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NONANIMAL RESEARCH METHODS
“Lung-on-a-Chip” Fights Human Disease
A memory-stick-sized polymer chip called “Lung-on-a-Chip” is designed to simulate the human lung and replace animals who are exposed to toxic airborne substances in inhalation toxicity tests. The chip is lined with hollow channels where researchers grow human lung cells that are exposed to airborne substances to test for toxicity.
Scientists from Harvard’s Wyss Institute for Biologically Inspired Engineering are now adapting the chip they created in 2010 to develop models of human lung diseases such as pulmonary edema, a condition characterized by fluid leakage in the lung tissue, and then treating the condition with investigational drugs.
“We learned more about the mechanisms by which this [fluid leakage] happens. That really wouldn’t have been possible through an animal model,” said Geraldine Hamilton, a senior scientist at Wyss.
“Lung-on-a-Chip” is part of a larger multimillion-dollar “human-on-a-chip” project funded by the National Institutes of Health, the Food and Drug Administration, and the Defense Advance Research Projects Agency.
Federal Government Paves Way for Reducing Animal Tests
The federal government’s Consumer Product Safety Commission has updated product-testing regulations with provisions to reduce animal testing.
Following input by PCRM and consumer groups, CPSC’s updated regulations indicate that human data from either human-based cell tests or clinical data are preferable to animal-tested data. Regulations also recommend that companies make every effort to avoid animal testing if sufficient information can be obtained without such tests. At PCRM’s urging, CPSC detailed all of the methods companies can use to gather information without animals, including “...in vitro, in silico, WOE analysis, QSAR, physicochemical properties, and chemical reactivity data.” Although CPSC cannot require testing, its recommendations are usually followed by most producers of chemical-containing consumer products.
The new regulations establish a website that details CPSC-approved methods that replace animal tests or use fewer animals. The regulations also indicate that methods that have not been expressly approved by CPSC—but have been approved by other regulatory bodies throughout the world—may be acceptable. Regulatory agencies such as the European Centre for the Validation of Alternative Methods have validated more methods than U.S. regulators.
Consumer Product Safety Commission: Codification of Animal Testing Policy (Final Rule). Federal Register 77:237 (December 10, 2012) p. 73286. Available at: http://www.cpsc.gov/BUSINFO/frnotices/fr13/animaltestfinalfr.pdf. Accessed December 20, 2012.
Vegetarians Live Longer
Vegetarian diets can extend life expectancy, according to early findings from the Adventist Health Study-2. Vegetarian men live to an average of 83.3 years, compared with nonvegetarian men who live to an average of 73.8 years. And vegetarian women live to an average of 85.7 years, which is 6.1 years longer than nonvegetarian women. This study is ongoing and includes more than 96,000 participants. The results further indicate vegan diets to be healthful and associated with a lower body weight (on average 30 pounds lower than that of meat eaters), and lower risk of diabetes, compared with diets that include animal products.
Fraser G, Haddad E. Hot Topic: Vegetarianism, Mortality and Metabolic Risk: The New Adventist Health Study. Report presented at: Academy of Nutrition and Dietetics (Food and Nutrition Conference) Annual Meeting; Oct. 7, 2012: Philadelphia, PA.
Excess Weight Increases Risk of Colon Cancer
Excess weight increases risk for colon cancer, especially among men, according to a new study published in the American Journal of Epidemiology. Researchers analyzed data from 324,524 men and women participating in the National Institutes of Health-AARP Diet and Health Study. These findings are consistent with a meta-analysis of 29 other studies which found a positive association between body weight and colon cancer risk for both men and women.
Renehan AG, Flood A, Adams KF, et al. Body mass index at different adults ages, weight change, and colorectal cancer risk in the National Institutes of Health-AARP cohort. Am J Epidemiol. 2012;176:1130-1140.
Renehan AG, Tyson M, Egger M, et al. Body-mass index and incidence of cancer: a systematic review and meta-analysis of prospective observational studies. Lancet. 2008;37:569-578.
Cutting Fatty Foods Helps You Lose Weight
Diets lower in total fat led to lower total body weights, compared with diets higher in fat, according to a new review published in the British Medical Journal. Researchers analyzed 43 studies with more than 180,000 participants from developed countries and determined that the lower the fat intake, the lower the body mass index (a measure of body weight adjusted for height), the smaller the waist size, and the greater the weight loss. Lower fat intake was also associated with lower levels of total cholesterol, LDL cholesterol, and blood pressure.
Hooper L, Abdelhamid A, Moore HF, Douthwaite W, Skeaff CM, Summerbell CD. Effect of reducing total fat intake on body weight: systematic review and meta-analysis of randomized controlled trials and cohort studies. BMJ. Published online Dec. 6, 2012.
Vegan Diets Have Lower Cancer Risk
Vegan diets are linked to a lower overall cancer rate, according to a new study published in the journal Cancer Epidemiology, Biomarkers and Prevention. The diets of 69,120 participants from the Adventist Health Study-2 were tracked for more than four years. Dietary patterns were divided into five categories: nonvegetarians, semivegetarians, lacto-vegetarians (consume dairy products and eggs), pesco-vegetarians (consume dairy, eggs, and fish), and vegans. Vegans had a 16 percent decreased risk of all cancers, and vegan women had a 34 percent decreased risk for other specific cancers including breast, ovarian, and uterine cancers, compared with nonvegetarians.
Tantamango-Bartley Y, Jaceldo-Siegl K, Fan J, Fraser G. Vegetarian diets and the incidence of cancer in a low-risk population. Cancer Epidemiol Biomarkers Prev. Published ahead of print Nov. 20, 2012.