Next time your doctor says “cut back on the salt, or else” ask him one question.

Or else what?

He’ll tell you how all that salt is responsible for the high blood pressure that leads to heart disease. But if you’ve tried to cut back on salt, then you already know how well it works — not at all.

It’s not just you.

A low-salt diet is actually scientifically proven to have little to no impact on your BP levels, and a new study confirms it: Researchers in Europe say cutting back on sodium trims just 1 percent off a healthy person’s BP levels, and 3.5 percent off those of someone battling hypertension.

And in exchange for those meaningless dips in blood pressure, patients who stuck to the low-salt lifestyle saw a 7 percent surge in deadly triglycerides and a 2.5 percent overall boost in cholesterol levels.

In other words, if your BP spikes a little and your doc tells you to stick to a low-salt diet to avoid hypertension meds, he’ll almost certainly end up giving you those meds anyway — and a statin to boot.

Consider that a bonus.

If this was the first study of its kind, it would be easy to be a little skeptical — and there’s absolutely nothing wrong with being skeptical. But it’s not — and it’s not the second or third study either.

In fact, it’s the fourth study just this year to find no benefit to a low-salt diet — not to mention the dozens of other studies that have reached the same conclusion over the years.

If you’re concerned about blood pressure, forget about salt. Cut back on sugar instead — because the research on this has been remarkably consistent: People who consume the most sugar have the highest blood pressure levels.

That’s why one of the most immediate benefits of a low-carb diet is a swift reduction in blood pressure.

Once you get the sugar out, don’t focus on salt so much as your salt-to-potassium ratio. Thanks to processed foods, most people get more salt than potassium. In reality, you should get about three times as much potassium as salt.

Make those two changes, and you can hit the saltshaker to your heart’s content — and never have to worry about your BP levels again.

Centuries before James Parkinson described the “shaking palsy” that would later bear his name, the Chinese were already treating the condition they called “the shakes” with a simple herb.

But gou teng is more than just a folk remedy with a funny name: A new study shows this stuff might have the power to help tame or even beat Parkinson’s disease.

Researchers in Hong Kong gave 115 Parkinson’s patients either a blend of traditional herbs including gou teng, or a placebo, for 13 weeks, and found that those who got the traditional treatment had better sleep, improvements in speech, and a lower risk of depression.

Even better, the patients who took the herbs along with the Parkinson’s drug levodopa suffered fewer of the med’s notorious side effects — including hallucinations and delusional thinking.

The researchers didn’t stop with the clinical trial — they also isolated the compounds in the herb and ran some tests to see if they could figure out what makes it work so well.

And they may have found it.

Hidden inside gou teng is an alkaloid called isorhy, which researchers say may have the power to normalize the cell death process that often goes haywire in the brains of Parkinson’s patients.

That’s the scientific explanation, anyway.

In traditional Chinese medicine, the description gets a little strange. I read one that explained how gou teng increases yin to counterbalance too much yang.

That’s a little “out there” for most of us here in the West — but it’s considered a perfectly reasonable explanation in the world of traditional Chinese medicine, where the balance between yin and yang is believed to play a key role in health.

Those yins and yangs must be pretty busy, too: Gou teng has been used in China to treat high blood pressure, tinnitus, headaches, sleep problems, and more.

The one caveat here is that the research team behind the Parkinson’s study has also applied for a U.S. patent for their herbal blend, and plan to bring it to market here after a second phase of the study ends in 2013.

That’s a big enough conflict that I’d want to see more independent research on this before anyone starts taking gou teng — but if it really works, I’m sure plenty of Parkinson’s patients would be willing to balance their yins and yangs.

The best person to check your blood pressure is you — and the best place to do it is in the comfort of your own home.

Your doctor might have the best technique in the world, but he could still get it wrong every single time — because his very presence could be causing your BP levels to skyrocket.

It’s a condition called “white coat hypertension” and a new study confirms that it not only leads to real and dramatic bumps in BP levels, but it’s also a lot more common than anyone realized.

Researchers from Duke University and the Durham VA Medical Center had 444 male veterans who were being treated for high blood pressure check their levels in a doctor’s office, at home, and at the research lab at the start of the 18-month study and again at 6 months, 12 months and 18 months.

The researchers say only a third of the patients had readings that were either consistently under control or consistently out of control in all three places.

For the rest, the researchers say the numbers varied wildly — and the highest readings were at the doctor’s office, where more than half of the patients saw increases of 10 points or more.

In fact, the researchers wrote in the Annals of Internal Medicine that systolic readings (that’s the top number)averaged 145 in the doctor’s office — but only 130 in the research lab.

That’s the difference between a hypertension diagnosis and no hypertension diagnosis — and it means that many patients could be taking drugs for a condition they don’t even have.

That’s not just the case for many of the 444 veterans in this study — that’s also the case for millions upon millions of Americans.

That might even be the case for you.

Fortunately, there’s a simple fix — and you can get it for less than $50: Buy your own blood pressure monitor and learn how to use it.

Your doctor can teach you, even if he’ll cause those levels to shoot right up as he does it.

Then, take your own readings at home regularly, keep careful notes and bring them with you to the doctor’s office.

It could mean the difference between walking out with yet another prescription… or leaving with no drugs at all.

How low can you go?

When it comes to sodium, don’t go too low — because despite what you’ve heard, too little can be positively deadly.

A new study is shaking up the conventional wisdom on salt, as researchers have found that people who consume “too much” of it actually have the lowest risk of death by heart attack.

And that means those who stick to mainstream low-salt guidelines could be facing big-time risk.

Researchers tracked 3,681 Europeans who did not have hypertension or any other sign of heart problems at the start of the eight-year study.

Then, after measuring 24-hour salt excretion levels at the beginning and end of the study, the researchers divided the volunteers into three groups: low salt (2,500 mg per day), medium salt (3,900 mg) and high salt (6,000 mg).

Going strictly by the guidelines, you might think the people in that last group had a death wish — that’s four times the most recent USDA recommendations!

But the researchers say only 0.8 percent of the patients in that ultra-high salt group died of heart-related causes during the study, versus 4 percent of those with the lowest levels.

In other words, less salt made these people up to five times more likely to die, according to the study in the Journal of the American Medical Association.

So much for the low-salt lifestyle… but in reality, the link between low sodium and heart risk isn’t as cut-and-dry as you might think.

Even the American Heart Association, which relentlessly pushes a low-salt diet as a means of combating hypertension, admits they don’t know the real cause of 95 percent of all high blood pressure cases.

If you don’t understand the cause, how can you possibly pretend to have the solution?

The fact is, there’s far more research linking sugar to high blood pressure and poor cardiovascular health than there’s ever been for salt.

One study last year found that people who consumed 74 grams of sugar a day — that’s actually less than the U.S. average — had a 77 percent increased risk of blood pressure readings greater than 160/100.

Once you’ve cut down on your sugar, increase your potassium. Your body needs about three times as much potassium as sodium — but most people have that ratio reversed, or worse.

One easy way to get back on track: replace some of your salt with a potassium-based salt substitute.

But don’t throw the real stuff away — because you do need your salt.

Sodium might not be as risky as you’ve been led to believe, but there’s something in your home right now that could be positively deadly.