play in the cold to limit heat loss and its stress on the heart.
  • Remember that the average shovel of snow weighs at least 10 to 15 pounds. Repetitive shoveling of these loads is a dangerous level of exertion for someone with cardiovascular risk factors, so buy a smaller shovel and take regular breaks.
  • Pay attention to early signs of a cardiovascular event—chest pain, dizziness, shortness of breath—and stop immediately if they occur. If symptoms persist, seek medical attention immediately.

If knowledge is power, then the research provides the power to protect us from heart attack risk in cold weather. Think this through the next time a winter storm approaches, and spread the word to help reduce snow-related heart attacks in your community.

Shawn Bender, PhD

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

Does Exercising in Warm Weather Make You Fitter for Cooler Temperature?

Hot Weather Exercise

Credit: Getty Images

Those who are active year-round know that summer workouts are more tiring than those done in cooler weather. The good news is that it’s not a sign that you’re suddenly out of shape. Exercising in warm temperatures is not the same as exercising in cooler temperatures and the body’s physiology has to adjust. How does the body adapt and can these changes translate to performance gains in cooler temperatures?

The body takes about 10 days to acclimate to exercising in heat. The most noticeable signs that it has adapted to warmer weather are sweating more easily and a lower exercising heart rate. Less perceptible physiological changes include greater volume of plasma—the liquid portion of the blood in which the red blood cells are suspended—less salt released through sweat and more efficient heart and muscle function.

Because these physiological adaptations improve exercise performance in heat, scientists and athletes have wondered if these changes also mean enhanced performance in cool conditions. The jury, though, is still out. A study in 2010 in the Journal of Applied Physiology reported that exercising in heat did improve exercise performance in cooler weather. A new study published last month in the American Journal of Physiology—Heart and Circulatory Physiology concluded the opposite: heat training only improved performance in hot conditions, but not temperate ones. Nonetheless, both studies show that the body can adapt to new conditions relatively quickly. So, when you find it hard to catch up when it’s hot, be patient. You’re not out of shape, it’s just your body is catching up.

Maggie Kuo

Get a Grip: What Grip Strength Can Tell Us about the Cardiovascular System

Anne Crecelius, PhD

Anne Crecelius, PhD

Most of us grab hold of something every day—the steering wheel of a car, the handle of a heavy shopping bag or the hand of a new acquaintance. Whatever we’re holding, we’ve got a grip on it.  But our grip strength can do more than help us hold on to an object. Handgrip is often used by physiologists to measure heart and blood vessel health. For example, the New York Times recently reported on a scientific article that found grip strength to be a predictor of heart attack and stroke. Researchers found that for each 11-pound decrease in grip strength there was “a 17 percent increased risk of cardiovascular death, a 7 percent increased risk of heart attack and a 9 percent increased risk of stroke.”

So, how is handgrip related to cardiovascular health? Researchers use handgrip as a technique to make muscles work so they can investigate cardiovascular responses including blood vessel expansion (dilation) during exercise. Handgrip exercise is easy to perform—most people can do it so scientists can study lots of different people. At low intensities, handgrip exercise only affects the blood vessels in the forearm and doesn’t bring in whole body cardiovascular reflexes, such as increasing heart rate, which could make the results of an experiment difficult to understand.

Many researchers use handgrip exercise to study blood vessel response during exercise. Recently, my colleagues and I showed that taking vitamin C (ascorbic acid) by mouth before exercising helped older people have greater blood flow and, therefore, oxygen delivery to their muscles while performing increasingly harder handgrip exercises. We’re not sure whether this would help with other types of exercise, but the results can help us understand one way to potentially improve exercise tolerance in older adults.

So the next time you shake someone’s hand, give it a firm squeeze. You’re working your cardiovascular system at the same time!

Anne R. Crecelius, PhD, is an assistant professor in the department of health and sport science at the University of Dayton in Dayton, OH.

