Healthy Heart Beats

October-December 2007
Vol 29, Issue 4

Nutrition and Research Updates

Counseling on Healthy Dietary Fats Helps Kids Reduce Cholesterol

Help Kids Reduce Cholesterol Children who received special counseling on dietary fat had lower cholesterol levels than children who didn't receive counseling, according to a recent study published in Circulation: Journal of the American Heart Association. Finnish researchers compared 540 children assigned to a dietary counseling group (starting at 7 months of age) to 522 children who did not receive special diet advice. At age 14, the dietary counseling group had a lower median cholesterol level which was statistically significant by a small margin. This finding could positively impact future efforts to encourage heart-healthy lifestyle changes.

"In the long run, even a minor decrease in serum cholesterol concentrations in a large population can have a major influence on coronary heart disease," said Harri Niinikoski, M.D., Ph.D., lead author of the study and a pediatric endocrinologist at the University of Turku in Finland. Studies have shown that high blood levels of total cholesterol and low-density lipoprotein (LDL, or "bad" cholesterol) in childhood predispose a person to early atherosclerotic changes in the large arteries, which increases the risk of early heart attack and stroke.

Source: http://www.americanheart.org/presenter.jhtml?identifier=3049564 (August)

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'Pot' Belly is an Indicator of Future Heart Disease

University of Texas researchers report that having a "pot" belly (or a high waist-to-hip ratio) is linked to early signs of heart disease. In a study of 2,744 Dallas residents, researchers used different measures of obesity: body mass index (BMI), waist circumference (WC) and waist-to-hip-ratio (WHR) as assessment tools. They assessed how these measurements were associated with coronary artery calcium and aortic plaque which are early indicators of atherosclerosis (hardening of the arteries). They found that WHR was more closely linked to increased calcium and plaque than BMI or WC suggesting that obesity contributes to cardiovascular mortality due to increased atherosclerosis.

"Fat that accumulates around your waist seems to be more biologically active as it secretes inflammatory proteins that contribute to atherosclerotic plaque build-up, whereas fat around your hips doesn't appear to increase risk for cardiovascular disease at all. We think the key message for people is to prevent accumulation of central fat early on in their lives," said James A. De Lemos, M.D., a professor of medicine at the University of Texas Southwestern Medical Center.

Source: Journal of the American College of Cardiology, 2007, 50(8):752-759 (August)

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Healthier Foods do not Prevent Harmful Effects of Fast Food

Recent research suggests that a single fast-food meal impairs endothelial function, a key marker for cardiovascular disease, according to lead investigator, Dr. Tanja K. Rudolph, University Hospital Hamburg-Eppendorf, Germany. Rudolph and colleagues measured the initial endothelial function and other markers of cardiovascular disease in 24 healthy volunteers. The 14 women and 10 men ate one of three readily available fast food meals during one week, a different meal the second week and the remaining meal the third week. Unexpectedly, the researchers found that endothelial function was adversely affected within 2 and 4 hours after eating each of the three meals, with no statistically significant differences among them. Furthermore, all three meals had a negative impact on other cardiovascular disease markers as well, Rudolph said. "When we planned the study, our hypothesis was that "healthy" components like orange juice or salad would be able to prevent impairment of endothelial function," Rudolph noted, "But we could not show this. You cannot prevent the harmful effects of fast food to the vascular system if you only add 'healthy components,"' Rudolph concluded.

Source: The American Journal of Clinical Nutrition, 2007, 86 (2):334-340 (August)

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Physical Activity and Public Health in Older Adults

A panel of scientists with expertise in public health, behavioral science, epidemiology, exercise science, medicine, and gerontology recently updated recommendations on the types and amounts of physical activity needed to improve and maintain health in older adults, aged 65 and older. The recommendation for older adults is similar to the Updated Recommendation from the American College of Sports Medicine (ACSM) and the American Heart Association (AHA) for Adults first published in 1995. The new recommendations emphasize the following key points:

The recommended intensity of aerobic activity takes into account the older adult's aerobic fitness.
Activities that maintain or increase flexibility are recommended.
Balance exercises are recommended for older adults at risk of falls.

In addition, it's recommended that older adults should have an activity plan for achieving physical activity that integrates preventive and therapeutic recommendations. The promotion of physical activity in older adults should emphasize moderate-intensity aerobic activity, muscle-strengthening activity, reducing sedentary behavior, and risk management.

physical activity in older adults "I think if you look back during the last ten years or so, there have been some misconceptions about exercise, especially as it relates to health and the specific benefits to the heart," according to Dr. Jennifer Mieres at the New York University School of Medicine and spokesperson for the AHA. "The new guidelines give a very good definition of what constitutes physical activity, as well as the benefits that this exercise can bring about. The guidelines also give a much better roadmap in terms of fitting exercise into our daily lives."

Source: http://circ.ahajournals.org/cgi/reprint/CIRCULATIONAHA.107.185650v1.pdf (August).

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Diet Foods May Contribute to Childhood Obesity

Researchers have reported a link between childhood obesity involving early learning about the taste of food and its caloric content. Children who have been conditioned to eat low calorie foods that are normally high in calories tend to overeat when low-calorie foods and drinks are served to them on a regular basis.

"Based on what we've learned, it is better for children to eat healthy, well-balanced diets with sufficient calories for their daily activities rather than low-calorie snacks or meals," said Dr. David Pierce, a University of Alberta sociologist and lead author of the paper. "One thing is clear at this point. Our research has shown that young animals can be made to overeat when low-calorie foods and drinks are given to them on a daily basis, and this subverts their bodies' energy-balance system," Pierce said.

The researchers used young rats in a series of elaborate experiments in which they substituted low-calorie versions of foods and drinks and observed overeating as a result, including both young rats that were lean as well as those who were genetically obese. This same observation did not prove to be true for adolescent rats.

Pierce added that his team's "taste conditioning process" theory may explain "puzzling results" from other studies, such as a recent one from researchers at the University of Massachusetts, who found links between diet soda consumption (among children) and a higher risk of obesity, diabetes and heart disease, but further research is necessary with older animals using a variety of taste-related cues.

Source: Obesity, 2007, 15(8):1969-1979 (August)

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Metabolic Syndrome Linked to Soft Drink Consumption

Though consumption of soft drinks has been linked to obesity in children and adolescents this research reports the incidence of metabolic syndrome and its components has been linked to soft drink consumption in adults. Over 6,000 adults in the Framingham Heart Study with a mean age of 52.9 years were pre-screened for the existence of the incidence of metabolic syndrome. Adjustments were made for age, sex, physical activity, smoking, dietary intake of saturated fat, trans fat, fiber, magnesium, total calories, and glycemic index. Researchers then examined the relationship of the incidence of metabolic syndrome to the consumption of soft drinks. The study concluded that in middle-aged adults, soft drink consumption as low as one soft drink per day was associated with a higher prevalence and incidence of multiple metabolic risk factors including obesity, increased waist circumference, impaired fasting glucose, higher blood pressure, hypertriglyceridemia, and low high-density lipoprotein cholesterol.