Now What? What we can learn from the NutriRECS article and the controversy that followed
By Nikita Bhuyan, dietetic intern and Katherine Petersen, MS, RD, CSO, CNSC
In 2019, the Nutritional Recommendations (NutriRECS) Consortium published a report evaluating the potential effect of red meat consumption on cancer and cardiovascular risk in developed nations1. Americans eat about five servings of red and processed meat per week, and the NutriRECS report recommended individuals continue current levels of unprocessed and processed red meat consumption. This report contradicts the recommendations for professional organizations such as the American Heart Association2, the American Cancer Society3, and the World Health Organization4, all of which recommend limiting or reducing intake of red and processed meat. Conflicting health information, especially highly publicized information such as this can erode public trust and create confusion for patients. It’s important for providers to be able to provide reliable information that can easily be understood to patients. Here’s what you need to know to help provide patients with consistent, evidence-based information that will help inform their decisions.
The NutriRECS group concluded that reducing red meat intake by three servings per week may result in seven fewer cancer deaths per 1000 people over a lifetime. Researchers also found that reducing processed red meat by three servings per week may result in eight fewer deaths per 1000 people over a lifetime. They used the Grading Recommendations, Assessment, Development and Evaluation, otherwise known as the GRADE criteria to grade the quality of the research and make recommendations. This system gives much more weight to randomized control trials over other research methods. For both findings, researchers scored these results as a low-quality evidence.
It is important to note that although these controversial findings go against current recommendations, the NutriRECS researchers took into consideration that other study groups have not considered the likelihood of individuals changing their eating habits in order to consume less meat. They did a second analysis of studies examining attitudes and beliefs toward red and processed meat which suggested that omnivores are attached to these foods and have low willingness to change. Based on these findings, they recommended no changes to current levels of red and processed meat intake and concluded that decreasing an individual’s meat intake would not be worth the perceived cost to patients1.
Many professional organizations have published statements opposing the results of the NutriRECS paper. According to a review by the American Diabetes Association, these recommendations are not justified because of the flawed methodologies that were used to review and grade the nutritional advice. The GRADE criterion was designed to grade the strength of evidence of clinical interventions. The improbable nature of conducting a large, long term randomized clinical trial on diet, lifestyle and environmental factors make the true effects of diet on cancer risk difficult to measure, making it an inappropriate grading system for the current literature, which is largely dependent on epidemiological data5.
Additionally, the study did not address what may be replacing red meat if people do reduce consumption. The group did not adequately specify if red meat would be replaced with plant-based proteins or even refined carbohydrates. In order fully address the issue, it is important for guidelines to consider how one lifestyle choice may impact others, such as increased fruit and vegetable consumption, whole grains, legumes and nuts.
The field of nutrition research is not exempt from serious conflicts of interest. This is partly due to poor institutional funding for nutrition research. Difficulty planning, recruiting and executing high quality randomized control trials may also contribute. Not surprisingly, both sides of this debate have significant conflicts of interest. Dr. Bradley Johnston of NutriRECS reported an undisclosed conflict of interest from this research after publication, but researchers from the other side of the debate have also had significant conflicts of interest from the wellness industry.7
As medical professionals, it is important to prioritize our patients and their needs in order to optimize their health care status. When counseling patients on meat recommendations, it is important to understand their health goals and what their priorities are. Our review of the current literature leads us to believe that red and processed meat intake probably does indeed increase cancer risk, albeit by a small amount.
As with most nutrition research, effect sizes are typically small, quality is low, and certainty is unclear. How do we process that into meaningful advice for patients?
[if !supportLists]1. [endif]Consider veteran values and readiness to change. If the patient chooses to consume red meat, it is important to support them and consider providing education on how to cook meats to limit carcinogens. Perhaps the greatest strengths of the NutriRECS article was that they considered the cost to patients. Supporting patient autonomy improves patient trust, decreases anxiety, and results in patient being more likely to open up and disclose information in the future8.
[if !supportLists]2. [endif]Consider risk factors. Red and processed meat consumption has the strongest correlation with GI cancers, particularly colorectal malignancies8. It is may not be clinically meaningful to recommend restriction of red and processed meat as a method for reducing cancer risk in other malignancies. Additionally, considering risk factors such as smoking, alcohol use, and inactivity, diet is likely to have a much lesser impact on cancer mortality and risk.
[if !supportLists]3. [endif]Provide veterans with adequate information to make an informed decision, and then support their decision. For veterans who do not wish to decrease red and processed meat intake there are alternative ways of preparing these foods that can help reduce the formation of potentially carcinogenic heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs)9. Refer veterans to your cancer team dietitian for help with these resources and additional questions about how diet may impact cancer risk.
[if !supportLists]1. [endif]Johnston BC, Zeraatkar D, Han MA, Vernooij RWM, Valli C, Dib RE, et al. Unprocessed red meat and processed meat consumption: dietary recommendations from the nutritional recommendations (NutriRECS) Consortium. Ann. Intern. Med.2019;171:756-764. doi:10.7326/M19-1621
[if !supportLists]2. [endif]https://www.heart.org/en/healthy-living/healthy-eating/eat-smart/nutrition-basics/aha-diet-and-lifestyle-recommendations
[if !supportLists]3. [endif]https://www.cancer.org/latest-news/6-steps-to-help-lower-your-cancer-risk.html
[if !supportLists]4. [endif]https://www.who.int/features/qa/cancer-red-meat/en/
[if !supportLists]5. [endif]Quian., F, Riddle., M., Wylie-Rosett., Judith, Hu., Frank. Red and Processed Meats and Health Risks: How Strong Is the Evidence? American Diabetes Association. Diabetes Care 2020 Feb; 43(2): 265-271.https://doi.org/10.2337/dci19-0063
[if !supportLists]6. [endif]World Cancer Research Fund/American Institute for Cancer Research. Food Nutrition, Physical Activity, and the Prevention of Cancer: a Global Perspective. Washington DC: AICR, 2007. Available from wcrf.org/about-the-report
[if !supportLists]7. [endif]Rubin R. Backlash. Backlash over meat dietary recommendations raises questions about corporate ties to nutrition scientists. JAMA. 2020;323(5):401-404. doi:10.1001/jama.2019.21441
[if !supportLists]8. [endif]Joffe S, Manocchia M, Weeks JC et al. What do patients value in their hospital care? An empirical perspective on autonomy centred bioethics. J Med Ethics 2003;29:103–108. doi: 10.1136/jme.29.2.103
[if !supportLists]9. [endif]Knize MG, Felton JS. Formation and human risk of carcinogenic heterocyclic amines formed from natural precursors in meat. Nutr Rev. 2005; 63(5):158-165.