Handling the Pain of Acid Reflux at Holiday Time

Acid reflux

Credit: iStock

With Thanksgiving coming up, eating—of all things rich, indulgent and delicious—is top of mind for many Americans. But for people with gastroesophageal reflux disease (GERD), eating this type of food often and in large quantities can be a challenge. This week is GERD Awareness Week, a good time to learn how to prevent GERD symptoms and still enjoy your holiday season.

GERD is the return of stomach contents, including acid, into the esophagus, sometimes known as acid reflux. More than 60 million people in the U.S. experience GERD symptoms, such as frequent heartburn, at least once a month.

You may have a higher risk of having GERD if you:

  • produce a lot of gastric acid
  • have a hiatal hernia
  • have a weak lower esophageal sphincter (the ring of muscle between the esophagus and stomach)
  • are obese
  • smoke
  • drink alcohol or a lot of caffeine

Women have additional risk factors, including being a young adult and adopting a stooping or slouching posture. Certain foods, including peppermint, chocolate, fatty or fried foods, and acidic fruits, also raise the risk of developing heartburn and acid reflux.

Simple dietary and lifestyle changes can be effective for many people to reduce the frequency and intensity of GERD symptoms, including:

  • losing weight if needed
  • quitting smoking
  • eating small meals throughout the day
  • avoiding foods that cause symptoms
  • waiting at least two hours before lying down after a meal

Another first line of treatment is medication, such as antacids or proton pump inhibitors. These drugs are available over the counter and by prescription from your doctor and reduce or stop the production of stomach acid to prevent symptoms.

If occasional heartburn bothers you after a big meal, try making lifestyle changes to help you feel better. If your symptoms persist, your doctor may look deeper into the possible causes for your discomfort. Knowing the risk factors for GERD can help you avoid complications and stay healthy throughout the holidays and all year long.

To learn more about GERD, visit the National Institute of Diabetes and Digestive and Kidney Diseases website

 

layla-al-nakkashLayla Al-Nakkash, PhD, is a professor in the Department of Physiology, at Midwestern University, Glendale, Ariz. She is the course director for medical physiology for medical and podiatry students. Her area of research relates to understanding how intestinal dysfunction (in diseases such as cystic fibrosis and diabetes) can be ameliorated by changes in diet.

How Many Hot Dogs Can You Eat in 10 Minutes?

Junk Food

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The competitive-eating elite will descend on New York City’s Coney Island this Fourth of July to flex their hot dog eating skills at the annual Nathan’s Famous Hot Dog Eating Contest. Last year, the male winner ate 62 hot dogs and the female winner ate 38 hot dogs in 10 minutes. Competitive eaters are surprisingly slight for the enormous amount of food they are able to consume. Where do all those hot dogs go?

The stomach is not a passive sack but an active organ that expands and contracts. An empty stomach holds about 1/4 cup, but when a meal is swallowed, the stomach expands to hold as much as 6 cups without stretching its walls. Besides relaxing to hold the meal, the stomach’s walls squeeze in and out and back and forth to move the food into the intestines, a process called gastric emptying. Researchers at the University of Pennsylvania wondered if speed eaters’ ability to keep down so many hot dogs was because their stomachs emptied faster or if their stomachs were trained to hold much more food than the average person.

The researchers recruited a professional speed eater and compared his gastric physiology to an individual with a big appetite. A gastric emptying test revealed that the professional speed eater’s stomach emptied slower than the regular eater. After 10 minutes, the regular eater consumed seven hot dogs, and his stomach was not stretched out. In contrast, the speed eater ate 36 hot dogs, and his stomach became a “massively distended, food-filled sac occupying most of the upper abdomen,” the researchers wrote. While the regular eater felt sick, the speed eater said he didn’t feel full, leading the researchers to wonder if the competitive-eating training made the stomach so stretchy and limp that the competitors never get the “full” physiological signal.

Although the study examined only one professional speed eater, the results support the idea that competitive speed eaters could eat large amounts of food in short periods of time not because their stomachs emptied faster but because their stomachs were able to enlarge dramatically.

The record for most hot dogs eaten is 69. How does the stomach look after that many? Not great, this video from ESPN shows.

