Diabetic Mediterranean Diet

Here’s my review of  The Blue Zones: Lessons for Living Longer From the People Who’ve Lived the Longest, a 2008 book by Dan Buettner.  I give the book four stars on Amazon.com’s five-star system (“I like it”). 

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The lifestyle principles advocated in The Blue Zones would indeed help the average person in the developed world live a longer and healthier life.  The book is a much-needed antidote to rampant longevity quackery.  Dan Buettner’s idea behind the book was “discovering the world’s best practices in health and longevity and putting them to work in our lives.”  He succeeds. 

Mr. Buettner assembled a multidisciplinary team of advisors and researchers to help him with a very difficult subject.  Do people living to 100, scattered over several continents, share any characteristics?  Do those commonalities lead to health and longevity? 

They studied four longevity hot spots (Blue Zones):

• Okinawa islands (Japan)
• Barbagia region of Sardinia (an island off the Italian mainland)
• Loma Linda, California (a large cluster of Seventh Day Adventists)
• and the Nicoya Peninsula (Costa Rica). 

Research focused on people who lived to be 100. 

Until recently, two of the Blue Zones—the Nicoyan Peninsula and Sardinia—were quite isolated, with relatively little influence from the outside world. 

Mr. Buettner et al identify nine key traits that are associated with longevity and health in these cultures.  Of course, association is not causation, which Mr. Buettner readily admits.  He draws more conclusions from the data than would many (most?) longevity scientists.  Scientists can wait for more data, but the rest of us have to decide and act based on what we know today.  Here are the “Power Nine”:

1. regular low-intensity physical activity
2. hari hachi bu (eat until only 80% full—from Okinawa)
3. eat more plants and less meat than typical Western cultures
4. judicious alcohol, favoring dark red wine
5. have a clear purpose for being alive (a reason to get up in the morning, that makes a difference)
6. keep stress under control
7. participate in a spiritual community
8. make family a priority
9. be part of a tribe (social support system) that “shares Blue Zone values”

Of these, I would say the available research best supports numbers 1, 4, 7, 8, and the social support system.

I doubt that hari hachi bu (eat until you’re only 80% full) will work for us in the U.S.  It’s never been tested rigorously.  The idea is to avoid obesity.  

The author believes that average lifespan could be increased by a decade via compliance with the Power Nine.  And these would be good, relatively healthy years.  Not an extra 10 years living in a nursing home.

Appropriately and early on, Mr. Buettner addresses the issue of genetics by mentioning a single study of Danish twins that convinces him longevity is only 25% deterimined by genetic heritage.  Environment and lifestyle choices determine the other 75%.  I believe he underestimates the effect of genetics. 

Over half the population of the Nicoya Peninsula Blue Zone are of Chorotega Indian descent, not from Spanish Conquistadores.  Would a Danish twin study have much tosay about Chorotega Indians’ longevity?  We don’t know, but I’m skeptical.  Also, the Sardinians and Okinawans would seem to have centuries of a degree of inbreeding, too, according to Buettner’s own documentation. 
 
Do the Adventists tend to marry and breed with each other (like Mormons), thereby concentrating longevity genes?  You won’t find the question addressed in the book.

Because I think genetics plays a larger role in longevity than 25%, I’d estimate that the healthy lifestyle choices in this book might prolong life by six or seven years instead of 10.  But I’m splitting hairs.  I don’t have any better evidence than Mr. Buettner, just a hunch plus years of experience treating diseased and dying patients.

These four Blue Zones do share a mostly plant-based diet of natural foods with minimal processing.  Two of the populations—the Okinawans and Costa Ricans—didn’t seem to have any choice.  Heavy meat consumption just wasn’t an option available to them.  Rather than promoting a low-meat plant-based diet, it might be more accurate to conclude that “you don’t have to eat a lot of meat, chicken, or fish to live a long healthy life.”

In other words, it may not matter how much meat you eat as long as you eat the healthy optimal level of fruits, vegetables, and whole grains.  It’s a critical difference not addressed in this book except among the Adventists.

Even if you could live an extra two years as a vegan, I’m sure many people would choose to eat meat anyway.  By the way, this book conflates vegan, lacto-vegetarian, lacto-ovo vegetarian, near-vegetarian, and vegetarian into one: vegetarian.  It’s a common problem when considering the health aspects of vegetarianism.  They are not necessarily the same.   

By the same token, plenty of my patients have told me they don’t like any kind of exercise and they won’t do it, even if it would give them an extra two years of life.  What many don’t realize is that from a functional standpoint, regular exercise makes their bodies perform as if they were ten years younger.  There’s a huge difference between the age of 80 and 70 in terms of functional abilities.

Why read the book now that you have the Power Nine?  To convince you to change your unhealthy ways, and indispensible instruction on how to do so.

Steve Parker, M.D.

Disclosure:  The publisher’s representative did not pay me for this review, nor ask for a favorable review.  They offered me a review copy and three give-aways, and I accepted.  I figure the cost of the books to the publisher was $16 USD total.  I gave away the books through my Advanced Mediterranean Diet Blog.  Cost of shipping the books to the winners came out of my pocket.