Everything We Thought We Knew About Salt and Health Was Right

An interview with health policy advocate Michael F. Jacobson about the decades-long struggle to regulate dangerous levels of salt in the food supply.

Photo of author Michael F. Jacobson and the cover of his book Salt Wars
(© 2020 The MIT Press, Photo by Chris Kleponis)

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Unlike sugar and trans fats, we might accept salt in our food as a human necessity, an ancient mineral that conveniently boosts flavors in bland fare.

But we’ve been fed a line about sodium chloride. That’s what Dr. Michael F. Jacobson claims in his new book Salt Wars: The Battle Over the Biggest Killer in the American Diet.

For decades, Jacobson has worked with the Center for Science in the Public Interest — a group he helped found — to advocate for tighter health regulations on American food, writing a heap of books along the way advising on the science behind nutrition.

It might seem as though scientists just can’t make up their minds about the health effects of a salt-heavy diet, but Jacobson says the conflicting messages are a mix of junk science and industry deception. He argues that science has long confirmed that we consume too much salt, leading to unnecessarily high rates of cardiovascular disease, and his book tracks the half-century-long fight between “Big Salt” and health advocates — like himself — seeking to reduce the stuff in our food. Jacobson says it’s finally time to cut the salt in our food by one-third and act on the facts we’ve known all along.

The Saturday Evening Post: How do you defend the science you put forth in your book? Is there a scientific consensus that sodium consumption is too high?

Michael F. Jacobson: There has long been a consensus that we should reduce sodium intake to reduce the risk of heart attacks and strokes. The consensus is reflected in statements from organizations like the U.S. Department of Health and Human Services, the World Health Organization, and the American Heart Association. These are not organizations that take risky positions or base their statements on flimsy evidence. Typically, in fact, they wait far too long to tell the public to do one thing or another.

In contrast, the “opposing side” — if you want to put it that way — has a comparative handful of studies that have been criticized for basic flaws from the day they were published. At this point, I hope that the debate over salt has ended. Last year the National Academy of Sciences issued a report that summarily dismissed those contrarian studies as being basically flawed. They dismissed them with a sentence, citing the other evidence that has long been mainstream.

SEP: You write about the “J-shaped curve” — the finding that lower salt intake also results in a high risk of cardiovascular disease — as the basis of a lot of these “contrarian” theories around salt. What do you make of the science behind it?

Jacobson: It’s junk. The PURE studies [Prospective Urban Rural Epidemiology], which have been the most widely publicized as showing that consuming less salt could be harmful, are based on taking one urine sample from a number of participants at the beginning of the study. One sample. It’s not even a 24-hour collection, which is the standard for measuring sodium intake. The next assumption they make is that one sample is representative of a person’s lifetime consumption, but it’s not. Maybe that person ate out that day, or maybe they had cancer and were barely eating. People have long criticized that research, but in the last few years two studies completely debunked it.

Last year, the NAS did a report on sodium and cardiovascular disease. They did a meta-analysis of the best studies that involve 24-hour urine collections and found the expected linear relationship. They dismissed the PURE studies and others that found the J-shaped curve, as fatally flawed. I hope that ends the controversy.

A few years ago, Congress said the government shouldn’t take action to reduce sodium until the NAS did a study to look at sodium’s direct relationship to cardiovascular disease. Well, now they have done that study, concluding that lowering sodium is beneficial and not harmful.

SEP: How would you say that news media figures into the controversy around diet science like this?

Jacobson: I don’t understand why health journalists have given unwarranted credence to the PURE studies and their predecessors, because they’re so contrary to what the bulk of the research says. I think they, starting with The Washington Post and The New York Times, have been really irresponsible. Maybe it is an example of “man bites dog” to some extent. I bet editors love those stories that publicize the contrarian view, especially when the researchers are at respected institutions.

In the case of the PURE studies, they’re not tainted with industry funding. Rhetorically, it’s easier to shoot down studies that are funded by the snack food industry or something. But I’m really puzzled, and many other people in the field of hypertension and cardiovascular disease are shocked that those [PURE] researchers continue to get funding for that kind of research, and that respected publishers — like the Lancet or British Medical Journal — accept these studies. They certainly confuse the public.