Maggie Kuo

Does Weight Have to Yo-Yo? Secrets for Keeping Weight Off

Weight scale

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It’s the million-dollar (possibly billion-dollar) weight loss question: How do you keep lost weight off? This question is receiving renewed attention after a recent study reported that most of the contestants on Season 8 of television’s “The Biggest Loser” regained the large amounts of weight they’d lost on the show. Studies in rodents and humans show that soon after dieting or exercising stops, fat rapidly comes back and insulin resistance and glucose tolerance deteriorate. A number of physiological factors contribute to this rebound, including increased appetite and slower metabolism, but new research reports that stress hormones called glucocorticoids may also have a role.

In the study, rats were fed less and ran everyday on a running wheel for three weeks. The rats were then allowed to be sedentary and eat as much food as they wanted. After one week of this relaxed lifestyle, the rats had more fat tissue and worse glucose tolerance and insulin sensitivity than when they were dieting and exercising. But, when given mifepristone—a drug that blocks glucocorticoid hormone activity—during the relaxed week, the rats gained back less weight and their metabolic health didn’t change.

Dieting and exercising is stressful on the body, the researchers wrote, and the stress may prime the body to get back the fat it lost when the dieting and exercising stops. The study finds that glucocorticoid hormones are involved in this process and that preventing their action can reduce weight regain and metabolic changes.

While a miracle pill to keep the weight off may sound like a great solution, the researchers noted that the exercising and dieting rats were still healthier than the rats taking mifepristone. It’s important to emphasize the health benefits of regular exercise and a proper diet, they wrote. While a lifestyle change is the key to keeping weight off, it’s much easier said than done, as the “The Biggest Loser” contestants demonstrate.

Maggie Kuo

Capsaicin Causes Pain, No Gain

Capsaicin is a chemical people love or hate. It’s the chemical in hot peppers and spicy foods responsible for their spicy (and sometimes painful) taste, but researchers in Maryland and Pennsylvania think it may have some health benefits. William Yang, a high school student who worked on the project at the Temple University Lewis Katz School of Medicine in Philadelphia, shared their findings at the Experimental Biology meeting in San Diego.

The research team gave mice capsaicin for a total of 90 days. Mice fed capsaicin gained 16.5 percent less weight than mice in the control group, suggesting that capsaicin either changed their appetite or their body’s metabolism. The mice also showed changes in their ability to handle high blood sugar and high insulin levels, indicating that capsaicin has effects on metabolism.

Yang says future studies are underway in the group’s laboratory to discover how and why these changes happened. In the meantime, the findings tell us that the beneficial effects of eating spicy foods might be worth a little bit of pain.

Emily Johnson, PhD

Emily Johnson Capsaicin

William Yang presents “Capsaicin suppresses body weight gain and pain reaction in mice” at the Experimental Biology 2016 meeting in San Diego. Credit: Emily Johnson

 

Is Fat the Sixth Taste?

Chocolate Cake

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Restaurant menus for Valentine’s Day can be described in one word: decadent. From molten chocolate cake to marbled steaks, fat makes these foods so palatable. For a long time, scientists thought that we find heavy foods more appealing because of their mouth feel and aroma. However, recent studies suggest that the tongue might be able to taste fat, along with the five basic tastes—sweet, sour, salty, bitter and umami. This could explain why we are extra perceptive to richness in foods.

As we chew and savor, chemicals released from the food stimulate proteins called taste receptors on the tongue’s taste buds. Each basic taste has dedicated taste receptors, and the basic tastes blend together to give food the flavor we perceive. Contrary to popular belief, the tongue does not have specific regions for each basic taste. Every taste bud has all the taste receptors. How do scientists judge if a flavor is really a basic taste? Many define a basic taste as having all of the following:

  • a source,
  • taste receptors that respond to it,
  • a signaling pathway between the taste receptors and the brain so that we perceive the taste,
  • sensitivity to it that’s controlled by the body, and
  • subsequent effects on the body’s physiology.

So far, the prospect of fat becoming the sixth taste is looking good. Researchers identified the taste source: molecules in fat called fatty acids. They have a few ideas on which receptors fatty acids from fat stimulate, with the strongest evidence supporting a protein called CD36. Along with studies showing that stimulating CD36 sends signals to the brain, other studies have reported that people can tell fattiness without knowing appearance, smell and texture. Certain hormones also appear to control the craving for fat, at least in mice, and there’s evidence that fatty acids on the tongue have physiological effects—they signal to the intestines to get ready to digest fat.

