One of the most interesting things you can study nutritionally are other cultures. In American and the West, we have an epidemic of heart disease and cancer. Most Westerners never stop to ask themselves if every culture and population on planet earth experiences these same epidemics.
The surprising answer is that there are a number of other population groups that have incredibly low rates of heart disease and cancer. These cultures are all almost universally "poor". They generally cannot afford luxuries such as a lot of meat and animal products. They eat and live simply. And, because of it, they bypass most of the frightening deaths that plague us more "wealthy" folks. (I cover other super-heart-healthy cultures, the Pukapuka and the Tokelua, in a link I call the High Testosterone Diet.)
So just how impressive are the Kuna with respect to protecting themselves from heart disease and cancer? A 2007 study, where the researchers compared mainlanders in Panama (eating a much more Westernized diet) versus the diet and lifestyle of the Kuna, showed the clear superiority of the Kuna people.  The researchers wrote, "In mainland Panama, as anticipated, cardiovascular disease was the leading cause of death (83.4 0.70 age adjusted deaths/100,000) and cancer was second (68.4 1.6). In contrast, the rate of CVD and cancer among island-dwelling Kuna was much lower (9.2 3.1) and (4.4 4.4) respectively."
These are incredible numbers: death from cardiovascular on the mainland was the leading cause of death just as it is in America and most other Western countires. The Kuna's death rate from heart disease was one ninth of that figure! And cancer, arguably the most frightening form of death, was only a sixteenth. (NOTE: Don't forget to read my link on Dark Chocolate, which works its magic by being chock full of cocoa, and Inflammation.)
This, of course, should be front page news. Scientist get excited when you can reduce heart disease by a half. Imagine going well beyond that! And the Kuna are not the only culture with these kind of numbers. So this is not just an anomaly or misreporting and there simply is no reason that we cannot enjoy the same kind of incredible health that the Kuna enjoy.
How do the Kuna do it? Well, one of the keys seems to be that the Kuna consume huge quantities of cocoa, which is nature's most flavenoid rich food. Cocoa has all kinds of magic qualities, including lowering blood pressure, reducing insulin resistance and increasing vasodilation (and Nitric Oxide).  The cocoa is so powerful that the Kuna do not even experience the normal rise in blood pressure that occurs with age!
How would this effect erectile function? Remember that Viagra and Cialis work by keeping Nitric Oxide in your system longer. So we can reasonably assume that erectile dysfunction, like cancer and heart disease, are a non-issue with the Kuna.
As I stated on the link about How to Improve Your Erectile Dysfunction: studies have shown that cocoa boosts Nitric Oxide and, as I often state, Nitric Oxide is the primary ingredient of an erection.  (And, no, don't think you can buy a Wendy's Frosty and solve your erectile dysfunction: it's low on cocoa and high on calories.) One recent study showed Nitric Oxide output increasing significantly in those who ate dark chocolate.By the way, just 3.5 oz./day of dark chocolate lowered blood pressure by 12 and 9 points after just 15 days!  Dark chocolate has even been shown to improve insulin sensitivity, one of the curses of the typical Western diet and a marker of Metabolic Syndrome. 
So is cocoa the only secret to the success of the Kuna? Well, it's certainly one of them: they drink over 40 ounces of hot cocoa per day! But it's undoubtedly not their only secret: they also eat a lot of fish, which is a very common theme among the Super Heart-Healthy Cultures of the world.
NOTE: Chocolate, which is of course made from cocoa, has been found to be more satisfying than kissing. It stimulates much a much larger region of the brain and its effects are much longer lasting according to one UK study. Also, did you know that two super-centenarrians were devoted chocolate fans, including the oldest woman on planet earth? (Stick to only dark chocolate which has high cocoa and relatively low sugar.)
If you want a lot of the gory details as to what exactly they eat, I recommend this link, which gives a nice summary: "In the first recent study, published in 1997, the Kuna diet is described as 29% lower in fat than the average US diet (56 g/day), 23% lower in protein (12.2 g), 60% higher in cholesterol, and higher in sodium and fiber. The study doesn't specifically mention this, but the reader is left to infer that 65% of their calories come from carbohydrate. This would be from plantains, corn, yucca, sugar and beans. The fat in their diet comes almost exclusively from coconut, cocoa and fish: mostly saturated and omega-3 fats."
1) Int J Med Sci, 2007, 4:53-58
2) Hypertension. 2005;46:398-405
3) JAMA. 2007 Jul 4;298(1):49-60
4) Amer J Clin Nutr, Vol. 81, No. 3, 611-614, March 2005
5) Amer J Clin Nutr,Mar 2005,81(3):611-4