Spotlight On: Tuberculosis

Pulmonary Tuberculosis

Credit: iStock

If you’ve ever volunteered or worked in a hospital, nursing home or laboratory, you may remember having a tuberculosis (TB) skin test. But did you fully understand what TB is and why the tests are necessary? Though TB may not seem to be a major health concern in the U.S., this cunning disease remains a leading cause of death worldwide and a major risk to people with weak immune systems.

A strain of bacteria called Mycobacterium tuberculosis causes TB. People who are exposed to the bacteria may develop a form of the disease without actually being sick. This is called latent TB infection and means the body is able to fight the bacteria without spreading it to others. However, if the immune system is not in top-notch shape, the bacteria can multiply and develop into a dangerous active infection. Active TB infection is very serious and can be deadly if not treated.

An active TB infection can be spread easily, especially when the disease attacks the lungs (pulmonary TB). The bacteria spreads from one person to another through the air. When someone with active pulmonary TB coughs or even speaks, tiny droplets sent out from the lungs carry bacteria through the air. The droplets can easily be inhaled by others, especially in close contact. Common symptoms of pulmonary TB include chest pain, coughing—sometimes coughing up blood and mucus—and wheezing. People with active TB infection may also feel weak and have fever, chills or no appetite.

You might wonder what all this has to do with skin tests. Because active TB is so dangerous and because latent TB can develop into active disease, people who have a high risk of developing TB and their caregivers need to be tested for the disease. A small amount of solution containing an inactive part of the bacteria is injected under the skin. If the skin at the injection site doesn’t change, everything is fine. But if the skin becomes red or swollen, this indicates there are TB bacteria in the body and treatment is necessary.

Although the number of people infected in the U.S. has been steadily declining, more than 10 million people worldwide were sickened by TB in 2016. March 24 is World Tuberculosis Day. Learn more about how to stop the spread of TB.

Audrey Vasauskas

Curcumin, the Golden Spice

Family having Indian food

Credit: iStock

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.

Can Eating Fruit Be Hazardous to Your Health?

Assortment of fruits

Credit: iStock

The U.S. Department of Agriculture recommends two cups of fresh, frozen, canned or dried whole fruits each day for most people following a 2,000-calorie diet. However, some people have difficulty breaking down fruit in their digestive tract or absorbing fructose into their bloodstream. Fructose is a type of sugar that is naturally found in fruit. Humans have a limited ability for absorbing fructose. A special protein called GLUT5 carries fructose into the small cells of the intestines, and another protein called GLUT2 takes fructose from the cells and into the bloodstream.

People with fructose malabsorption (formerly called dietary fructose intolerance) have a deficiency of GLUT5 in their intestinal cells. Bacteria in the intestinal tract break down the fructose that the body can’t absorb. The undigested fructose forms gas and often causes gastrointestinal discomfort. Symptoms may include bloating, gassy pain and diarrhea. Up to 50 percent of adults can’t absorb large amounts of fructose, and about 10 percent can’t absorb even moderate amounts of fructose.

In addition to fruit, a number of sweeteners are high in fructose. High-fructose corn syrup, honey, maple-flavored syrup, molasses, sorghum and invert sugar may also cause uncomfortable symptoms. One possible reason why fructose malabsorption rates in the U.S. are high is from the widespread consumption of beverages—such as soft drinks—sweetened by high-fructose corn syrup.

People who have fructose intolerance should limit their consumption of high-fructose foods, such as:

  • fruit juices,
  • apples,
  • grapes,
  • watermelon,
  • asparagus,
  • peas, and
  • zucchini.

Fruits and vegetables that are lower in fructose may be easier to digest, especially when they are part of a full meal. Lower-fructose foods include:

  • bananas,
  • blueberries,
  • strawberries,
  • carrots,
  • avocados,
  • green beans, and
  • lettuce.

So, if you are trying to eat the recommended servings of fruit every day but have digestion issues, ask your doctor if you may have fructose malabsorption and try lower-fructose foods as an alternative.

barb-goodmanBarb Goodman, PhD, is a professor of physiology at the University of South Dakota.

2017’s 10 Most-read Posts

Using technology to take brainstorming to the next level

Credit: iStock

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 

Exploring Causes and New Treatments for Sickle Cell Disease

genemarker

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 

The Trouble with E-Cigs: Why They May Pose More Harm than Good

E-Cigs

Credit: iStock

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.

no smoking no vaping sign ban cigarette and electronic cigarette not allowed blue e-cigarette and cigarette in red circle realistic vector illustration

Credit: iStock

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 croppedLeigh 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.

Why Does Air Pollution Affect More Women than Men?

Los Angeles Smog

Credit: iStock

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 OrtizNathalie 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.

 

 

The Hispanic Paradox: Why Are Some Ethnic Groups Living Longer than Others?

Senior couple smiling together

Credit: iStock

In the U.S., we focus much attention on the health behaviors that can help us live a longer life: the “secrets” of centenarians and long-lived animal species such as the naked mole rat, the optimal amount of exercise to help us maintain muscle tone and independence, and the best eating style—whether it’s eating like we live in the Mediterranean, restricting calories or something in between. Yet part of the U.S. population seems to be unlocking the keys to increased longevity despite having risk factors traditionally linked to a shorter lifespan.

Approximately 55 million people in the U.S. are of Hispanic descent, and on average, they live two years longer than non-Hispanic whites. The Hispanic population in the U.S. has a lower overall risk of dying from 7 of the top 10 leading causes of death, including cancer and heart disease. Known as the “Hispanic paradox,” these positive health outcomes are often achieved among immigrant populations and in people with a greater likelihood living in poverty, having less education and health insurance, being overweight and several other factors that can negatively affect health. Additionally, rates of illness and death from other chronic conditions such as diabetes and liver disease remain higher among Hispanics than whites.

