Public health takes aim at sugar and salt

[Fall 2009]

The war on obesity and other lifestyle ills has opened a new battlefront: the fight against sugar and salt.

It may be a fight for our lives.

In the last few years, evidence has mounted that too much of these appealing ingredients—often invisibly insinuated into beverages, processed foods, and restaurant fare—harms health.

Research at the Harvard School of Public Health and elsewhere, for example, has tied sugary drinks to an epidemic of obesity in the United States. The average 12-ounce can of soda contains 10 teaspoons of sugar, and the average teenage boy consumes nearly three cans of sugary drinks a day. Is it any wonder that about two-thirds of Americans are now overweight or obese?

Obesity, in turn, raises the risk of type 2 diabetes, heart disease, arthritis, and certain cancers. Meanwhile, studies have linked salty diets to high blood pressure, which increases the risk of heart attacks and strokes, the first and third leading causes of death in the United States.

At HSPH, the Department of Nutrition is helping to lead the charge for healthier consumer fare. In April, at a widely covered press conference, the department’s faculty publicly challenged beverage makers to create a class of drinks with 70 percent less sugar—a partial reduction that could lower obesity and diabetes rates within a year, they believe. On the salt side, experts estimate that cutting average sodium consumption by one-half could prevent at least 150,000 deaths annually in the United States.

Bolstering this two-pronged public health campaign has been a shift in national political philosophy. “The previous administration believed that market forces solved everything and that regulation was off the table. But market forces, left alone, damaged the economy,” says Walter Willett, Chair of the Department of Nutrition and Fredrick John Stare Professor of Epidemiology and Nutrition. “That also applies to the food supply and health. Market forces don’t promote a healthy diet—in fact, they do exactly the opposite. We made a lot of progress on trans fat. Now the biggest issue, outside of too many calories, is the huge amount of sugar and salt.”

As in many recent public health campaigns, New York City has been ahead of the pack. Its “Healthy Heart-Cut the Salt” program, now a nationwide effort by a coalition of health organizations and public agencies, works with food industry leaders on a voluntary framework to cut salt in their products. “New York City created a market for trans-fat-free foods, and it will create a market for lower-sodium foods,” Willett predicts. In May, President Barack Obama picked Thomas R. Frieden, New York City’s health commissioner, to direct the U.S. Centers for Disease Control and Prevention (CDC), installing a fierce advocate for lowering salt and taxing sugary beverages in a position to bring about change.


In the School’s current battle plan, the prime target is sugar in sodas, fruit juices and other cloying drinks. Here’s why:

  • Downing just one 12-ounce can of a typical sweetened beverage daily can add 15 pounds in a year.
  • In children, one sweetened beverage a day fuels a 60 percent increase in the risk of obesity—and American teenaged boys drink almost three times that much.
  • This April, an HSPH study linked sugary drinks to increased risk of heart disease in adults. Scientists have long known that sugar reduces the “good” HDL cholesterol in the blood. Consistent with this effect, the April study showed that it wasn’t just weight gain that raised heart disease risk, but sugar itself—eating an otherwise healthy diet or being at a healthy weight only slightly diminished the risk.
  • In 2004, the Nurses’ Health Study found that women who had one or more servings a day of a sugar-sweetened soft drink or fruit punch were nearly twice as likely to develop type 2 diabetes as those who rarely imbibed these beverages.

As a dietary enemy, sugar is cleverly camouflaged, because it is dissolved in liquid. A typical 20-ounce soda contains 17 teaspoons of sugar. “If people thought about eating 17 teaspoons of sugar, they’d become nauseated,” Willett says. “But they are able to drink it right down and go for another.” While we normally balance a big meal by taking in fewer calories later, that compensation doesn’t seem to occur after guzzling soft drinks—possibly because fluids are not as satiating as solid foods, or because sweet-tasting soft drinks whet the appetite for high-carbohydrate foods.

Willett and Lilian Cheung, lecturer in the Department of Nutrition and editorial director of The Nutrition Source, urge people to choose drinks far lower in sugar and calories: options such as water, tea, seltzer with a splash of juice, coffee with one lump of sugar.

“If we can shift the present American norm back to a lower expectation of sweetness, people will adjust their palates, particularly the younger population,” says Cheung.


Almost 80 percent of the salt in the American diet comes not from the salt shaker, but from processed or restaurant foods. According to the U.S. Department of Agriculture, in 2005 and 2006, the average American on a 2,000-calorie-per-day diet devoured more than 3,400 mg of salt per day (mg/d). That’s substantially more than current dietary guidelines, which recommend that adults in general consume no more than 2,300 mg/d—about a teaspoon.

