Inflammation is emerging as a significant risk factor for various chronic illnesses, such as cardiovascular disease (CVD), and the relationship between nutrition and inflammation is becoming a subject of growing scientific interest. For instance, there are often suggestions to limit the intake of red meat, partly driven by earlier research indicating a detrimental impact of red meat on inflammation. However, it’s worth noting that recent studies have not consistently confirmed this association.
“The role of diet, including red meat, on inflammation and disease risk has not been adequately studied, which can lead to public health recommendations that are not based on strong evidence,” said Dr. Alexis Wood, associate professor of pediatrics – nutrition at the USDA/ARS Children’s Nutrition Research Center at Baylor College of Medicine and Texas Children’s Hospital.
“Our team sought to take a closer look by using metabolite data in the blood, which can provide a more direct link between diet and health.”
Wood and her colleagues conducted an analysis of cross-sectional data derived from approximately 4,000 older individuals who participated in the Multi-Ethnic Study of Atherosclerosis (MESA). Their findings have recently been published in The American Journal of Clinical Nutrition. Cross-sectional data serves as a valuable source of evidence for understanding the impact of nutrition on health because it involves information collected from individuals living their everyday lives without any attempts to modify their regular routines. Consequently, the insights from such studies may be more readily applicable to real-life, non-research settings. Additionally, the research encompassed self-reported dietary intake and a wide array of biomarkers, including various dietary intake metabolites in the bloodstream. The analysis of plasma metabolites can help in detecting the effects of dietary intake as it undergoes metabolism, digestion, and absorption.
In their study, scientists discovered that after accounting for body mass index (BMI), the consumption of both unprocessed and processed red meat (such as beef, pork, or lamb) did not exhibit a direct connection with any indicators of inflammation. This finding implies that it may be body weight, rather than red meat consumption, that serves as the primary factor influencing elevated systemic inflammation. Notably, the absence of a correlation between red meat consumption and C-reactive protein (CRP), a prominent marker for chronic disease-related inflammation, is particularly intriguing.
“Our analysis adds to the growing body of evidence that indicates the importance of measuring plasma markers, such as metabolites, to track diet and disease risk associations, versus relying on self-reported dietary intake alone,” Wood said. “Our analysis does not support previous observational research associations linking red meat intake and inflammation.”
Due to the limitations of observational studies in establishing cause-and-effect relationships, it is imperative to complement them with randomized controlled trials (RCTs). In RCTs, individuals are randomly assigned to either include or exclude a specific dietary element, providing a more conclusive perspective on whether red meat has an impact on inflammation. Several RCTs have provided evidence that lean, unprocessed beef can be included in heart-healthy dietary regimens without adverse effects.
“We have reached a stage where more studies are needed before we can make recommendations to limit red meat consumption for reducing inflammation if we want to base dietary recommendations on the most up-to-date evidence,” Wood said. “Red meat is popular, accessible and palatable – and its place in our diet has deep cultural roots. Given this, recommendations about reducing consumption should be supported by strong scientific evidence, which doesn’t yet exist.”