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Salt: Known as the "Deadliest Nutrient" But There's No Meaningful Evidence

August 20, 2011 | 242,751 views
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Gary Taubes is a science and health journalist, and author of several books, including Good Calories, Bad Calories: Fats, Carbs, and the Controversial Science of Diet and Health, and Why We Get Fat: And What to Do About It. While his earlier work focused on physics, in recent years his interests have turned toward medicine and nutrition. Here he discusses the research upon which his books are based, and reveals the truth behind several common health- and diet myths.
 

Dr. Mercola's Comments:

Gary Taubes is a prominent scientific journalist and author of several books, two of which delve into the fallacies of conventional wisdom with respects to diet and health. I actually published one of his articles on this site nearly 10 years ago, in which he expounded on the misguided dietary advice to "eat less fat and more carbohydrates," stating that this advice just might be the cause of the skyrocketing rates of obesity in America.

Today, of course, there's no shortage of evidence supporting this claim. Many of my articles touch on this each and every week. It just goes to show that if you're really a seeker of the truth, the truth will eventually make itself known.

More recently, I commented on his excellent expose on sugar, featured in the New York Times. This is definitely a highly important health topic, and I was thrilled to see an article speaking such powerful truths in the mainstream media. In this interview, Taubes shares a variety of insights from his own research as a health journalist, so I highly recommend listening to the interview in its entirety.

Interestingly, we are both about the same age and have very similar physical characteristics, and both have a passion for scientific journalism that communicates to the public.  We really connected well and I look forward to many more engaging future discussions with Gary as he is clearly a leader in the field and has a wealth of solid knowledge from his voracious review of the scientific literature. 

Mechanisms that Maintain Dogmatic Beliefs, Regardless of the Evidence

Today, it's easier than ever to connect the dots and see how health- and dietary recommendations are the result of massive conflict of interest, perpetuated by self-interested i groups, and industries that push unfavorable research findings under the proverbial rug. The medical- and health- fields are now absolutely riddled with dogmatic beliefs that defy both common sense and scientific truth. And yet they prevail, even though it's clear to see that many of these recommendations are doing more harm than good.

Why is that?

According to Taubes, part of the problem is that, contrary to research in physics, where a lot of attention must be paid to the many variables that may influence the result, and where negative results that do not confirm your beliefs are meticulously evaluated, medical research does not adhere to many of these same exacting standards. One of the reasons for this is the perceived need for speed, or as he likes to call it, "the Jurassic Park mentality."

"[A]bout every 10 minutes they would go, "But people are dying out there! People are dying out there!" As we're talking, I don't know; another 100 Americans have dropped dead from a heart attack. So you've got to move fast. You can't wait for the definitive evidence to come through," he says.

"I would look in the literature and I was always told this by the research: "We can't dot every i and cross every T. We're not like the physicist who… have the time and the patience to reproduce the experiment and make sure they control for all the variables." I say, basically, "What you're saying is you don't have the time to figure out whether you're really right or not, because if you don't dot every i and cross every T, you don't know." That's how cruel science is. But because people are dying out there, we have to move fast… We have to jump to conclusions and we have to hope that we're right. Unfortunately, all too often… when people do that, they're NOT right."

Unfortunately, once nutritionists, dieticians, personal trainers, and the average person has fully embraced a pre-conceived conclusion, it's very hard to reverse. It's even more difficult once the government agencies have bought into it and turned it into dogma.  

"[I]magine if the American Heart Association… decide they were wrong. What do they do? You can't just put out a press release saying, 'We apologize for the last 40 years of advice we've been giving you. We apologize if we got a lot of stuff wrong and we killed a lot of your loved ones…  Now, we're going to tell you what the real answer is and we have confidence in this one'… It just can't be done. All that stuff is institutional self-interest too."

Then there's the issue of what psychiatrists calls 'cognitive dissidence,' where, when faced with the possibility that you've been wrong for a long time, perhaps most of your career, your brain simply invents ways to convince you that you're still right. These are some of the mechanisms that keep dogmas firmly in place for extended periods of time. This is not only true for nutrition, but also in other areas of public health, such as the issues of water fluoridation, the use of mercury in dentistry, and the ever-growing childhood vaccination schedule.

"[A]nd then you have the funding mechanisms," Taubes says. "They tend to fund people who agree with the conventional wisdom."

How You Get Fat—Has it All Been a Big, Fat, False Dogma?

Taubes' latest book, Why We Get Fat and What to Do about It, is far more of a lay person friendly book than his previous masterpiece, Good Calories Bad Calories, which is the book that any nutritional professional will want to read.

So, do you really get fat because you eat too many calories and don't exercise enough? Or is this just another deeply flawed dogmatic belief?

"The argument I've been making is that we're making a fundamental mistake even thinking in terms of the calories," Taubes says. "This is one of the places where the… obesity research community went off the rails. Heart disease research did it with dietary fat, and then that spread and affected everything else.

