Is it possible to live to be 100? Your odds are better today than they ever were. The stopper is your diet and lifestyle for the most part. If you smoke, drink heavily, use recreational drugs, have unsafe sex, eat unhealthy, and well you get the message that there are lifestyles that shorten your life.
To look for longevity, one must go where people live long and how they get there. Lets go to Okinawa. We may as well give the statistics to Japan to which Okinawa is a part. Still there is proof that the diet and lifestyle really work. The key is the weight and BMI that comes from healthy eating.
I'm not crazy about tofu or soy so it is out. Although I will not drink cow milk, I have 4 oz. of yogurt daily and cheese occasionally. I also from time to time drink goat's milk.
We really can't change our genes and if our parents didn't give us longevity, we must live as healthy as we can until our death. And there are more than one way to beat the odds. Even Dr. Oz gives a prescription to longevity.
Don't confuse the Okinawa diet with a Calorie Restriction Diet which is more harmful than helpful. You want calories coming from the right foods. Case in point. Just be aware that a real longevity diet may not exist.
Keep in mind that genes and environment may play a role. If people live longest in Japan, it is possibly due to parents passing on their genes to their progeny. What they consume is possibly abundant and fresh in their country. What works for them, may or may not work for you, but that doesn't mean that there won't be benefits and it couldn't hurt. It is yet a step up in your healthy lifestyle goals.