Now, sushi is a staple in the Japanese diet and that can help people there live longer.
Now, sushi's main ingredients, fresh fish and dried seaweed, have positive health effects.
Dr. Sanjay Gupta explains.
There are some cities around the world that have extraordinarily high life expectancy rates
and health officials are trying to figure out exactly what is it about those places that is somehow different.
A good place to start looking is Japan.
One thing I can tell you right off the bat, it has less to do with genetics and a lot more to do with the environment,
and specifically the types of food that they eat.
This is one of the most popular places you'll find in cities [countries] like Japan --
you have octopus, over here, you have squid -- fresh fish markets.
This is a place that a lot of people come [to] and they buy fish every single day and this is particularly fresh fish as well, as you can tell.
Just looking around here, you can see how fresh this is.
But there are some fish you really should pay attention to.
You have crabs over here, you have big clams, small clams,
but there are certain fish, for example, that are really high in Omega-3 fatty acids.
Mackerel over here; if you've ever had this, it's a great fish, very high in Omega-3 fatty acids.
Salmon is another one.
And if you look at the blood of Japanese people versus people in other parts of the world,
often those levels of Omega-3 fatty acids are twice as high.
It's probably not surprising that heart disease, such a big killer in the United States,
you have rates that are about half of that here in Japan.
So, and this is a big reason why, specifically, Omega-3 fatty acids, terrific at lowering your blood pressure,
decreasing the clots and the clogging in your arteries and lowering your triglyceride levels.
Tuna, another great fish, for example, great pieces of tuna here, again, all of it very fresh.
People come here every single day.
On average, people in Japan eat about one to two servings of this type of fish per day.
As compared to in the United States, for example, where they eat one to two servings per week.
Just really quickly as well.
Seaweed, you may be hard-pressed to find this at many stores in the United States,
but that's another great source of antioxidants and it's also often eaten with fish.
Now, if you hate fish, there's there are other ways to get the antioxidants soybeans,
for example, tofu, flax seed, walnuts. Those are all great sources as well.
But again, really trying to figure out why people live longer in big cities around the world,
a lot of it has to do with the type of diet they eat.
And in Japan, where they do it better than anywhere else,
fish -- specifically Omega-3 fatty acids -- make a difference.
You know, there's something else they taught me here as well,
and it's this idea that you should push your plate away before you're ever full.
They call it hara hachi bu; it's a really good phrase. Never stuff yourself.
That's advice you can use no matter where you live anywhere in the world.