The Problem With Coconut

If you're not a Pacific Islander, your genes may not be compatible with a 63% coconut diet.

The coconut was first domesticated in Southeast Asia, and spread through sea voyage as far east as the Pacific Islands and as far west as the eastern coast of Africa thousands of years ago.

While coconut has been traditionally used across the tropics, the populations that consumed the most coconut ever recorded are those of the Pacific Islands.

In particular, the natives of Tokelau hit the world record, obtaining 63% of their calories from coconut. Their neighbors in Pukapuka consumed only 34% of their calories as coconut.

On the somewhat neighboring island of Kitava, they obtained something on the order of 18% of calories from coconut.

The coconut use in Tokelau was mixed between coconut oil, cream, meat, and milk.

The problem with coconut is if you consumed 1500 Calories from it, you’d get 6.4 milligrams of manganese. Then you’d have to eat other food, which would give you even more manganese.

A 1992 study found that four months of 15 milligrams of manganese per day caused no adverse effects in women, but it didn’t report anything specific about how it solicited information about adverse effects, so I don’t really trust it. Regardless, at face value it suggests much higher manganese intakes are harmless to the average person.

In Iron Overload: Forget What You Thought You Knew, I made the case that approximately 9% of people globally should be concerned about manganese intakes above two milligrams per day, since they could be vulnerable to manganese overload.

This is driven by hemochromatosis genes, which cause combined iron and manganese overload.

The most common of these genes is HFE. The two most common variants in it are C282Y, which is more severe, and H63D, which is less severe. The rates of H63D are almost three times lower and those for C282Y are more than five times lower in Pacific Islanders surveyed in California and Hawaii compared to whites. Asians have the lowest rates, whites the highest, other racial groups in between.

They are not found at all among the natives of Brazil, which led the authors to speculate as follows:

The absence of both defects in the Amerindians suggests that these mutations could have emerged after the migration of Polynesians to America, or that they may not have reached the Polynesian population until after the migration to America had occurred. Corroborating this hypothesis, the C282Y and the H63D mutations have a very low prevalence in populations of Asian origin. Therefore, the C282Y mutation may have been introduced into these populations by Caucasian admixture . Another possible explanation would be that the Parakana Indians lost these mutations sometime during their evolution through a combination of founder effects and genetic drift.

This raises the possibility that Pacific Islanders in California and Hawaii only have these mutations as a result of admixture with whites. If that’s the case, the rate of these mutations in the populations that traditionally eat coconut as a major source of calories such as in Tokelau were probably zero.

In further support of this, an Australian study from the late 1990s found that every single Pacific Islander who had one of these variants also had HLA genes that were typically found in whites with hemochromatosis, suggesting that these mutations originated in whites and the prevalence in Pacific Islanders prior to admixture with whites was zero.

The manganese doesn’t make it’s way into coconut oil, and some of it was probably lost in cooking water when boiling the meat.

Still, the proportion of people with hemochromatosis genes in Tokelau during the evolution of their 63% coconut diet was probably zero.

So emulating their diet has its risks for those of us who are likely to have such mutations.

There are plenty of other high-manganese foods, one in the animal kingdom — mussels — and the rest in the plant kingdom. But most of the foods with very high manganese-to-energy ratios are herbs and spices, where you may get a boost from them, but are unlikely to get 5-10 milligrams.

Any diet that is rich in fruits and vegetables is going to add up to at least a few milligrams of manganese. But there are not a whole lot of foods where it would be traditional to use them as the primary source of energy that are high in manganese. For example, white rice, corn, and potatoes are all relatively low in manganese, with corn winning the record as low-manganese starchy calorie-stuffer.

Coconut is very high in manganese, which is great if you have no impairments in your regulation of manganese absorption, because it’s also super-convenient as one of the few magnesium-rich, potassium-rich, low-anti-nutrient sources of fat.

If you have a genetic predisposition to overload of iron and manganese, however, it’s better to steer clear of coconut meat and cream and just stick to coconut oil, or to just steer clear of coconut entirely.

I covered how to know if this applies to you in “The Bottom Line” of the Iron Overload: Forget What You Thought You Knew article.

If you find yourself with headaches, irritability, insomnia, depression, loss of balance, problems walking normally, or Parkinson signs such as rigidity and tremor, and you’re eating coconut all day long, stop.

If you love coconut and this doesn’t apply to you, enjoy! You’re the majority.