Just after I pushed the post button for my blog, I had two other thoughts: people might want to know where I'm getting my data about the longevity of Costa Rican men, and if I were smart, I'd write a diet book.
The first part is easy: Dan Buettner, in his book, The Blue Zones, describes the daily life of elderly men and women who live near the city of Nicoya on the Nicoya Peninsula in Costa Rica. He emphasizes their diet, and its roots in the culture of the Chorotega people who lived in Nicoya long before the Spanish conquest that began in 1502. It's a good book, and I recommend it for people interested in diet and longevity. However, there is a scientist who really discovered the phenomenon of the old men of Nicoya, a man named Luis Rosero-Bixby, originally from Ecuador, but who did his principle research as a demographer at the University of Costa Rica. You can easily obtain the original papers from Dr. Rosero-Bixby's web page, http://web.me.com/lrosero/RoseroBixby/Bienvenida.html
And here is his seminal paper, http://ccp.ucr.ac.cr/creles/pdf/rosero60.pdf
Now about that diet book!
The Chorotega Diet book is about one page long. I'm afraid that nobody is going to get rich off this, either the concepts or some fancy packaged foods or calorie counting diet plan. Here are the basics:
Equipment: a crock pot is nice. So is a rice cooker.
Beans: Any kind are good. Black beans are the softest and cook most quickly. Some people favor lentils. There are micro-differences in the nutritional content of each legume, so it may pay to vary them.
Take some beans. Maybe a cup or more. Soak them over night. Rise them off. Put them in the crock pot and cook on low until you are hungry or ready to eat. Don't add salt or acid to the beans until they are truly soft and mushy. Then add anything you want. I like garlic, carrots, and onions. Cooked beans last up to 3 days in the refrigerator.
Rice: I prefer brown, but it is more expensive. Cook in a rice cooker or on the stove. 1 part rice to 2 plus a little parts water. It helps keep the rice from sticking if you coat the pan with oil first. Cook for about ½ hour, until the rice is done. Rice can wait one day in the refrigerator, but my sister the infectious disease specialist says no more than one day.
Corn: This is hard, and most people don't do it by hand anymore. You can buy perfectly good maize, or corn meal, at most grocery stores. Add water to make a dough, and fry to make tortillas. Or buy corn tortillas made in stores.
That is it. I don't see any way to make money off this diet book. The key is to have lots of nice fruits and vegetables available, and spices and sauces. In Costa Rica, the favorite sauce is called Lizano Sauce, but really you could use ketchup or tomato sauce or tamari. There is a very nice apple/chipotle pepper sauce at the local grocery store in Flamingo. The key is to think ahead with the beans, soak them and slow cook them. And don't expect Parisian delicacy or Japanese art from this diet. It is just plain good food.