What is a plant-based diet?
Do those who follow a plant-based diet really live longer?
For most people, a plant-based can be defined as a diet which consists of all minimally
processed fruits, vegetables, whole grains, legumes, nuts and seeds, herbs, and spices, with
few or no animal products, including red meat, poultry, fish, eggs, and dairy products.
It’s sounds like a healthy diet for most people, but because of it’s very ambiguous nature,
examining the research and comparing studies for and against plant-based diets for longevity is
quite the challenge.
Unfortunately, the term ‘plant-based’ is thrown around rather loosely and can imply a variety of
For some, it’s another way to say they’re vegan. For others, it simply means they eat a lot of
plant food but still consume some animal products, such as vegetarians or flexitarians.
People choose to eat plant-based, vegetarian or vegan for ethical reasons, religious beliefs,
animal welfare, environmental concerns and health considerations.
According to Roy Morgan Research , almost 2.1 million Australian adults now say their diet is all
or almost all vegetarian.
But does eating a plant-based diet really help you live longer?
PLANT-BASED DIET AND LONGEVITY – THE
There have been a number of studies conducted around whether or not going vegan, reducing
your meat intake, or eating a plant-based diet increases the average person’s life span.
The problem is, each study varied with what they tested, what they considered as a plant-based
diet, and if they also tested their results against any other confounding factors such as smoking
and a sedentary lifestyle, which can influence the results.
On the surface, some popular studies showed that those who eat a plant-based diet live longer
than those who eat more meat.
As an example, a 2013 study, which followed more than 95,000 men and women in the United
States from 2002 to 2009, found vegetarians had a 12% lower risk of death from all causes than
In another study from 2012, data was collected from 131,342 participants over 32 years.
The results showed a 2% increased risk of overall death and an 8% increase in risk of death
from heart disease for those who ate more animal protein.
Whereas, a plant-rich diet was associated with a 10% reduction in overall mortality risk and a
12% reduction in heart disease risk.
Great news! But, it’s not so black and white. The researchers acknowledged that this associated
increased risk only occured in those with another unhealthy lifestyle factor, such as obesity, lack
of activity, smoking, heavy drinking, etc.
Once these other factors were taken into consideration, and those individuals with another risk
factor were removed from the study, those who remained, including meat-eaters and
plant-based dieters, showed no statistically significant difference in longevity or overall risk of
Other studies came to the same conclusion.
The Australian Sax Institute’s 45 and Up Study compared the longevity of meat eaters and
vegetarian/plant-based eaters for over 6 years. A total of 267,180 men and women participated.
Both meat eaters and vegetarians/plant-based eaters lived the same amount of time. Even after
the researchers adjusted for other factors including age, smoking, and diseases like type 2
diabetes, they found no evidence that foregoing meat could help you live longer.
In 2015, a United Kingdom-based cohort study also concluded vegetarians had a similar risk of
death from all causes when compared with non-vegetarians.
In fact, one US study with around 200,000 American health workers, found a vegetarian diet
based on less healthy food options, such as refined grains, could increase the risk of heart
This particular study also found a high plant-based diet did not reduce the risk of heart disease
any more than a low plant-based/high meat-based diet.
But even though it doesn’t seem to matter much as to whether or not you eat animal products,
there was a common trend that contributed to good health and longevity in all the studies
HEALTHIER PLANT-BASED DIETS MAKE A
Plant-based dieters who eat a diet rich in fruits, vegetables, and healthy fats, including those
who eat meat and animal products, are likely to live a little longer, or at the least, have a
reduced risk of heart disease.
In one US study, the plant-based participants were further categorised into an overall plant
based diet, a healthy plant-based diet, or an unhealthful plant-based diet.
When comparing healthy and unhealthy plant-based diets (even those including meat), a
healthy plant-based diet reduced the risk of heart disease by 25%.
However, an unhealthy plant-based diet (high in sweets, cakes, chips and crisps etc) showed an
increased risk of heart disease by 32%!
PLANT-BASED EATING AND A HEALTHIER
LIFESTYLE IMPROVES LONGEVITY
It’s important to acknowledge that in most studies vegetarians, or plant-based eaters, tend to be
the “health-conscious” people, with overall healthier lifestyle patterns than others.
For example, among the Sax Institute’s 45 and Up participants, vegetarians were less likely
than non-vegetarians to report smoking, drinking excessively, insufficient physical activity and
being overweight/obese. They were also less likely to report having heart or metabolic disease
or cancer at the start of the study.
In most previous studies, vegetarians did have lower risk of early death from all causes in
unadjusted analysis. However, after controlling for other lifestyle factors, such as the ones listed
above, the risk reduction often decreased significantly (or even completely vanished).
So, regardless of whether or not you choose to include animal products into your diet, the
current evidence suggests a healthy lifestyle with a diet rich in fresh vegetables, fruits and other
plant products is likely the key to increasing longevity.
Larina Robinson is a Wholefood Dietitian, author and founder of The Body Dietetics. Specialising in gut health, food intolerances and alternative diets, Larina empowers people to embrace a diet unique to their own dietary needs and supports them to find freedom from long-term digestive complaints.