Posted 10/18/2019 10:07 PM (GMT -7)
Following is something I recently received in a newsletter. The author is a vegan, but doesn't necessarily promote a vegan diet. She says "whole-foods, plant-based diet." Like Dr. Joel Fuhrman, she allows 2-3 small servings of animal products per week, though I think she'd prefer people omit eggs and dairy.
Anyway, the article is just FYI, as I know you study a variety of topics and opinions. Personally, I find that a lot of vegetables, a little meat, and a little fruit seems to work best for me. Though, as you know, there's even a war against vegetables at the moment, like with the Carnivore diet. We'll see how this plays out, over 20+ years.
I hope you're doing well,
Are Red and Processed Meats Safe to Eat?
Pamela A. Popper
In 2014, the Annals of Internal Medicine published an article stating that concerns about saturated fat were unfounded, and people no longer needed to worry about limiting intake. (1) People do like to hear good news about their bad habits, and it did not take long for this to become a media sensation. Headlines like "Butter is Back" started appearing in major publications, and Time Magazine featured a cover story titled "Eat Butter." As it turned out, the Annals article contained major errors, and, in fact, the journal had to issue a correction. (2)
Here we go again. The same journal recently published a group of papers recommending that adults do not need to change the amount of red and processed meat they are eating. The authors of the papers say that the evidence of a link between eating these foods and degenerative disease and death is weak. (3) The studies were conducted by NutriRECS, which describes itself as "an independent group with clinical, nutritional, and public health content expertise." (4)
How "Independent" Is NutriRECS?
Bradley C. Johnson, an epidemiologist at Dalhouse University in Canada, led a team of over a dozen researchers, and none claimed any conflicts of interest. The study was conducted without any outside funding. Johnson himself reported that he had no conflicts of interest during the last three years.
But in December 2016, Johnson was the lead author of a study that concluded that dietary advice to consume less sugar was unwarranted. This study was also published in the Annals of Internal Medicine, (5) and was paid for by the International Life Science Institute (ILSI). ILSI was created by executives at Coca Cola over forty years ago and is funded by agricultural organizations, food manufacturers, and drug companies. The group has a colorful history, defending the interests of tobacco companies in the 1980s and 1990s. ILSI has so blatantly ignored science and been criticized so much for its industry-friendly "research findings" that Mars, the maker of M&Ms, withdrew its membership in 2018. In its announcement, Mars stated that it would no longer tie its funding for research to specific outcomes, and would allow any research study it funded in the future to be published regardless of the results. (6)
Johnson defended his decision not to disclose his authorship of this study and his ties to ILSI, stating that because the funding from ILSI was given in December 2015, it technically was outside of the 3-year window for disclosing conflicts. But the article based on this funding was published within the 3-year time period, which gives the appearance that Johnson felt that it was better to protect himself from scrutiny than to promote scientific integrity.
Johnson’s background includes other episodes in which he tried to avoid disclosure. When the sugar study was initially published, he and the other authors stated that while ILSI had funded the study, the organization had no direct influence over the research. But after the Associated Press dug up emails showing that ILSI had both "reviewed" and "approved" the study’s protocol, an amended disclosure statement was published in Annals.
There are good reasons why a researcher might not want to disclose an association with ILSI. Marion Nestle is a professor of nutrition, food studies, and public health at New York University, and author of many books on the food industry. She says, "Behind the scenes, ILSI works diligently on behalf of the food industry; it is a classic front group. Even if ILSI had nothing to do with the meat papers — and there is no evidence of which I am aware that it did — the previous paper suggests that Johnston is making a career of tearing down conventional nutrition wisdom." (7)
Exactly What Did the Analysis Show?
The Annals paper included analysis of mostly observational studies and only one randomized controlled trial. I was surprised that the data, as reported by Johnson’s group, actually showed a significant reduction in both the disease and mortality rate when red and processed meat intake is reduced. It appears that the interpretation of the findings may be the issue, which I will address later.
