The Fat-blocking Powers of Fiber

Leafy green vegetables

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An estimated 610,000 people in the U.S. die from heart disease each year. One common cause of heart disease is the narrowing of blood vessels due to the buildup of fatty deposits (plaque). Many factors—including eating a lot of fatty foods—can lead to plaque buildup in blood vessels.

Your liver processes excess fat by packaging it into cholesterol droplets known as low-density lipoproteins (LDLs). LDLs travel throughout the body in the blood. Often, the droplets get stuck to the blood vessel walls, where they accumulate. The buildup of plaque eventually blocks blood flow, most often in the blood vessels that supply blood to your heart. However, eating fiber can help prevent the early stages of heart disease and plaque buildup.

Fiber is a plant’s supply of stored energy, but your gut can’t digest it. During a meal, your small intestine breaks down the food you eat and absorbs nutrients. Fiber resembles a mesh-like structure. Indigestible fiber acts like a large net—think of a butterfly net—to block places where fat can be absorbed. A meal high in dietary fiber blocks some of the absorption of fats, stopping fats from moving outside the gut into the bloodstream.

When there is less fat absorbed from your gut, your liver does not have to package it into LDL droplets, which lowers LDL levels in the blood. In addition, when your liver needs fat to make hormones and bile, it can produce another kind of cholesterol called high-density lipoproteins (HDL). HDL can remove some of the plaque in blood vessels and send it back to the liver. HDL is known as “good cholesterol” for this reason. Consuming meals high in fiber can help HDL with this process.

Recent studies have shown that eating fiber-rich brown rice or taking more than 5 grams of fiber supplements daily can improve some measures of cardiovascular function in adults. Leafy or green vegetables such as spinach, lettuce and broccoli are also good sources of fiber. So make a salad or try adding greens to an entree or a smoothie—I promise you can’t even taste blended spinach in a fiber-packed smoothie. There are plenty of options to fiber up your diet and keep your heart healthy.

Gabrielle RoweGabrielle Rowe is a PhD candidate in the physiology program at the University of Louisville. She is interested in studying small heart vessel function, stem cells and aging.

Curcumin, the Golden Spice

Family having Indian food

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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.

The Anti-Aging Cure May Be in Your Medicine Cabinet

Older dog - Younger dog

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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 KuoMaggie Kuo, PhD, is the former Communications and Social Media Coordinator for APS. Catch more of her writing in the Careers Section of Science Magazine.

You Don’t Have to Leave the Stratosphere to Feel Like You’ve Been in Space

view of Earth from space

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Astronaut Scott Kelly came back from 340 days in space two inches taller. Along with height, many aspects of the body change because of the weightlessness environment of space. The body loses muscle, heart and bone mass because it no longer has to support itself as it does on Earth. There is also no feeling of “down” in space. The brain uses this signal for balance, so it has to change how it processes sensory information. While Kelly went to space to study the health impacts, scientists can investigate the effects without leaving the planet. Here are some of the ways scientists recreate weightlessness on Earth. Most of the studies are done for several days to several weeks.

Long-Duration Bed Rest

Study participants lie in bed 24 hours a day. In some studies, the bed tilts towards the head (referred to as head-down tilt, or HDT) to mimic the blood and fluid flow towards the head that happens in space.

Bed Rest

Dry Immersion

Study participants sit in a tub of water. This method takes advantage of water’s buoyancy to suspend participants similar to how they would float in space. Participants are wrapped in a waterproof cloth to keep them dry.Dry Immersion

Unilateral Limb Suspension

Study participants wear a platform shoe on one foot to keep the other foot off the ground. They balance and get around with crutches. This method focuses on how the muscles change in the hovering leg.

Lower Limb Suspension

Parabolic Flight

The airplane recreates the weightlessness of space by flying up and down in a wave pattern. Unlike the other methods, the suspended period is very short. Participants float in the air and feel weightless for about 20 seconds when the plane is changing directions to return towards the ground.

Findings from these studies on the health effects of the space environment will help astronauts prepare for long space missions such as going to Mars. For updates on space research, tune in to the National Academies’ Space Science Week March 29 through 31. Experts will share information about ongoing research programs and discuss issues and advances in their fields.

