New study clarifies stroke risk from red meat consumption
A number of studies have been conducted regarding the stroke risk from red meat consumption; however the findings have been inconsistent. Therefore researchers at Warsaw University of Life Sciences–SGGW (Warsaw, Poland) and Karolinska Institutet (Stockholm, Sweden) conducted a meta-analysis to summarize the evidence regarding the effects of red meat (fresh, processed, and total) consumption on stroke risk. (A meta-analysis is a compilation of results from several studies to clarify the results.)
They published their findings July 31 in the journal Stroke.
The investigators searched the PubMed database through May 26, 2012 and retrieved relevant studies. Prospective (forward-looking) studies that reported relative risks (RR) with 95% confidence intervals (CI) for the association between red meat consumption and risk of stroke were included in the analysis.
The researchers identified five articles, which included results from six prospective studies; ultimately, 10,630 cases of stroke and 329,495 participants were included in the meta-analysis. The researchers found that for each serving per day increase in fresh red meat, processed meat, and total red meat consumption, the RR of total stroke were 1.11 (1.03–1.20) for fresh red meat, 1.13 (1.03–1.24) for processed meat, and 1.11 (1.06–1.16) for total red meat consumption. In addition, among four studies that provided information regarding stroke subtypes, the risk of ischemic stroke was positively associated with consumption of fresh red meat (RR: 1.13), processed meat (RR: 1.15), and total red meat (RR: 1.12).
However, the researchers found no statistically significant associations for hemorrhagic stroke. (An ischemic stroke is caused by blockage of a blood vessel; a hemorrhagic stroke is caused by a rupture of a blood vessel into surrounding brain tissue). In summary, each daily increase in a single serving of fresh, processed, and total red meat consumption was also associated with a 12% to 15% increased risk for ischemic stroke.
The authors concluded that the results from their meta-analysis indicate that consumption of fresh red meat and processed red meat as well as total red meat is associated with increased risk of total stroke and ischemic stroke; however, it is not related to hemorrhagic stroke.
Take home message:
This study adds clarification of the stroke risk from red meat and note that it is higher with processed meat compared to fresh meat. Processed meats contain nitrates and nitrites, which have are associated with cancer risk. They also have a high sodium content, which can increase blood pressure. Hypertension increases the risk of stroke. Both red and processed meat consumption has also been associated with an increased risk of colorectal cancer, stomach cancer, and possibly other cancers; in addition, they have been reported to increase the risk of type 2 diabetes.
The best course of action is to avoid red and processed meats and replace them with other protein-rich foods, such as poultry, seafood, and legumes. So the public health message is to reduce consumption of red meat, especially processed meats, and replace them with other protein-rich foods such as poultry, fish, and legumes. For die-hard red meat lovers, leaner cuts are preferable. For example, grass fed bison meat is healthier than meat from beef that have been fattened in feed lots before slaughter.