First, here is some detail as to what the studies showed:
Observational studies on cardiometabolic outcomes and cancer (8)
Diets that are low in red and processed meat were associated with:
13% lower risk of all-cause mortality
14% reduction in cardiovascular mortality
14% reduction in nonfatal stroke
24% reduction in type 2 diabetes
10% reduction in overall cancer incidence
11% reduction in cancer mortality
59% reduction in extrahepatic cancer incidence
64% reduction in gallbladder cancer incidence
56% reduction in pancreatic cancer mortality
Observational studies on mortality and cardiometabolic outcomes (9)
Reducing red meat intake by three servings per week would:
reduce cardiovascular mortality by 10%
reduce stroke by 6%
reduce myocardial infarction by 7%
reduce type 2 diabetes by 10%
Reducing processed meat by three servings per week would:
reduce cardiovascular mortality by 10%
reduced stroke by 6%
reduce myocardial infarction by 6%
reduce type 2 diabetes by 12%
Observational studies on cancer mortality and incidence (10)
A reduction of three servings of meat per week would reduce overall cancer mortality by 7%
A similar reduction in processed meat would:
reduce incidence of esophageal cancer by 30%
reduce incidence of colorectal cancer by 7%
reduce incidence of breast by 10% cancer
reduce overall cancer mortality by 8%
Randomized clinical trials ( 11)
Only one randomized trial was included – the Women’s Health Initiative. This trial was designed to look at the risks and benefits of hormone replacement therapy, and also the results of minor changes in dietary pattern. The study did not specifically involve evaluating or reducing meat intake. But participants in the intervention group did report a slight reduction in meat consumption, and experienced a 16% reduction in breast cancer deaths and a 13% reduction in the risk of becoming an insulin-dependent diabetic as compared to the control group. (12)
Interpretation of the Studies
The authors of the meta-analysis concerning red and processed meat reported what they deemed to be insignificant reductions in the risk of many diseases like diabetes, cardiovascular disease, stroke, several forms of cancer; and death.
I don’t think the reductions in disease and death rates are as insignificant as the authors infer. Based on the data the authors present, reducing red meat and processed meat consumption would have the following impact on Americans (these data are based on CDC statistics):
Number of deaths in U.S. 2,813,503 13% reduction = 365,755 fewer deaths
Cardiovascular deaths in U.S. 647,457 20% reduction = 129,491 fewer deaths
Overall Cancer mortality in U.S. 599.108 15% reduction = 89,866 fewer deaths
In other words, the data presented by these researchers showed that the death rate in the U.S. would be lowered significantly if people would just reduce, not even eliminate, their consumption of red and processed meats! 365,755 fewer deaths every year would represent a major leap forward in public health. (13) I just love when the "other side" proves me right!
General Critique of the Annals Article
It seems that the research group decided in advance to publish an analysis supporting the idea that red meat and processed meats are safe to include in the diet. There are many ways in which meta-analyses can be structured in order to show a predetermined outcome. One method is to develop selection criteria that omits studies with results that contradict the foregone conclusion of the researchers. In this case, only one randomized trial was included, and many very good studies were excluded from the NutriRECS analysis. PREDIMED (Prevención con Dieta Mediterránea) was a large study that showed that a Mediterranean diet that replaced red meat with more plant foods reduced cardiovascular risk. (14) In this study, those who ate the most plant food had the biggest reductions in all-cause and cardiovascular mortality. (15)
The DASH (Dietary Approaches to Stop Hypertension) study showed that more plant food and less animal food, specifically red meat, reduced blood pressure." (16)
The Lifestyle Heart Trial showed that a low-fat vegetarian diet, as part of an overall healthy lifestyle, could reverse the progression of even severe coronary heart disease." (17)
The authors ignored other significant evidence showing that consuming red and processed meat increases the risk of disease and early mortality. Processed meat (bacon, sausage, hot dogs, ham, etc.) was classified in 2015 by the World Health Organization as a group 1 carcinogen. WHO stated that evidence of cancer risk was clear and convincing for colorectal cancer, and the WHO also reported associations between red and processed meat consumption and stomach, pancreatic, and prostate cancers. (18) Processed meat was also shown to be associated with breast cancer risk, among other health problems. (19) In 2017, the American Medical Association called for the elimination of processed meat from hospital menus, (20) as did the American College of Cardiology.
