Whenever a new study comes out that makes some big health conclusions, we like to put it through the wringer, using the International Food Information Council (IFIC) Study Evaluation Checklist to systematically evaluate the hypothesis, design, methods, and analyses. Below, check out our evaluation of the newly published study ‘A red meat-derived glycan promotes inflammation and cancer progression,’ written by Marcia D. Greenblum MS, RDN, Senior Director of Health and Wellness Communications.
For an expert perspective on the conclusions the study drew and how they impact consumers, check out our interview with Roger Clemens, DrPH, CFS, CNS, FACN, FIFT, FIAFST, Adjunct Professor of Pharmacology & Pharmaceutical Sciences at the USC School of Pharmacy International Center for Regulatory Science.
| Q1. Do the title and abstract reflect the study? | |
| Yes / No. View Results Skeptically. | |
| A1. No, the title “A red meat derived glycan promotes inflammation and cancer progression” leads one to believe that there is evidence that can be generalized to normal human physiology. The title should state “in mice or laboratory animals.” |
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Q2. Is the study useful, novel, and/or relevant to humans? |
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| Yes / No. View Results Skeptically. | |
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A2. No. The study may be novel, but relevance to humans is questionable and still unproven. In humans, colon cancer, not liver cancer, has been associated with red meat consumption, but this research only looked at liver carcinomas. There is no discussion of average human intake levels or meat preparation effects. |
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Q3. Is the hypothesis clearly stated? |
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A3. No. The authors appear to have a technique for measurement of a substance that they wish to prove is carcinogenic. |
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Q4. Was the study methodology described in detail? |
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Yes / No. Do the authors cite a paper for the methods? |
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A4. No. The procedure for extracting the Neu5Gc glycan was described in detail although it was not validated by an outside laboratory. The procedure for preparing and feeding the mice was discussed; however, evidence of relevance to human health risk at normal intake levels is not provided. |
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Q5. Are the methods valid, accurate and reliable? |
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| Yes / No. View Results Skeptically. | |
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A5. As stated above, the glycan extraction technique is not validated. The accuracy and reliability are unknown and should be repeated. What is currently known about glycans is: 1) an estimated 10-30% that are consumed from food are absorbed. There is no control or discussion of bioavailability of the substance in this experiment. 2) The content of glycans in different foods varies greatly and depends on factors such as the protein and fat content of the food, cooking methods, heat, and processing. This is not discussed or considered. |
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Q6. Does the analysis of the results make sense? |
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A6. Yes, as a one-time measurement of inflammation in response to large doses of a foreign substance in a small population of genetically prepared mice. |
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Q7. Are the conclusions supported by the data? |
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A7. The broad applications that they authors make regarding human pathophysiological implications are not valid. There was no justification for suggesting that red meat intake at average American intake levels would pose a similar risk nor any results that consider the impact of other foods or nutrients or food preparation methods. |
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Q8. Are there conflicts of interest? |
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Yes / No If yes, compare findings to the totality of evidence. |
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A8. Yes. Two authors of this study are co-founders and advisors to SiaMab Therapeutics, Inc., which holds a license with UC San Diego technologies related to anti-Neu5Gc antibodies in cancer. |
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Q9. Does the study fit into the totality of evidence? |
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Yes / No. View Results Skeptically. |
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A9. No. Red meat consumption has been associated with several non-communicable diseases, including obesity, cardiovascular disease, diabetes and some cancers. None of these associations identify Neu5Gc as a possible promoter of or contributor to these conditions. A few publications suggest differences in glycation in red meat may impact diabetes. |