miércoles, 18 de febrero de 2015

Diet, exercise alone not sufficient obesity treatment for most

Researchers suggest that obesity is a chronic disease with a number of biological causes that make it impossible to be cured with diet and exercise alone in a recently published comment in The Lancet Diabetes & Endocrinology.

Eighty percent to 95% of people with obesity who lose weight eventually regain it. Several biological systems are triggered when caloric intake is reduced, which drives people to eat more high-calorie foods and, in turn, gain or regain weight. According to the researchers lifestyle changes are not enough to override the fat-loss defense for most individuals with sustained obesity.

“Although lifestyle modifications may result in lasing weight loss in individuals who are overweight, in those with sustained obesity, bodyweight seems to become biologically ‘stamped in’ and defended,” Christopher N. Ochner, PhD, assistant professor of pediatrics and psychiatry at Icahn School of Medicine at Mount Sinai and a research associate at the New York Obesity Nutrition Research Center at Columbia University Medical Center, said in a press release. “Therefore, the current advice to eat less and exercise more may be no more effective for most individuals with obesity than a recommendation to avoid sharp objects for someone bleeding profusely.”

Biological adaptations that occur with the development of obesity and undermine health weight loss effors can persist even in people who were are formerly obese and achieve a healthy bodyweight through dieting.
“Few individuals ever truly recover from obesity; rather they suffer from ‘obesity in remission,’” Ochner said in the press release. “They are biologically very different from individuals of the same age, sex and bodyweight who never had obesity.”
The researchers suggest that biological factors should be addressed to help sustain long-term weight loss, but current biologically-based interventions are limited to antiobesity drugs, weight loss surgery and intra-abdominal vagal nerve block. According to the researchers these interventions do not permanently correct the biological factors adaptations undermine healthy weight loss efforts. However, during use, the interventions alter neural or hormonal signaling associated with appetite, which can yield a 4% to 10% reduction in weight.
“Many clinicians are not aware of the reasons individuals with obesity struggle to achieve and maintain weight loss,” Ochner said. “Obesity should be recognized as a chronic and often treatment-resistant disease with both biological and behavioral causes that may require biologically-based interventions, such as pharmacotherapy or surgery, in addition to lifestyle modification. Ignoring the biological adaptations that undermine healthy weight loss efforts and continuing to rely solely on behavioral modification will surely result in the continued inability to treat obesity effectively and the premature deaths of millions of individuals each year.” 
Tomado de:Halo.org
Ochner CN, et al. Lancet Diabetes Endocrinol. 2015;doi:10.1016/S2213-8587(15)70010.

lunes, 16 de febrero de 2015

Cannabis: A new frontier in therapeutics

Wile debate about recreational marijuana use continues, researchers are investigating the effectiveness of cannabis for treating pain, spasticity, and a host of other medical problems. In a symposium organized by the McGill University Health Centre (MUHC) as part of the 2015 American Association for the Advancement of Science Annual Meeting held this week in San Jose, California,  experts from North America and the U.K. share their perspectives on the therapeutic potential of medical cannabis and explore the emerging science behind it.
"We need to advance our understanding of the role of cannabinoids in health and disease through research and education for patients, physicians and policy-makers," says Dr. Mark Ware, director of clinical research at the Alan Edwards Pain Management Unit at the MUHC, in Canada.
As a pain specialist Dr. Ware regularly sees patients with severe chronic pain at his clinic in Montreal, and for some of them, marijuana appears to be a credible option. "I don't think that every physician should prescribe medical cannabis, or that every patient can benefit but it's time to enhance our scientific knowledge base and have informed discussions with patients."
Increasing numbers of jurisdictions worldwide are allowing access to herbal cannabis, and a range of policy initiatives are emerging to regulate its production, distribution, and authorization. It is widely believed that there is little evidence to support the consideration of cannabis as a therapeutic agent. However, several medicines based on tetrahydrocannabinol (THC), the psychoactive ingredient of cannabis, have been approved as pharmaceutical drugs.
Leading British cannabis researcher Professor Roger Pertwee, who co-discovered the presence of tetrahydrocannabivarin (THCV) in cannabis in the 70's, recently published with collaborators some findings of potential therapeutic relevance in the British Journal of Pharmacology. "We observed that THCV, the non-psychoactive component of cannabis, produces anti-schizophrenic effects in a preclinical model of schizophrenia," says Pertwee, professor of Neuropharmacology at Aberdeen University. "This finding has revealed a new potential therapeutic use for this compound."
Neuropsychiatrist and Director of the Center for Medicinal Cannabis Research (CMCR) at the University of California, San Diego Dr. Igor Grant is interested in the short and long-term neuropsychiatric effects of marijuana use. The CMCR has overseen some of the most extensive research on the therapeutic effects of medical marijuana in the U.S. "Despite a commonly held view that cannabis use results in brain damage, meta analyses of extensive neurocognitive studies fail to demonstrate meaningful cognitive declines among recreational users," says Dr. Grant. "Bain imaging has produced variable results, with the best designed studies showing null findings."
Dr. Grant adds that while it is plausible to hypothesize that cannabis exposure in children and adolescents could impair brain development or predispose to mental illness, data from properly designed prospective studies is lacking.

Tomado de sciencedaily.com
FUente: McGill University Health Centre. (2015, February 15). Cannabis: A new frontier in therapeutics. ScienceDaily. Retrieved February 16, 2015 from www.sciencedaily.com/releases/2015/02/150215070209.htm