Do you want to live to be 100? Maybe you can. At the very least, you can extend your life by 12 years past the American average if you change how you do things just a little bit. That's the surprising lesson that National Geographic writer Dan Buettner shares in his engaging TED Talk "How to Live to Be 100+".

Buettner studied this question by traveling the world to visit what he calls "Blue Zones"--places where surprisingly large segments of the population live past 100, usually spending those extra years in vigorous health and enjoying their families and lives. What, he wondered, do these centenarians in places as diverse as Sardinia, a small island off the coast of Italy, Okinawa, and a Seventh-Day Adventist enclave in Loma Linda, California have in common? 

More than you would think, it turns out. Here are some common habits Buettner found among his first set of Blue Zones--and that he's continued to find as he visited more Blue Zones around the world. 

Amazingly, these are things all of us can do, without making dramatic changes to our lifestyles or living environments. I'm going to try them all. How about you?

1. Eat mostly plants.

Most of these groups are not vegetarian. But in every case, plant-based foods form the biggest part of their diet. That means vegetables, legumes, nuts, and, in the Okinawans' case, lots and lots of tofu. Meat, and animal-based foods in general, play a much smaller role. The Adventists actually are vegetarian because they eat only foods mentioned in certain passages of the Bible. And the Sardinians' biggest source of animal protein is cheese from grass-fed sheep, much healthier and higher in beneficial Omega-3 fatty acids than the dairy products from corn-fed animals common in the United States. They also drink a small amount of alcohol every day.

Many of these groups have subtle strategies to encourage themselves to eat less. For instance, the Okinawans, following a Confucian principle,  remind themselves before every meal to stop when they feel 80 percent full--a good idea because there's a half-hour delay between when your stomach is full and when your brain gets the message.

2. Walk a lot.

None of these groups have much in the way of organized exercise, and none of them go to the gym. But their lives are set up for constant movement that adds up to exercise. The Sardinians live in tall houses with lots of stairs, and they walk most places they're going, for instance. People in all groups tend to socialize by taking walks together.

Walking, Buettner says, is "the only proven way to stave off cognitive decline." It's also a proven mood elevator. Whatever else you may do for exercise, make sure to do lots of walking as well.

3. Plant a garden.

People in these long-lived groups tend to have their own gardens. For one thing, that's a great way to get the freshest, healthiest produce for your dinner table. It also requires you to exercise, and to get up and down off the ground a lot, something that seems to add to agility and longevity. The Okinawans sit on the floor, Buettner notes, and they get up and down 30 to 40 times a day.

4. Take at least one day off every week.

There's plenty of evidence that at least one day a week away from work makes you more productive and is actually beneficial for your brain. It's also something all these groups do, usually for religious reasons. The Seventh Day Adventists do this as part of their religious practice. The Okinawans have ancestor worship. In every case, there's one day out of the week to recharge and focus their attention away from work and the usual concerns. 

5. Pray or meditate.

All the Blue Zone groups tend to gather in faith-based communities, something Buettner says is worth 4 to 14 extra years of life expectancy if you do it at least four times a month. But what about people like me who don't belong to any church or other religious group? Make sure to at least take time to slow down and decompress regularly, ideally on a daily basis. 

"When you're in a hurry or stressed out, that triggers something called the inflammatory response, which is associated with everything from Alzheimer's disease to cardiovascular disease," explains. "When you slow down for 15 minutes a day you turn that inflammatory state into a more anti-inflammatory state."

6. Hang around healthy people.

Longevity-supporting habits are part of the social structure in these communities, and that's a good thing, Buettner says. "We know from the Framingham studies that if your three best friends are obese there is a 50 percent better chance that you'll be overweight," Buettner says. "So, if you hang out with unhealthy people, that's going to have a measurable impact over time. Instead, if your friends' idea of recreation is physical activity, if your friends drink a little, but not too much, and they eat right, and they're engaged, and they're trusting and trustworthy, that is going to have the biggest impact over time."

7. Spend a lot of time connecting with your family and your community.

One common thread through all these long-lived communities is that they put family first. Entire families, from small children up to very old people tend to live together and take care of each other, he observes. Indeed, these cultures tend to celebrate their older members and venerate them for their wisdom. They are all tight-knit communities, and the Okinawans have a system called Moai, translated as a group for common interest which gives each Okinawan a solid social and practical support system. All of this, Buettner says, is life-extending.

8. Know why you're here.

One of the things that most helps you lead a long life is a strong sense of purpose, something the Okinawans call "ikigai." Having a powerful reason to live can be a strong antidote to early death. This is why, Buettner says, the year people retire is one of the most dangerous years of their lives. In our culture, he adds, people who've worked at something they cared about all their lives suddenly stop and go off to Arizona to play golf, whereas "retirement" isn't even a word in the Okinawan language. This is the kind of reason 85-year-old Warren Buffett says he tap dances to work every day and plans never to retire--investing is his ikigai. 

Some of the Okinawans told Buettner their ikigai was to fish three times a week to feed their families, or perform a martial art. And one 102-year-old Okinawan said her ikigai is her great-great-great-granddaughter--for this 102-year-old holding her baby descendent feels like "leaping into heaven." 

Which is great motivation for staying a little longer here on Earth.