Teens whose diets include lots of sugary drinks and foods show physical signs that they are at increased risk for heart disease as adults, researchers from Emory University report. Among 2,157 teens who took part in the National Health and Nutrition Examination Survey, the average amount of added sugar eaten in a day was 119 grams (476 calories), which was 21.4 percent of all the calories these teens consumed daily, the researchers noted. “We need to be aware of sugar consumption,” said lead researcher and postdoctoral fellow Jean Welsh. “It's a significant contributor of calories to our diet and there are these associations that may prove to be very negative,” she said. “Sugar-sweetened soft drinks and sodas are the major contributor of added sugar and are a major source of calories without other important nutrients.” Awareness of the negative effects of added sugar may help people, particularly teens, cut down on the amount of sugar they consume, Welsh added. “Parents and adolescents need to become aware of the amount of added sugar they are consuming and be aware that there may be some negative health implications if not now, then down the line,” she said.
The report is published in the Jan. 10 online edition of Circulation.
Welsh's team found that teens who consumed the most added sugar had 9 percent higher LDL (“bad”) cholesterol levels, and 10 percent higher triglyceride levels (another type of blood fat), compared with those who consumed the least added sugar. Teens who took in the highest amount of added sugar also had lower levels of HDL (“good”) cholesterol than those who consumed the least amount of added sugar. In addition, teens who consumed the highest amount of added sugar showed signs of insulin resistance, which can lead to diabetes and its associated risk of heart disease, the researchers found.
The American Heart Association has recommended an upper limit for added sugars intake, based on the number of calories you need. “Most American women [teens included] should consume no more than 100 calories of added sugars per day; most men, no more than 150 calories,” the association states.
One caveat to these findings is that because of the way the study was done it is not clear if added sugars caused the differing cholesterol levels, only that they are linked. In addition, the data are only for one day and may not reflect the teen's usual diet, the researchers noted. Commenting on the study, Dr. David L. Katz, director of the Prevention Research Center at Yale University School of Medicine, said that “this study does not prove that dietary sugar is a cardiac risk factor in this population, but it strongly suggests it.”
The paper has three important messages, he said. First, dietary sugar intake in a representative population of teenagers is nearly double the recommended level. Second, the higher the intake of sugar, the greater the signs of cardiac risk, including elevated LDL (“bad”) cholesterol and low HDL (“good”) cholesterol. Third, the apparent harms of excess sugar are greater in overweight than in lean adolescents.
“Sugar is by no means the sole dietary threat to the health of adolescents, or adults,” Katz said. “But we now have evidence it certainly counts among the important threats to both. Reducing sugar intake by adolescents, to prevent them becoming adults with diabetes or heart disease, is a legitimate priority in public health nutrition,” he said.
SOURCES: HealthDay; Jean Welsh, M.P.H., Ph.D., R.N., postdoctoral fellow, Emory University, Atlanta; David L. Katz, M.D., M.P.H., director, Prevention Research Center, Yale University School of Medicine, New Haven, Conn.; Jan. 10, 2011, Circulation, online
The researchers fed 12 piglets a calcium-rich diet and another 12 piglets a calcium-deficient diet during the first 18 days of their lives. When the researchers examined samples of bone marrow, organs, and hind leg bone at the end of the study, they found that the piglets fed a calcium-deficient diet had compromised bone density and strength. The bone marrow tissue of these same piglets also seemed to be predisposed to become fat cells rather than osteoblasts (bone-forming cells). The presence of fewer osteoblasts during infancy may result in a reduced ability of bones to grow and repair themselves during later years.
Osteoporosis affects an estimated 10 million men and women in the United States, with about 80 percent of cases diagnosed in women. According to the National Osteoporosis Foundation, approximately 34 million additional people are believed to have low bone mass, which places them at increased risk for osteoporosis. Most people who have osteoporosis or low bone mass do not even know they have it, and the first clue is often a fracture associated with a fall or, in severe cases, simply bending over or turning around.
The lead researcher, Dr. Chad Stahl, an associate professor in the Department of Animal Science at North Carolina State University, noted that maintaining good calcium nutrition for children and adolescents is known to be important, but that this recent study “suggests that calcium nutrition of the neonate may be of greater importance to life-long bone health due to its programming effects on mesenchymal stem cells” (bone marrow tissue from which osteoblasts are formed). This idea might cause healthcare professionals “to begin thinking about osteoporosis not so much as a disease of the elderly, but instead as a pediatric disease with later onset.”
While vegetarians tend to eat healthier diets and are less likely than non-vegetarians to be overweight or obese, they may be at increased risk for binge eating with loss of control, and former vegetarians may be at increased risk for extreme unhealthful weight-control behaviors, according to researchers at University of Minnesota, University of Texas and St. John's University.
The researchers analyzed vegetarianism, weight, dietary intake and weight-control behaviors data from a population-based study in Minnesota of more than 2,500 males and females between 15 and 23. They found vegetarians ate healthier diets than non-vegetarians when it came to fruits, vegetables and fat intake. Among young adults, current vegetarians were less likely to be overweight or obese.
However, adolescent and young adult vegetarians were also more likely to report binge eating with loss of control compared to non-vegetarians. Among adolescents, former vegetarians were more likely to engage in extreme unhealthful weight-control behaviors. And among young adults, former vegetarians were more likely to engage in extreme unhealthful weight-control behaviors than people who either were currently vegetarians or had never followed a vegetarian eating plan.
Examples of extreme unhealthful weight-control behaviors included “took diet pills,” “made myself vomit,” “used laxatives” and “used diuretics.”
The researchers conclude: “Adolescent and young adult vegetarians may experience the health benefits associated with increased fruit and vegetable intake and young adults attain the added benefit of decreased risk for overweight and obesity. However, vegetarians may be at increased risk for disordered eating behaviors, such as binge eating and unhealthful weight-control behaviors.
“Study results indicate that it would be beneficial for clinicians to ask adolescents and young adults about their current and former vegetarian status when assessing risk for disordered eating behaviors. Furthermore, when guiding adolescent and young adult vegetarians in proper nutrition and meal planning it may also be important to investigate an individual's motives for choosing a vegetarian diet.”
Source: Journal of the American Dietetic Association