Friday, September 18, 2009

FitBits - Fitness News You Can Use

Good research.

American Heart Association Reignites the Fat vs. Carbohydrate Debate

In the September edition of Circulation, the American Heart Association published its first aggressive position stand on the role of sugar in the development of heart disease. Although previous publications encouraged Americans to moderate sugar consumption this is the first time the AHA has taken the position that excess sugar consumption could lead to heart disease.

According to the paper, it is now advised that women consume less than 25 grams or 100 calories of added or processed sugar daily, while intakes for men should remain below 37.5 grams or 150 calories daily. At first glance, this might appear higher than what is desirable for optimal health. However, when you consider that the average American consumes over 90 grams of sugar or 355 calories a day it is definitely a move in the right direction.

Through this position stand, the American Heart Association is primarily targeting the soft drink and beverage industry. The report claims that 1/2 of the 150-300 calorie per day increase in total caloric intake that has occurred since the 1980's is due to calorie-laced beverages.

Although the food and beverage industry refutes these claims, instead arguing that a lack of physical exercise causes obesity, their position has now been considerably weakened. Interestingly, researchers along with the AHA continue to avoid stating a direct link for sugar to heart disease and obesity. Instead, they point to the secondary effects of consuming calorie-laced beverages, which include increased overall calorie intake, greater body mass, and displacement of essential nutrients.

This position paper is sure to re-ignite the 1/2 century-old debate over which food substrate has the greatest influence over the development of cardiovascular disease, fat or sugar. Come along for the ride!

Johnson, R.K., et al (2009) Dietary Sugars Intake and Cardiovascular Health: A Scientific Statement from the American Heart Association. Circulation. 120:1011-1020.

Fat Gain May Cause
Brain Shrinkage

If you needed another reason to lose weight, scientists have just uncovered something that might be of interest. Researchers at UCLA recently reported that body fat may be inversely related to brain size.

According to a Healthday interview with lead scientist Paul Thompson, being overweight or obese ages the brain by 8 to 16 years, respectively. Moreover, the areas of the brain most affected by excess body fat are the frontal and temporal lobes. The frontal lobe is responsible for everything from problem solving ability to memory, impulse control and social behaviors whereas the temporal lobe coordinates both visual and auditory information. Increased degeneration of these areas has been suggested to lead to Alzheimer's disease.

To make the above determinations brain images from 94 elderly adults were studied. The individuals were then followed for five years. The brains of obese participants were 8% smaller than those of normal-weight participants, whereas overweight participants had 4% less brain tissue.

Although a cause-and-effect relationship could not be determined from this study, the researchers suggest that it could be a result of poor nutrient delivery to the brain in obese individuals. If this is the case, exercise, which increases nutrient delivery throughout the body, might play an important role in preventing the loss of brain tissue in overweight and obese.

HealthyDay News (2009) As Waistlines Widen, Brains Shrink. Wednesday, August, 26.

Yoga Improves
Back Pain Outcomes

With more than 200 million Americans potentially suffering bouts of chronic back pain, simple cost-effective treatment programs are necessary to improve outcomes. Yoga has been studied previously as one such solution, although it has produced mixed outcomes. Most recently, a study published in the journal Spine optimistically reported that Iyengar Yoga improved the symptoms of chronic back pain suffers. Iyengar Yoga is known for its more progressive nature and adaptability to special needs.

Researchers divided ninety participants into yoga and control groups, which were provided typical medical care for their symptoms. The yoga group participated in 6 months of Iyengar yoga classes twice weekly. Information was collected at baseline, following 12 and 24 weeks, in addition to a 6-month follow-up. Researchers incorporated a variety of questionnaires to determine the outcomes.

Following the intervention researchers reported significantly greater improvements among participants in the yoga program compared to controls. For example, there was less disability in the yoga group, the self-reported pain intensity was lower among yoga participants, and mental wellbeing was improved in the yoga group.

Although there were greater improvements among the yoga participants, the use of pain medications was not different between groups after 24 weeks. However, there was a reduction for both groups. Benefits appeared to be sustained at the 6-month follow-up although there was a slight trend toward regression.

A variety of treatments currently exist for chronic back pain sufferers. Iyengar Yoga is a relatively inexpensive activity that, when used consistently may provide cost-effective pain-relief.

Williams, K. et al (2009) Evaluation of the Effectiveness and Efficacy of Iyengar Yoga Therapy on Chronic Low Back Pain. Spine. 34(19): 2066-2076.

Strong Quads Mean
Less Knee Pain Arthritis

The management of osteoarthritis (OA) represents one of the biggest medical challenges of the 21st century. A condition that mostly affects people over age 45, OA or degenerative joint disease is on of the most frequent causes of disability in American adults. OA primarily affects the load-bearing joints of the body as a consequence of genetics, aging, and abuse or overuse. Some researchers speculate that muscle imbalances, which modify how a joint articulates, may also be responsible.

In a study published this month in Arthritis & Rheumatism, researchers reported that quadriceps or knee extensor strength is linked to the onset of symptomatic OA, but the balance between the hamstring and quadriceps is not predicative of OA.

As part of the Multicenter Osteoarthritis Study (MOST), researchers tracked radiographic and symptomatic changes in the knees of 1617 and 2078 participants, respectively. No degenerative changes were present in radiographic imaging at baseline, and all participants were asymptomatic, indicating that none of the participants had OA.

After 30 months, 131 participants had developed incident radiographic OA, 48 men and 93 women. Moreover, 310 knees had developed symptomatic OA, 201 in women and 109 in men.

The researchers found that knee extensor strength was 2.3% greater for women and 6.2% greater for men that did NOT develop radiographic OA. Similarly, those who were asymptomatic after 30 months had ~12% greater knee extensor strength than those who developed symptomatic OA.

Although the quadriceps is not the only muscle group that can affect the articulation of the knee it would appear pertinent that emphasizing strong thighs among men and women over 45 is desirable to maintain pain-free knees.

Walsh, Nancy (2009) Strong Thighs Protect Against Symptoms of OA. Medpage Today. August 27.

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