The same phenomenon has taken place on a whole range of public health issues of great importance. With the lead industry — defending lead in gasoline — it goes back 100 years. Typically, it’s industry either sponsoring the research, or, if the research is independent, then ballyhooing the research that supports their views, saying, now government can’t act until we do studies that may be impossible to do.

With salt, there’s been a “moving of the goalposts.” Thirty years ago, the evidence was clear that increasing sodium intake increased blood pressure, and increased blood pressure then increased the risk of cardiovascular disease. Almost every researcher agreed then that raising salt increased the risk of cardiovascular disease, but after a couple of studies contrarians said that those conclusions couldn’t be coupled, that we had to prove directly, with randomized controlled studies, that raising sodium increases the risk of cardiovascular disease. Those studies are almost impossible to do. A few studies (I mention them in Salt Wars) provide some evidence, but they’re all limited in one way or another. But the American Heart Association and the WHO and others say that that research is totally unnecessary, they are certainly not funding the research, and we have far more evidence than we need to call for policies to reduce salt in the food supply and diet.

The thrust of the bulk of the field is to say, let’s reduce sodium throughout the food supply to “make the healthy choice the easy choice.” There are studies showing that if you start with lower-sodium foods and add salt, you’ll generally end up with less salt than what we see in most of our foods now.

SEP: You’ve been involved in health advocacy for many decades. What have you seen change in industry and policy as far as the American diet is concerned?

Jacobson: With salt, the policy battles began in 1969 when the White House Conference on Food, Nutrition, and Health said that sodium in the food supply should be lowered. At that time, and currently, the Food and Drug Administration considers salt to be “generally recognized as safe,” and could be used in any amount. But on the basis of the existing research back in 1978, we [Center for Science in the Public Interest] petitioned the FDA to adopt regulations to lower sodium, and top researchers supported the petitions.

A few years later, the FDA in the Reagan administration was headed by a hypertension expert, and he said that we should lower sodium by taking a voluntary approach and that if industry didn’t lower sodium, he would mandate it. That commissioner left the agency after two years, and meanwhile industry did next to nothing. Then, CSPI focused on getting sodium labeling on all foods, and we helped get the nutrition labeling law passed, which mandated labeling like the Nutrition Facts labels that list sodium on all packaged foods. So we waited to see whether labeling would reduce sodium intakes, and when I looked at it 10 years later I saw that, no, it didn’t seem to have any effect. Sodium consumption stayed the same. So in 2005 we re-sued the FDA and filed a new petition. By then, the evidence was far greater that sodium boosted blood pressure. But the government did nothing. So we then succeeded in getting Congress to fund the NAS to do a study on how to lower sodium intakes.

In 2010, the NAS published a landmark report saying the FDA should mandate lower sodium levels in the food supply, but the FDA commissioner immediately said they would push again for voluntary reductions. It took a while — six years in fact — for the FDA to come up with voluntary targets for lowering sodium in packaged foods. That was in June 2016, just months before the Obama administration left office, so clearly there was not enough time to finalize those targets.

Four years later, the Trump administration still has done nothing. Absolutely nothing. Although, two years ago, the FDA commissioner Scott Gottlieb — who’s been in the news about COVID-19 — said that reducing sodium is probably the single most important thing the FDA could do in the nutrition world. Unfortunately, he left office a few months later and the FDA did nothing.

It’s been 10 and a half years since the NAS called for mandatory reductions in sodium, and the last time that the CDC looked, in 2016, there had been no change in sodium intake in 30 years. At this point, I think the most we can hope for is the implementation of those voluntary targets. The FDA chose targets that would lower sodium to recommended levels — if all food manufacturers complied, which they won’t — in 10 years. In 10 years, a lot of people are going to be dying unnecessarily.

SEP: What was the Salt Institute? Would you characterize it in the same way that people think of the tobacco lobby or the oil lobby?

Jacobson: Steven Colbert said that the Salt Institute shouldn’t be confused with the Salk Institute, because the Salk Institute cures polio while the Salt Institute cures hams. That got a laugh from the audience [when Jacobson was a guest on Comedy Central’s The Colbert Report in 2010]. The Salt Institute was long a lobbying group set up by salt manufacturers, like Morton Salt and Cargill.

