A research review of current fitness news from Exercise Etc. - some good information here, especially on the topic of soy for women, one of my pet issues.
Can Watching Too Much TV
Cause Heart Disease?Most experts agree that watching too much television contributes to weight gain because it adds to sedentary time and potentially increases the likelihood of excessive snacking. A recent study has now linked TV time to the development of heart disease, irrespective of an individual’s daily physical activity level. This, according to a recent presentation at the American Heart Association’s Joint Conference on Nutrition, Physical Activity and Metabolism as reported by HealthDay.
The television viewing and physical activity habits of over 5,000 British men and women were assessed at age 23 and again at age 44. Researchers also measured triglycerides, HDL, LDL and total cholesterol, C-Reactive Protein, BMI, waist circumference and blood pressure.
After 21 years, the amount of television viewing was positively correlated with a greater risk of heart disease based on the measurements taken. Moreover, the risk remained even for individuals with higher physical activity levels. The more television one views, the greater his/her risk for heart disease even if he/she participates in some form of exercise.
According to researchers, as interviewed by HealthDay News, exercise cannot offset the effects of being sedentary. In addition, the increase in Heart Disease risk factors could be applied similarly to an increased risk for certain types of Cancer and Type II Diabetes.
Healthday News. (2010) You Can’t Exercise Away TV’s Toll on the Heart. March 3.
Lack of Sleep Leads to Fat Gain
The effects of sleep deprivation are slowly gaining attention amongst fitness and wellness professionals. Getting adequate sleep quantity and quality is not only essential to optimizing mental and physical recuperation, it may be essential to preventing obesity.
In a recent study published in the journal Sleep, researchers from Wake Forest University reported that getting less than 5 hours of sleep or more than 8 hours leads to increased intra-abdominal fat when compared to those who sleep for 6 or 7 hours.
More than 1,000 African- and Hispanic-Americans were interviewed to obtain information on sleep habits, nutrition, physical activity and lifestyle. They also participated in a CT scan, which was used to assess both visceral and subcutaneous abdominal fat. Baseline measurements were then compared to a re-assessment at 5 years.
Participants who slept less than 5 hours a night experienced a 32% increase in deep abdominal fat over 5 years, while those with averaged more than 8 hours of sleep increased by 22%. Subcutaneous abdominal fat increased similarly.
After factoring in lifestyle factors such as total calorie intake, education levels, physical activity and smoking, sleep duration persisted as an independent risk factor for increased abdominal adiposity, especially in participants under 40.
Researchers offer broad speculation to explain the cause and effect relationship of sleep to fat gain. The primary explanations involved increased daytime fatigue, which limits energy to participate in physical activity. In addition, some believe in the potential for sleep deprivation to inhibit appetite-suppressing hormones, thus leading to overeating.
Although this study replicates previous finding on sleep and abdominal fat, it is the first to assess this factor in minority populations.
Hairston, K.G., et al (2010) Sleep Duration and Five-Year Abdominal Fat Accumulation in a Minority Cohort: The IRAS Family Study. Sleep. 33(03): 289-295.
Amy Norton. (2010) Sleep habits linked to fat gain in younger adults. Reuters Health. March 1st.Rethinking the Role of
Soy After MenopauseSoy is commonly recommended to post-menopausal women for its estrogenic properties. Consequently, it is believed by some to potentially inhibit menopausal symptoms, reduce the risk of body fat gain, and improve heart disease risk in this population. Although previous studies may support such beliefs, two recent studies have reported that soy is ineffective.
Researchers studied the effects of soy isoflavones on the body composition of 229 post-menopausal non-obese women. Participants were randomly assigned to consume a once daily tablet that contained either 80 mg or 120 mg of soy isoflavone, or placebo for 12 months.
In addition to recording changes in body composition, appetite-controlling hormones such as insulin, leptin, ghrelin and adiponectin were assessed. Although the soy did significantly affect some hormones, researchers determined that only one factor influenced changes in body fat; the amount of dietary fat consumed. Hence, soy does not appear to have a significant impact on body fat.
In a second study published in the same journal, researchers determined that soy isoflavones did not improve the lipid profile in post-menopausal women with mildly high cholesterol. Sixty-two women were recruited to eat either soy-based foods or control-foods for 1 year.
After 12 months, participants on the soy-based diet saw slight increases in both total cholesterol and HDL cholesterol, but no changes in LDL or triglycerides were apparent. Because the changes did not achieve levels of significance it was determined that soy is not beneficial to reducing heart disease risk in post-menopausal women.
Although soy remains an adequate source of protein, there are definitive limitation to its use in the treatment of menopausal symptoms and consequences that include fat-weight gain and increased heart disease risk.
Oksana, M.A., et al (2010) Appetitive hormones, but not isoflavone tablets, influence overall and central adiposity in healthy postmenopausal women. Menopause. Epub ahead of print. February 5th.
Campbell, S.C., et al (2010) One-year soy protein supplementation does not improve lipid profile in postmenopausal women. Menopause. Epub ahead of print.
Is Endurance in the Genes?
Can you remember a time when knowing your true genetic potential seemed more like science fiction than science fact? Well, scientists are one step closer to being capable of predicting whether you should select endurance sports for your children and grandchildren. Researchers in Israel have uncovered a consistent genetic variance displayed by exceptional endurance athletes.
Variations in the NRF2 gene were evaluated and compared between more than 150 elite track athletes, both long-distance athletes and sprinters, and 240 non-athletic adults. The NRF2 gene has previously been found to play a role in mitochondrial biogenesis, or the production of mitochondria. Consequently, it may help moderate oxidative stress and reduce inflammation.
Researchers determined that the genetic variant was found in 80% of the elite endurance athletes, whereas only 46% of sprinters exhibited similar characteristics.
Although an exact understanding of how this particular gene affects endurance performance is not available, this information may eventually lead to the ability to predict athletic prowess. Moreover, according to researchers, we may truly be capable of knowing if we were "Born to Run."
Robert Preidt. (2010) Long-Distance Runners May Have Endurance in Their Genes. HealthDay News. February 18th.
Eynon. N., et al (2010) Interaction between SNPs in the NRF2 gene and elite endurance performance. Physiological Genomics. 41: 78-81
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