Prior to the Second World War, the European medical researchers had a different conception of what caused obesity. They said the human body, in essence, is very well regulated… Cells will not take up excess energy unless they're signaled to do so. If you think about it, that's what insulin does… Hormones are out there to say 'take up this, take up that because there is too much of it.' So if there is too much fat accumulating in the fat tissue, that's because the various factors in your body, the hormones, the enzymes, the central nervous system that regulate the uptake of fat by the fat tissue, and the release of fat are telling the fat to be taken up, and we got to figure what that is."

I personally agree with this school of thought. I believe your body is designed to always strive toward a healthy equilibrium. Self-healing is not only possible, but a built-in mechanism that is remarkably effective, as long as all the raw materials are supplied. The same applies to your weight. The fact that we now have an obesity epidemic on our hands is an unmistakable sign that something has gone terribly awry.

In the late 1950s and early 1960s, researchers discovered a mechanism that regulates fat tissue, namely insulin. And insulin is secreted primarily in response to carbohydrates in your diet.

"You could say the type of carbohydrates and the quantity of carbohydrates more or less regulate our insulin levels," Taubes explains, "So this led to the concept of a carbohydrate-restricted diet. But, if you're going to cut fat, you've got to add carbohydrates. If you're going to cut carbohydrates you have to add fat.

… Physicians started looking at what happened when they put their patients on very carbohydrate-restricted, high-fat diets, and they lost weight effortlessly. And then some very successful books were written on this… Calories Don't Count by… Herman Taller, and then 11 years later, the Atkins Diet revolution. They were pushing high-fat diets when we began to think that dietary fat cause heart disease, and the nutrition and heart disease community came down on them like a ton of bricks saying, "You guys are killing people."… [Yet] this was the exact same time that researchers had realized insulin causes fat accumulation. If you want to lower your insulin level, the way you do it is cut the carbs out of your diet."

The end result of this conflict of two hypotheses was an alternative hypothesis that said, "It's not about how much you eat or exercise. To get fat, you have to consume more calories than you expend." But is that correct?

Weight Gain—It's Really NOT about the Calories…

While the laws of thermodynamics tell us that this is true, there's much more to weight gain than consuming more calories than you use up during physical exertion. Certain nutrients, namely carbs (fructose and grains) affect the hormone insulin, which is a very potent fat regulator. And ever since the advent of processed high fructose corn syrup, the truth of what's really causing the obesity epidemic is becoming ever more self-evident.

"White sugar (sucrose) is half glucose, half fructose. And high fructose corn syrup is 55% fructose, 45% glucose… The fructose is mostly, about 90-95 percent, metabolized in your liver. It's fundamentally different. The pathway by which it's metabolized is fundamentally different. The place at which it's metabolized is different. It makes the liver do more work than just eating a starch, which will break down to glucose only," Taubes explains.

"… The phrase that [Dr. Robert] Lustig uses is 'isocaloric but not isometabolic,' which means you can have the same amount of calories from fructose or glucose, or fructose and protein, or fructose and fat, but you're going to have an entirely different metabolic fate. And that metabolic fate is going to determine the hormonal response, and that hormonal response is going to determine, among other things, how much fat you accumulate.

So this idea that it's only about calories, [and that] all calories are created equal; well, in terms of the energy in the calories, yes… But in terms of the fate of the nutrient downstream, entirely apart from the caloric content; the same amount of calories of different nutrients will have a dramatically different effect."

As I've discussed in numerous previous articles, fructose is FAR worse than other kinds of carbs—despite the fact that it's a low glycemic carb—because the vast majority of it converts directly to FAT. This fat not only accumulates in your fatty tissues, but fructose also accumulates in your liver. Amazingly, half a million British children now suffer from non-alcoholic fatty liver disease, according to a recent article in The Telegraph.

Fructose and the Low Glycemic Index

The fact that fructose ranks low on the low-glycemic index can cause a lot of confusion.

Chronically elevated insulin levels result in insulin resistance, which is at the heart of metabolic syndrome that is now pervasive in the Western world, and is a potent risk factor for a number of deadly diseases, including heart disease and cancer. But if fructose is low glycemic, why is it being pegged as the primary culprit in the obesity epidemic?

Taubes offers a summary of the basics:

"I talked about this in Good Calories, Bad Calories… [The] glycemic index… is a measure of the blood sugar rise and effect after consuming a set amount of a food, a hundred grams of, usually, a carbohydrate-rich food. The reason you don't want your blood sugar to rise is [because] you don't want the insulin secreted afterwards. Fructose doesn't count in blood. It doesn't go into the bloodstream. It goes directly to the portal vein into the liver. It doesn't raise blood sugar. It doesn't stimulate insulin. It's got this very, in the short term… low glycemic index.

When this concept came down in the 1980s it was popularized. The American Diabetes Association immediately said, 'then fructose is good, and sugar is good for diabetics because of the relatively low glycemic index since half the carbohydrates in sugar are fructose.' The corn refiners producing high fructose corn syrup pounced on this and used it... To portray it, they would talk about fructose as fruit sugar. Fructose is found naturally in fruits and vegetables in small amounts. So they made high fructose corn syrup look like this healthy product that was entirely different from sugar.

