Eat to extend your life (and save the planet too)
Did you know it's possible to eat in a way that optimises your health and longevity, while also being great for our community and environment?
It's called the planetary health diet - and it tastes good too 😋
The EAT-LANCET report
In 2019, a global collaborative study called the EAT-LANCET, bought together leading experts from around the globe. Their aims were to look at how we could feed our rapidly expanding worldwide population (predicted to be 10 billion people in 2050), in a way that was environmentally sustainable; prevented the collapse of our natural world, and would also improve the health of our population, as well as reducing the number of early deaths caused by poor diet.
It was a massive task and a lofty goal, but they drew on all available nutritional and environmental research, to construct the first global benchmark diet, capable of sustaining health and protecting the planet at the same time.
And they came up with a simple solution - eat more whole plant foods!
By doing so, the authors estimated we could prevent up to 25% of early deaths, and minimize our impact on the planet as well. The study results are in this graphic.
How our diet affects our environment
Research has consistently shown that what we eat, has one of the biggest impacts on our climate - impacting both on our current environment, and the future health of our planet.
In NZ for example, almost 50% of greenhouse gas emissions come from agriculture- namely dairy, sheep, and beef farming. In contrast, vehicle emissions account for under 18% (New Zealand's Greenhouse Gas Inventory 1990–2021).
In countries where animals are farmed intensively, these figures are even worse.
New Zealand's Greenhouse Gas Inventory 1990–2021
Our world now produces 3x more meat and more than twice as much milk as it did 50 years ago.
While farming is an important part of the NZ economy, we can't ignore the fact that agriculture can have proven negative effects on the environment, such as the destruction of native ecosystems to support livestock grazing, increased cultivation of animal feedstocks, and nitrogen runoff into water supplies.
Livestock farming accounts for 50% of methane and 60% of nitrous oxide emissions worldwide, which respectively have 25 and 298 times the global warming potential of carbon dioxide (Personal and Planetary Health—The Connection With Dietary Choices JAMA 2023)
It’s pretty hard to deny the scary truth anymore - that our ever-increasing appetite for meat and dairy is harming our planet.
According to the EAT-Lancet Commission, for the world to reach environmentally sustainable diets by 2050, we need to reduce our global meat consumption by more than 50%!!.
While the Intergovernmental Panel on Climate Change recommends major changes in what we eat, and how food is produced to meet these goals.
Again, their recommendation is to eat less animal products and more plants.
So what can we do to make a difference?
This doesn't mean we have to exclude animal foods altogether if we still wish to eat them - but we need to look at the balance of how and what we eat in our diets.
Currently, standard 'western' diets are heavy on meat, dairy, and processed foods - and we're suffering the consequences with skyrocketing rates of chronic diseases such as diabetes, obesity, mental illness and cancers.
Not to mention the impact on our environment.
In contrast, research shows that people who follow plant-based (vegetarian and vegan) diets have a 12–15% lower risk of premature death, as well as a 29–52% lower risk of dying from cancer or heart, kidney, diabetes, or hormone-related diseases.
Another analysis in 2020, called ‘Healthy and Climate-Friendly Eating Patterns in the New Zealand Context’ looked at how we could improve the health of our population, while also preserving our environment.
In New Zealand, as we covered earlier, beef and lamb farming have the biggest overall environmental impact, with butter and cheese not far behind.
This summary again found ‘Eating patterns emphasising the consumption of whole, plant-based foods offer an opportunity to achieve substantial emissions reductions while simultaneously realising considerable health gains and health system cost savings'.
In simple terms, eating more plants is good for both our health and our environment!
To compare animal and plant food sources, global greenhouse gas emissions from animal-based foods are twice those of plant-based foods, with animal-based food production (including livestock feed) contributing 57% of food production-related greenhouse gas emissions , compared to only 29% from plant-based foods.
Transitioning to the dietary patterns recommended above is estimated to reduce global mortality by 6% to 10%, and food-related greenhouse gas emissions by 29% to 70% in 2050.
We need to flip our diets upside down.
The graphic below shows a standard Western diet, compared to a Mediterranean style diet - widely recognized as being best for our health, and closely mirroring the planetary diet mentioned above.
The difference is massive. Our current ‘typical’ diet is almost the exact opposite of what we should be eating for a healthier future.
But while eating for our planet is a noble cause, how does it help us on a personal level?
To answer this, let’s look at a number of huge population studies, that have examined how diet can help us live longer healthier lives.
Global Burden of Disease Study
One of the most famous of these is the Global Burden of Disease study. This research initiative has been running since 1990, in 204 countries around the world, involving more than 9000 researchers.
It's the largest study of human nutrition and disease in existence.
Data from the Global Burden of Disease study shows that nutrition accounts for around 11 million premature deaths worldwide each year - and most of these are from a lack of plant foods, and an excess of salt and processed foods.
From this research they've developed an 'optimal diet for longevity'.
Not surprisingly, it’s virtually identical to the planetary health diet, and the Mediterranean diet we've discussed above.
And the Global Burden of Disease findings were impressive.
If we follow an 'optimal' diet from age 20, we can expect to live an average of 10 years longer than people who don't.
Changing to a healthy diet at age 60 can increase our life expectancy by 8 years, and even changing at age 80 can increase it by 3.5 years.
What is this diet?
Again, whole foods, mostly plants (whole grains seeds legumes fruit, and veggies) with minimal animal products.
