undergoing chelation therapy can be attributed to the placebo effect and generally recommended lifestyle changes such as "quitting smoking, losing weight, eating more fruits and vegetables, avoiding foods high in saturated fats and exercising regularly." they also are concerned that patients could put off proven treatments for heart disease like drugs or surgery. a systematic review published in 2005 found that controlled scientific studies did not support chelation therapy for heart disease. it found that very small trials and uncontrolled descriptive studies have reported benefits while larger controlled studies have found results no better than placebo. in 2009, the montana board of medical examiners issued a position paper concluding that "chelation therapy has no proven efficacy in the treatment of cardiovascular disease, and in some patients could be injurious." the u.s. national center for complementary and alternative medicine (nccam) conducted a trial on the chelation therapy's safety and efficacy for patients with coronary artery disease. nccam director stephen e. straus cited the "widespread use of chelation therapy in lieu of established therapies, the lack of adequate prior research to verify its safety and effectiveness, and the overall impact of coronary artery disease" as factors motivating the trial. the study has been criticized by some who said it was unethical, unnecessary and dangerous, and that multiple studies conducted prior to it demonstrated that the treatment provides no benefit. the us national center for complementary and alternative medicine began the trial to assess chelation therapy (tact) in 2003. patient enrollment was to be completed around july 2009 with final completion around july 2010, but enrollment in the trial was voluntarily suspended by organizers in september 2008 after the office for human research protections began investigating complaints such as inadequate informed consent. additionally, the trial was criticized for lacking prior phase i and ii studies, and critics summarized previous controlled trials as having "found no evidence that chelation is superior to placebo for treatment of cad or pvd." the same critics argued that methodological flaws and lack of prior probability made the trial "unethical, dangerous, pointless, and wasteful." the american college of cardiology supported the trial and research to explore whether chelation therapy was effective in treating heart disease. evidence of insurance fraud and other felony convictions among (chelation proponent) investigators further undermined the credibility of the trial. the final results of tact were published in november 2012. the authors concluded that disodium edta chelation "modestly" reduced the risk of adverse cardiovascular outcomes among stable patients with a history of myocardial infarction. the study also showed a "marked" reduction in cardiovascular events in diabetic patients treated with edta chelation. an editorial published in the journal of the american medical association said that "the study findings may provide novel hypotheses that merit further evaluation to help understand the pathophysiology of secondary prevention of vascular disease." critics of the study characterized the study as showing no support for the use of chelation therapy in coronary heart disease, particularly the claims to reduce the need for coronary artery bypass grafting (cabg, pronounced "cabbage"). autism main article: thiomersal controversy quackwatch says that autism is one of the conditions for which chelation therapy has been falsely promoted as effective, and practitioners falsify diagnoses of metal poisoning to trick parents into having their children undergo the risky process. as of 2008, up to 7% of children with autism worldwide had been subjected to chelation therapy. the death of two children in 2005 was caused by the administration of chelation treatments, according to the american center for disease control. one of them had autism. parents either have a doctor use a treatment for lead poisoning, or buy unregulated supplements, in particular dmsa and lipoic acid. aspies for freedom, an autism rights organization, considers this use of chelation therapy unethical and potentially dangerous. there is little to no credible scientific research that supports the use of chelation therapy for the effective treatment of autism.