(PRWEB UK) 7 November 2013
Chemist Direct finds, according to the most comprehensive review on aspirin, that healthy people should not take aspirin to ward off heart attacks and cancer, as the risks outweigh the benefits.
Aspirin is extremely important for many people at high risk of a heart attack or stroke as it makes the blood less sticky so it reduces the odds of a blood clot forming inside the body, which could cause a heart attack or stroke. The possible benefits of a daily dose have been promoted as a primary prevention for people who are currently free of, but at risk of developing, cardiovascular disease or colorectal cancer. However, any such benefit needs to be balanced alongside a fuller understanding of the potentially harmful side effects such as bleeding and gastrointestinal problems. 1
A review, conducted by the research arm of the NHS, due to the growing debate about the necessity of those over 50 taking a daily low dose of aspirin, concluded it was a "fine balance" as the drug makes it harder for the blood to clot it can cause problems inside the body due to the dangers of bleeding in the brain and stomach. There are also studies which show small benefits in reducing cancer for those who take aspirin daily.
The reported benefits of taking aspirin each day ranged from 10% reduction in major cardiovascular events to a 15% drop in total coronary heart disease. In real terms, that would ultimately mean 33-46 fewer deaths per 100,000 patients taking the treatment. There was also evidence of a reported reduction in incidents of colorectal cancer, which showed from approximately five years after the start of treatment. This would equate to 34 fewer deaths from colorectal cancer per 100,000 patients. The adverse effects of aspirin were also noted with a 37% increase in gastrointestinal bleeding, an extra 68-117 occurrences per 100,000 patients, and between a 32%-38% increase in the likelihood of a haemorrhagic stroke which is an extra 8-10 occurrences per 100,000 patients. 2
A team at Warwick Medical School, and led by Prof Aileen Clarke, Professor of Public Health Research and Director of Warwick Evidence at Warwick Medical School,was asked to assess the evidence by the NHS National Institute for Health Research. For heart attacks and strokes, they concluded giving everyone aspirin would cause "net harm due to increased potential for bleeding". This was in part due to better management of at-risk patients including prescribing drugs to lower blood pressure. On cancer, they concluded the evidence was not strong enough to base a decision on, but trials taking place would give clearer proof in the next five years.
Aileen Clarke said, "This study looks deeper into the range of research on regular aspirin use than anything before, using more innovative methods, and it makes it clear that there is an incredibly fine balance between the possible benefits and risks of the intervention. We need to be extremely careful about over-promoting aspirin intervention without having first fully understood these negative side effects.
"There are a number of ongoing trials that will be completed in the coming six years which may help to clarify this further, including the impact of different dose regimens."
The paper, published by the National Institute for Health Research Health Technology Assessment (NIHR HTA) Programme, reviews the wealth of available randomised controlled trials (RCTs), systematic reviews and meta-analyses, allowing the team from Warwick Evidence to quantify those relative benefits and risks. 3