Sunday, January 25, 2009

The Tokelau Island Migrant Study: The Final Word

Over the course of the last month, I've outlined some of the major findings of the Tokelau Island Migrant study. It's one of the most comprehensive studies I've found of a traditional culture transitioning to a modern diet and lifestyle. It traces the health of the inhabitants of the Pacific island Tokelau over time, as well as the health of Tokelauan migrants to New Zealand.

Unfortunately, the study began after the introduction of modern foods. We will never know for sure what Tokelauan health was like when their diet was completely traditional. To get some idea, we have to look at other traditional Pacific islanders such as the Kitavans.

What we can say is that an increase in the consumption of modern foods on Tokelau, chiefly white wheat flour and refined sugar, correlated with an increase in several non-communicable disorders, including overweight, diabetes and severe tooth decay. Further modernization as Tokelauans migrated to New Zealand corresponded with an increase in nearly every disorder measured, including heart disease, weight gain, diabetes, asthma and gout. These are all "diseases of civilization", which are not observed in hunter-gatherers and certain non-industrial populations throughout the world.

One of the most interesting things about Tokelauans is their extreme saturated fat intake, 40- 50% of calories. That's more than any other population I'm aware of. Yet Tokelauans appear to have a low incidence of heart attacks, lower than their New Zealand- dwelling relatives who eat half as much saturated fat. This should not be buried in the scientific literature; it should be common knowledge.

Overall, I believe the Tokelau Island Migrant study (among others) shows us that partially replacing nourishing traditional foods with modern foods such as processed wheat and sugar, is enough to cause a broad range of disorders not seen in hunter-gatherers but typical of modern societies. Changes in lifestyle between Tokelau and New Zealand may have also played a role.
The Tokelau Island Migrant Study: Background and Overview
The Tokelau Island Migrant Study: Dental Health
The Tokelau Island Migrant Study: Cholesterol and Cardiovascular Health
The Tokelau Island Migrant Study: Weight Gain
The Tokelau Island Migrant Study: Diabetes
The Tokelau Island Migrant Study: Asthma

11 comments:

rahmin said...

Stephen,

Thanks for your thoughtful discussion of the Tokelau.

The data clearly supports the idea that a large intake of plant and fish based saturated fats does not correlate to increases in CHD. Do you think this also holds for diets high in saturated fats sourced from red meats / dairy? That seems to be the case based on your discussion of the Masai...

Maybe more directly, the questions i have in my mind are:

1.) Are all saturated fats created equal? or are there variances like the contrast between omega3 and omega6 unsaturated fats? plant vs. animal?

2.) if one would assume that there are different sub-types of saturated fats, are saturated fats from plants quite different than those from animals for human health? am i better off eating an avocado or coconut meat vs. a steak for example?

3.) i am personally a big fan of dietary saturated fat (via whole raw milk, animal meat, pastured butter, etc. -- tastes good and packed with nutrition). But I've tried to cut down on relative proportion of meats and increase my intake of vegetables. this is consistent with the thinking i've found michael pollen and mark bittman espousing (eat food, not too much, mostly plants). is this sensible if i'm trying to a.) minimize CHD risk and b.) maximize overall health and nutrition?

apologize for throwing the kitchen sink at you, but i've found no better discussion of food, health, and nutrition anywhere on the web than through your writing and the discussion of the community of readers on this blog.

Matt Stone said...

My two cents...

Lots of veggies or very few, I doubt either is going to change your risk for cardiovascular disease and other issues signficantly.

Just make sure your stomach is flat, digestion is perfect, teeth are white, strong, and free of pain, basal body temperature (armpit)is within the normal ranges (97.8-98.2), and that you feel good and have no nagging health problems. The diet, or combination of dietary therapies that can do that for you is your best bet, no matter what it consists of. I'd keep an open mind, and not get entrenched in dogma that your body disagrees with.

Looking at broad correlation studies of people who eat white flour, processed sugars, and veggie oils and deciding what you should or shouldn't eat borders on retardation.

The interesting thing about Pollan is that he feels like he is the brainiac of the century, yet he falls hook, line, and sinker for the same type of propaganda that the food industry purports - eat plants, not animals. Veggie fats good, animal fats bad. Veggie protein good, animal protein bad. Enjoy those whole grains, fruits, and legumes bud. Let me know how that works out for your digestion in the long run. Do lots of cardio and stay out of the sun while you're at it.

If you want to glimpse into the future at what a plant-based diet with lots of exercise looks like, check out Dr. Schulze, Dr. Weil, Wayne Dyer, or Bikram. I notice a theme there - premature aging, potbellies, severe baldness...

Wait a second. Aren't those prime risk factors for heart disease? By jove, I think they are! In fact waist circumference is probably the leading diagnostic tool, other than basal body temp, for assessing heart disease risk.

Rut roh!

Aaron Blaisdell said...

Very funny Matt! Time for your Scooby snack? Make sure it's a nice hunk of fried dough (white flour of course) deep fried in a "heart-healthy" vegetable-seed fat. In fact, the packaging should have this phrase from the manufacturer printed in big bold letters with three exclamation marks: "Heart Healthy!!!" And if the label also says "no trans fat. No cholesterol!" then you know it's good food.

Enjoy!

Carl M. said...

All this talk about trim and healthy Polynesians has me wondering: what about Samoa? They are noted for being rather large. Is their traditional diet different? Have they been eating more Western foods longer? Or is it genetics?

