by Marion Nestle

Currently browsing posts about: Salt

Jan 23 2010

The new salt study

The current issue of the New England Journal of Medicine has an article from investigators at the University of California San Francisco School of Medicine (where I worked from 1976 to 1986) and Columbia using computer models to predict the effect of relatively small reductions in salt intake on health.  Their conclusion:

Modest reductions in dietary salt could substantially reduce cardiovascular events and medical costs and should be a public health target.

The article also is discussed in an accompanying editorial, and was the topic of a long discussion in the New York Times.

I never know what to make of computer models, but one thing is clear: many people consume two or three times the amount of salt recommended.  It’s hard to avoid doing so.  Australian investigators surveyed processed foods and found more than 60% of them to contain salt above recommended levels.  Ours are unlikely to be any different.

While we are on the subject of salt in processed foods:  Juli Mandel Sloves of Campbell Soup correctly points out that my observation that the company’s kids’ soups contain 480 mg sodium per 4 ounce serving is incorrect.  A serving of soup is 8 ounces, not 4.  I see how I made this mistake.  The label states that a serving is half a cup (4 ounces) and that one serving contains 480 mg sodium.   But you are supposed to dilute what’s in the can with another can of water.  That makes it 480 mg sodium per 8 ounces, the same amount of salt but diluted.  The confusing serving sizes are another good reason to rethink and redesign the Nutrition Facts label.

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Jan 20 2010

The perils of interpreting food composition

Thanks to Sodium Girl (see comments under Feedback) for giving me a chance to talk about one of my favorite nutrition topics: how do we know what’s in food.  Her question:

I am on a very low sodium diet…I am beginning to have less and less faith in the nutritional labels – who is regulating them and what process/research do they use to define the amounts? And it is not just produced goods. I find it hard to know what information to trust when it comes to whole foods as well. I know that the USDA reports nutritional values which are the standard. Even with their documents though, a raw egg is 70 mg of sodium while a boiled egg is upwards of 120 mg of sodium – are they taking salted water into account?

This comment sent me straight to the USDA’s nutrient composition data base.  Despite the daunting home page, it’s a lot of fun to use once you get the hang of it.  Start with where it says Search the data base online.  Type in Egg (not Eggs) at Keyword.  Click on Dairy and Egg where it says Select Food Group, pick what you are looking for (I checked “egg, whole, raw;” on the next round, I checked “egg, whole, cooked, hard boiled”), click on Submit, and then decide how you want the data presented.  I chose one large egg.  Bingo.

USDA reports large eggs as 50 grams.  A 50-gram raw egg has 70 mg sodium and a cooked one has 62.  My interpretation: no significant difference.

Here’s the deal on food composition tables: you have to consider these numbers as ballpark figures, not as something engraved in stone.

  • Foods grown and raised in different places under different circumstances have different nutrient compositions, so the food you are eating is unlikely to be identical to the ones tested by USDA.
  • Nutrient amounts depend on weight; if your egg is a little bit bigger or smaller, the nutrient numbers change accordingly.

So you need to interpret food composition numbers leaving a lot of wiggle room.  That’s why I think reporting calories the nearest calorie is silly.  A 50-gram hard-cooked egg is 78 calories?  Plus or minus 10 maybe.

The USDA figures are the most authoritative available.  The office in charge of the nutrient composition data base is an unsung treasure of American government.  The scientists who work there are first rate, but they struggle daily with two problems: (1) not enough money to do their own testing, and (2) food companies know quite well what is in their products but they won’t give the USDA any information about nutrient composition beyond what is on the food label; they consider that information “proprietary” and don’t have to.

When it comes to sodium, which we eat in gram amounts per day, the difference between 70 and 62 mg is trivial.  I use the USDA figures as ballpark estimates and don’t pay any attention to small differences.

Sodium Girl: unprocessed foods like eggs are all relatively low in sodium so you don’t have to worry about it if that’s what you routinely eat.   Things start getting salty when you eat foods like cheese, pickles, and soy sauce, or anything commercially processed or prepared for you by others.  That’s why I’m for getting food companies and restaurants to cut down on salt so it will be easier for you to follow your doctor’s orders.

Jan 17 2010

Eating Liberally asks about salt

The ever curious Kerry Trueman, Eating Liberally’s kat, wants to hear more about Bloomberg’s salt assault.  And well she might.  Today’s New York Times has a bunch of letters weighing in from all points of view.    Here’s how our conversation went:

(With a click of her mouse, EatingLiberally’s kat corners Dr. Marion Nestle, NYU professor of nutrition and author of Pet Food Politics, What to Eat and Food Politics🙂

Kat: New York City’s new initiative to persuade food manufacturers and restaurants to voluntarily reduce the salt in their foods by 25% over the next five years is eliciting the usual outrage from the “nanny state” naysayers, for whom excess salt consumption is yet another matter of personal responsibility.