Heart-Healthy Diets: Why the Low Sodium?

BloodEat less salt. It’s advice often recommended as a way to reduce blood pressure, but why? And if the body needs sodium (salt) to work properly, how does eating too much of it become unhealthy? In the cardiovascular system, excess sodium changes the body’s physiological processes to encourage high blood pressure, or hypertension. Sodium affects blood volume and the way two key organs—the kidneys and the heart—do their jobs.

Blood is made up of blood cells suspended in plasma—water containing proteins, nutrients, dissolved minerals and cellular waste. The kidneys purify blood by moving the water and everything in it, besides the proteins, out of the bloodstream into its ducts. The nutrients and minerals the body uses, including sodium, are then moved back into the bloodstream. Water is attracted to salt, so it follows sodium back into the bloodstream. The extra minerals and water left behind are filtered out, joined with waste products and excreted as urine.

Eating salt raises the sodium level in the plasma. As a result, more water gets reabsorbed into the blood and the total volume of the blood increases. The heart senses blood volume through how much its chambers are filled. When more blood is present, the heart contracts with greater force and pumps more blood out to the body. This increase in output causes blood pressure to rise.

The kidneys are eventually able to filter out excess sodium into the urine. However, constantly eating a lot of sodium maintains the elevated plasma sodium concentration, slowing down the return to normal blood volume levels and keeping already high blood pressure high.

Limiting dietary salt breaks this cycle. Blood volume decreases, the heart does not pump as strongly and blood pressure falls towards a healthy range. This is why “eat less salt” is heart-healthy advice to remember during American Heart Month and beyond.

Maggie Kuo, PhD

Reviewed by Barbara E. Goodman, PhD

Correction (3/16/15): An earlier version had said “The kidneys purify blood by moving plasma and everything in it out of the bloodstream into its duct.” Protein actually remains in the blood vessels and do not filter into the kidneys’ ducts. The text has been edited accordingly.

Your Childhood Happiness Can Predict Your Heart Health as an Adult

Dao Ho, PhD

Dao Ho, PhD

The idea that the environment during childhood can shape or program adult cardiovascular health is nothing new. Many studies over the last decade have shown that adversity during childhood, such as low socioeconomic status, parental discord, physical and sexual abuse, and war-time atrocities, is strongly associated with an increased risk for diabetes, heart disease and stroke. A new study published in Circulation in January supports this idea, and suggests that there may be a whole host of good things parents can do to enrich their children’s life and help ensure they have ideal cardiovascular health as adults.

Dr. Laura Pulkki-Raback and her research team at the University of Helsinki, Finland, asked whether a good psychosocial environment during childhood is associated with good cardiovascular health in adulthood. They followed more than 1,000 people for 27 years, from about 10 years old to about 37 years old. At the beginning of the study, the parents of these children were asked to fill out surveys assessing their child’s psychosocial environment based on six criteria: socioeconomic factors, emotional family environment, optimal health behaviors of the parents, lack of stressful events, self-regulatory behavior and social adjustment. Based on the parents’ response, each child was given a psychosocial factor score. Twenty-seven years later, as 37-year-old adults, the participants were asked to return for a health check-up.

The authors found that the more favorable the psychosocial environment the person experienced as a child, the healthier the individual was as an adult. Those that had higher favorable psychosocial factor scores had a leaner body mass index and more ideal glucose level. They were also more likely to be nonsmokers. All these factors play a huge role in maintaining ideal cardiovascular health.

With all the warnings and cautionary tales that point to what not to do to prevent heart disease and stroke, it is refreshing to see a study that may guide us on what more we should do to further improve our cardiovascular health. This study not only highlights the importance of having a psychologically healthy and enriching childhood on cardiovascular health, but it also provides us with the tools to make future generations even healthier.

Dao Ho, PhD, is a postdoctoral researcher in the Cardio-Renal Physiology and Medicine section at the University of Alabama at Birmingham.