The researchers found that consumption of both processed and unprocessed red meat was not associated with inflammatory markers, suggesting that body weight, rather than red meat, may be the factor causing the increase in disease
Inflammation is a risk factor for many chronic diseases, including cardiovascular disease, and the influence of diet on inflammation is an area of growing scientific interest. In particular, recommendations to limit red meat consumption are often based in part on older studies suggesting that red meat negatively affects inflammation More recent studies have not confirmed this.
“The role of diet, including red meat, in inflammation and disease risk has not been adequately studied, which may result in public health recommendations that are not based on convincing evidence,” said Dr. Alexis. Wood, associate professor of pediatrics – nutrition at the USDA/ARS Child Nutrition Research Center at Baylor College of Medicine and Texas Children’s Hospital. “Our team wanted to take a closer look by using data on blood metabolites that could provide a more direct link between diet and health.”
Wood and his team analyzed cross-sectional data from about 4,000 older adults participating in the Multi-Ethnic Study of Atherosclerosis (MESA) and recently published their findings in the American Journal of Clinical Nutrition. Cross-sectional data are a useful source of evidence on how diet affects health. They use data observed on people living freely without trying to influence their usual lifestyle. In this way, it may be easier to apply the results of these types of studies to settings outside of research. In addition to assessing self-reported food intake and several biomarkers, the researchers also measured a range of food intake metabolites in the blood. Plasma metabolites can help capture the effects of ingestion as food is processed, digested, and absorbed.
It’s about body weight, not meat
The researchers found that intake of processed and unprocessed red meat (beef, pork or lamb) was not directly associated with inflammatory markers after adjusting for body mass index (BMI), suggesting that body weight and not red meat Meat may be the factor causing increased systemic inflammation. Particularly interesting was the lack of association between red meat intake and C-reactive protein (CRP), the key inflammatory risk marker for chronic disease.
“Our analysis adds to the growing body of evidence indicating the importance of measuring plasma markers such as metabolites to track nutritional and disease risk associations, rather than relying solely on patients’ self-reported dietary intake,” says Wood . “Our analysis does not support the associations of previous observational studies linking red meat consumption and inflammation.”
Because observational studies cannot provide evidence of cause and effect, randomized controlled trials in which people are randomly assigned to consume or not consume a dietary factor of interest are needed as an additional line of evidence to adequately understand whether red meat does not alter inflammation. Several of these trials have shown that lean, unprocessed beef can be enjoyed as part of heart-healthy eating habits.
“We have reached a stage where further studies are needed before we can make recommendations to limit red meat consumption to reduce inflammation if we are to base dietary recommendations on the most current evidence,” Wood said. “Red meat is popular, accessible and appetizing and its place in our diet has deep cultural roots. Against this background, recommendations to reduce consumption should be supported by solid scientific evidence, which is not yet available.
Untargeted metabolomic analysis to examine associations between unprocessed red meat intake and inflammatory markers