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

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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

A Nutty Way to Curb Cravings

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Although walnuts are recommended as an effective way to control appetite in people with diabetes, just how they regulate appetite has only recently been discovered. In a new study published in the journal Diabetes, Obesity and Metabolism, researchers examined the brains of 10 obese volunteers who drank breakfast smoothies for five days. Some of the volunteers drank smoothies containing walnuts, while others drank nut-free smoothies that looked and tasted identical. One month later, the participants repeated the study, but this time those who received walnut smoothies during the first trial drank the nut-free beverage and vice versa. Neither the volunteers nor the researchers knew which smoothie the participants consumed during each phase of the study.

At the end of each five-day trial, the volunteers—on an empty stomach—looked at images of “desirable” high-fat foods such as cake and onion rings, healthy foods like fruits and vegetables, and non-edible things like rocks or trees. The people who consumed the walnut smoothies consistently showed more activity in the area of the brain associated with regulating the behavior of eating and feeling satisfied (satiety) when they looked at the high-fat foods. By stimulating this area of the brain called the insula, the researchers think that walnuts promote weight loss by reducing cravings. In fact, the study participants reported feeling less hunger and feeling like they could eat less food after their walnut trial as compared to their nut-free trial.

In addition to reducing food cravings, walnuts are low in saturated fats and high in omega-3 fatty acids and are good sources of fiber and protein. The next time you have the urge to snack, grab a handful of walnuts.

 

Karen SweazeaKaren Sweazea, PhD, is an associate professor in the School of Nutrition & Health Promotion and the School of Life Sciences at Arizona State University.

Sugars, Fructose and Your Health

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Early humans were probably jacks of all trades when it came to food—they ate what was available, and the amount of carbohydrates, proteins and fats in their diet varied dramatically depending on where they lived. Except for honey, there were likely no sweeteners to “spice” up their meals. That all changed 200 years ago when table sugar—a combination of the sugar molecules glucose and fructose—began to be manufactured. This provided a steady supply of inexpensive sweeteners to the general population. From that time on, the amount of sweeteners humans ate began to rise drastically. It’s no coincidence that obesity and diabetes rates increased a few decades later. The cost of sweeteners were further reduced (and the availability increased) with the introduction of high-fructose corn syrup (HFCS) 40 years ago. HFCS is a processed form of glucose that can be easily added to many beverages and foods.

High sugar intake may cause physiological changes in the body that can interfere with the way organs are supposed to function and the way the body burns energy (metabolism) attained through food. The average non-obese person has a very low blood fructose concentration that may be as much as 100 times lower than blood glucose levels. Consuming fructose-laden desserts and sodas quickly increases blood fructose levels, flooding liver cells that are not used to such high doses. Fructose is rapidly broken down into easily processed substances (metabolites) that can be building blocks for fats.

Consuming a lot of fructose often leads to a marked increase in fat-forming enzymes and fatty deposits in the liver.  Coincidentally, a decade after HFCS was widely introduced, a new metabolic disease—nonalcoholic fatty liver disease (NAFLD)—cropped up. NAFLD has been linked to overconsumption of fructose and added sugars. A fatty liver is associated with high triglycerides and “bad” cholesterol, increasing the risk for cardiovascular disease and obesity.

The good news is that these associations between added sweeteners, particularly fructose, and metabolic diseases have resulted in serious efforts to reduce consumption, like Mexico’s tax on sugary drinks and New York City’s (unsuccessful) attempt to ban sales of large sodas. In light of these efforts, people in the U.S. now seem to be eating less added sugars.

It is important to remember that moderate consumption of added fructose is most likely fine for most people. Fructose is the sweetest of the naturally occurring sugars and a little goes a long way. This is one case where “less is more.”

Ronaldo FerrarisRonaldo Ferraris, PhD, is a professor of pharmacology, physiology & neuroscience at the New Jersey Medical School at Rutgers University.  He studies intestinal epithelial biology and cell differentiation as well as integrative regulatory processes involving sugar sensing, transport and metabolism in the small intestine.

When’s the Best Time to Eat? Your Body Clock Knows

 

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The American Heart Association recently released a statement suggesting that when and how often you eat could affect your risk for developing heart disease and stroke. Until now, the focus on diet has been primarily about how much and what you eat. This news—that the time of day you eat may also be important—could change the way people are able to manage their health.

Our bodies have natural daily patterns called circadian rhythms that occur roughly over a 24-hour cycle. Many biological processes are driven by circadian rhythms, including when you go to sleep and wake up, your body temperature, heart rate, blood pressure and the release of various hormones. A “master clock,” a tiny group of cells called the suprachiasmatic nucleus (SCN), located in the hypothalamus area of the brain manages circadian rhythms. This master clock is mostly controlled by changes in light.

Every cell in the body also has its own internal clock called a “peripheral clock.” Peripheral clocks make sure all of the cells’ functions are coordinated with the master clock. Animal studies show us the importance of keeping peripheral clocks in sync with the brain’s master clock. For example, when the peripheral clock in a mouse’s heart is disrupted, the mouse develops heart failure and dies at a much younger age than normal mice.