Researchers are also exploring if obesity is related to fat as a taste. Obese mice seem less sensitive to fat and prefer the high-fat chow as a result. People who underwent gastric bypass surgery to treat obesity have said that fatty meals became less appealing after the procedure. More work needs to be done to say conclusively that fat is a basic taste, but imagine eating molten chocolate cake with a dash of “taste of fat” powder. Too decadent?

Maggie Kuo

How Our Bodies Turn Food into Energy

Assorted food

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Low carb, high protein, paleo—diet trends often single out a nutrient group as the culprit of unwanted weight gain and an unhealthy lifestyle. But our body needs food for energy, and all three groups—carbohydrates, fats and proteins—have important roles to play. What is energy to the body, and how does the body turn what we’ve eaten into a form it can use?

To the body, energy is a molecule called adenosine triphosphate (ATP). Many of the body’s processes need ATP to happen. For example, for a muscle to contract, ATP needs to be on the muscle cells’ moving parts for the contraction to continue. Rigor mortis, the stiffening of muscles after death, happens because no ATP is around.

Cells have three ways to convert food into ATP: glycolysis, the Krebs cycle and oxidative phosphorylation. Each pathway processes specific nutrient groups: Glycolysis only uses carbohydrates, while the Krebs cycle and oxidative phosphorylation can use all three. In each pathway, the nutrient is broken down in a multi-step process by specialized proteins, and new ATP molecules are regenerated from used ATP along the way. Besides using different transformation steps, the reaction pathways also take place in different parts of the cells. The proteins that carry out glycolysis float throughout the cell, which means glycolysis can happen anywhere. The proteins for the Krebs cycle and oxidative phosphorylation, on the other hand, reside in cell compartments called mitochondria, so these conversions only happen there.

For most cells, glycolysis produces the least amount of ATP. Most of the ATP formation occurs through oxidative phosphorylation and the Krebs cycle. This is why the mitochondria, where these reactions occur, are commonly referred to as the powerhouses of the cell. Both oxidative phosphorylation and the Krebs cycle need oxygen to work, and the Krebs cycle releases carbon dioxide as a byproduct. As a result, most of the oxygen we breathe in goes to the mitochondria for these reactions, and most of the carbon dioxide we’re breathing out comes from them.

What’s the chemistry behind ATP’s energy? Watch this video from Khan Academy for details.

Maggie Kuo

A New Meaning for ‘Food Baby’: How the Burmese Python Digests Big Meals

PR Python 3

Credit: Stephen Secor

Thanksgiving dinner can leave the stomach feeling and looking stuffed beyond capacity. The Burmese python goes beyond the post-meal bulge: Its intestines and other organs grow too, and these changes happen within days of eating. A recent study in Physiological Genomics examined how the organs can grow so much so soon.

The Burmese python takes about 10 days to digest its meal.  Within two days of eating, its metabolism and digestive processes are working 10 to 44 times faster. Three days after eating, its heart, liver, small intestines and other organs have grown to up to double in size. The meal is digested by the 10th day after eating, and these bodily changes have reversed. The Burmese python shrinks and returns back to its pre-meal state to go through this cycle again the next time it eats.

A multi-institutional team of researchers led by Todd Castoe, PhD, of the University of Texas at Arlington tracked how gene expression changed as the Burmese python’s body transformed. A gene is expressed when the protein it codes for is made. Greater expression of a gene means more of its protein is produced and present in the body. The researchers found that the expression of at least 2,000 genes changed after the snake ate. To their surprise, most of the shifts occurred soon after eating—within six hours. Genes that varied included those involved with organ structure and nutrient absorption. Gene expression matched and often preceded physiological changes and, like the bodily changes, returned to pre-eating state by the 10th day after eating.

According to the researchers, this study is the first to link the extreme and rapid eating-induced transformations of the Burmese python’s body directly to changes in gene expression and also the first to show how quickly gene expression changed.

Maggie Kuo

Hungry, Hungry Hormones: What Keeps You from Saying No to a Second Slice of Pie?