What was originally missed, was the fact that while fructose may not have an immediate effect on your insulin levels, it still causes insulin resistance in the long term. In the meantime, it's making you pack on extra fat.

"I believe the reason we started consuming more and more of what the USDA calls caloric sweeteners… was because the corn refiners did a very good job of never having us realize that they were marketing another kind of sugar, so we just ate more and more of it—in foods in which fat was removed and high fructose corn syrup put in to replace it…You can take a little [fat] out of a food, put in some sugar, and you have what the U.S. government considers a health food because it's low fat. So we ate more and more sugars total. We got fatter and fatter. We got more and more diabetic."

Saturated Fat—Friend or Foe?

While many are under the impression that decades' worth of studies provide clear substantiation for the hypothesis that saturated fat is harmful, Taubes has news for you:

"Those previous studies never actually confirmed the hypothesis," he says.  "… I lectured at the NIH a couple of years ago and afterwards I was talking to a guy who ran an… NIA-funded childhood obesity research program. He said their primary concern with obese kids is to keep their saturated fat content down because these kids are going to be at high risk of heart disease as they get older. He said there are thousands of studies showing that this is the thing to do confirming the evils of saturated fat.

I said to him, 'The difference between you and I is I actually spent a significant portion of my life reading those studies and 'getting' them all.'

In 1984 when there was a consensus conference by the NIH saying every American over the age two should eat a low-fat diet, there were actually about eight or nine studies… [but] they could never show that eating a reduced saturated fat diet would make you live longer. It might reduce heart disease rates; it did in some studies, but it increased cancer rates. And then since 1984 there have been about another dozen [where]… people are put on low fat diets not because they're looking at heart disease risk factors… but they might be looking at something else, like cancer. When you look at the meta-analyses that have been done looking at these issues, and a couple of them came out in the last two years, the results are always the same.

There is not enough evidence to say that saturated fat is bad for you, and there has never been that evidence."

Most of us don't have the scientific training and education, not to mention the time to really read and digest large amounts of scientific research, which is what makes interviews like this one so valuable. For Taubes, reading and really understanding the research was and is his primary job.

What Does the Research Say about Salt?

Another hypothesis that has become more or less cemented as a dogmatic principle is the idea that salt is bad for you and contributes to heart disease.

"[T]he data on salt has always been terrible," Taubes says. "Basically one study has managed to show that a salt-restricted diet will lower blood pressure by any significant amount. It's called… the DASH diet… which everyone pushes now… as the healthiest weight loss diet according to nutritionists, even though it's not a weight loss diet.

The DASH diet is very low in fructose… DASH is a low-sugar diet; a low-fructose diet. That's what it fundamentally is.  So after 40 years have come to this: basically one study, in which they refused to release, by the way, all of the data on the study. They were challenged. They were even sued to release it. One study suggesting that salt is the problem."

It's true that if you repeat something long enough, people will believe it's true. Such seems to be the case with salt. Even though researchers have repeatedly failed to link salt to heart disease, agencies like the National Institutes of Health (NIH), and the US Department of Agriculture (USDA) climbed aboard the anti-salt train, and it became, as Taubes says, "the deadliest nutrient with no meaningful evidence."

But why?

Well, one reason could be because it directs attention away from whatever the real culprit is. Whether or not that culprit is known by these agencies is up for debate, but at least it gives the appearance that they're 'doing something' about the pervasive problems of high blood pressure, hypertension, and heart disease.

"I point out in my book that hypertension is associated [with] obesity… Gout is a hypertensive state; [so is] heart disease. So that's why we want to avoid hypertension; because of heart disease and stroke… The simplest possible hypothesis is: Whatever causes all these diseases causes hypertension too.

The way we think about it now is you get fat because you eat too much. You get heart disease because of saturated fat. You get diabetes because you're sedentary. You get hypertension because of salt, and you get gout because of meat and alcohol. Yet hypertension is a common condition on all of them, so maybe it's something else."

That "something else" appears to be insulin resistance. And what do we know causes insulin resistance? Sugar, primarily fructose, and grain carbohydrates. Taubes agrees:

"Your simplest possible hypothesis is [that] it's the carbohydrates from the diet; the sugar and the refined carbohydrates that raise insulin and in turn raises blood pressure, causes hypertension, causes obesity, causes diabetes, causes heart disease.

The funny thing is the research community doesn't like these unified theories because it makes you sound like a quack. And yet… remember these clinical trials where you put somebody on a high-fat, high-saturated fat but low-carbohydrate diet without sugars; not only all their heart disease risk factors improve and their diabetes risk factors improve, but their blood pressure drops. It drops just as much in those studies as it does in this DASH-sodium study.

… What I'm trying to do is to get the medical research community and these public health authorities to look at this evidence, and look at it in an unbiased perspective. If you do that, everything implicates the carbohydrates."

Diet has a profound impact on your health. Of this there can be no doubt. And I hope this interview will have given you more ammunition with which to resist the status quo and turn a deaf ear to what many call "conventional health wisdom," which in many cases turns out to be little more than half-baked theories that fall apart upon closer scrutiny.


[+] Sources and References