Obesity is increasing in epidemic proportions in most countries and poses a public health problem by enhancing the risks for cardiovascular diseases and metabolic disorders such as type 2 diabetes. According to the Centers for Disease Control and Prevention, the prevalence of overweight and obesity has increased sharply for both adults and children since the 1970s. Data from two National Health and Nutrition Examination surveys show that among adults aged 20-74 years the prevalence of obesity increased from 15 percent (in the 1976-80 survey) to 32.9 percent (in the 2003-04 survey).

The two surveys also show increases in overweight children and teens. For children aged 2-5 years, the prevalence increased from 5 percent to 13.9 percent; for those aged 6-11 years, prevalence increased from 6.5 percent to 18.8 percent; and for those aged 12-19 years, prevalence increased from 5 percent to 17.4 percent.

In a new study discussed in Nature, a team has found that there is a direct correlation between the measures of fat mass (measured from body mass index (BMI) and fat cell volume in subcutaneous fat, which represents about 80 percent of all fat, and visceral fat.

Women who breast feed for longer have a smaller chance of getting rheumatoid arthritis, suggests a study published online ahead of print in the Annals of the Rheumatic Diseases.

The study also found that taking oral contraceptives, which are suspected to protect against the disease because they contain hormones that are raised in pregnancy, did not have the same effect. Also, simply having children and not breast feeding also did not seem to be protective.

The researchers compared 136 women with rheumatoid arthritis with 544 women of a similar age without the disease. They found that that those who had breast fed for longer were much less likely to get rheumatoid arthritis.

Being obese can increase the risk of Alzheimer’s Disease by as much as 80 percent, according to a study in the May issue of Obesity Reviews. But it's not just weight gain that poses a risk. People who are underweight also have an elevated risk of dementia, unlike people who are normal weight or overweight.

US researchers carried out a detailed review of 10 international studies published since 1995, covering just over 37,000 people, including 2,534 with various forms of dementia. Subjects were aged between 40 and 80 years when the studies started, with follow-up periods ranging from three to 36 years.

The review, which included studies from the USA, France, Finland, Sweden and Japan, also included a sophisticated meta-analysis of seven of the studies, published between 2003 and 2007 with a follow-up period of at least five years.

A new approach to estimating tumor growth based on breast screening results from almost 400,000 women is published today in Breast Cancer Research. This new model can also estimate the proportion of breast cancers which are detected at screening (screen test sensitivity). It provides a new approach to simultaneously estimating the growth rate of breast cancer and the ability of mammography screening to detect tumors.

The results of the study show that tumor growth rates vary considerably among patients, with generally slower growth rates with increasing age at diagnosis. Understanding how tumours grow is important in the planning and evaluation of screening programs, clinical trials, and epidemiological studies. However, studies of tumour growth rates in people have so far been based mainly on small and selected samples.

Children who speak a second or third language may have an unexpected advantage later in life, a new Tel Aviv University study has found. Knowing and speaking many languages may protect the brain against the effects of aging.

Dr. Gitit Kavé, a clinical neuro-psychologist from the Herczeg Institute on Aging at Tel Aviv University, together with her colleagues Nitza Eyal, Aviva Shorek, and Jiska Cohen-Manfield, discovered recently that senior citizens who speak more languages test for better cognitive functioning. The results of her study were published in the journal Psychology and Aging.

However, Kavé says that one should approach these findings with caution. “There is no sure-fire recipe for avoiding the pitfalls of mental aging. But using a second or third language may help prolong the good years,” she advises.

A common weedkiller in the U.S., atrazine, already suspected of causing sexual abnormalities in frogs and fish, has now been found to alter hormonal signaling in human cells, scientists from the University of California San Francisco (UCSF) report.

Atrazine is the second most widely used weedkiller in the U.S., applied to corn and sorghum fields throughout the Midwest and also spread on suburban lawns and gardens. It was banned in Europe after studies linked the chemical to endocrine disruptions in fish and amphibians.

In studies with human placental cells in culture, the UCSF scientists found that atrazine increased the activity of a gene associated with abnormal human birth weight when over-expressed in the placenta. Atrazine also targeted a second gene that has been found to be amplified in the uterus of women with unexplained infertility.

More and more U.S. college students are smoking tobacco using hookahs, a kind of water pipe, and it’s becoming a growing public health issue, according to a new study led by a Virginia Commonwealth University researcher.

In a hookah, tobacco is heated by charcoal, and the resulting smoke is passed through a water-filled chamber, cooling the smoke before it reaches the smoker. Some waterpipe users perceive this method of smoking tobacco as less harmful and addictive than cigarette smoking.

Principal investigator Thomas Eissenberg, Ph.D., associate professor in the VCU Department of Psychology, notes that current and prospective waterpipe tobacco smokers should be made aware that waterpipe tobacco smoking is not as benign as they might think. Waterpipe and cigarette smoke contains some of the same toxins -- disease-causing tar and carbon monoxide, as well as dependence-producing nicotine. Additionally, the exposure to these toxins through waterpipe smoking may be greater due to longer periods of use.

A review of scientific data in CMAJ (Canadian Medical Association Journal) finds that, in some cases, stun guns may stimulate the heart in experimental models. This evidence is contrary to current views that stun guns only affect skeletal muscles.

Dr. K. Nanthakumar and colleagues point out that most theoretical and some experimental studies reveal that cardiac stimulation does not occur with stun gun discharges. However, experimental studies on pigs by 3 independent groups of investigators found that “a stun gun discharge can stimulate the heart” depending on the location of the stun gun barbs. Barbs that are located such that they form a vector across the heart have greater effect than those focused on the abdomen.

The researchers caution against applying data from pigs to humans, although “most of the basic mechanistic concepts in cardiac fibrillation and defibrillation are derived from animal studies, not humans.”

Researchers at McGill University and the McGill University Health Centre (MUHC) have performed the world’s first totally automated administration of an anesthetic.

Nicknamed “McSleepy,” the new system developed by the researchers administers drugs for general anesthesia and monitors their separate effects completely automatically, with no manual intervention.

The anesthetic technique was used on a patient who underwent a partial nephrectomy, a procedure that removes a kidney tumor while leaving the non-cancerous part of the kidney intact, over a period of 3 hours and 30 minutes. To manipulate the various components of general anesthesia, the automated system measures three separate parameters displayed on a new Integrated monitor of anesthesia (IMATM): depth of hypnosis via EEG analysis, pain via a new pain score, called AnalgoscoreTM, and muscle relaxation via phonomyographyTM, all developed by ITAG. The system then administers the appropriate drugs using conventional infusion pumps, controlled by a laptop computer on which “McSleepy” is installed.

The electromagnetic fields produced by incubators alter newborns’ heart rates, says a small study published in the Fetal and Neonatal Edition of Archives of Disease in Childhood.