Maggie KuoMaggie Kuo, PhD, is the former Communications and Social Media Coordinator for APS. Catch more of her writing in the Careers Section of Science Magazine.

Don’t Take a Load Off: Too Much Sitting Is Bad for You

Office Chair

If you’ve considered getting in on the standing desk trend, you’ve probably heard the public health warnings about the dangers of too much sitting. (Would you get a standing desk? Tell us on our poll.) Several studies report an increased risk of developing cardiovascular disease with too much sitting. The good news is you can prevent it. The key may be to keep the blood moving to combat the decreased blood flow caused by sitting.

Blood vessels are lined with cells called endothelial cells. Besides keeping the blood vessels healthy, endothelial cells make sure that blood goes where it needs to by releasing molecules that either enlarge or narrow the blood vessels. They constantly feel the force of the blood flowing over them, and changes in blood flow patterns, including decreased blood flow, can reduce their effectiveness. Impaired endothelial activity increases the risk of developing diseases that affect the blood vessels such as atherosclerosis (the buildup of cholesterol, fat and other substances within and along the walls of blood vessels).

A new study discussed in this AJP-Heart podcast examined whether sitting-related diminished blood flow impaired endothelial function. To do this, the researchers compared endothelial function in the leg of their study subjects—one leg’s blood flow was reduced from sitting while the other leg’s blood flow was maintained by placing the foot in a warm water bath. After a three-hour sitting session, the researchers found that the blood vessels in the leg of the dry foot did not dilate as well as before the session, a sign of impaired endothelial function. The blood vessels in the leg on the warm water side, however, were able to dilate normally. The researchers also confirmed that leg blood flow on the dry foot side was lower after the three hours of sitting while blood flow on the warm water side remained similar.

The researchers concluded that prolonged sitting caused endothelial dysfunction because blood flow through the legs decreased. The flip side was that maintaining blood flow—in this study with a warm water bath—prevented the decline in endothelial function.

What can you do to keep your blood flowing? Jaume Padilla, PhD, the study’s lead investigator, thinks even small amounts of physical activity can help. He tries to stand as much as possible during his work day. When he’s sitting for very long periods of time, such as during long flights, he finds ways to keep his legs moving (check out these leg and other stretches from Virgin Atlantic airline that you can do while sitting). Walks are good, too. Another study from Padilla’s group also showed that a short ten minute walk could restore blood vessel health and flow in people who were sitting for six hours.

Get up and move around regularly during your day. It’s all-around good for you.

Stacy Brooks & Maggie Kuo

Maggie KuoMaggie Kuo, PhD, is the former Communications and Social Media Coordinator for APS. Catch more of her writing in the Careers Section of Science Magazine.

Out of Sight, Out of Mind? Don’t Forget About the ‘Hidden’ Benefits of Exercise

Shawn Bender, PhD

Shawn Bender, PhD

I approached an article in The New York Times titled “To Lose Weight, Eating Less Is Far More Important Than Exercising More” with a bit of trepidation. I don’t disagree with the statement (or the science behind it), but I felt the importance of exercise could be dismissed if the title was misinterpreted. Reading the full article—which I am guilty of not always doing—revealed that the author fully acknowledges the importance of exercise beyond weight loss for overall health. “Exercise has a big upside for health beyond potential weight loss. Many studies and reviews detail how physical activity can improve outcomes in musculoskeletal disorders, cardiovascular disease, diabetes, pulmonary diseases, neurological diseases and depression,” he wrote. My compliments to the author!

One of the other advantages of exercise is a clear reduction in blood vessel disease and cardiovascular-related deaths. We can’t see these improvements like we could see a number on a scale, but the long-term value of exercise on the heart and blood vessels is immense.

The reasons for the cardiovascular benefits are complex, so let’s focus on one part of the puzzle. The inside of blood vessels is lined with a layer of cells, called endothelial cells, which is in contact with blood as it flows by. Endothelial cells play a critical role in normal blood vessel function. In conditions like obesity, these cells do not operate correctly, leading to blood vessel malfunction and disease, as my colleague and I recently discussed in a review article. Damage to these cells can predict future cardiovascular disease.