In the book I call it “the mouse that roared.” It was a small organization — five or six staff members and an annual budget of about three million dollars — but they were real tigers when it came to defending salt. Any time people criticized sodium levels in the food supply and recommended changes, the Salt Institute would be out there with vitriolic statements, pamphlets, interviews. They generated a large amount of press that I think contributed significantly to muddying the waters. They made much of that J-shaped curve theory, that reducing sodium dramatically could actually increase the risk of heart disease. But in March of 2019, they abruptly went out of business, and no one, to my knowledge has explained why.

SEP: Since the Salt Institute has disbanded, do you see an opening for salt regulation?

Jacobson: Well, the Salt Institute was never the real powerhouse. The major player was the mainstream food industry, including Kellogg’s, General Mills, McDonald’s — all the big companies, through their trade associations, and especially the Grocery Manufacturers Association. The industry kind of begrudgingly went along with voluntary reduction, but when the FDA proposed action, they nitpicked almost every single number in the FDA’s proposal. The butter and cheese industries wanted their products entirely dropped from the plan. Surprisingly, at the beginning of 2020, the Grocery Manufacturers changed its name [to Consumer Brands Association], changed its focus away from nutrition labeling and nutrition issues in general. The two main lobbying groups essentially withdrew from the playing field.

That certainly should make it easier for the government to take stronger action on sodium. But will it? I don’t know. Many of those big companies will lobby on their own. The snack food industry has SNAC, frozen food companies have the Frozen Food Institute, pickle makers have Pickle Packers International, restaurants are defended by the National Restaurant Association, and the meat industry has the North American Meat Institute. It’s hard to know how the disappearance of those two groups will affect things but making progress won’t be a cakewalk.

Between voluntary and mandatory approaches, the voluntary approach rewards companies that don’t do anything. I talked to one official at Kraft Foods, and he said that Kraft has tried to reduce sodium, but its competitors didn’t, so Kraft felt it had to go back and restore the salt. The advantage of mandatory regulation is that it provides a level playing field for companies that want to do the right thing.

SEP: Looking at the whole scope of the last 50 years or so, what would you say makes it so difficult for the U.S. to make and pass policy regarding dietary health?

Jacobson: It’s the power of industry. But also, much of the public sees a smaller role for government compared to countries in Europe, for example. Here, we have a culture of “rugged individualism.” There’s a feeling that people can lower their sodium intake if they want, a much more voluntary, individual approach.

In contrast, the British government, in the mid-2000s, adopted recommendations to lower sodium and backed that up with a pretty aggressive public education campaign. Then they used the bully pulpit to press industry to lower sodium. Within five years, the UK achieved a 10 to 15 percent reduction in sodium intake, compared to a goal of 33 percent reduction. But after a change in government, the new government lost interest.

Chile, Mexico, Israel, and a couple of other countries have passed laws requiring warning notices on packaging when foods are high in calories, saturated fat, sodium, or sugar. These are put on front labels and are very noticeable. In Chile, the law has been in place long enough to measure some results. There have been a significant number of products that have lower sodium, sugar, or fat content to escape those warning labels. That has been the most effective policy I know of to lower the sodium content in foods and presumably to lower sodium intake.

SEP: Have we seen better health outcomes in Chile as well?

Jacobson: It’s too early to know. Something like cardiovascular disease takes so long to show up. There are also so many other things going on in Chile that come into play.

SEP: Do we see sodium affecting communities differently in the U.S.? For instance, African-American communities?

Jacobson: African Americans seem to be more salt-sensitive than whites. They also have higher rates of hypertension. African-American women have much higher rates of obesity. So, when you couple obesity with hypertension, that’s a formula for cardiovascular disease. But every subgroup of the population ends up with hypertension. By the time Americans are in their 70s and older, 80 to 90 percent have hypertension. That’s why people should lower their sodium intake, lose weight, and avoid too much alcohol, to avoid gradually increasing blood pressure.

SEP: What would a lower sodium diet look like for a lot of people?

Jacobson: Packaged foods and restaurant foods would be lower in sodium. At restaurants, portions would even be smaller. There would be little effect on taste. Let me remind you that no one is saying that industry should eliminate all salt. Rather, it’s lowering salt as much as possible without destroying the taste of the food, and maybe replacing some of the salt with flavorful ingredients.

