Myth busting – Part 4
Continued from Myth busting – Part 3
Myth: But longevity studies show that most 90 and 100 year old folks are vegetarians, right?
Truth: The truth is that in many longevity studies we see people in their 90s and 100s who ‘don’t eat much meat’ but that does not make them strict vegetarians.
In almost all the longevity studies I have read, very few of these people in their 90s and 100s were reported as specifically being vegetarians, most often they just “don’t eat much meat” because they tend to be quite poor (financially) and they can only afford to eat meat once or twice per week at most. Many of these elderly folks eat fish or eggs a few times per week. Fish is often readily available as many of the demographic groups studied (where exceptional longevity has been noted) live near the coast or on islands, so fresh fish is often a staple of the local diet.
This in itself is, to my mind, all far more interesting than whether or not these people are vegetarians. One of my all-time favourite books is ‘Blue Zones’ by Dan Buettner, an excellent review of the lifestyles of several societies where a high proportion of folks enjoy far-above-average longevity. In four of the five communities he and his team studied around the world, they live between the coast and the hills/mountains. A lifestyle including regular hill walking, daily clean fresh air, fresh fish and home-grown vegetables feature as key ingredients to living a long and healthy life. Many of the people studied “ate little meat” but only one of the five communities identified themselves as vegetarians, and this was in the case that vegetarianism came as a part of their religious belief system.
We see that in societies living above-average life expectancy, they all tend to eat a diet very high in fresh vegetables. Why? Because they often grow their own, so those vegetables are cheap, and abundant. This also couples with light manual labour; people working on their own land. They all tend to eat fresh fish because they almost always live near the sea. Time and again we see in these longevity studies that these old folks are aged 95, or 98, or 104 or whatever, and they’ve lived in that same village their entire lives. One of the characteristics of these long-lived peoples, is that they live in rural communities and they have fantastic community networks, they are respected locally, as pillars of their community (you can imagine the local knowledge and connections someone would have after living in one place for 100 years!) and loved members of their society. Ensuring the local fishermen send a fine fish or two their way every week is not going to be a problem for one of these people.
So poverty dictates that these people rarely eat meat, once or twice per week seems typical, but fresh fish is often available throughout the week. They all live near the sea, and typically they live in hilly or mountainous areas. Perfect human habitat – access to coast, and exercise walking in the hills every day. Lots to learn there!
Interestingly, I have not yet found any longevity studies that separate out vegetarianism from caloric restriction.
What I mean is, one factor that often – in fact almost always – shows up in these longevity studies is that most folks who live a very long life, habitually practise some form of caloric restriction. I.E. they go through repeated periods of eating quite a low-calorie diet. This observation is indeed where the modern ‘trend’ for intermittent fasting (IF diets) comes from. Far from practising intermittent fasting to lose excess accumulated body weight, these folks living far into their 90s and 100s simply have to go to bed hungry often because of poverty – they don’t eat much because they can’t afford to! A calorie restricted diet has been a feature of life for many of these folks because life has been poor, and hard.
It’s worth remembering that anyone hitting 100 years of age in the first decade of the 21st century has lived through some tough times, including two world wars. Even in my lifetime (I am 45 years of age, at time of writing, early 2016) here in the UK, I can cast my mind back to childhood and a time when an entire supermarket when I was a child, would have fit into just one or two aisles of a large modern supermarket today. Supermarkets today will hold 80,000 product lines on their shelves. 40 years ago, we did not have 100 choices of breakfast cereal, 50 flavours of fruit juices, 78 imported types of fruit to choose from! Times have changed, and calories are easier to get than ever today – hello obesity epidemic!
Anyway, studies of folks living very long lives don’t seem to differentiate the factors driving this caloric restriction – have these little old Okinawans lived to 112 because they didn’t eat many calories, because they regularly went to bed hungry? Or was the diet typically low in calories compared to modern standards because the diet was low in animal foods, making it a low fat diet? A diet low in fats and high in fibrous vegetables might be filling, but low in calories, because fats are calorie-dense foods, and fibrous vegetables typically are not.
In truth, we just don’t know this stuff, we don’t have this data. Studying the diet and lifestyle of a bunch of centenarians is not an easy thing. How do we pick which 20 and 30 and 40 year olds we should start following now, to track their diet and lifestyle habits…when we don’t know which ones are going to live to 100? And if we go knocking on the door of a bunch of centenarians saying “Oh please can I drag a film crew and some researchers in and ask you what you had for breakfast 72 years ago and jab some needles in you for blood samples? And please will you poop in this pot so we can send it to a lab and analyse your gut flora.” we just might get told where to go by the overwhelming majority of potential subjects!!
In summary, the research just does not tell us the whole truth, but there seems to be little solid evidence that ‘vegetarians live longer’ than meat eaters. There is evidence that folks practising caloric restriction live longer, and it seems many folks living into their 100s are ‘not big meat eaters’ but currently, that’s as far as the evidence goes. Caloric restriction seems to be a far more important factor for longevity than vegetarianism.
As Dan Buettner says in Blue Zones, life doesn’t have a brake pedal, we can’t slow down time, but it does seem to have an accelerator, and we can ease off pushing it too hard.