But as you noted last Monday, “nearly 80% of salt in American diets is already in packaged and restaurant foods and if you eat them at all you have no choice about the amount of salt you are getting.” Many Americans consume more than double the daily recommended intake of sodium, contributing to thousands of deaths and billions in medical costs annually.

Mayor Bloomberg equates the food industry’s overuse of salt to such health hazards as asbestos. But Mark Kurlansky, author of Salt: A World History, insisted to WNYC’s Amy Eddings that this analogy is false because “we could reduce our salt intake on our own, if we wanted to.”

Technically, this is true, if you’re willing and able to eliminate packaged foods from your diet, stop eating out, and start cooking all your meals from scratch. Unfortunately, the percentage of folks who have the time, inclination, and resources to do this is roughly on a par with those who think that Wall Street’s robber barons earned those big bonuses.

The food industry maintains that it would gladly reduce the sodium in its products–and some are doing so surreptitiously–if only consumers conditioned to crave super salty foods would be more willing to accept reduced sodium products.

The “invisible hand” of the market can’t seem to let go of the salt shaker. Mayor Bloomberg’s proposal is a step in the right direction, but do you think it will achieve meaningful reductions, or will we ultimately end up having to regulate salt?

Dr. Nestle: I love nanny-state accusations. Whenever I hear them, I know either that food industry self-interest is involved or that the accuser really doesn’t understand that our food system already is government-regulated as can be. These kinds of actions are just tweaking of existing policy, in this case to promote better health.

At issue is the default. Right now, companies have free rein to add as much salt to their processed or prepared foods as they like. The makers of processed foods do focus-group testing to see how consumers like the taste of their products. They invariably find that below a certain level of salt–the “bliss” point—their study subjects say they don’t like it. Soups are a good example. A measly half-cup portion of the most popular Campbell’s soups contains 480 mg of sodium or more than a full gram of salt (4 grams to a teaspoon).

To someone like me who has been trying to reduce my salt intake for years, those soups taste like salt water. That’s because the taste of salt depends on how much you are eating. If you eat a lot, you need more to taste salty. If you are like me, practically all processed and restaurant foods taste unpleasantly salty.

So what to do? I say this is indeed a matter of personal choice and right now I don’t have one. If I want to eat out at all, I know I’m going to feel oversalted by the time I get home.

I want the default choice to be lower in salt. Nobody is stopping anyone from salting food. You don’t think your food tastes salty enough? Get out the salt shaker.

But let me make two other comments. One is that the amount of salt we eat is so far in excess of what we need that asking food makers and sellers to cut down can hardly make a dent in taste. A new Swedish study just out says that young men consume at least twice the salt they need and the authors are calling on government to require food makers to start cutting down.

And yes, the science is controversial and not everyone has blood pressure that goes through the roof when they eat something salty. But lots of people do. And almost everyone has blood pressure that goes up with age. As a population, we would be better off exposed to less salt in our diets.

Some food makers are already gradually cutting down on salt, but quietly so nobody notices. If every food company were required to do that, everyone would get used to a less salty taste and we all might be able to better appreciate the subtle tastes of food.

My guess is that Bloomberg has started a movement and we will be seeing much more effort to lower the salt intake of Americans. As I see it, this is about giving people a real choice about what they eat.

Correction, January 22:  Juli Mandel Sloves of Campbell Soup correctly points out that I am in error.  A serving of soup is 8 ounces, not 4, even though the label says that a serving is half a cup.  How come?  Because the can is to be diluted with another can of water, making it 21 ounces divided by 2.5 servings per can, or about 8 ounces.    Complicated, no?  But this means the sodium content is 480 mg per cup, not half cup, despite what the label says.   I apologize for the error.  But here is an excellent reason to redesign the Nutrition Facts label, alas.

Jan 11 2010

New York City’s new health initiative: Salt!

The New York City Health Department is at it again.  First trans-fat, then calories, then sodas.  Now, it’s going after salt in packaged foods and restaurant meals.   It is asking for a 25% reduction in the next five years.   How come? Because nearly 80% of salt in American diets is already in packaged and restaurant foods and if you eat them at all you have no choice about the amount of salt you are getting (see previous posts).

The Health Department is sending a clear message: reducing the salt content of packaged and restaurant foods will help New Yorkers stay healthy.

The initiative is voluntary.  But if everyone complied, we would all get used to a less salty taste and the current high salt levels will taste too salty.

This is actually a modest proposal.  We still have a long way to go.  The proposed standard for marketing foods to children, for example,  is 480 mg sodium (more than a gram of salt) per serving.  A mere half-cup of Campbell’s low sodium soups contains that much.  Campbell says it’s up to you to get the company to do better.

