Health News

“Live healthy...Live well”

Dedicated to providing pertinent information on health, fitness, and nutrition to foster a culture of wellness among Southwest Airlines flight crews and their families.

by Larry Kline

email: livehealthy-livewell@cox.net

RUN LONGER, SLEEP BETTER – a good workout can aid in quality of sleep.  A Dutch study found that people who burned 2,500 calories a day spent more time in bed sleeping (not just lying awake) than those who burned 1,500 calories.  The higher intensity workouts diminish the body’s energy stores which lead to better sleep efficiency.  Men’s Health, 03/13.

FRUCTOSE AND YOUR BRAIN – high-fructose corn syrup and table sugar are roughly half fructose and half glucose.  But fructose (which is found only in sugars) and glucose (found in sugars and digested starches) may have different effects on the brain.

            Researchers took MRI images of the brains of normal-weight volunteers before and after they drank a beverage that contained 75 grams (300 calories) of either fructose or glucose.

            Glucose reduced cerebral blood flow, which reflects brain activity in key areas of the brain that regulate appetite and reward, while fructose did not.  Likewise, glucose increased the participants’ feelings of fullness and satiety, but fructose did not.

            Cut back on all added sugars.  This study did not prove that fructose leads people to overeat, but it adds to the evidence that sugary beverages promote obesity.  Journal of the American Medical Association, 309:63, 85, 2013.

ENERGY DRINKS BUSTED – a study in the Journal of Strength and Conditioning Research reports that noncaffeine ingredients in energy drinks do not enhance athletic performance.  Cyclists who downed Red Bull consumed as much oxygen and felt just as tired as athletes who drank a beverage that contained the same amount of caffeine but lacked ingredients like taurine or B vitamins.  In other words, a cup of coffee provides the same athletic boost as energy drinks that are filled with extra ingredients.  Men’s Health, 03/13.

MILK AND THE PROSTATE – only whole milk, not low-fat or fat-free, may be linked to a higher risk of fatal prostate cancer.

            Scientists tracked over 21,000 men in the Physicians’ Health Study for 28 years.  Those who drank at least one serving of whole milk a day were twice as likely to die of prostate cancer than those who rarely consumed whole milk.  Men who drank at least one service of fat-free or low-fat milk had a 19 percent higher risk of localized or low-grade prostate cancer, but no higher risk of advanced, high-grade, or fatal cancer.

            Drink low-fat or fat-free milk instead of whole.  The saturated fat in whole milk raises LDL (bad) cholesterol and adds calories that most people do not need, and appears to increase the risk of fatal prostate cancer.  Nutrition Action Healthletter, 03/13.

75 MINUTES A WEEK – the number of minutes of moderate exercise you need weekly to add nearly 2 years to your life. PLoS Medicine.

GO LIGHT TO GROW BIG – high weight, low reps is the classic way of adding size and strength to muscles using resistance exercises.  But a study in the Journal of Applied Physiology found that lifting lighter weights for more reps (3 sets of up to 30) can boost growth as much as lifting heavy weights in the 8- to 12-rep range.  As long as the muscles reach fatigue, the researchers found that the muscles will grow.  Men’s Health, 03/13.

SLEEP AND DIETING – dieters lose more fat and less muscle is they get enough sleep.  Researchers put sedentary overweight middle-aged men and women on a lower-calorie diet.  For two weeks, roughly half were allowed to sleep for 5 ½ hours a night, while the other half got to sleep for 8 ½ hours.  After a three-month break, they switched.

            Sleep had no impact on how many pounds the participants lost, but when they were sleep-deprived, they lost 55 percent less fat and 60 percent more lean body mass (mostly muscle) than when they were allowed to sleep for 8 ½ hours a night.

            The participants also had a lower metabolic rate, felt more hunger, and had higher ghrelin levels when they were sleep-deprived.  Ghrelin is a hormone that stimulates appetite.  Annals of Internal Medicine, 153:435, 2010.

WHOLE GRAINS AND BELLY FAT – people who eat more whole grains have less visceral belly fat, the kind that is linked to a higher risk of heart disease and diabetes.

            Scientists measured both subcutaneous (below the skin) fat and the deeper layer of visceral fat in more than 2,800 middle-aged participants in the Framingham Heart Study.  People who reported eating at least three servings of whole grains a day had 10 percent less visceral fat than those who said they ate less than a serving per week.

            However, whole grains were not linked to less visceral fat in people who also consumed at least four servings of refined grains per day.  Whole-grain eaters also had smaller waist sizes than refined-grain eaters. 

            The Framingham participants got most of their whole grains from bread, ready-to-eat breakfast cereals, oatmeal, popcorn, and brown rice.  Pasta, English muffins, white bread, pizza, and white rice were the major sources of refined grains.  Nutrition Action Healthletter, 11/10.

NOT MUCH TIME FOR A WORKOUT? – if you do not have time for long workouts, short bouts of exercise can be just as good.  A British study found that 10 three-minute bouts of brisk walking over the course of about five hours were as effective in lowering triglycerides (fats in the blood) and resting blood pressure as one 30-minute exercise session.  Most studies on short bouts have compared three or four 10-minute sessions to a single 30- or 40-minute session, and found that the repeated short bouts can be just as healthful as longer ones.  University of California Berkeley Wellness Letter, 02/09.

POTASSIUM POWER – potassium seems to affect the body very differently than sodium.  While sodium is linked to hypertension, potassium helps lower blood pressure.  Sodium tends to be found in junk food, while potassium is mostly found in very nutritious foods.  A simple test for urinary potassium levels (which closely follows dietary potassium intake) provides an accurate picture of how good a person’s diet is.  The higher the potassium level, the better the diet tends to be (accompanied by lower blood pressure and body weight as well). 

            Like sodium, potassium helps control blood pressure, among other vital functions.  While Americans consume far too much sodium, they get too little potassium.  In developing countries where diets tend to be relatively rich in potassium and low in sodium, high blood pressure is nearly nonexistent.             

            The U.S. government recommends at least 4,700 milligrams of potassium a day – well over double the maximum daily recommendation for sodium.  Most Americans get only half that much potassium and most consume less potassium than sodium.

            An easy way to cut down on sodium is to choose more potassium-rich foods.  As one mineral consumption goes up in the diet, the other tends to go down.  Vegetables (especially leafy greens and potatoes), bananas, citrus fruits, and beans are rich in potassium.  Dairy products, fish, and nuts are also good sources.  Do not take potassium supplements, unless prescribed by your physician.  Supplements can supply dangerous amounts , resulting in abnormal heart rhythms.

            People with impaired kidney function or taking certain medications may need to limit their intake in order to prevent potentially dangerous arrhythmias.  University of California Berkeley Wellness Letter, 03/07.