Using less salt is the cheapest, easiest thing to do. Another way is to replace salt with potassium salt. It doesn’t taste as salty, but it helps counteract the blood pressure-raising effect of a high-sodium diet. Companies can also add more real ingredients and herbs and spices. For home chefs, McCormick, Chef Paul Prudhomme, and Mrs. Dash sell salt-free seasonings. The classic study is the DASH-sodium study. It’s a randomized controlled study — the best you can do — done by researchers at Harvard, Johns Hopkins, and elsewhere. They lowered sodium by one third, from 3,400 mg, the current average daily intake, to 2,300 mg, the recommended intake, and they found that people consuming the 2,300-mg level of sodium liked the food even more than the higher level! So, I think concerns about taste are completely overblown. People quickly get accustomed to less-salty foods.

SEP: What are some personal decisions that people can make to decrease their sodium intake?

Jacobson: Sodium levels in the food supply will not drop to healthy levels instantly, no matter what the FDA does. In the meantime, consumers have to protect their health. When you’re eating processed foods, you should compare labels, because there is wide variation among different brands of the same or similar foods. Swiss cheese has one-fifth or less of the sodium in American cheese, and you can make a perfectly good sandwich with Swiss cheese. For that sandwich, you can also choose a lower-sodium bread. Bread, because we consume so much of it, turns out to be one of the major sources of sodium. You can make lots of modest changes to achieve major reductions in sodium.

We should also be cooking more natural ingredients from scratch. That invariably results in lower-sodium foods, because we’re controlling the salt. The third thing is to eat out less often. Restaurant foods have huge amounts of sodium, especially table-service restaurants like IHOP or Chili’s. That’s partly because the portions are enormous. The more food you eat, the more sodium you consume. From a chef’s point of view, the two magical ingredients are salt and butter. And it’s not just chain restaurants. Chefs have generally not been trained to lower sodium. The best thing you could do is to cook at home from scratch using lower-sodium recipes.

I mentioned how some companies are using potassium salt, and consumers can use it too. Look for “lite salt” at the supermarket. Morton and other companies sell this, and half of the table salt has been replaced by potassium salt, so you automatically cut back when you’re cooking or sprinkle it on your meal.

SEP: Looking back at the last year of presidential debates, moderators always ask a question about the biggest issue facing Americans, and I’ve never heard a candidate say that it’s salt. So, what would you say to people who think we have bigger problems and salt just isn’t that important?

Jacobson: We do have other pressing problems. Tobacco is killing a lot more people than salt. But high-sodium diets are killing tens of thousands of people each year. Health economists and epidemiologists estimate that if we can cut our sodium intake by one-third to one-half, that would prevent 50,000 to 100,000 premature deaths every year. We’re seeing the same thing around the world, where high-sodium diets are causing more than one million deaths a year. I see salty diets as the cause of a pandemic.

We have to deal with COVID-19, that’s the immediate pandemic. High-sodium diets are harmful over a longer time frame. But our society really needs to take these problems seriously even though the deaths are not immediately linked to the cause. An airplane crash kills 300 people and that gets a lot of attention, and it should. But with public health crises, where deaths are less easily associated with the cause, solving the problem is easily postponed, especially when industry stands to gain by not solving the problem. High-salt diets are absolutely something that political leaders need to address.

Featured image: © 2020 The MIT Press, Photo by Chris Kleponis

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Comments

  1. This is really important information. Less is more (healthy) when it comes to salt consumption. With the pandemic (and less money) it’s been getting easier to wean one’s self off of going out to eat for lunch or dinner. Sprinkling (key word) lite salt on foods you make at home give you close to complete control over your salt consumption.

    Salt does taste good, so a little combined with the various choices of Mrs. Dash plus other seasonings fill the rest of the ‘salt gap’ with some incredible flavoring. Healthy olive oil helps a lot too. I saw an online ad for Stuart Anderson’s Black Angus Restaurant with the well-done steak, baked potato with sour cream, chives & more, and my brain said ‘this is what we really want, c’mon you s.o.b.—give in, you know you want to’. What to do? Continue to dine at home, and if I do go for takeout, get the vegetarian choices and fish. That’ll teach my brain (at war with itself) who’s the boss.

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