This one’s bound to make some pretty big waves: Yet another new study backs marijuana for medicinal purposes in a big way.

This time, researchers have found that pot can not only help beat pain — as people who already take it for that purpose, legally and illegally, have been saying all along — but it may even help steer patients away from dangerous and addictive painkillers.

And that includes the meds responsible for some of society’s biggest drug problems: opioid painkillers.

Twenty-one chronic pain patients who were already taking either long-acting morphine or long-acting oxycodone were given marijuana vaporizers to use for five days — in a hospital, where they could be carefully monitored in case any complications arose.

Researchers were especially worried that the pot might boost levels of opioids in the blood to dangerous levels. In reality, it led to no changes at all — while delivering 33 percent more pain relief to the morphine patients and 20 percent more pain relief to the oxycodone patients.

The patients didn’t experience any major side effects, beyond feeling “high” after getting their marijuana dose.

No one in the study actually took fewer meds — but since the patients were already growing more resistant to their opioid painkillers and got extra relief from marijuana, the indication is that eventually they could cut back on the meds if they were allowed to stick with the pot.

Of course, the study does have its problems: It didn’t have a placebo, for one. And it was small — but size is almost always a problem when it comes to studies on medical marijuana.

Researchers simply can’t get the funding they need for bigger studies since marijuana isn’t exactly popular with the folks who control the purse strings.

But the studies we do have are pretty clear: Medical marijuana comes with some very real benefits… and minimal risk.

Despite what you’ve heard, it’s not even addictive in most cases. Sure, people can overdo it — but that’s a risk we already take each day with every drug already on the market (especially opioid painkillers).

This isn’t a popular opinion, but it’s a scientific one — not to mention a humane one: For some conditions, especially chronic pain, marijuana is safe and effective — and that means it should also be legal.

The last thing anyone with a sore back wants to do is move it around.

I know — I’ve been there myself, and the natural reaction is to find a spot where you can sit as stiff as a board and move as little as possible.

The other natural reaction, of course, is a fistful of painkillers.

Don’t give in to either reaction: There isn’t a bad back on the planet that’s been cured by painkillers, and a new study confirms that sitting tight can actually make the pain worse — and even boost your risk of depression, too.

Researchers randomly assigned 109 back patients to either stay active through the pain or limit their activities as much as possible — and if you’re suffering from back pain you might want to get up for this one: Those who moved had quicker recoveries, less pain and less depression than those who limited their activity.

The researchers say a person who goes into statue mode when they feel back pain could be setting themselves up for the classic downward spiral: Since they’re not moving, they feel more pain. When they feel more pain, they get depressed — and since depressed people feel pain more, it can feel even worse than it really is.

Of course, anyone who’s battled back pain — and that’s nearly everyone at some point — knows there’s no one-size-fits-all formula for treatment, but too many doctors stubbornly insist on giving everyone the same advice.

Along with a big jar of painkillers.

Now, another new study confirms that docs have it all wrong — because patients given a more customized treatment plan get better results at a lower cost.

Researchers divided back pain patients into three categories based on their risk of long-term pain and disability, and assigned them to different levels of advice and/or therapy based on that risk.

A year later, these patients all had less pain and more improvements than a group that got the standard one-size-fits-all advice.

Sounds good — but make sure your customized treatment plan isn’t a choice between one bad mainstream option and another.

Despite what you’ve heard, you can beat the pain — even extreme pain — without meds or surgery. Acupuncture, massage therapy, chiropractic care and more have all shown to help put back pain on the back burner.

And in many cases, time alone can heal those invisible wounds.

For more on natural back pain options, visit the Web site of the Health Sciences Institute and enter “back pain” into the “Find a Cure” box.

And don’t forget to keep moving.

I’m always puzzled by the millions of people who take dangerous meds that barely work in the first place — but now I’m starting to see why: They have no idea what they’re in for.

A new survey finds that 40 percent of Americans believe the FDA only gives the OK to “extremely effective” meds — and 25 percent believe FDA-approved drugs don’t have serious side effects.

Even the FDA will tell you that’s not the case.

Drugs don’t have to be safe to win approval: Meds that win passage often have severe and terrifying side effects, up to and including death itself. And they don’t even have to be especially effective, either: Some meds work for less than half of the people who take them… yet get approved anyway.

Just look at all the studies on everything from painkillers to antidepressants in which the drugs barely beat placebos.

So the real secret to drug approval isn’t in safety or even effectiveness — it’s in passing the FDA’s nebulous and industry-friendly “risk vs. benefits” calculation.

Sounds like some delicate balancing act, right?

In reality, it’s about as delicate as a hippo playing seesaw with a mouse. I don’t think I need to tell you which one of those animals represents “risk” — and in many cases, meds win approval before all those risks are even known.

The survey also finds that warning labels might help people reconsider meds… sort of.

In one case, when given a choice between two fictional heartburn meds, patients reflexively chose the one they believed to be newer. But when given a warning that new drugs might carry more serious risks that aren’t yet known, the majority switched to the older one.

In another, participants choosing between two cholesterol meds reconsidered when told one contained a warning that said “It is not known whether it will help patients feel better or live longer.”

But out in the real world, patients rarely compare meds they way they do spaghetti sauce. In most cases, the doctor prescribes and the patient complies — and that’s why millions of people take drugs they barely understand for conditions they might not even have… like cholesterol and heartburn.

You should always read the warnings, of course — but before you even get a prescription bottle in your hand, you need to ask your doctor a series of questions.

Keep reading for more.

You wouldn’t dream of pumping a newborn full of powerful painkillers like ibuprofen — yet nearly a fifth of all pregnant women take these meds during pregnancy… and it’s killing their unborn children.

Some of the most common painkillers of all — non-steroidal anti-inflammatory drugs like ibuprofen — can dramatically boost the risk of miscarriage.

Canadian researchers compared data on 4,705 women who suffered a miscarriage during the first five months of pregnancy to 45,050 women who did not, and found that those who took the painkillers had 2.4 times the risk.

Putting that into stark real terms, a woman has a 15 percent risk of miscarriage right off the bat — but if she’s been popping these painkillers, that risk shoots up to 35 percent.

And believe it or not, those numbers might be on the low side: The researchers used prescription drug records, not self-reported use, to figure out who had taken the painkillers.

That leaves out the scores of women who take over-the-counter drugs — because in Canada, as in the United States, both ibuprofen and naproxen are widely available.

Other NSAIDs include rofecoxib, diclofenac and celecoxib — but don’t put too much effort into memorizing those names. Most of the drugs that have become a common part of the household medicine chest aren’t nearly as safe as you’ve been led to believe, and that’s especially true during pregnancy.

On the other hand, you never needed those drugs in the first place — and pregnancy is a great opportunity to wean yourself off them for good as you explore the safe and effective nondrug alternatives that have helped millions beat pain, even during pregnancy.

One study a couple years back found that 81 percent of pregnant women who suffered from back pain got at least some relief from acupuncture — versus 59 percent of women who got a sham treatment.

The needles don’t hurt — in fact, you’ll barely feel them.

But if acupuncture’s not for you, try a good rub: Not only is massage therapy proven to bring pain relief to pregnant women, but it also can have a powerful stimulating effect on the immune system.

And that’s something that can benefit mom and baby alike.