About the Book
The Blue Zones discusses areas across the world where people live unusually long, fulfilling lives. In these regions, the rate of people reaching 100 years old three times as many as those in the USA. In the book, author Dan Buettner states that studies on twins show that roughly 75% of the factors that play into longevity are environmental, with 25% genetic. As such, a change in habit or behavior can have a significant impact on one's quality of life, and how long they live.
Dan then goes into each blue zone, and discusses the factors that are likely to play into their longevity.
Keys to Longevity
Reading through the four regions (Sardinia, Okinawa, Adventists in Loma Linda, and Nicoya), there are several common themes. I've grouped them as such below
Mostly Vegetarian Diet
A diet heavy on beans, vegetables (especially green, leafy ones), and nuts are common elements across all the regions. Each group consumes their set of vegetables regularly, and many include superfoods that are known to help prevent inflammation and cancer.
In the Adventist Health Study, a survey of thousands of Seventh-Day Church Adventists in Loma Linda, California, vegetarians had a 2 year longevity advantage in the study. In the same study, nut eaters had a 2 year advantage.
Regular, Moderate Alcohol
All of the regions drank alcohol regularly. Sardinians in particular drank Cannonau wine, a local variant that has three times the flavonoids of regular wine. Flavonoids help reduce inflammation, and risk of cancer, stroke, and heart disease.
Regular Tea and Coffee Consumption
Throughout the day, everyone drinks a significant amount of tea and coffee.
Reduced Added Sugar Consumption
The added sugar consumption of most surveyed is under 25 grams, half of the daily added sugar recommendation of 50 grams. Many only take added sugar with their coffee.
The book calls out the significant amount of sun that the older generation of Okinawan get, with several hours of time out in the sun harvesting and growing vegetables.
In the Adventists in Loma Linda, Men who 5-6 glasses of water per day had a substantially lower risk of a fatal heart attack. Drinking increased soda, coffee, and cocoa resulted in a much higher fatal heart attack rate.
In the Adventist Health Study, physical activity (30 minutes 3 times a week) resulted a 2 year longevity increase and decreased incidence of heart and stomach cancer. Modest activity and the benefit levels out at the marathoner level.
Eat a Light Dinner
Eat a light dinner. There's no studies that support this, but it is common across all the regions for the dinner to be light. Most calories are consumed by noon, for those living in the region.
Have a Strong Social Network
All of the citizens in the region had a strong social network, visiting each other regularly. The feeling of need and purpose was common for all of those interviewed.
Thoughts on the Book
The Blue Zones was a pleasant and easy read, mixing in individual interviews and Dan's perspective with discussions around specific behaviors that may contribute to longevity, with studies and summaries near the end.
From a statistical point, correlation does not always equal causation, and it's important to keep that perspective when reading the book. The book highlights multiple behaviors that are linked to increased longevity, but it is hard to identify the individual factors that truly contribute to long term health.
However, sans some sort of manual on how the human body works, having a group of researches that have done the diligence of identifying the areas where people live the longest, healthiest lives, and extracting common elements, is extremely valuable. There will most likely be many parts of this book that will be disproved, but there is a lot of empirical evidence that these behaviors and practices will lead to a prolonged life with a higher quality of life.