According to today’s Wall Street Journal, companies are already cutting the salt, albeit surreptitiously.   And according to the account in the New York Times, a Campbell official said: “We will continue to reduce sodium as long as there’s consumer acceptance in the marketplace.

So they think it’s up to you.   Fine.  Give companies plenty of reason to cut the salt.  Tell companies you want real consumer choice.   You want to decide how much salt to eat.  In the meantime, FDA: get busy on this one.

Correction, January 22:  Juli Mandel Sloves of Campbell Soup correctly points out that I am in error.  A serving of soup is 8 ounces, not 4, even though the label says that a serving is half a cup.  How come?  Because the can is to be diluted with another can of water, making it 21 ounces divided by 2.5 servings per can, or about 8 ounces.    Complicated, no?  But this means the sodium content is 480 mg per cup, not half cup, despite what the label says.   I apologize for the error.  But isn’t this a good reason to redesign the Nutrition Facts label?

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Jan 1 2010

What’s up with food and nutrition in 2010?

My San Francisco Chronicle column, now appearing in print on the first Sunday of the month, is also online.

Its title:  “Hot food issues ready to boil over this year.”

Q: What do you think will happen with food and nutrition in 2010?

A: I wish I could read the leaves while I drink tea, but the best I can do is tell you which issues I’m going to be watching closely this year.

Hunter Public Relations recently asked 1,000 Americans which food-related issues they thought were most important in 2009. The top three? Food safety, hunger and food prices. For the decade, the winner was childhood obesity.

I have my own top 10 list of hot-button issues for 2010, and here they are:

  • Hunger: More than 35 million Americans get benefits to which they are entitled under the Supplemental Nutrition Assistance Program (formerly, food stamps). The economy may be improving, but not quickly enough for millions who have lost jobs, health care and housing. Will Congress do anything this year to strengthen the safety net for the poor? It needs to.
  • Childhood obesity: Rates of childhood obesity may have stabilized, but we all want to figure out how to prevent kids from gaining so much weight that they develop adult chronic diseases. I expect to see more efforts to improve school food and make neighborhoods more conducive to walking to school, riding bikes and playing outside.
  • Food safety regulation: Congress is sitting on a bill to give the Food and Drug Administration some real authority for food safety. The bill does not do what is most needed – establish a single food-safety agency – but is a reasonable step in the right direction. Let’s hope Congress gets to it soon.
  • Food advertising and labels: The long-dormant FDA and Federal Trade Commission are getting busy at last. In the wake of the Smart Choices fiasco, the FDA is working to make package labels less misleading and easier to understand. The agencies have proposed nutrition standards for products marketed to children. These voluntary standards fall far short of my preference – an outright ban on marketing junk foods to kids – but puts food companies on notice that their products are under scrutiny. The FDA is also working on designs for front-of-package labels. I’m hoping it chooses a “traffic-light” system that marks foods with a green (any time), yellow (sometimes) or red (hardly ever) dot. Expect plenty of opposition from the makers of red-dotted products.
  • Meat: The meat industry has been under fire for raising food animals under inhumane conditions, using unnecessary hormones and antibiotics, mistreating immigrant labor, and polluting soil and water. Now it is also under fire for contributing to climate change. Recent films like “Food, Inc.” and “Fresh” and books such as Jonathan Safran Foer’s “Eating Animals” are encouraging people to become vegetarians or to eat less meat to promote the health of people and the planet. I’ll bet the meat industry pushes back hard on this one.
  • Sustainable agriculture: The back-to-the land movement has loads of people buying local food, choosing foods produced under more sustainable conditions and growing their own food. The number of small farms in America increased last year for the first time in a century. Seed companies cannot keep up with the demand. It will be fun to follow what happens with this trend.
  • Genetically modified (GM) foods: My book, “Safe Food,” comes out in a new edition this year, so I am paying especially close attention to debates about GM foods. The FDA’s 1994 decision to prohibit labeling of GM foods continues to haunt the food biotechnology industry. By now, nearly all American soybeans and sugar beets (95 percent) are GM, as is most corn (60 percent). But when the U.S. Department of Agriculture approved GM sugar beets in 2005, it neglected to perform the required environmental impact assessment. On that basis, environmental groups want to ban further planting of GM sugar beets. The dispute is now in the courts.
  • Chemical contaminants: The FDA has yet to release its report on the safety of bisphenol A, the plastic chemical that acts as an endocrine disrupter. Shouldn’t it be banned? The bottling industry says no. Watch for fierce arguments over this one.
  • Salt: Nutrition standards allow 480 mg sodium (the equivalent of more than 1 gram of salt) per serving. A half cup of canned soup provides that much. A whole cup gives you 4 grams and the whole can gives you 8 grams – much more than anyone needs. Nearly 80 percent of salt in American diets comes from processed and restaurant foods. Companies are under pressure to cut down on salt. Will they? Only if they have to.
  • Dietary advice: The new edition of Dietary Guidelines for Americans, which the government publishes every five years, is due this year. What will it say? I can’t wait to find out.

