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RESEARCH ETHICS By Kristie Sullivan, M.P.H.
ADVANCES IN NEUROSCIENCES RESEARCH
This year has already brought major breakthroughs in the use of human cells to study a range of neurological and psychiatric diseases. These new methods are more ethical and more efficient than tests in animals and signify a new avenue of scientific inquiry focused on the human condition.
Genetic Parkinson’s Brain Cells Made in Lab
Scientists at SUNY Buffalo have created neurons that develop genetically caused Parkinson’s disease. One in 10 patients with Parkinson’s disease has a mutation in the “parkin” gene, and by taking skin cells from patients with this mutation, scientists can see how these cells differ from nongenetic Parkinson’s. This is impossible in animals, because animals with a mutated “parkin” gene do not develop Parkinson’s disease. Using this new approach, scientists have already been able to show that changing the gene back to its normal form reverses neuron degeneration.
Jiang H, Ren Y, Yuen EY, et al. Parkin controls dopamine utilization in human midbrain dopaminergic neurons derived from induced pluripotent stem cells. Nature Communications. 2012;3. doi:10.1038/ncomms1669.
Human Cells Could Revolutionize Mental Illness Research
Researchers in Scotland are beginning a project to grow neurons from the skin cells of people with mental illnesses such as bipolar disorder and schizophrenia, or from unaffected people with a family history of these diseases. Too few effective treatments have been developed for these illnesses, but by studying neurons grown in the laboratory, the investigators hope to find new approaches.
Edinburgh scientists grow human brain cells to study mental illness. BBC. February 29, 2012. Available at: http://www.bbc.co.uk/news/uk-scotland-17204910. Accessed March 6, 2012.
Scientists Grow Alzheimer’s Cells
Research teams at the University of Cambridge and the San Diego School of Medicine at the University of California have created Alzheimer’s brain cells using stem cell technology. The scientists convert skin cells taken from patients at high risk for developing Alzheimer’s disease to stem cells, which are then developed into neurons in the laboratory. The cells go on to develop characteristics of brain cells of patients with Alzheimer’s disease. Watching these cells over time allows the researchers to study disease progression and test treatments in real time. This approach has the potential to speed research, which has been hampered by approaches using animals, since no nonhuman animals develop Alzheimer’s.
Israel MA, Yuan SH, Bardy C, et al. Probing sporadic and familial Alzheimer’s disease using induced pluripotent stem cells. Nature. 2012;482:216-220. doi:10.1038/nature10821.
Shi Y, Kirwan P, Smith J, et al. A human stem cell model of early Alzheimer’s disease pathology in down syndrome. Sci. Transl. Med. 2012. doi: 10.1126/scitranslmed.3003771.
NUTRITION by Susan Levin, M.S., R.D.
Vegetarian Diets Improve Mood and Reduce Stress
Vegetarian diets improve mood and reduce stress, according to a new study in Nutrition Journal. Researchers asked 39 meat-eaters to begin one of three different diets—a vegetarian diet, a meat-based diet, or a meat-and-fish-based diet. They found that after just two weeks, vegetarians scored significantly better on standardized mood and stress tests. The mood tests measured depression, anxiety, and stress. The vegetarians consumed less eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), animal sources of omega-3 fatty acids, and less arachidonic acid, an animal source of omega-6 fatty acids.
Beezhold BL, Johnston CS. Restriction of meat, fish, and poultry in omnivores improves mood: a pilot randomized controlled trial. Nutr J. 2012;11:9.
Processed Meat Linked to Diabetes in Native Americans
Processed meat consumption increases Native Americans’ risk of diabetes, according to a new study in the American Journal of Clinical Nutrition. Researchers followed more than 2,000 Native Americans living in the Southwestern United States. All were free of diabetes at the beginning of the study, but those who ate processed meat (e.g., sausage, bacon) were more likely to develop diabetes over a five-year period. The association was particularly strong with Spam.
Fifty percent of Native Americans develop diabetes by age 55. Many have limited access to healthful foods and may depend on the USDA commodity foods program, which includes processed meats.
PCRM has developed a six-session diabetes education and cooking skills curriculum for Native American communities that has been successfully piloted in New Mexico and Arizona, and was presented in an educational session at the 2011 Annual Meeting of the American Association of Diabetes Educators.
Fretts AM, Howard BV, McKnight B, et al. Associations of processed meat and unprocessed red meat intake with incident diabetes: the Strong Heart Family Study. Am J Clin Nutr. Published ahead of print Jan 25, 2012.
Red Meat Intake Linked to Kidney Cancer
The risk of kidney cancer appears to be increased by eating red meat and grilled and pan-fried foods. The authors of a new study in the American Journal of Clinical Nutrition tracked approximately one-half million men and women in the NIH-AARP Diet and Health Study. Those who ate the most meat, around 4.5 ounces of red meat per day (about the size of an average hamburger), had a higher risk of kidney cancer.
Daniel CR, Cross AJ, Graubard BI, et al. Large prospective investigation of meat intake, related mutagens, and risk of renal cell carcinoma. Am J Clin Nutr. 2012;1:155-162.
Dietary Fiber from Whole Grains Cuts Colorectal Cancer Risk
Whole grains reduce the risk of colorectal cancer, according to a study in the British Medical Journal. People who eat three servings of whole grains each day could decrease their risk by 17 percent. One serving of whole grains corresponds to one slice of whole grain bread, one-half cup of oatmeal, or one-half cup of brown rice. Whole grains contain fiber that moves intestinal contents along more quickly, dilutes carcinogens, and fosters good bacteria that protect digestive tract health.
Aune D, Chan DS, Lau R, et al. Dietary fibre, whole grains, and risk of colorectal cancer: systematic review and dose-response meta-analysis of prospective studies. BMJ. 2011;343:d6617.