Exercise is key to keeping endothelial cells in good shape. Why? You may know that exercising muscles need more oxygen-rich blood to operate at their best. It turns out that getting more blood to muscles during exercise is also good for endothelial cells. Exposing them to the increased exercise-related blood flow protects the cells and improves overall blood vessel health.

Keeping endothelial cells healthy requires regular exposure to increased blood flow, so get up and walk around—even 10 minutes of walking benefits these cells (not to mention your entire cardiovascular system). Make exercise a regular part of daily life to promote overall health regardless of your weight. Go for a walk…and remember to always read the full article before you interpret the title!

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.

Feeling Lightheaded after Exercise? Use the Heart in Your Legs!


John Halliwill, PhD

Do you ever get lightheaded or feel a little dizzy after hard exercise? Maybe you have felt a little bit of “tunnel vision” after a hard sprint or when you stand up in the first hour after a long training session? This is a surprisingly common occurrence in healthy people, as recently reviewed in the European Journal of Applied Physiology. Physiology can help you understand how to use the “heart in your legs” to pump away those symptoms.

You probably know that the heart is a pump and it works to keep blood moving around your body to supply your brain, your muscles and other body organs with oxygen and nutrients. When you perform exercise, such as walking, running and biking, the heart is also being helped out by another pump—the muscle pump—which is like having a second heart in your legs.

How does that work? When we exercise, with every step, stride or pedal stroke, the muscles in our legs compress the blood vessels that pass through them. This compression pumps blood from the legs, moving it back to the heart and greatly assisting the ability of the heart to move blood around your body. But when we stop moving, like at the end of exercise or while resting from a hard workout, lots of blood flows into the legs but doesn’t get the extra push from flexing muscles to move back toward the heart. This makes us susceptible to feeling lightheaded when standing up.

Be active, and be pro-active! Don’t skip the workout, but definitely remember to cool down. A cool down of easy activity keeps the muscles pumping blood back to the heart and helps maintain blood flow to your brain. After your cool down, if you happen to feel a little lightheaded, just flex your leg muscles to turn on the pump in your legs to give blood an extra boost back to the heart and to your brain.

John Halliwill, PhD is a professor of human physiology at the University of Oregon.

The Pregnancy Condition that Can Predict Future Heart Disease Risk

Jessica Faulkner

Jessica Faulkner

With rising rates of obesity and diabetes in the United States, high blood pressure in pregnant women is becoming increasingly prevalent. This can result in many pregnancy complications, the most severe of which include preeclampsia. Preeclampsia is a serious pregnancy-related condition that can affect the placenta, kidneys, liver and other organs. It can be life-threatening for mother and baby and is known to cause miscarriage and premature birth. Women who have had preeclampsia also have a greater risk of developing cardiovascular disease later in life.

A recent study published in the American Heart Association journal Hypertension showed that the time at which preeclampsia developed during a pregnancy may predict a woman’s future risk of cardiovascular disease.

Researchers measured several cardiovascular risk factors in 306 Dutch women who had experienced preeclampsia or high blood pressure in pregnancy two to five years after they gave birth. Then, they separated the women into two groups: those who developed preeclampsia early in pregnancy and those who developed it late in pregnancy. The study showed that women who developed early-pregnancy preeclampsia had significantly higher blood pressure, increased cholesterol, and higher blood sugar levels and insulin sensitivity (characteristics of diabetes) than those who developed preeclampsia in late pregnancy or who had high blood pressure without preeclampsia.

This study highlights the importance of prenatal care. The timing of a preeclampsia diagnosis (early vs. late in pregnancy) may be important information not only for mothers and babies during pregnancy, but also for physicians who treat women who had the condition later in life.

Cardiovascular disease is the #1 killer of women worldwide and prevention is the best medicine. This study indicates that women with preeclampsia, particularly those who develop it early in pregnancy, need to be continually conscious of their cardiovascular health as they age. It also highlights the importance of research in helping us uncover and understand unknown risk factors to fight cardiovascular-related deaths in women.

Jessica Faulkner is a graduate student in the Department of Pharmacology and the Cardiovascular-Renal Research Center at the University of Mississippi Medical Center.