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1. [check mark] 4 Are there benefits to taking soy supplements?


2. [check mark] 4 Overweight Girls May Be at Risk for Early Puberty


3. [check mark] 4 The Science Behind Low-Carb Diets


Many Body-Conscious Teens Use Supplements to Improve Physique

A nationwide survey of more than 10,000 adolescents reports a high rate of concern about body image in both boys and girls. It finds that adolescents with such concerns are much more likely to use hormones and dietary supplements to enhance their physique than others. Moreover, adolescent supplement users appear to be heavily influenced by the media.


In this large population-based study to explore the use of hormones and supplements, body image, and media influences, 8% of all girls and 12% of all boys reported using products in the past year to improve their appearance, muscle mass, or strength. Nearly 5% of boys and 2% of girls used such products at least weekly. About 30% of both sexes reported thinking frequently about wanting more toned or defined muscles. After adjustment for other factors, boys with such thoughts were 60% more likely than their peers, and girls twice as likely, to use supplements at least weekly.


The most commonly used products were protein powders and shakes. Others that were popular mostly among boys, included creatine, amino acids, the amino-acid metabolite HMB, the hormone dehydroepiandrosterone (DHEA), growth hormone, and anabolic steroids.


Anabolic steroids have serious health effects, including testicular atrophy, impotence, liver and kidney damage, an increased risk for heart disease, and the widely reported "roid rage" (uncontrolled aggression). The safety of creatine, DHEA, and other products purported to increase muscle mass and tone has been questioned and is not well established.


The survey of adolescents aged 12 to 18 was done in 1999 as part of the Growing Up Today Study (GUTS), which involves children of nurses enrolled in the Nurses' Health Study based at Brigham and Women' Hospital.


Source: Pediatrics


Early Puberty a Concern for Overweight Girls

Overweight and obesity in young girls appears to speed puberty but girls who experience their first period at a relatively young age are not predisposed to become obese as adults. Girls who were overweight before their first menstrual periods were almost 8 times more likely to be overweight as women, the study found. But there was no link between precocious puberty alone and being overweight later in life.


The research, lead by Aviva Must from Tufts University, suggests that childhood obesity helps drive both early puberty and adult weight troubles. According to Must, for parents concerned about the potential for obesity in their daughter's future, the focus should be on the child being overweight rather than the timing of her first period.


The study defined early puberty as a first period before age 12. During the past 25 years, the average age for a girl's first period hasn't changed much, but it has creeped earlier by about 2.5 months.


Source: Pediatrics


New Report on Soy Finds Limited Evidence for Health Outcomes

Daily consumption of soy protein found in tofu and other soybean products may result in a small reduction in low-density lipoprotein (LDL, known as bad cholesterol) and triglyceride levels, according to a new evidence review supported by HHS' Agency for Healthcare Research and Quality. In addition, isoflavones found in soy may reduce the frequency of hot flashes in postmenopausal women. However, the available studies on the health impacts of soy were limited in number, of poor quality, or their duration was too short to lead to definite conclusions.


Overall, across the 68 studies that examined the impact of soy on cholesterol levels, consumption of soy products resulted in a 5-mg/dL (about 3%) reduction in LDL and an 8 mg/dL (about 6%) decrease in triglyceride levels in the populations studied. Among these studies, a large variety of soy products, doses of soy protein, and doses of soy isoflavones were tested. The average dose of soy protein in the studies was equivalent to about 1 pound of tofu or 3 soy shakes daily.


There was some indication that soy consumption may be more effective at lowering LDL among people with higher LDL levels. Also, larger amounts of soy protein, but not soy isoflavones, are more effective in people with abnormally elevated LDL levels. Similarly, soy consumption may be more effective at lowering triglycerides among people with higher triglyceride levels; however, there was no evidence of how much soy protein or isoflavones would be needed to affect triglycerides.


Reviews on the relationship between soy consumption and high-density lipoprotein (HDL, known as good cholesterol) levels and between soy consumption and blood pressure did not find significant effects. Among 21 studies evaluating the consumption of soy isoflavones for menopause-related symptoms, there was a net reduction in hot flash frequency ranging from 7% to 40%, however, these trials were mostly rated as poor quality. Among studies with statistically significant improvements in symptoms, the dose of soy isoflavones ranged from 17.5 to 100 mg/d.