Those are the issues I am tracking these days. My one crystal-ball prediction? We will be hearing a lot more about them this year.

Happy new year!

Nov 25 2009

The latest on too much salt

The British Medical Journal has a new meta-analysis of 13 studies of the health effects of high salt intake.  Its conclusion:

High salt intake is associated with significantly increased risk of stroke and total cardiovascular disease. Because of imprecision in measurement of salt intake, these effect sizes are likely to be underestimated. These results support the role of a substantial population reduction in salt intake for the prevention of cardiovascular disease.

In commentary, the authors insist that regulation is needed.  The effects of salt are large:

a 5 g reduction in salt intake at the population is associated with a 23 per cent difference in stroke rates, and a 17 per cent difference in total cardiovascular disease….eating less salt could avert 1.25 million deaths from stroke and almost 3m deaths from cardiovascular disease – and these projections are…conservative because of imprecision in assessing salt intake.

Why regulation?  Because nearly 80% of salt enters the diet through processed and pre-prepared foods.  The rest is about equally divided between naturally occurring salt in foods and salt added at the table.   To reduce salt, food manufacturers and restaurants need to cut down, and all of them have to do it.

This is because the taste for salt depends on how much is eaten.  On a low salt diet, even lightly salted foods taste salty.  But if you are used to eating a lot of salt, it takes even more to taste salty.  So the object needs to be to reduce salt in the diet across the board.

I’m hearing a lot these days about how federal agencies are getting interested in the salt issue.  Stay tuned on this one.

And have a safe, healthy, delicious, and lightly salted thanksgiving!

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Oct 22 2009

Much to-do and to do about salt

It is one of the great oddities of nutrition that public health guidelines invariably recommend salt reduction but the science is so hard to do that the value of doing so can’t be proven unequivocally.  Hypertension specialists insist that salt reduction is essential for controlling high blood pressure, and many people with high blood pressure can demonstrate that this is true.

So why can’t the science show it?  I’d say because even the lowest salt intakes are higher than recommended.  Because everyone consumes higher-than-recommended amounts, it’s impossible to divide people into meaningful groups of salt eaters and see whether low-salt diets work.

With that said, here are the latest events in the salt wars:

1.  An article by a group of investigators in California and Washington state, “Can dietary sodium be modified by public policy,” argues that it makes no difference who you are, everybody consumes salt in the same range.  Therefore, there is no point in trying to lower it.

2.  Not so, say critics, who point out that the authors of that study consult with the food and salt industries (and, therefore, have conscious or unconscious biases) and that plenty of evidence demonstrates the value of salt reduction.

3.  ConAgra says it will cut the salt in its products by 20% in the next few years, according to an article in Bloomberg News (in which I am quoted).  Why is ConAgra doing this? To lower the salt before the company is forced to.  Regulators are well aware that nearly 80% of the salt in American diets comes from processed and pre-prepared foods, not salt shakers.

Expect to hear lots more about the need to reduce salt intake this year.

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Sep 28 2009

The cost of obesity (and fixing it)

I don’t usually take estimates of the cost of bad diets and obesity too seriously because they are necessarily based on multiple assumptions, none of them verifiable.  But I do like to collect them.  Here are two papers from the American Journal of Health Promotion estimating such costs.  One estimates the health benefits and savings in medical costs from diets reduced in saturated fat, sodium, and calories (a savings of $60-120 billion), and the other estimates cost savings and productivity increases for reduction in calories and sodium ($109-256 billion).  Whatever the real savings are, they are likely to be enormous.  And that’s just money.  It’s harder to put a value on quality of life.  Maybe that’s all we need to know at this point.

Yale’s Rudd Center for Food Policy has invented a Revenue Calculator for Soft Drink Taxes for estimating the amounts of money states and cities could raise from taxes on soft drinks.  You type in the state or city, estimate the size of the tax, decide what kinds of drinks it’s for, and push the  button.  Bingo.  California could raise about $1.8 billion a year from a 1 cent tax.

And the Department of Health and Human Service has hooked up with the Advertising Council for a new kids’ activity campaign on the Internet, this one using Maurice Sendak’s Wild Things tied in to a movie coming out in October.  I wasn’t so happy about the last such campaign, which featured Shrek and is still up on the site.  Shrek also advertises junk foods.  Maybe this one will work better?