Where have all our nutrients gone?
A loaf of white bread has been sitting on my desk for three weeks. I’ve been watching it, waiting for something to happen. Mold, perhaps. A touch of staleness. Bugs maybe. Its sell-by date came and went 14 days ago, but a peek through the wrapper reveals a tanned crust completely devoid of fungus, and a firm press of the package produces a springy return to a perfect rectangular shape, just as it did the day I bought it.
My Stepford loaf was spawned on the bottom floor of a five-story factory by a 2,500-pound mother dough ball that contained more than 36 ingredients, from refined flour to dough conditioners for softness and cellulose gum for “mouthfeel.” (See Enriched White Bread vs. Artisan Whole-Wheat Bread,”) A mechanized knife chopped the mound into 27-ounce balls and another machine rolled the balls into logs and deposited them into pans. The pans spiraled through an oven large enough to hold six full-size school buses and 16 minutes later the logs emerged baked. My loaf was one of 150,000 from the oven that day to be sliced, packaged and trucked to stores all over the region. Production people told me that it would take about 15 days for my loaf to begin to mold. My desktop experiment says it takes a lot longer than that.
In my refrigerator, on the other hand, sits a two-day-old lopsided trapezoid of whole-wheat bread made by a local company called Small Planet Bakery. Aaron, son of one of the bakery’s owners, stirred together eight ingredients in a Hobart Upright mixer to make the loaf, adding more water and flour by sight and touch. Some days, the loaves he makes are small and dense; other days, they are so big the slices won’t fit in a toaster—it all depends on the weather, the wheat and his whim. He uses whole-wheat flour, honey, canola oil and 38 percent less salt than my fluffy white loaf. His co-workers carve a 100-pound mother dough ball into 27-ounce mounds on a long maple tabletop, and after letting the logs rise solely by the heat of the Tucson summer, they set the pans in a large oven to bake. By the end of the day, the team has made a grand total of 400 loaves—each of which they estimate takes about a week to mold if left out. They pack the loaves into a truck that delivers the bread to local stores and restaurants.
Both processes produce a perfectly fine-looking loaf of bread. I can make sandwiches with
either one; each seems wholesome and tasty. Both are “processed”—we’re not munching on raw wheat berries here—but the paths each of these loaves followed couldn’t have been more different. With growing alarms about the unhealthy state of the Western diet, packed full of overprocessed foods, I wanted to know how making food the white-bread way affects our health, and whether making it the Small Planet way is any better.
Lost in Transition
Most of the food consumed in this country passes through a factory or processing plant before ever reaching our tables, and for simple reasons: food needs to be safe, transportable and to stay sellable in the supermarket. Minnesotans want to eat canned peaches in January and working parents want to buy a loaf of bread at the store instead of spending all day baking it themselves. The result is that less and less can be called “unprocessed” anymore. Yet the transition from field to shelf happens in wildly divergent ways, from the simple baking of a few ingredients, like my Small Planet loaf, to inventing a sports drink that comes in a choice of several different neon colors, the product of food chemists and marketers hoping to create mega-demand.
A growing number of voices question whether extreme processing is just making modern food safe and convenient or if it may actually be creating a long-term threat to our society’s nutritional health.
“During processing, a lot of beneficial nutrients like fiber, minerals and antioxidants are lost—especially in highly processed, refined-grain products,” says Frank Hu, an epidemiologist at Harvard School of Public Health who tracks the effects of food on diseases in the American population. “Manufacturers also add a lot of sugar and trans fats back in to enhance the taste,” he says. “So you get rid of the good stuff and add a lot of bad stuff and that’s the reason those kinds of foods are really detrimental.”
The $450 billion food industry packs superstores full of 40,000 different food items in cans, boxes, pouches and packages. “This food has become so much a part of the culture that we don’t even realize it,” says Loren Cordain, professor of health and exercise science at Colorado State University. “If you’re an average American and you’re not really too health conscious, you eat these foods every single day, and you’ve eaten them every single day of your life.”
Whole Grains: The Protective Elements
Consider the very first ingredient in my loaf of white bread, “enriched wheat flour”—refined and reformulated wheat. At the grain mill, long rollers with hundreds of metal teeth hum noisily as they crush raw wheat berries over and over, sifting and separating them between large screens and eventually stripping the strongly flavored nutrient- and fiber-packed germ and bran from the starchy, bland endosperm. Throughout history, people considered this white flour superior to coarse whole-wheat, but it wasn’t until millers began using steel rollers in the 19th century that refined flour became cheap enough for everyone to afford. Ironically, although long a staple for the privileged, white flour contains barely any fiber, vitamins or minerals, the building blocks of healthy food. One slice of white bread has 65 percent less fiber, magnesium and potassium than whole-wheat bread. The bran alone in whole-wheat bread gives it 20 times more antioxidant power.