Unlike the master clock, peripheral clocks are more responsive to the availability of food than changes in light. As a result, eating at the “wrong” time of day could shift the rhythms of the peripheral clocks so they are out of sync with the master clock. For example, shift workers who work in the middle of the night are active when they would normally be asleep and eat at times when their body doesn’t expect food. They are at much greater risk for being overweight, becoming insulin resistant and developing cardiovascular disease because their master and peripheral clocks are likely to be out of sync.

Research in mice has shown that if they consume a high-fat meal at the end of their active period (the equivalent of a high-fat dinner for humans) they gain more weight, develop insulin resistance and have impaired cardiac function compared to mice that eat the same high-fat meal at the beginning of their active phase (breakfast).

Studies in people suggest that eating meals late in the day is linked to negative health effects, but a direct relationship has not been shown. Nevertheless, if when you eat is just as important as what you eat, it might not hurt to eat your larger meals earlier in the day if you can.

 

John Chatham

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

Are You at Risk for Type 2 Diabetes?

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During American Diabetes Month in November, you may notice more people are talking about diabetes, a disease that affects 29 million Americans. It’s a great time to learn more about diabetes and the ways that you can decrease or manage your risk of developing the disease.

Diabetes mellitus is a problem with how your body handles blood glucose (sugar). People who have type 2 diabetes aren’t able to use the hormone insulin properly to remove glucose from the bloodstream for use in the fat and muscle cells.  Ultimately, this causes people with type 2 diabetes to have higher than normal levels of glucose in their blood.

You may have heard that someone who is overweight and has a large, apple-shaped body is more likely to develop metabolic syndrome—a group of health conditions such as elevated blood pressure, blood sugar and cholesterol levels—which may increase the risk of developing diabetes.  However, there are a number of less well known risk factors for type 2 diabetes including:

Some research even links non-health-related factors such as job security to an increased diabetes risk. A recent study published in the Canadian Medical Association Journal  analyzed data from 19 different studies including almost 141,000 participants which suggested that job insecurity was associated with a modest increased risk of diabetes.  Job insecurity has also been associated with weight gain (a diabetes risk factor) and coronary artery disease (a complication of diabetes).

Recognizing risk factors for diabetes and dealing with them, if possible, is important for both children and adults. Consuming a healthy, nutrient-rich diet and staying physically active can help maintain weight, manage stress and avoid type 2 diabetes and its many related complications. To learn more about ways to prevent diabetes, visit the American Diabetes Association website.

barb-goodman

Barb Goodman, PhD, is a professor of physiology at the University of South Dakota.

Depression + Pregnancy = Diabetes?

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Morning sickness, swollen ankles and a growing belly are just a few of the many physiological changes that women experience during pregnancy. The changes  we can see are just the tip of the iceberg. Blood volume, bones, heart rate, skin and many other parts of a woman’s body function differently during pregnancy.

Pregnancy-related changes can sometimes lead to more serious health consequences for mother and baby during pregnancy and beyond. For example, gestational diabetes—a temporary condition in which the body can’t process sugar during pregnancy the way it usually does—can lead to a higher risk of other pregnancy complications, including having a large baby and increased chances of developing diabetes mellitus down the road. Now researchers have found a link between gestational diabetes and depression during pregnancy, a condition which affects an estimated 13 percent of moms-to-be.

A recent study showed that women who had more symptoms of depression in the first and second trimesters were at the greatest risk of developing gestational diabetes. The study also found that women who had gestational diabetes were four times more likely to develop postpartum depression after giving birth. Researchers say the relationship between the two conditions needs more study, but they think that the chemical changes in the brain that occur with depression during pregnancy may affect how we break down sugar.

These links emphasize the need to tune in to emotional shifts that many pregnant women experience. When crying jags and lack of energy lasts for more than two weeks or if symptoms get increasingly worse, it may be more than just pregnancy hormones at work. Women should also look out for the physical symptoms of depression which may include:

  • headaches
  • general aches and pains
  • stomach problems
  • loss of appetite (which may sometimes be mistaken for a side effect of morning sickness)

Now that doctors are learning more about the link between depression and gestational diabetes, they can monitor their patients more closely for both conditions during pregnancy. For more information about depression during and after pregnancy, visit the federal Office on Women’s Health website.

Erica Roth

 

 

What Blood Vessels Tell Us about Childhood Obesity

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Did you know that blood vessels can “talk?” That’s right: Changes in the cells within blood vessels can communicate important information about the overall health of the cardiovascular system. The inside of blood vessels are lined endothelial cells—protective cells that form a tight barrier through which only certain substances such as water or glucose can enter. Endothelial cells also make many substances that keep the vessels healthy so that the heart can effectively pump blood to all of the tissues and organs. While strong, endothelial cells are also sensitive to changes or inflammation within the body. So, if the cells become damaged or stop functioning properly, it can indicate that there is a problem occurring elsewhere in the body.

