Living longer doesn’t always mean living better–and for too many people, those later years are anything but golden.

Now, researchers have found a new way to show what’s a stake when bellies get big and knees buckle under the weight: lost years, even if you happen to be using them while you’re losing them.

How can that be? Easy: The years aren’t lost to death… but to pain and poor health.

For example, someone with obesity and osteoarthritis in both knees–usually caused by that obesity–might live as long as someone who has neither condition… but lose 3.5 years to chronic pain and misery, according to the study in the Annals of Internal Medicine.

That’s a lot of time lost to pain.

Someone who is obese but manages to avoid knee osteoarthritis will lose 2.5 years to pain and suffering, while slim people who suffer from knee osteoarthritis will lose about 1.9 years.

The shame of it is that both conditions are preventable: You can lose weight and keep osteoarthritis at bay by committing to simple lifestyle changes.

But these aren’t tiny, incremental changes–and that’s where the new study falls apart, because the researchers insist that just dropping a few pounds can make all the difference in the world.

They say that losing just 3.74 pounds, for example, would eliminate 178,000 cases of heart disease and 890,000 cases of diabetes.

Fat chance.

It’s highly unlikely that someone who’s 250 pounds will somehow have a better, healthier life than someone who’s 253.74 pounds.

The fact is, if you want to avoid obesity, diabetes, knee osteoarthritis and more, you need to bring your weight under control–and that means doing something far more dramatic than cutting back to an Extra Value Meal every other day instead of five times a week.

No one likes to be lectured about weight so I’ll keep this short and sweet: If you’ve put on a few too many pounds over the years–and don’t feel too bad about it, because you’re hardly alone–the best way to make sure you’ll reach a ripe, old age and have the power to enjoy those later years is to lose the weight now.

Tai chi is one of those things that can look awfully funny to outsiders: A group of people, standing in rows, moving slowly and silently as if fighting in a low-speed martial- arts tournament.

But did you know that those slow, deliberate movements could bring some serious pain relief? Maybe these folks are the ones getting the last laugh… because a new study finds that tai chi can help people cope with knee osteoarthritis.

Tufts University researchers looked at 40 OA sufferers. Half of them did 60 minutes of tai chi twice a week for 12 weeks. The other half served as a control group – they were given two 60-minute classes twice a week that went over OA information, diet, education and discussions of more traditional therapies.

In the end, the patients in the tai chi group reported significantly less pain than those who sat through the classes.

The research is promising and it certainly won’t hurt to try. My concern is that tai chi exercises don’t appear to do anything to the underlying condition behind knee osteoarthritis, specifically the loss of cartilage in your knees.

But pain relief is pain relief – and simple exercises are a much better option than painkillers that can destroy your stomach and lead to other problems.

If you’re willing to give tai chi a shot, I’d suggest doing it in concert with something else, like a glucosamine supplement. Many people add chondroitin to this, but I’d suggest seeing if you can get by without it. Some studies have linked chondroitin to prostate cancer, and while the research is early there’s no reason to take the chance when so many people get relief without it.

It’s pretty easy to find a tai chi group if you live in a big urban area. Elsewhere, it may be a bit trickier – but you can start by asking the workers at your local park. Since many tai chi groups meet in parks in the morning, the staff here might be able to point you in the right direction.

You can also try local martial arts schools – even if they don’t offer tai chi, they may know someone who does.

And even if tai chi doesn’t deliver on the promise of pain relief, it’s still a great way to get outside, get moving and socialize.

If you want to be healthier, quit smoking. Few people, even many smokers, would deny that at this point.

Now let’s get a little more controversial here: If you want your whole community to get a health boost, then ban those cancer sticks in every public place you can.

I know that’s not a popular move among smokers — they already feel like a persecuted minority. But you just need to look at the numbers to see what a difference it makes.

One study finds that U.S., Canadian and European cities that impose smoking bans have 17 percent fewer heart attacks over the course of the first year of the ban, as compared to cities that don’t curb cigarettes.

Fantastic, right? But it gets better…

Those numbers continue to decline by between 26 and 36 percent over three years, according to studies published in Circulation: Journal of the American Heart Association and the Journal of the American College of Cardiology.

Researchers believe that a nationwide smoking ban in public places and offices would prevent up to 225,000 of our 1.26 million annual heart attacks.

These benefits extend to smokers and nonsmokers alike. Remember, of the 440,000 U.S. deaths linked to smoking every year, 38,000 are due to secondhand smoke — many from heart attacks.

Now, some people still argue over this, in part because many smokers want to believe that they’re hurting only themselves. But the truth is cigarette smoke causes blood vessels to constrict and leads to blood clots in both the smoker and the guy standing next to him.

These changes can take place in as little as 20 minutes of exposure to cigarette smoke… and that’s why nonsmokers who live or work with smokers have a 30 percent higher risk of heart attack than nonsmokers who live and work with other nonsmokers.

The science is clear on this — secondhand smoke is not a myth. It’s a fact, and that’s why public smoking bans are leading to such dramatic health improvements.

And if they get a few smokers to finally throw up their hands in frustration and quit for good, so much the better. Smoking is hands-down one of the worst things you can voluntarily do to yourself, and a terrible habit to subject your friends and loved ones to.

The risks of smoking are well known and well documented. Tobacco is addictive, and the addicts suffer from everything ranging from that persistent smoker’s cough and diminished lung capacity right up to lung cancer, heart disease, hypertension and early death.

Smoking has even been linked to knee osteoarthritis.

And with apologies to all my friends who love their cigarettes, smokers always smell like smokers. So in addition to being a health hazard, smoking is also a social one.