Nicoya, Costa Rica: A Puzzling Blue Zone Diet Light on Vegetables and High in Carbohydrate and Sugar

My fourth investigation into exactly what our Blue Zone folks eat has left this dietitian, well, intrigued.  I have been exploring the data reported by National Geographic and Dan Buettner in the Blue Zones Solution: Eating and Living Like the World’s Healthiest People¹.  I am attempting to understand how to eat to increase my odds of living a long, robust life to 100 and perhaps beyond.  This hot equatorial Central American community, while not an island like Okinawa, Sardinia or Ikaria, is a peninsula surrounded by ocean on three sides.  Again, equatorial.  Again, surrounded by ocean.  Yet again, they eat little if any fish.

Gallo Pinto (Rice and Black Beans), Corn tortillas and Squash: The “Three Sisters” Native American Triad Staple

Breakfast, lunch and dinner are all varying amounts of pretty much the same things with some variations on sides.  My daughter recently went on a mission trip to a rural part of Nicaragua, just north of Costa Rica and came home to inform me that that was it.  Rice and black beans, homemade corn tortillas and fried plantain with a little salsa or jalapeno, avocado or fresh fruit, an occasional fried egg or small piece of chicken or pork or sprinkle of cheese, maybe some squash, sweet potato or shredded cabbage salad.  The same thing every day for every meal.  I have to tell you, it blows the concept of health being borne out of variety out of the water!  What is it about their food, lifestyle and/or environment that gives Nicoyans such long-lasting robust health?

Breakfast in Nicoya, Costa Rica

What other foods do Nicoyan centenarians eat?  A lot of sugar!  What?

According to the book, in addition to corn tortillas, rice and beans, about 4 ounces of low-glycemic vegetables like tomato, peppers, cabbage, carrot and onion.  They eat about 2 ounces a day of fried or boiled plantain, sweet potato or a local variety of winter squash, both rich in beta carotene.  They eat about 4 ounces of local fruit, including papaya, lime, orange and banana.  They eat a very small amount of cashews that grow regionally.  But according to the book, they consume 11% by weight of added sugar.  That is 33 teaspoons or about 2/3 cup every day.  They start their day with very strong, very sweet coffee.  And again in the afternoon, more very sweet coffee or nanju (Hibiscus esculentus seeds).  So if they drink 4 cups of a hot beverage a day, there is almost 3 tablespoons of sugar, and probably some of the milk, in each one.  I cannot lie.  There is a part of me that does not want to shine a light on this part of their diet.  But it is truth and I wish to share the whole truth.  If I can figure out how this does not produce adverse health effects somewhere along the way, I will be sure to come back and let you know.  No doubt, high antioxidant content of their local coffee to offset the pro-oxidant effects of the sugar is part of the story.

Lime treated grains, something Okinawa and Nicoya share!

I was surprised to find that a local Nicoyan dietitian described the way corn is treated to prepare it for grinding into flour is to soak it in lime (a caustic water solution of calcium hydroxide).  This treatment adds an enormous amount of calcium, breaks down some proteins to more absorbable forms and makes minerals more bioavailable.  In fact, the nutritionist believed this to be the most important food contribution to Nicoyan longevity.  While not noted in the book regarding Okinawa tradition, I actually read on line that this is also used in Okinawa to prepare wheat for making into noodles.  Huh!  With all the talk about various intolerances to grain, I wonder if the answer is here in these ancient cultures and traditions that render grains both more nutritious and more tolerable.

In addition to the generous amounts corn, rice and black beans, modest amounts of fruits, vegetables and meats, Nicoyans consume a rather generous amount of dairy, about ¼ of the total weight of their food, a little cheese and about a cup of milk a day.  The following table compares their consumption to the US and other Blue Zones I have discussed so far.

The Nicoyan diet contained more protein and fat and less carbs than Buettner “implies”.  To thoroughly understand amounts and proportions of food in terms that we normally think about, I carefully entered all the foods in the weight percent amounts described in the book’s pie chart and the food descriptions provided into my nutrient analysis software.  Here is what I found:

I don’t have a bias toward or against any macronutrient.  I just want the truth.  I am seeking meaningful and translatable information.  A deep dive again reveals recipes in the book modified traditional recipes to substitute canola oil for traditional lard and soy milk for their traditional whole cow or goat milk.  The recipes completely omit the cheese that their 107 year old host Panchita considered an important garnish on her gallo pinto.  But the food weight % numbers did not lie and created a very clear picture of exactly what the macronutrient distribution looks like.  The idea that all fat and saturated fat is damaging to health must be very hard to let go of based on the subtle misleading information in the book.  Research is very clear now that these ideas that fat in general and saturated fat are bad have had serious adverse consequences in increased diabetes and cardiovascular health in the US.  There are important lessons hidden in surprises.  Rather than suppress unexpected information in research, wouldn’t it be better to fully reveal and explore them?

A Moderate Protein Diet:  Once again, this diet is moderate in protein, not low protein.  In fact, again, this population is very small in stature, averaging about 5’ ½” tall for women.  The proper way to characterize protein intake is per kilogram of body weight.  So here is how protein intake in the traditional Nicoyan diet compares to the other Blue Zones and the typical US diet.

Beyond Food Again:  Faith and Gratitude

Dan Buettner and his team did a wonderful job of capturing the “beyond food” side of living well to 100 and beyond!  I want you to know that there is clearly more to the story and he has told it well.  What struck me as I read about his experience in Nicoya, Costa Rica and the lovely 107 year old Panchita that he befriended was her enormous sense of joy and gratitude.  She had a faith practice and was spiritual.  She continued to live with a family member and contribute in a meaningful way, giving her life continued purpose, including cooking an example meal for her surprise guests.  She wore a bright colored dress and beads to do her daily chores and greeted strangers with a big smile and reminder that…

“God blesses us.”

If you know me, you know that a bright colored dress and beads and a big smile certainly resonates with me personally (though my dress would be purple flowers).  In truth, a plant-based diet might just fade in importance by comparison to these things.  I am grateful to Dan Buettner and National Geographic for researching and publishing their findings which has allowed me to translate the information into practical dietary changes that might just enhance your quality and quantity of life!

1. Buettner, D. (2015) The Blue Zones Solution: Eating and Living Like the World’s Healthiest People. Washington, D.C.:National Geographic Society.
2. Buettner, D. (2016) Blue Zones: The Science of Living Longer. Washington, DC: National Geographic.
3. United States Department of Agriculture Economic Research, Food Availability (Per Capita) Data System. https://www.ers.usda.gov/data-products/food-availability-per-capita-data-system/food-availability-per-capita-data-system/#Loss-Adjusted%20Food%20Availability