Apple Pie

Credit: Brandie Kajino / Flickr

Now is the time of year when family and friends gather together and share large meals. We eat … and keep eating … and keep eating. Our body has a number of signals that tell us to stop eating, but the mashed potatoes and stuffing tempt us to ignore them. What are those signals?

The hypothalamus sits in the center of our brains; among the many things it regulates is our hunger. The hypothalamus produces proteins that can increase or decrease hunger. The system works like a seesaw: Both types of proteins are always present, but which effect is stronger depends on which is produced more. This type of regulation is known as “antagonistic control,” and it’s an important way for the body to maintain homeostasis, the body’s internal balance.

The hypothalamus’s seesaw hunger control is in turn influenced by hormones. Hormones circulate around your body and come from parts of the body related to our energy intake and storage, including the gut, fat and pancreas. Changes in the body, such as by weight loss or physical activity, can affect how much of each hormone is released.

You’ll notice when you’re eating that it takes a little while to feel full. This 20- to 30-minute delay between when we start eating and when our body tells our brain to stop eating is due in part to the time it takes hormones that stimulate hunger, such as ghrelin, to reach a low and hormones that stimulate satiety (fullness), such as cholecystokinin, to reach a peak.

So, when you sit down for that holiday meal and you don’t want to overeat, take a few minutes to think about the signals in your body controlling your hunger before reaching for that last turkey leg!

Anne Crecelius

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

 

Getting the Most out of What You Do: Your Body’s Strategy

Life is hectic. To keep you running, your body absorbs oxygen from the air you breathe and nutrients from the food you eat. How does your body make sure it’s getting the most it can to get you through your day?

Your body increases the surface that’s exposed to the air and food. In the lungs, oxygen is absorbed from the air into the blood in tiny sacs that cluster around the ends of the lung’s airways. A person’s lung has about 480 million of these tiny sacs. With so many little sacs, the total surface that oxygen is absorbed through is about the size of a tennis court.

The digestive tract has a different trick to increase surface. The inside surface of the intestines is fuzzy like toothbrush bristles. The fuzziness increases the portion of the intestines that’s in contact with the food, maximizing the amount of nutrients that can be absorbed.

Try out this concept of maximizing exposed surface to maximize absorption by making a soup stock. Traditional methods to making stocks recommend simmering the vegetables and meat in water for six to eight hours to extract all the flavors. However, dicing the vegetables into smaller pieces can produce the same flavor intensity with only two hours of cooking. How? Finely dicing increases the vegetables’ surface that is exposed to the water. More flavor molecules can come out, shortening the total time needed to extract the flavors.

Credit: Getty Images

Credit: Getty Images

For more details on the cooking experiment, view this Advances in Physiology Education article.

Maggie Kuo

How Food Snakes and Shimmies through the Digestive System

Credit: Getty Images

Credit: Getty Images

Moving food through your digestive system is not a simple process: Food does not just drop down into your stomach when you swallow. It’s actually a controlled journey coordinated by muscle cells that line the digestive tract. These cells are organized in two directions: crosswise, circling around the tract, and lengthwise, along the length of the tract.

The cells that circle the tract squeeze together behind the lump of swallowed food and relax in front of it. The muscle cells that run lengthwise do the opposite: They relax behind the food and squeeze together in front. Together, the actions narrow the tract behind the food and widen the section in front, pushing the food forward. This motion—called peristaltic movement—happens throughout the entire digestive tract, from the esophagus to the small and large intestines.

It’s easy to visualize how the tract narrows and widens with the help of the crosswise cells, but the action of the lengthwise cells can be trickier to imagine. A fun way to visualize this is by placing a marble inside a Chinese finger trap. Pulling the ends away from each other, like in the top image, narrows the tube and keeps the marble in place. Pushing the ends of the finger trap toward each other, like in the bottom image, widens the tube and allows the marble to pass through easily.

Chinese finger trap illustration. Credit: S. DiCarlo

Chinese finger trap illustration. Credit: S. DiCarlo

When the muscle cells relax, it’s like pulling the ends of the finger trap, and when the cells squeeze together, it’s like pushing the ends. Learn more about this visual experiment in Advances in Physiological Education. Try it at home today.

– Maggie Kuo