It’s the attitude adjustment that could save your life: A new study finds that happy people live longer — which means a smile might turn out to be the cheapest, safest, and easiest longevity-booster on the planet.

Can you think of any drug or supplement that can slash your risk of a premature death by 35 percent? I can’t — but the study of 3,800 people between the ages of 52 and 79 found that happiness did just that, even after adjusting for age, gender, depression and other health and lifestyle risks.

All told, just 3.6 percent of the happiest people died during the five-year study — versus 4.6 percent of those who had average levels of happiness and 7.3 percent of those who were unhappy.

The volunteers also answered questions about fear, anxiety and worry — but none of those other attitudes seemed to have any effect on who lived and who died.

Just happiness — although it could also be that the very things that make us happy also help us to live longer.

Married people, for example, live longer… and people who’ve been married a long time tend to be happier than those who are alone (even if we might joke otherwise).

Happier people also have a tighter circle of friends — something that’s also known to boost both longevity and happiness.

On the other hand, attitude alone really can have a direct and measurable impact on health, like a study a couple of years back that found happy people have a 22 percent lower risk of heart disease.

Another study I told you about over the summer found that an attitude closely linked to happiness — optimism — slashed the risk of a stroke.

And last year, researchers found that the most disagreeable people were more likely to have thicker carotid arteries — which would explain that increase in stroke risk, not to mention the thick bulging neck veins seen on angry cartoon characters.

I know changing your attitude is easier said than done — especially if you have years of experience in the grouch department. But while it’s difficult, it’s not impossible — and if you can pull it off, it might just save your life.

You might think the only “exercise” you’ll get from drinking wine comes from lifting the glass — or maybe struggling to open the bottle.

But it turns out resveratrol, the famous “red wine antioxidant,” can actually trick the body into thinking it’s getting some actual exercise — giving you a big-time metabolic boost with every little sip.

In just 30 days, 11 obese-but-healthy volunteers — as healthy as obese people can be, anyway — given 150 mg of resveratrol a day had real and measurable changes throughout their bodies.

They shaved five points off their blood pressure, lowered their blood sugar, and even reduced their levels of liver fat. In fact, just about the only thing it didn’t do would be one thing you’d really hope for the most — because none of the volunteers actually lost any weight.

I know. So much for the “red wine diet.”

But while they didn’t look any different from the outside, what took place on the inside was nothing short of amazing: The researchers wrote in Cell Metabolism that the volunteers had dramatically slower metabolisms during sleep.

These were the kinds of changes normally seen in people who try the impossible-to-follow ultra-low calorie diet… except these volunteers didn’t cut back on their calories at all.

The only “catch” here is that you can’t expect to get these types of benefits from red wine alone — because while it might be the tastiest way to get the antioxidant, it’s not actually the best way to get it.

In fact, you’d need between 50 and 100 glasses of red wine a day to get the 150 mg of resveratrol used in the study!

So clearly, if you want the benefits of resveratrol, you’re going to have to invest in a quality supplement or an antioxidant blend with resveratrol in it. It’s worth the money: Other studies have shown that it can protect the heart, save your vision, reduce blood sugar levels and even help you live longer.

But don’t toss the wine, either. It’s loaded with polyphenols that can boost your heart health and stimulate your immune system.

And booze in general is packed with benefits: Studies have also shown that moderate drinkers who enjoy any type of alcohol live longer, healthier lives than people who don’t drink.

So get a little exercise tonight and raise a glass to your lips. It’s the best workout of all.

Resveratrol isn’t the only way to boost your health and longevity — keep reading for something even simpler.

Gentlemen, listen to your wives: What you might dismiss as nagging could save your life — especially if she’s nagging you to get to the hospital.

A new study finds that married men who suffer a heart attack are more likely to get to a hospital quicker than their bachelor counterparts — and researchers believe it’s because their wives are urging them to go at the first sign of trouble.

Men on their own, on the other hand, stubbornly refuse to seek help until the last minute — or even until it’s too late.

Canadian researchers looked at data on 4,403 heart attack patients with an average age of 67, including 1,486 women, and found that married patients got to the hospital an average of 30 minutes sooner than single ones.

That’s 30 crucial minutes to get treatment for a condition in which every second counts.

But the benefit went almost entirely to men: The researchers say that married men were 60 percent less likely to arrive late when compared to single men, while women reached the hospital in the same amount of time regardless of marital status.

The researchers say women take on a “caregiver” role when they’re married and will push their husbands to seek treatment when something’s wrong. What’s more, they say married men will even seek help when their wives aren’t around — because they know their wives would want them to.

“As my husband put it, even if I wasn’t there telling him to go to the hospital, he’d hear my voice telling him to do so,” lead author Dr. Clare L. Atzema told the New York Times. “Even when they’re not there, women have a pronounced effect.”

Either that, or marriage causes voices in a man’s head.

If that’s the case, at least they’re good voices: Other studies have found that married men are healthier and live longer than their single and divorced counterparts. Women also enjoy some benefits from marriage — although, generally speaking, the differences are not as pronounced as in men.

But since they already live longer than men anyway, maybe it’s simply of a case of “he needs her more than she needs him.”

Years ago, researchers tried using olive oil as a placebo in trials for heart drugs.

As it turned out, olive oil — not widely known at the time for its heart benefits — protected the patients in placebo groups better than some meds.

And today, it’s routinely given to cardiac patients instead of drugs.

Just kidding!

The reality is much more predictable. Big Pharma quickly put the kibosh on olive oil in its studies and found a placebo that made its drugs look better… and today, docs would rather prescribe those meds than urge patients to use more olive oil.

It’s too bad — because it turns out this stuff isn’t just great for your heart. It can also reduce your risk of a stroke.

Researchers tracked 7,625 French seniors who had never suffered a stroke, then broke them down into three categories based on olive oil use: none, moderate, and intensive.

When you see the results, you’ll want to start putting olive oil on everything — because researchers say that over five years, the folks in the “intensive” group were 41 percent less likely to suffer a stroke even after adjusting for diet, weight, physical activity, and other risk factors.

In a second experiment, researchers took blood samples from 1,245 seniors and measured levels of oleic acid.

That’s the key monounsaturated fat found in olive oil, and the researchers wrote in Neurology that the third of patients with the highest levels were 73 percent less likely to suffer a stroke than the third with the lowest.

But the benefits, of course, don’t end with a lower risk of stroke. Other studies have found that olive oil can help lower levels of LDL cholesterol, reduce blood pressure, slash your risk of heart attack, and even help you live longer.

If you’ve already had one heart attack, olive oil can help you to avoid a second one.

It can even help you to lose weight.

Some people use this stuff on their skin and hair, but you don’t have to go that far. Just cook with it and be sure to add it to your salads, and you’ll get everything you need to protect your heart and mind.