In an effort to boost longevity across ethnicities, scientists are studying how these unlikely circumstances—being high risk in certain areas, yet having a longer lifespan—can coexist. Theories include:

  • A study of lung disease in Hispanics suggests that their genes may protect against chronic obstructive pulmonary disease (COPD), an inflammatory lung disease, in addition to other factors.
  • Hispanics who come to live in the U.S. are generally younger than the average population and stay healthier.
  • With the exception of people from Puerto Rico, immigrants from Hispanic cultures smoke less than the overall population, leading to less lung disease. One study found that Hispanics in New Mexico are diagnosed less often with COPD than those living in other areas. Puerto Ricans, however, tend to smoke more and have a higher asthma risk.
  • A diet rich in beans and lentils, common in some Hispanic cultures, may curb inflammation to reduce chronic health risks.
  • Researchers think the strong family ties and support system seen in extended Hispanic families may play a role in staying healthy, particularly in the area of mental health.

Researchers continue to study Hispanic populations in the U.S. to try to find concrete reasons behind the Hispanic paradox to help them live even longer, healthier lives. During National Hispanic Heritage Month, we celebrate Hispanic heritage and culture in the U.S.—and all that these communities can teach us about living a healthier and longer life!

Erica Roth and Stacy Brooks

When Hormones Take Your Breath Away

Pretty woman using her inhaler

Credit: iStock

After a healthy childhood, my best friend suddenly started having breathing difficulties when she was 20 years old. The doctor diagnosed her with asthma. With the help of inhaled medications, she was able to control her symptoms. But a year later, the medications were no longer effective and she started having monthly, life-threatening asthma attacks. The severe attacks became more frequent a few days before her menstrual period, and the symptoms disappeared days after her period ended. At that time, I wondered if hormones could be to blame.

As a graduate student investigating the role of male and female hormones in lung inflammation, I know now that asthma can be a hormone-related health issue. Unfortunately, many people are unaware of this relationship. Hormones are chemicals that travel as messengers around the body through the bloodstream. They affect many bodily functions and play a large role in a woman’s life cycle from birth through puberty, adulthood, pregnancy and menopause. In proper balance, hormones help the body communicate and thrive. But sometimes hormone levels can be too high or too low, causing serious health problems, especially in people with asthma.

Although more young boys have asthma than girls, the pattern is reversed in adults: More women have asthma than men. During puberty girls begin to produce higher levels of the sex hormones estrogen and progesterone, which rise and fall throughout their menstrual cycle. About one-third of females with asthma report premenstrual-related asthma symptoms, which may lead to severe attacks. A research study of girls ages 8 to 17 found that those who started menstruating at earlier ages developed more severe asthma after puberty, perhaps because their hormone levels began to change earlier in life. Studies have shown that hormonal changes can disturb the airways and inflammatory responses in the lungs. As hormone levels go up and down, new blood vessels in the lungs form and disappear, affecting the lungs’ ability to take in oxygen. In addition, female hormones do not just cause breathing problems in women with asthma, but also in those who smoke or are overweight.

Researchers are working to discover how sex hormones affect the lungs in order to develop personalized treatments for asthma. Ideally, specialized treatments in the future will be gender-specific and take into consideration a person’s hormonal status.

Nathalie Fuentes OrtizNathalie 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.

 

 

Beer Does a Body Good?

Drinks: Beer Isolated on White Background

Credit: iStock

Bone is a living organ that constantly breaks down and rebuilds itself. As we get older, bone breaks down more and rebuilds less, which often leads to weaker bones over time. If we lose too much bone, we increase our risk of fracture and developing osteoporosis.

Women tend to have weaker bones and a faster rate of bone loss—particularly after menopause—than men. Approximately 50 percent of women in the U.S. over the age of 50 will break a bone due to osteoporosis. If the broken bone is in the hip, there is about a 20 percent chance that the individual will die within one year. Breaking a bone in our later years can significantly affect quality of life and the ability to live independently. Therefore, it is important to do everything we can to minimize age-related bone loss.

Lifestyle choices can help minimize bone loss, including:

  • following a healthy diet with enough calcium and vitamin D;
  • participating in regular physical activity; and
  • refraining from smoking.

Believe it or not, drinking a beer now and then may even help.

Researchers in Spain have discovered a link between beer consumption and bone health in women. They found that women who drank moderate amounts of beer—defined in the U.S. as up to one 12-ounce beer per day—had stronger bones than those who did not.

Beer contains two important nutrients that could be beneficial to bone health: phytoestrogens and silicon. Phytoestrogens are naturally occurring nutrients in plants that act similar to the hormone estrogen. Estrogen protects women from bone loss, but levels drop significantly after menopause. Estrogen deficiency is the primary cause of bone loss after menopause. Silicon is a naturally occurring mineral that may be used as a supplement to reduce bone breakdown and increase bone rebuilding in women with osteoporosis. Beer is one of the most plentiful sources of silicon in the Western diet.

It’s likely that the combination of phytoestrogen and silicon in beer helps limit bone loss. This finding has potentially important implications for bone health, although more study is needed.

It is also important to remember that drinking too much alcohol has many negative health effects, including reduced bone strength. Keep beer intake at a moderate level. That said Aug. 4 is International Beer Day. Drink a toast to healthy bones!

 

Kim HenigeKim Henige, EdD, CSCS, ACSM EP-C, is an associate professor and undergraduate program coordinator in the department of kinesiology at California State University, Northridge.