But what is the harm in eating a few random slices of white bread? According to whole-grains researcher Joanne Slavin at the University of Minnesota, one loaf of white bread is nothing compared to the damage done by the hefty volume of refined products eaten by the average American.
Twenty percent of the typical American diet now comes from refined grains—bread, pasta, doughnuts, chips, meals-in-a-box, muffins, crackers. Slavin points me to reams of epidemiological studies that associate a diet high in refined grains with a higher risk of stroke, weight gain and metabolic syndrome—a constellation of conditions that predisposes a person to type 2 diabetes and heart disease. A diet high in whole grains, on the other hand, is associated with a lower risk of heart disease, less weight gain, fewer cases of type 2 diabetes and reduced risk of colon cancer and metabolic syndrome. People who eat more whole grains also tend to have lower bad (LDL) cholesterol and higher good (HDL) cholesterol, all good reasons to opt for a chewier loaf and more foods made with whole grains.
One reason refinement takes a toll on health comes from the fact that instead of being digested in the small intestine, fiber ferments in the gut, and the products of fermentation have been shown to lower cholesterol and reduce the risk of certain cancers. Whole grains also appear to increase insulin sensitivity—the body’s ability to use the hormone insulin to balance blood sugar. On the flip side, refined grains have been linked to lower insulin sensitivity and unhealthy spikes in blood sugar, troublesome outcomes that can eventually lead to the development of type 2 diabetes. Not only that, whole grains burst with antioxidants and other compounds, including plant stanols and sterols and phytoestrogens: a party of health ambassadors that science has only begun to understand.
In fact, Slavin thinks the synergy of hundreds of compounds in whole grains creates much of the magic. While manufacturers “enrich” white flour to replace some of the nutrients lost during refining—niacin, thiamine, riboflavin and iron—and “fortify” with folic acid, chemistry can’t do it all, she says. (See “Putting Humpty Dumpty Back Together”.)
“People say, ‘Let’s just make this white bread the same as a whole grain,’” Slavin notes. “You really can’t. If we take a whole grain and we completely blow it apart and then stick it back into a product, is it still whole? White bread that has some fiber and magnesium or whatever other nutrient dumped into it isn’t the same as whole wheat,” she explains. “Nobody really knows which particular nutrients are most important.”
Turn Up the Heat...
As food journeys from farm to table, most of it, including both of my breads, shares one important side trip: a high-heat experience. Besides the obvious cooking, heat is necessary to kill micro-organisms, reduce oxidative changes that cause rancidity and prevent other chemical reactions that may produce off-flavors. My loaves have been baked in industrial ovens. Milk and juices are pasteurized in huge stainless-steel vats. Pasta is dried in vast machines that circulate hot air.
Along with changing flavor and color, thermal processing takes a toll on nutrients, says food scientist Steven Schwartz at Ohio State University, a student of the processing road map. His laboratory frequently scrutinizes cooked vegetables to determine just what has been lost or gained during processing. In canned peas versus fresh peas, for example, the nutrient content has faded as much as the color. Vitamins, especially water-soluble vitamins like C and the B vitamins, are heat-sensitive and some leach into cooking water in the factory, which is why steaming or microwaving, not boiling, vegetables is the best cooking method at home. Peas from a can have 72 percent less vitamin C, 59 percent less niacin, 56 percent less B6 and 17 percent less potassium than the same amount of raw peas. The food industry tries to find the best balance between safety and nutrition, but the longer and hotter the cooking, the more a food will be altered. Frozen vegetables, plunged briefly into boiling water and then cooled, have a much better track record for keeping their nutrients. In fact, they can exceed the nutrition of “fresh” vegetables, depending upon how long produce has been traveling and waiting in the grocery bin.
...Pump Up the Salt
Taste is also lost during refinement and heating. Manufacturers often try to add it back in the form of salt, also an aid in preservation, but the result is devastating to our health: most Americans get 75 percent of their total salt from processed foods. Meanwhile processing robs fruits and vegetables of potassium, a mineral that helps to keep sodium’s damage at bay.
“Potassium helps to mitigate the adverse effects of salt on blood pressure,” says Lawrence Appel, a Johns Hopkins researcher who studies the effects of diet on blood pressure. “Processing tends to remove potassium and add sodium—a bad combination.” In fact, while 95 percent of men and 75 percent of women regularly exceed the recommended salt intake, most adults consume less than half the recommended potassium, one reason that 50 million Americans suffer from hypertension. In England, public-health experts have made enough noise that the government is beginning to regulate the sodium that goes into canned goods, but no such plans are afoot in this country.
Out with the Good Fats, In with the Bad
Look at a bread with an incredibly long shelf life and you’re likely to find “partially hydrogenated soybean and cottonseed oil” on the ingredient label. Hydrogenated oils are one of the ingredients that put the spring and longevity into my mass-produced loaf.