Many randomized controlled trials and meta-analyses have shown that eating less animal food and more plant foods improves risk factors for coronary artery disease, diabetes and cancer such as plasma cholesterol, (21) weight, (22) blood pressure, (23) and blood sugar. (24)
The Authors’ Justification for Not Recommending Dietary Change
The authors cited articles showing that omnivores enjoy eating meat and that many people feel, rightly or wrongly, that meat is important to health. They think that the benefits of reducing meat consumption are small and uncertain, and that many people just won’t reduce their meat intake, despite the known risks. They wrote, "…the panel believed that for the majority of individuals, the desirable effects (a potential lowered risk for cancer and cardiometabolic outcomes) associated with reducing meat consumption probably do not outweigh the undesirable effects (impact on quality of life, burden of modifying cultural and personal meal preparation and eating habits)."
Perhaps one of the reasons for this conclusion is that lead author Johnson disclosed in an appendix to the article called "Summary of Panelists’ Potential Conflicts of Interest" that he does consume red and processed meat. Perhaps he was looking for some good news about his own bad habits.
I take issue with the idea that minds and habits cannot be changed. Americans (and others around the world) are interested in health, and millions of them have already changed their diets after finding out that plant-based eating lowers the risk of disease and early death. To suggest that informing people about the impact of better diets on health is a fruitless endeavor shows, in my opinion, a profound disrespect for people and their ability to learn and apply good information in order to improve their lives.
Thankfully this was not the prevailing attitude about smoking. When overwhelming scientific evidence showed that smoking increased the risk of disease and death, public education and intervention programs were successfully utilized to both prevent smoking and help those who smoked to quit. People can and will change when provided with solid information and support from health professionals.
Why Did Annals Publish This Article?
First, it appears that the journal’s rules are a bit lax. Dr. Christine Laine, editor in chief of Annals, says that authors are asked to disclose their financial interests but the journal relies on the integrity of the researchers and does not perform any independent verification. (25) Apparently the journal also does not disqualify articles submitted by authors who have already proven to lack integrity. The lead author of this paper, Johnson, had already been caught not disclosing industry influence, as reported above.
Dr. Gordon Guyatt, who chaired the 14-member peer review panel, said, "Perhaps Brad was a little naïve, and both I and perhaps Christine Laine were a little negligent in it not occurring to us that he should probably declare the previous money he got from the previous project." (26)
Lax rules, naiveté, and "a little negligence," however, do not entirely explain why a peer-reviewed journal would get caught up in this same type of controversy again and again. There is a growing suspicion that perhaps Annals actually seeks to publish questionable articles that almost certainly will generate a media frenzy and a lot of controversy. The reason is that this type of attention, as negative as it should be for the journal, positively influences the journal’s impact factor, a form of ranking for medical journals that is similar to Nielsen ratings for television stations.
The Bottom Line
The evidence is clear – a low-fat, high fiber, plant-based diet comprised of whole foods offers the best protection against disease and premature death. Unfortunately, it is becoming easier to publish poorly written, conflicted, and misleading information, such as that presented in the analysis reviewed in this article, in journals that used to be reliable sources of information. Marcia Angel, writes "It is simply no longer possible to believe much of the clinical research that is published, or to rely on the judgment of trusted physicians or authoritative medical guidelines. I take no pleasure in this conclusion, which I reached slowly and reluctantly over my two decades as an editor of The New England Journal of Medicine."
This sorry state of affairs means that the consumer must take responsibility for becoming informed. This requires learning how to look at information with skepticism and to investigate thoroughly before making any health-related decision.
Note: Wellness Forum Health has been helping people to become InforMED™ consumers for 25 years. For information about our programs and how they can help you, please email [redacted].
(1) Chowdhury R, Warnakula S, Kunutsor S, Crowe F, Ward HA, Johnson L, et al. Association of dietary, circulating, and supplement fatty acids with coronary risk: a systematic review and meta-analysis. Ann Intern Med. 2014;160:398-406.