This doesn't mean you have to be vegetarian if you choose not to (and most traditional diets do contain small amounts of animal foods), but you should aim to include as many whole plant foods in your diet as you're able to.
The GREEK epic cohort
Another large study (the GREEK epic cohort), looked at exactly what changes we could make to our diet to get the biggest health benefits.
They again found that eating more plants, and less meat, had the most impact on health and disease.
These findings are mirrored in other large famous studies such as the Nurses health study, the Health Professionals study, and the Adventist study, as well as countless other studies on nutrition and health.
And they're backed up in real life by the 'blue zones' - areas around the world where people consistently live long healthy lives - and living to 100 is not uncommon!
Blue Zones
The blue zones have several key features, but from a diet perspective, it's almost identical to all the dietary patterns already mentioned- with 95% of those living to 100, eating a mostly vegetarian diet. The blue zones dietary pattern is shown in the graphic below.
Mediterranean, blue zones, planetary health diets and longevity diets all have the same basic features.
They're based largely around whole plant foods and are rich in veges, fruit, whole grains, legumes, nuts and seeds.
They include some fish, poultry, dairy and eggs, but get most of their protein from plant sources (legumes, nuts, seeds and whole grains.
They're very low in red meat, processed foods, alcohol and added sugar.
And they work.
Why are plants good for our health and the planet?
There is consistent evidence that people who eat 5 or more servings of fruit and veges each day live longer healthier lives on average.
And a whole food plant-rich diet is linked to a lower risk of premature death, as well as a reduced risk of many cancers, metabolic syndrome, type 2 diabetes, heart disease, depression, autoimmune disease and dementia - all of the main diseases that currently plague our society.
Plants contain specific nutrients and antioxidants - such as fibre, polyphenols, carotenoids, folate, and vitamin C - many of which are not found in animal foods.
These are highly effective in helping our body reduce inflammation, improve circulation, fight age related cell damage, and be able to repair damaged cells and kill cancer cells before they can spread.
So assuming eating more plants and less animal products is good for both us and the planet, exactly how much impact can it have?
Animal agriculture is a major contributor to deforestation, species extinction, and freshwater contamination, as well as fresh water consumption.
Swapping just one serving of beef with one serving of beans can save 57 square km of land usage, 2078 litres of water and the energy equivalent to driving 15km!
While in the US for example, research shows that if people simply replaced beef with beans, the US would immediately reach 75% of it’s climate emission goals.
And from a health perspective, two studies published in the prestigious BMJ, and JAMA, found that swapping out just 3% of animal protein (ie meat/ dairy/ eggs) for plant protein, can reduce our risk of early death by 10-24%.
Most plant proteins are found in whole grains and legumes (aka beans), and legumes are thought to be one of THE most important foods for longevity.
For every extra 20g of beans we add to our diet, we can extend our lifespan by up to 8 years. While eating beans just four days per week can slash the risk of heart disease by 22%, and eating 1/2 cup of legumes daily can cut it by a whopping 38%.
Eating 2-3 servings of whole grains per day reduces our risk of early death by 16- 20%, and risk of dying from heart disease by 25%, and eating nuts daily can reduce the risk of early death by up to 39%.
These foods all have some of the lowest environmental impact too.
Processed foods
It's also important to note that these are WHOLE plant foods we're talking about - while ultra-processed plant foods are better for our environment, they're not so good for our health, with some research showing no benefit or even harm.
To take a quick look at why it's SO vital to eat whole foods rather than ultraprocessed, lets explore the research.
The evidence around the harms of ultra-processed foods is growing rapidly- with a recent study of 20,000 people followed up over 15 years, showing that higher consumption of ultra-processed foods (>4 servings daily) can increase the risk of early death by 62% (with each additional serving of ultra-processed food eaten per day increasing mortality by 18%).
Ultra-processed plant foods don’t get off the hook either - a recent analysis of data in one large study showed that eating ultra-processed plant foods were actually worse for our health than whole animal foods, increasing overall risk of death by 14%, and risk of death from respiratory, kidney, or neurological causes by 30-50%.
And let's not forget added sugar - while this has a relatively low environmental impact, it has a huge impact on our health, being almost as bad for us as processed red meat (which is classified as a class 1 carcinogen by the WHO), and a major contributor to chronic diseases such as diabetes, obesity and heart disease.
Added sugar is found in a whopping 70% of prepackaged foods, and as a society, we've gone from eating 1.8kg sugar /person /year, to 68kg/person /year - in less than 300 years !
Its also important to differentiate added sugar from sugar in whole foods such as fruit, as these whole foods are actually highly beneficial for our health, and are included in longevity diets. To learn why, and our tips for healthy sugar, check out our blog post here
So how can we eat to help our health and wellbeing, live longer, and look after our planet?
From a practical perspective, aim to make whole plant foods the main focus of your diet, rather than the afterthought, with animal foods occasionally added if desired.
Fill up your plate with veggies some fruit and whole grains
Try having at least one meat-free day per week, and experiment with beans, legumes, and whole grains for protein.
Think of cheese, butter, meat and foods with added sugar as occasional foods, rather than everyday foods
Bulk out meat-based meals with legumes - this not only reduces your meat consumption, it also boosts the nutritional content of your meals and costs less too
Snack on nuts and fruit rather than processed foods or cheese/ meat
You don't have to change everything at once, but every little step counts!
As Michael pollen famously said 'Eat whole foods, mostly plants, not too much'.
Why not give it a go - your body (and planet) will thank you for it 😊