Mortality Rates of Vegetarians and Vegans
A paper came out in December reporting mortality rates of different diet groups from the large EPIC-Oxford study containing 60,310 people from the UK (1).
The mortality rate before age 90 was no different between vegetarians (including vegans) and regular meat-eaters (1.02, 0.94-1.10). Vegetarians had lower rates of mortality from pancreatic cancer (0.48, 0.28-0.82) and lymphatic cancer (0.50, 0.32-0.79). Semi-vegetarians had lower rates of death from pancreatic cancer (0.55, 0.36-.86). Pesco-vegetarians had lower death rates from all cancers (0.82, 0.70-0.97) but higher rates of cardiovascular disease (1.22, 1.02-1.46).
In the main analysis (in the paragraph above), some participants were recategorized based on a change in their diet over the course of the study which included over one million person-years of follow-up. The researchers did a second analysis in which participants who changed their diets were removed, and found an 8% reduced risk of early death in vegetarians that was just statistically significant (0.92, 0.84-0.99). Limiting the results further, to deaths before age 75, strengthened the finding (0.86, 0.77-0.97).
When vegans were separated from other vegetarians, there were no statistically significant differences in mortality rates for the six main categories of death. Eliminating participants who had changed diet categories didn’t significantly change the results for vegans. There were only 166 vegan deaths as distinct from 1,929 deaths in the entire cohort; meaning that reaching statistical significance was going to be unlikely.
Results above were not adjusted for differences in body mass index (BMI); such adjustments were performed but they didn’t change the results substantially.
The fact that vegetarians didn’t have lower rates of death from heart disease in this study is surprising given that a 2013 report from EPIC-Oxford showed a highly statistically significant, 31% reduction in heart disease incidence among vegetarians (0.69, 0.58-0.82). This discrepancy as well as the lower death rates for vegetarians before age 75, but not before age 90, might be explained by cases of nonfatal heart disease leading to effective treatment.
See the link in the reference for a free copy of the paper. For results of other similar studies, please see Disease Rates of Vegetarians and Vegans.
References
1. Appleby PN, Crowe FL, Bradbury KE, Travis RC, Key TJ. Mortality in vegetarians and comparable nonvegetarians in the United Kingdom. Am J Clin Nutr. 2016 Jan;103(1):218-30. | link
January 28th, 2016 at 11:03 am
Hi Jack,
Great post. Do you know what type of vegan diet these vegans in the study were on? Were they low fat vegans or other style vegans?
If there were no difference in the mortality rates before age 90 between vegetarians (including vegans) and regular meat-eaters, I’m wondering whether dietary fat content played a part. Or should vegans concluded we are all human after all and diet has less part to play in determining one’s death? (I’m playing Devil’s advocate but you see what I’m getting at) . Thanks
January 29th, 2016 at 5:27 pm
Harry,
You can see the general nutrient intakes of the different diet groups in EPIC at this link:
http://veganhealth.org/articles/nutrientintakes
You will see that vegans’ percentage of fat hovers around 28% of calories. The non-vegetarians don’t have much higher fat intakes as a percentage of calories, either. If you go by grams of fat, the vegans have much lower fat intakes (because they eat less calories *and* have a lower percentage of fat).
That said, I have no idea if the vegans would have lived longer if they ate less fat and nor, I would argue, does anyone else because we don’t have comparable data on vegans eating less fat than that.
I think it’s interesting that populations of free living vegans, who aren’t on a vegan diet to treat heart disease or other metabolic issues, tend to gravitate towards 27-29% of calories as fat.
February 4th, 2016 at 8:35 am
It would be interesting to get more data comparing different kinds of vegans to one another, for sure. A lot of vegans don’t ensure that they get all their nutrients, and many eat a lot of junk food. As veganism grows, access to vegan junk food grows as well. Research has to separate these sort of “SAD vegans” from ones that strive to eat healthy, and even the ones striving to eat healthy have to be separated because many of these people aren’t eating enough calories, protein, calcium, etc.
June 20th, 2016 at 3:11 am
Kim,
You are so right. I subscribed to a Facebook group called Vegan Food UK (veganuk.com which seems to consist in the main of newbies who are just making or have just made the change, trying out new menu ideas on one another, posting photos and recipes of their latest creations. A great many seem to rely on the plethora of ready-made meals which are available and refer to other products which are far from healthy.
August 1st, 2017 at 4:53 am
What is more interesting then mortality is morbidity. I wonder how the morbidity compares between vegans and meat eaters.
August 6th, 2017 at 6:28 pm
Carl,
If you go here: http://veganhealth.org/ and scroll down to Research on Vegetarians and Vegans there are a number of articles talking about the morbidity in vegans.