(2) Correction: Association of Dietary, Circulating, and Supplement Fatty Acids With Coronary Risk. Ann Intern Med. 2014;160:658. doi: 10.7326/L14-5009-9
(3) Johnston BC, Zeraatkar D, Han MA et al. "Unprocessed Red Meat and Processed Meat Consumption: Dietary Guideline Recommendations From the Nutritional Recommendations (NutriRECS) Consortium." Ann Intern Med 2019 Oct; (Epub ahead of print 1 October 2019) doi: 10.7326/M19-1621
(5) EricksonJ, Sadeghirad B, Lytvyn L, Slavin J, Johnson BC. "The Scientific Basis of Guideline Recommendations on Sugar Intake: A Systematic Review." Ann Intern Med 2017 Feb;166(4):257 -267
(6) Prentice C. "M&M’s maker publishes science policy in bid to boot transparency." Science News Feb 5 2018
(7) Parker-Pope T, O’Connor A. "Scientist Who Discredited Meat Guidelines Didn’t Report Past Food Industry Ties." New York Times Oct 4, 2019
(8) Vernooij RWM, Zeraatkar D, Han MA. et al "Patterns of red and processed meat consumption and risk for cardiometabolic and cancer outcomes. A systematic review and meta-analysis of cohort studies." Ann Intern Med October 2019 (Epub ahead of print
(9) Zeraatkar D, Han MA, Guyatt GH. et al. "Red and processed meat consumption and risk for all-cause mortality and cardiometabolic outcomes. A systematic review and meta-analysis of cohort studies." Ann Intern Med October 2019 (Epub ahead of print)
(10) Han MA, Zeraatkar D, Guyatt GH. et al. "Reduction of red and processed meat intake and cancer mortality and incidence. A systematic review and meta-analysis of cohort studies." Ann Intern Med October 2019 (Epub ahead of print)
(11) Zeraatkar D, Johnston BC, BartoszkoJ. et al. "Effect of lower versus higher red meat intake on cardiometabolic and cancer outcomes. A systematic review of randomized trials." Ann Intern Med October 2019 (Epub ahead of print)
(12) Prentice RL, Aragaki AK, Howard BV, et al. "Low-fat dietary pattern among postmenopausal women influences long-term cancer, cardiovascular disease, and diabetes outcomes." J Nutr. 2019 Sep;149(9):1565-1574.
(14) EStruch R, Ros E, Salas-Salvado J et al. "Primary Prevention of Cardiovascular Disease with a Mediterranean Diet Supplemented with Extra-Virgin Olive Oil or Nuts." NEJM 2018 Jun;378(25):e34
(15) Martinez-Gonzalez MA, Sanchez-Tainta A, Corella D, et al. « A provegetarian food pattern and reduction in total mortality in the Prevención con Dieta Mediterránea (PREDIMED) study." Am J Clin Nutr. 2014 Jul;100(suppl):320S-328S.
(16) Appel LJ, Moore TJ, Obarzanek E, et al. "A clinical trial of the effects of dietary patterns on blood pressure." NEJM 1997 Apr;336:1117-1124.
(17) Ornish D, Scherwitz L, Billings J, et al. "Intensive lifestyle changes for reversal of coronary heart disease. Five-year follow-up of the Lifestyle Heart Trial." JAMA. 1998 Dec;280(23):2001-2007.
(18). Bouvard V, Loomis D, Guyton KZ, et al. Carcinogenicity of consumption of red and processed meat. Lancet Oncol. 2015;16:1599-1600.
(19). Farvid MS, Stern MC, Norat T, et al. Consumption of red and processed meat and breast cancer incidence: a systematic review and meta-analysis of prospective studies. Int J Cancer. 2018;143(11):2787-99.
(20) American Medical Association. Healthy Food Options in Hospitals H-150.949. 2018. https://policysearch.ama-assn.org/policyfinder/detail/Healthy%20Food%20Options
(21) Wang F, Zheng J, Yang B, Jiang J, Fu Y, Li D. "Effects of vegetarian diets on blood lipids: a systematic review and meta-analysis of randomized controlled trials." J Am Heart Assoc. 2015 Oct;4(10):e002408
(22) Farvid MS, Stern MC, Norat T, et al. « Consumption of red and processed meat and breast cancer incidence: a systematic review and meta-analysis of prospective studies." Int J Cancer. 2018 Dec;143(11):2787-99
(23) Yokoyama Y, Nishimura K, Barnard ND, et al. Vegetarian diets and blood pressure: a meta-analysis. JAMA Internal Medicine. 2014 Apr;174(4):577-587.
(24) Yokoyama Y, Barnard ND, Levin SM, Watanabe M. "Vegetarian diets and glycemic control in diabetes: a systematic review and meta-analysis." Cardiovasc Diagn Ther. 2014 Oct;4(5):373-382
(25) Parker-Pope T, O’Connor A. "Scientist Who Discredited Meat Guidelines Didn’t Report Past Food Industry Ties." New York Times Oct 4, 2019