Of Meat and Mortality – Part 1: EPIC
I have tried to steer clear of writing about papers comparing high meat intakes to low meat intakes and the association with various diseases because there is no end to the flow of these studies and I don’t find them particularly relevant to vegan nutrition. But there have been quite a few papers released on meat and mortality recently and people, including myself, are feeling a bit confused.
So I have decided to review some of these papers in blog posts, one at a time, until it no longer seems useful to continue. Here is the first one…
The European Prospective Investigation into Cancer and Nutrition (EPIC) released a study in March looking at the association with mortality of red meat, processed meat, and poultry (1). There were 448,568 participants from 10 European countries, followed for a median of 12.7 years.
The highest intake categories were ≥ 160 g (5.6 oz) per day for red meat and processed meat, and ≥ 80 g (2.8 oz) per day for poultry. A serving of meat in the U.S. is considered to be 3 oz which is about the size of a deck of cards. The comparison categories were 10 to 19.9 g for red and processed meat, and 5 to 9.9 g for poultry (in other words, not much).
They looked at the data in a number of different ways, adjusting results for age, gender, education, body weight and height, total energy intake, alcohol consumption, physical activity, smoking status and duration, and intake of the other meat intake categories.
After all was said and done, processed meat was associated fairly strongly with all-cause mortality. Processed meat intake was also associated with dying from cardiovascular disease and dying from cancer.
Red meat and poultry were neutral in the fully adjusted models, though red meat had some trends towards increased mortality and poultry had some trends towards decreased.
Adjusting for fruit and vegetable intake didn’t affect the results nor did removing the first two years of follow-up.
The body mass index (BMI) of the participants in the highest red meat category was higher than in the rest of the categories combined (27.0 vs. 24.4 for men, 24.8 vs. 22.9 for women). There was a similar difference in BMI for poultry categories. So it seems reasonable that if they had not adjusted for body weight and height there might have been more of an association for red meat.
But what would cause a higher BMI for those who eat more red meat (or poultry)? That would most likely be explained by a higher energy intake. However, they did perform a model where they removed the energy adjustment and it didn’t affect the results. That said, in the basic model adjusting only for age, gender, and study center, they found a strong association with red meat (1.37, 1.23-1.54), so I’m not fully convinced that removing the body weight/height adjustments would not have produced a strong association with increased mortality for red meat.
On the other hand, recent studies have not found such a strong association between a BMI less than 30 and increased mortality, so perhaps this isn’t a good line of reasoning. I have written the lead author to ask about this.
Why would processed meat be so much worse than red meat or poultry? According to the authors:
• Processed meat has a higher saturated fat and cholesterol content.
• Processed meat is treated by salting, curing, or smoking which leads to more carcinogens and precursors to carcinogens.
I will add that processed meat is also higher in sodium (which has been in the news quite a bit lately as being linked with increased mortality).
The authors declared no conflicts of interest.
Other than my question about the body weight adjustments, my remaining question is whether the meat intake categories in this study were too low to detect more of an effect for red meat or poultry. Certainly, there must be a point at which eating too much red meat has to be bad – one would think.
Or, on the other hand, maybe these meat intakes are entirely too high! Some will point out that, of course, people who eat a standard American diet (or European diet in this case), but a little less or a little more poultry or red meat, aren’t going to have much different mortality outcomes. But people who eat a whole-foods-only, low-fat vegan diet will definitely have better health outcomes. They just cannot be measured in a study like this.
Perhaps. Stay tuned…
1. Rohrmann S, Overvad K, Bueno-de-Mesquita HB, Jakobsen MU, Egeberg R, Tjønneland A, Nailler L, Boutron-Ruault MC, Clavel-Chapelon F, Krogh V, Palli D, Panico S, Tumino R, Ricceri F, Bergmann MM, Boeing H, Li K, Kaaks R, Khaw KT, Wareham NJ, Crowe FL, Key TJ, Naska A, Trichopoulou A, Trichopoulos D, Leenders M, Peeters PH, Engeset D, Parr CL, Skeie G, Jakszyn P, Sánchez MJ, Huerta JM, Redondo ML, Barricarte A, Amiano P, Drake I, Sonestedt E, Hallmans G, Johansson I, Fedirko V, Romieux I, Ferrari P, Norat T, Vergnaud AC, Riboli E, Linseisen AJ. Meat consumption and mortality – results from the European Prospective Investigation into Cancer and Nutrition. BMC Med. 2013 Mar 7;11:63. | link