Stephan Guyenet said...

Rahmin,

Saturated fats from coconut are not the same as those from animal fat. Coconut is more saturated than any animal fat. Also, the fatty acids are shorter in coconut and are metabolized a bit differently. That being said, I'm not aware of any convincing evidence that any type of saturated fat is harmful. If I had to guess, I would say they're somewhere between harmless and beneficial, due to their extreme resistance to oxidative damage. Animal fats also come with the added bonus of important vitamins and long-chain omega fats.

I'm not convinced that vegetables are much good for CHD risk or overall health. If you look at hunter-gatherers and healthy non-industrial societies, there is no real pattern in their vegetable eating habits. Most eat very few vegetables or none at all, some eat more, but virtually none eat large amounts at every meal like we're told to do by mainstream authorities. The hunter-gatherers and non-industrial populations are the ones who aren't having heart attacks, so I'll be listening to them first.

I respect Michael Pollan's work but I don't always agree with his nutrition adice. I think he has the basics right, but that "eat food, mostly plants, not too much" thing is 2/3 hogwash.

If you want to cut back on meat, I think it's possible to do that and be healthy. It's not necessary to be a carnivore to be healthy either. Just treat your plant foods with care, especially grains and legumes (soak, sprout or ferment them, avoid gluten). And make sure to keep a good source of fat-soluble vitamins around, such as pastured dairy.

Matt,

I'm interested in the basal body temp association with CHD risk, are there any studies to back that up?

CSM,

Samoans have been modernized for a long time. It's a large island so it was "discovered" by Europeans early on. Early accounts describe the Samoans as very attractive people, like all Polynesians seemed to be before modernization. I don't know exactly how much fat they carried, but they certainly were not obese.

Unknown said...

We might not know for sure how healthy the Tokelauan population was when the traditional diet was the norm but I'd love to see more studies tracking the transition from modern processed foods to natural indigenous diets.
For awhile there was diet fad in Hawaii marketed as a traditional Hawaiian diet but recommended less fats than what was probably in traditional diets.

rahmin said...

@matt

i agree, there isn't a one shoe fits all solution, and maximizing for personal health is sound advice. nevertheless, i find continued physiological evidence that diets high in carbohydrates, particularly refined ones, are bad for overall health and these population studies seem to support the conclusion. (of course, stephen has covered much of this).

re: pollen, i tend to agree with stephen - pollen is directionally right when he suggests that we avoid processed foods - though you've got it wrong matt, pollen is not a proponent of vegetable oils. in fact, he probably deserves credit for bringing the omega3/omega6 question into broader discussion.

@stephen

are you aware of any population studies that explore the health of long term vegetarians? some cultures in india may fall into this camp. my assumption is that their intake of saturated fats is still relatively normal to high based on their use of dairy.

further, are you aware of any populations that are traditionally vegan? it appears that veganism is only made possible modern society and no evolutionary minded population would choose such a diet.

Stephan Guyenet said...

Reid,

That's a tough one. There are a few studies on the subject, I do think they would be worth a couple of posts. It's so hard to get people to return to a native diet when they have processed food in their face all the time, even if they know it's killing them.

Rahmin,

I haven't looked into it much but there have been some studies in India on CHD. If I recall correctly, there was a study showing that near-vegetarians in Southern India were dying 6-7X more from heart attacks than Northern Indians. The Southerners were eating mostly PUFA vegetable fats, the Northerners ghee.

Weston Price visited several vegetarian groups looking for one that showed normal cranial development and resistance to tooth decay. He was very keen on finding a vegetarian diet that could support robust health, but he never found one.

There are studies of vegetarian individuals in the U.S. and Europe that show variable results. Typically they die less of CHD but die younger in general. I don't take much from these studies though because vegetarians also tend to be people who take care of themselves in general, are comfortable financially, etc.

Petro said...

Got a question for you.

I'm stuck in a place where my diet is largely not under my control (Military base in the mid-east), and while I have access to some fresh vegetables, the meat is over cooked, and the rest of the food is way over processed. I'm not complaining--it's very hard to cook "whole"some meals for fifteen thousand at a sitting.

Back in November I started taking some supplements--Omega 3s, a D3/k2 mix, Vitamin A and a "probiotic" to help help maintain stomach flora (our water here has LOTs of anti-bacterial agents in it, and if you'd seen the contents of the lakes and streams around here you'd be ok with that). I've run out of the D3/K2, and substituted the Green Pasture butter based supplement. It does seem a little better (at least based on my skin not being quite so dry)

I need to get some more D and A supplements, what would you suggest?

I would prefer to get it from food, but that simply is not an option here.

Thanks,
Petro.

Stephan Guyenet said...

Petro,

Do you get a lot of sun? If so, you don't have to worry about D3 too much unless you're dark-skinned or older. I personally like the cod liver oil-butter oil combination. If you do need D3, I like Carlson's Ddrops. 2,000 IU per drop in medium-chain triglycerides (from coconut).

Petro said...

Stephan:

I'm working 12 hours a day, 6 days a week.

I get a little (morning) sun on the way in, and a little when I go to lunch (6 minute walk each way).

Maybe a *bit* more if I take a break outside.

I get one day a week off and I'll walk outside a bit on that day, assuming i'm not completely exhausted.

Anyway, thanks for the information.