Lifespan & Plant-Based Diets
Updated: Apr 11, 2021
By Cass Warbeck (IG: @plant_fueled)
With all the hype surrounding various fad diets these days (e.g. keto and carnivore), it’s easy to get lost in the tiny nuances of the never ending nutrition debate. But let’s take a step back and focus on the bigger picture for a second: which dietary pattern is best for longevity?
Well, in order to have longevity, you need to avoid dying from all the diseases that plague our world today. And there are no surprises here: dietary patterns that are centered around plants, including vegetarian and vegan diets are associated with reduced mortality, meaning that people eating plant predominant diets generally have a lower risk of death.
One well known study, the Adventist Health Study 2, followed 73,308 men and women over an average of six years looking at the relationships between diet and all-cause and cause-specific mortality. What is most interesting about this study is that researchers categorized the results into five different patterns, stratified by the amount of animal products each contained: nonvegetarian, semi-vegetarian, pesco-vegetarian, lacto-ovo–vegetarian, and vegan. Findings from this study showed that the dietary patterns with reduced animal product consumption (the vegans, lacto-ovo–vegetarians, and pesco-vegetarians) were associated with lower mortality rates.
When looking at pure longevity, the California Adventists have “perhaps the highest life expectancy of any formally described population.” And although these people engage in other healthy lifestyle behaviours, specifically in regards to diet, a vegetarian status contributes to longer life expectancy (plus lower weight and body mass index values). Vegetarian Adventist men and women live on average 9.4 and 6.1 years longer when compared to other Californians.
And then there are the famous Blue Zones: five areas of the world with the greatest proportion of the population living to over 100 years old. These people have mastered a whole list of health principles we should all live by, but notably, all these populations thrive on a predominantly plant-based diet. Legumes are the common cornerstone of every diet and eating meat is a rare occurrence (approximately five times a month).
Indeed, one of the reasons that plant-based dietary patterns are associated with reduced risk of mortality may be because they avoid meat and other animal protein sources. In fact, high plant protein intake, but not animal protein intake is associated with reduced risk of all-cause and cardiovascular mortality. Researchers even found that there was a positive benefit to substituting plant protein for animal protein, especially that from processed red meat, which suggests the importance of protein source.
It is important to mention here that although avoiding animal meat, eggs, and dairy is a great start, it also matters what you are replacing those calories with. In one recent, observational study, researchers analyzed the diets of 11,879 participants in relation to all-cause and cardiovascular specific disease mortality. But they did not just compare vegetarians and vegans to omnivores, rather they created three different dietary indexes: an overall plant-based dietary index, a healthful plant-based diet index, and an unhealthy plant-based diet index. Essentially they set up a system to compare an omnivore diet to a healthy, whole food plant-based diet and to an unhealthy “junk food vegan” diet. So what did they find? A healthy plant-based diet was associated with a lower risk of all-cause mortality, but a “vegan junk food” pattern was not. So, just a friendly reminder that not all plant foods are necessarily healthful (think sugar-sweetened beverages and white bread). To get the longevity and health benefits of a plant-based diet, we need to be focusing on dietary quality and filling our plates with whole grains, vegetables, fruit, and plant-based proteins like legumes.