It all started back in the 1960s when the public began to suspect that saturated fat threatens the heart. Manufacturers responded by replacing animal fats in their products with partially hydrogenated vegetable oils, which were low in saturated fat, extended shelf life, tasted good and provided great texture to processed foods. But these oils contained trans fats, the result of heavy processing to make them more shelf-stable, and trans fats have now been conclusively linked to heart disease and premature death. Harvard’s Frank Hu thinks trans fats may be the worst part of eating processed foods.
“One of the most important things to do is to get rid of trans fats,” says Hu. “We found a very clear association between trans fats and diabetes and heart disease.” By increasing bad (LDL) cholesterol, reducing good (HDL) cholesterol and causing systemic inflammation, trans fats contribute to heart disease. While many food processors are reforming their products in anticipation of the mandatory labeling rule on trans fats in the U.S. in 2006, others continue to
add trans fats liberally to their foods. Hu’s colleagues at Harvard estimate that replacing partially hydrogenated oils in the U.S. diet with nonhydrogenated vegetable oils would prevent at least 30,000—perhaps up to 100,000—premature coronary deaths each year.
Having Your Bread and Eating It Too
Hungry for my lunchtime PB&J, I take another look at my plastic-bagged loaf, eyeballing the long list of ingredients and thinking about all the effort that went into producing it, an amalgam of additions and subtractions that satisfies strict rules of marketing, safety and convenience. Health’s role in the equation is minor in comparison.
Loren Cordain at Colorado State recently published data that show just how much processed foods dominate our diet today. He found that 57 percent of most Americans’ calories come from only three foods: refined grains, vegetable oils and added sugar.
“This mixture is ubiquitous in the Western diet. You can call it a slice of bread, you can call it a doughnut, you can call it a pizza, you can call it a cracker, you can call it a pretzel, you can call it whatever you want, but it’s basically a mixture of those same three ubiquitous foods—vegetable oil, refined flour and sugar, with a little bit of flavoring,” says Cordain. “Sugars are devoid of any micronutrients, refined oils are also devoid of any nutrients except for vitamins E and K. And then when you tack that onto white flour, you’ve basically got a diet that can easily produce nutritional shortfalls.”
He lists concerns for nutrient after nutrient—73 percent of Americans didn’t meet requirements at last count for zinc, 65 percent weren’t getting enough calcium, 56 percent were short on vitamin A, 54 percent didn’t consume enough B6, 39 percent lacked sufficient iron, and the list goes on. How does the future look for these people? “They will become a statistic,” says Cordain. “If they continue eating those kind of foods throughout their lives, they will become a statistic, if they aren’t already.”
Some manufacturers are making changes—General Mills has converted all its cereals to a half or full serving of whole grains. Frito-Lay has eliminated trans fats from many of its snack foods, including Doritos, Cheetos and Tostitos. ASDA, a British food and clothing superstore, is
in the process of removing salt from all its private-label canned vegetables, which is projected to result in customers consuming 185 tons less salt each year.
No health expert will tell you that eating a heavily processed food on occasion will kill you, but they do agree that relying on them for most of your calories and nutrients is a bad idea. A degree of processing can be found in almost any food at the supermarket. Simply choose among them wisely, suggests Minnesota’s Slavin. Frozen fruits and vegetables should have only one or two ingredients on their label; make sure the first ingredient begins with “whole” in any bread or grain-related food. When choosing cans, meals-in-a-box or frozen dinners, choose low-salt varieties. Avoid foods with “partially hydrogenated oil” on the ingredient list and foods that have several layers of processing: refining, drying, freezing, preserving, additives and salt. Instead choose foods that limit processing and sport a minimum number of ingredients, all of which you recognize. Tomato paste, for example, needs only tomatoes, not “tomatoes, high-fructose corn syrup, partially hydrogenated vegetable oil, salt, natural flavor.”
After four weeks, my white bread has finally begun to sprout tiny bruise-colored mold spots (the calcium propionate added to the dough slowed the fungi’s growth). It’s still springy, though. Who would have thought 100 years ago that a loaf of soft bread would stay good for almost a month?
“People are so used to foods lasting forever,” says Slavin. “I think from a consumer standpoint, for people to say, ‘Well, I don’t want processed foods,’ they’re going to have to learn how to cook, be willing to shop regularly, learn how to store foods. It’s going to be this huge paradigm shift before we can get away from the processing that everybody is used to. As long as convenience is such a leading force in people’s lives, processed foods have to be there. People expect it, they want it. Are they willing to put more time and more money into less-processed foods? It’s a big decision.”
Slavin chooses her foods judiciously at the supermarket, and Cordain says he has eaten mostly “real” foods for the past 15 years and believes that others can follow his example. “The strategy I have is that less than 15 percent of your diet should be processed foods,” he says. “The balance is real foods—seafood, lean meats, fresh fruits and vegetables—and you’ll be in great shape, healthwise.”
Rachael Moeller Gorman, a health and science writer, contributes regularly to EatingWell.