How do Okinawan citizens outlive the rest of the world when their diet consists of a large amount of fish?


I know fish has its laundry list of benefits, but surely consuming a large amount can have detrimental effects due to mercury, microplastics and PCBs, yet it doesn’t seem to affect blue zones like Okinawa where their citizens outlive most other nations (with a large amount of centenarians) and consume large amounts of fish.

Why is this?

In: 5

The Japanese in general have a very long life expectancy, largely because of extremely low obesity rates. In the US, for example, heart disease is the #1 cause of death and stroke is #5. Fish might contain some harmful chemicals, but it’s also a pretty lean source of protein. What’s important here is not just that they *are* eating fish, but that they *aren’t* eating a lot of high-fat land meats like beef.

That said: nutrition is really complicated. We can be pretty confident that obesity is bad for you, but exactly why obesity occurs is an active area of research (yes, calories-in/calories-out, but there’s lots of variables that influence both).

I used to live in Japan. A few things granny in Japan did, that granny in US cannot do:

Sit on the floor while watching TV & entertaining guests

Walk to the grocery store, taking a rolling tote with her

Drinking green tea every day (until the caffeine became too much)

Eating very small portions (extremely small portions of fish too, by the way)

No red meat, semi-vegetarian diet
LOADS of veggies

Rarely eats bread. Eats rice daily.

Soaking in a hot bath up to her neck most nights


Mercury is a bigger problem for larger fishes like sharks, swordfish. Fish commonly eaten in Japan like Mackerel, Cod or Saury should be very low risk. Salmon and Tuna are slightly higher but those are not eaten as often. For those fishes, eating 150 grams a day or so shouldn’t have any long term effects of mercury poisoning.

Fishes are usually much lower in saturated fats compared to pork or beef so the risk of heart disease at an early age is lower.

With the good and bad of eating fish, we don’t fully understand the effects of some thihgs. Mercury we do have a pretty good understanding, eating too much deep sea fish will cause issues. But mercury only causes real problems in high food chain hunting fish. The higher up the food chain a fish is, the more mercury becomes a concern, because mercury accumulates in the flesh of fish and each time a fish is eaten by a larger fish, mercury accumulates. But Not all ocean fish have significant mercury problem, some can be eaten just fine with less concern about mercury intake.

Maybe they naturally have longer telomeres in their DNA?