Tuning in to the messages that blood vessels can reveal what’s going on inside our bodies, not just what’s happening within the vessels themselves.  For example, vessels can expose the effects of obesity and can help scientists discover links between body composition and the body’s response to food and sugar intake.

In a recent study published in the Journal of Pediatrics, researchers measured the endothelial function of teens ages 12–19 years for clues into the relationship between obesity and how the body handled sugar. By conducting the study in teenagers with a wide range of body compositions—from normal weight to obese—they were able to make conclusions about blood vessel health, how it relates to obesity, and how obesity contributes to the development of problems in the body’s ability to handle sugar properly. They found that obese young people had higher levels of endothelial cell damage that correlated with the body’s inability to handle sugar. Indeed, in this example, the endothelial cells in the vessels “spoke” to the researchers about the health of the study participants.

This study also underscores the importance of preventing childhood obesity, which has been linked to a reduction in the body’s ability to regulate the amount of sugar in the blood. Limiting the intake of processed, high-sugar food and drinks is a great start. The second step is to increase physical activity during childhood and adolescent years. These habits, when started early, may carry into adulthood and lead to a healthier life. September is Childhood Obesity Awareness Month. Find more tips for helping kids maintain a healthy weight on the CDC website.

Audrey Vasauskas

How Your Immune System Can Make You Sick

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Your immune system has a Dr. Jekyll and Mr. Hyde complex when it comes keeping you healthy.  Traditionally, the immune system is seen as a good guy that kills off viruses and eats up bacteria attacking your body. However, it can also turn against you and cause disease.

To fight infection, the cells of your immune system produce proteins called cytokines that cause the infected area to swell, turn red, heat up and hurt. This reaction is called inflammation, and it helps you recover from viral and bacterial invaders relatively quickly.

Cytokines can also reduce inflammation, allowing for a system of checks and balances that prevents inflammation from lasting too long and hurting you instead of helping you. For example, the immune cell called “natural killer T cell” produces cytokines that cause inflammation and is kept in check by the immune cell “regulatory T cell”, which produces cytokines that counteract inflammation. Some immune cells can even produce both types of cytokines and switch roles. The immune cell “macrophage” can go from causing inflammation to kill the infection to preventing inflammation to help the injury heal.

Inflammation becomes bad when it lasts too long or is turned on at the wrong time. The cytokines can cause changes to your body that lead to disease, including stroke, heart disease, obesity and diabetes. Scientists are still unsure why the immune system can ignore its own safeguard. For obesity and diabetes, scientists at Harvard Medical School think the culprit is a hormone called leptin.

The researchers noticed that in obese people and obese mice immune cells found in fat called “mast cells” had five times more leptin than their lean counterparts. Moreover, mice that did not have leptin in their mast cells did not become obese or diabetic when put on a high-fat diet. Interestingly, obese mice lost weight and improved blood sugar levels when they were injected with mast cells with no leptin. This happened because mast cells with no leptin produced inflammation-reducing cytokines, while mast cells with leptin produced inflammation-causing cytokines, the research team said. In obesity and diabetes, leptin turned the immune system into a bad guy.

This is the first study to show that simply reducing the amount of leptin in mast cells can prevent, and even reverse, obesity and diabetes caused by a high-fat diet. Understanding the details of how our immune system causes disease can lead to new and better treatments to help people stay healthy.

Dao Ho, PhD

 

Dao H. Ho, PhD, is a biomedical research physiologist at Tripler Army Medical Center.

Look to the Sky for Lessons in High Blood Sugar

Karen SweazeaSo much of what we hear in health news today involves how what we eat or how much we move affects the way we live. For example, if we overeat sugar or unhealthy foods and don’t get enough exercise, we can find ourselves at increased risk for diabetes and cardiovascular disease. These can affect our quality of life or even shorten our lifespan.

As a comparative physiologist, I compare examples of animals and humans, how their diets affect their health and the factors that drive the development of cardiovascular disease with poor nutrition and diabetes.

I find birds to be the most interesting natural animal model of living successfully with high blood sugar. These amazing animals have blood sugar levels that are 1.5–2 times higher than the amount measured in mammals of similar body size, yet they display none of the typical characteristics that we associate with diabetes. This is because living with high blood sugar is just a normal part of their physiology. Another surprising fact: Unlike endurance athletes, who rely on sugar stores to power exercise, birds use fat to power flight. This is contrary to what people often assume.

Birds also defy the “rate of living theory of aging.” This theory suggests that animals with higher metabolisms (such as mice) do not live as long as those with low metabolisms (such as sloths). But birds go against this theory because they have very high metabolisms and are known to live relatively long lives.

We’ve still got a lot to learn about human health and disease from our fine, feathered friends and many other animals, too! To learn more about comparative physiology, check out the APS Dr. Dolittle blog.

Karen Sweazea, PhD, is an associate professor in the School of Nutrition & Health Promotion and the School of Life Sciences at Arizona State University.