The evidence review completed by AHRQ's Tufts-New England Medical Center Evidence-based Practice Center also found insufficient data among the 200 human studies examined as part of this analysis to suggest that soy had an effect on bone health, cancer, kidney disease, endocrine function, reproductive health, neurocognitive function, or glucose metabolism. A wide variety of soy products were studied, including foods such as soybeans, soy flour, soy milk, tofu, miso, tempeh, natto, and okara; isolated and textured soy protein that is added to foods; and soy-derived isoflavone supplements. Aside from minor gastrointestinal problems reported in some short-term studies, consumption of soy products by study participants was not associated with adverse events. However, long-term safety data are lacking.


Echinacea May Be Something to Sneeze At

New research finds that taking the popular herbal remedy echinacea does nothing to treat or prevent a cold. The federally funded study found that patients who took an echinacea plant extract fared no better than those who took a dummy treatment.


Echinacea, or purple coneflower, is sold over the counter in pills, drops, and lozenges. With reported annual sales of more than $300 million, echinacea is one of the most popular medicinal herbs used by people to treat colds. Several animal studies and small human trials have pointed to the possible benefit of the herb in preventing respiratory infections. However, one of largest studies--involving 407 children in 2003--found that echinacea failed to alleviate cold symptoms and even caused mild skin rashes in some cases.


In the newest experiment, researchers recruited 399 healthy patients who got one of three laboratory-made echinacea plant extracts or a dummy preparation. The patients were then exposed to the cold virus and their symptoms were evaluated. Scientists found no difference in infection rates between the groups who received the herb or placebo. About 90% in both groups wound up becoming infected. Signs and symptoms such as sneezing, runny noses, and sore throats were also about the same, with more than half in both groups showing classic signs of a clinical cold. The study was funded by the National Center for Complementary and Alternative Medicine, part of the federal National Institutes of Health.


Source: New England Journal of Medicine


Robotic Gastric Bypass Surgery Shows Promise

A system that allows surgeons to perform laparoscopic gastric bypass surgery from a remote console was successfully tested in 10 patients. The laparoscopic gastric bypass surgery (a Roux-en-Y procedure) is often considered the most challenging minimally invasive procedure in general surgery. It takes a learning curve based on 75 to 100 cases for even experienced surgeons to achieve the highest level of proficiency, according to background information in the article. The study reports the first 10 patients to undergo a totally robotic laparoscopic Roux-en-Y gastric bypass surgery (during March and April 2004) using a technique developed to minimize robot repositioning, which had been a problem in the past. Results were compared with a sample of 10 patients of similar general health, age, and body mass index who had undergone standard laparoscopic Roux-en-Y gastric bypass surgery during July to September 2002.


The number and severity of major and minor complication were comparable with both techniques. However, the researchers found the median length of time to complete the procedure was significantly shorter with the robot (169 vs. 208 minutes).


Source: Archives of Surgery


Added Calcium Benefits Women on the Pill

Women who take oral contraceptives can counteract bone loss by making sure they have enough calcium in their daily diet, especially early in life. According to a study done by Purdue University researchers it is estimated that 8 out of 10 women in the United States use oral contraceptives at some time during the years in which peak bone mass is developing.


The recommended dietary allowance of calcium for women age 19 to 50 is 1,000 milligrams a day. The Recommended Dietary Allowance of calcium for adolescents age 9 to 18 is 1,300 milligrams a day.


The study compared 135 oral contraceptive users to nonusers between the ages of 18 and 30. Three groups were randomized to receive one of three diets: control (less than 800 mg calcium a day), medium dairy (1,000-1,100 mg calcium a day), and high dairy (1,200-1,300 mg calcium a day). At the end of the year, women using oral contraceptives who consumed the medium- or high-dairy diet gained significantly more bone mineral density in their hips and spines compared to the low-dairy group.


The researchers suggest that many women who are using oral contraceptives in their peak bone-development years could reduce their risk of osteoporosis by approximately 3% to 10% over one year by making sure they get enough calcium in their diet.


Source: Journal of Clinical Endocrinology and Metabolism