Several years ago, the National Institutes of Health’s Dietary Approaches to Stop Hypertension-Sodium clinical trial (DASH-Sodium), led by HSPH’s Frank Sacks, professor of cardiovascular disease prevention, found that the biggest blood-pressure-lowering benefits came to those eating at the lowest sodium level tested, 1,500 mg/d. For those prone to high blood pressure, people over 40 and African Americans—groups that together represent nearly 70 percent of the population—the CDC likewise advises no more than 1,500 mg/d.

That 1,500 mg/d threshold would require cutting sodium in processed and restaurant foods by about 80 percent. Though it may sound drastic, the goal is more urgent than ever. In 1982, the U.S. Food and Drug Administration (FDA) called on the food industry to voluntarily reduce sodium levels in processed foods—yet sodium consumption has steadily drifted upward. By 2000, men were eating 48 percent more salt than they did in the early 1970s, and women 69 percent more.


To wean ourselves from excess sugar, the Department of Nutrition’s challenge uses a benchmark of one gram of sugar per ounce, which equates to a 12-ounce soda that contains three teaspoons of sugar and 50 calories. “We’ve suggested that manufacturers provide an option in between high-sugar and sugar-free drinks,” Willett says, “to help people step down if they can’t go cold turkey from full sugar to no sugar.”  The department is currently discussing the challenge with Obama administration officials. While Willett and others are not directly in contact with manufacturers, the challenge’s press coverage has stirred debate within the beverage industry, and several small start-ups are introducing low-sugar drinks.

The HSPH challenge further proposes that the FDA require manufacturers to label the fronts of their cans and bottles with information on total contents rather than per-serving quantities. Currently, most consumers assume that a single package of chips or bottle of soda is a single serving. Only upon close inspection do they discover that there are two or more “servings” in the package. Willett has called for an initial reduction of salt in processed foods of up to 20 percent—a change that studies show does not perceptibly affect taste.


In its forceful call to action, HSPH joins a growing chorus of health experts demanding change. “New Horizons for a Healthy America: Recommendations to the New Administration,” a report issued in April by the Commission on U.S. Federal Leadership in Health and Medicine: Charting Future Directions, describes sugary beverages and salty processed foods as “serious concerns” for the Obama administration. The Washington, D.C.-based Center for Science in the Public Interest (CSPI) has also pressed Congress and the administration to act.

Looking to economic levers to cut consumption, Willett proposes a national sales or excise tax of up to 18 percent on sodas and candy. Along with CSPI, the Department of Nutrition submitted a letter to Congress in June supporting a tax on full-sugar beverages; Willett has also testified before the Massachusetts Legislature in support of such a bill. Some of this tax could be used to subsidize healthy but relatively expensive alternatives, such as fresh fruits and vegetables. Willett would also rewrite government procurement policies to help set new industry standards. In his view, food services at military facilities, hospitals, government organizations, and schools should all phase out highly sweetened beverages in favor of low-sugar options.

And Willett has called for a ban on child-focused marketing for sweetened drinks—since children and teens drink most of their sugary calories at home. “There should be strong regulations, with real teeth in them, against advertising to children. It’s immoral—criminal, even—to have children’s health undermined for the sake of profit,” he says. To this end, Willett has also contemplated lawsuits on behalf of children: “If a child is encouraged to consume these beverages by a fast-food chain, without being warned of the consequences, and they develop diabetes, is there not some liability?

“We will use all levers possible, as we have done for trans fat elimination,” he adds.  “Public education is central to this effort, and talking to journalists is a great multiplier of information.” A Reuters news service story on the department’s industry challenge was picked up from Canada to China, and in JuneUSA Today ran a major story on the topic. Nutrition department investigators are also preparing a scientific review article for a leading medical journal about the deleterious consequences of high-sugar drinks.

The HSPH Department of Nutrition is raising funds to set up a research and information center that would conduct, compile, and disseminate studies on the health implications of sugar-sweetened beverages. The center’s mission: to educate policy makers and the public.

So far, food manufacturers have not widely reformulated their products, for fear of losing customers and getting ahead of taste trends. But other nations, such as Finland, have proven not only that palates can grow more refined when governments embark on full-scale efforts steering people toward more wholesome fare, but that population health dramatically improves when they do. (See: What Other Countries Have Done)

For now, Willett intends to point public health’s artillery toward sodas and other sweetened drinks. “Going for the low-hanging fruit is the first step, and the sugared beverage area is the place,” he says. “These products are in a class with tobacco. There’s only harm, no benefit.”

Photograph: Kent Dayton/HSPH

Larry Hand is associate editor of the Review.
Madeline Drexler is guest editor of this issue of the