As a health-conscious person who loves to eat, I often find myself chasing nutrients with a knife and fork the way I chased fireflies with a net and Mason jar in my youth. My kitchen is stocked with soymilk fortified with calcium and vitamin D, pomegranate juice enriched with antioxidants, and an embarrassingly large selection of supplements. Did I mention I’m perfectly healthy?
Clearly I’m not alone in my nutrient-obsessing ways. Last year, Americans dropped more than $56 billion on dietary supplements, fortified foods, and functional foods and beverages, according to the Nutrition Business Journal and the Natural Marketing Institute. If you’re not up on the lingo, functional foods proffer health benefits beyond basic nutrition, such as snack chips laced with Ginkgo biloba and diet soda brimming with B vitamins, zinc and magnesium. All of which begs the question: What exactly are we getting in return for our investment?
The answer? Not much. Scientists have spent years mapping what these misappropriated nutrients do for the body. The news isn’t good. Nutritionally speaking, distilling whole foods to a grab bag of single nutrients and then pumping them one by one back into the body leaves a lot to be desired, says Kevin Spelman, a research scientist in the department of chemistry and biochemistry at the University of North Carolina, Greensboro, and an expert in plant chemistry and its biological effects.
“The idea that one isolated nutrient will change the body in a positive way is a bit naive,” he says. “The body’s biology is an ecosystem — throw in too many rabbits and you’ll disrupt the system in ways you couldn’t have predicted.”
Win Some, Lose Some
For a naive idea, it certainly has legs. Since the beginning of the 20th century, scientists have teased nutrients out of whole foods only to inject them back into processed ones. As a case in point, look no further than the United States’s food fortification programs. Once the government connected the dots between missing nutrients in the nation’s food supply and widespread health problems, they got to work.
In some cases, the results were dramatic. Shortly after iodine went into salt in 1924, the rate of iodine deficiency fell from 38 percent to 9 percent. The next stop was grains. During the following decades, iron, riboflavin, thiamin and niacin were ladled into refined wheat, rice and corn. Along the way, milk got a dollop of vitamin D. As recently as 1996, folate got the green light to be added into grains.
The pros and cons of fortification are thorny, but let’s just say that fortified foods have the most to offer people on the verge of malnutrition. The benefits are far less clear for healthy, affluent consumers — the same people who can afford a pint of Breyers Smart!, a frozen yogurt laced with algae.
Out of Isolation
People nutrient-conscious enough to pay for algae in their dessert should reach for whole foods instead. That’s because the nutrients thrown willy-nilly into functional foods, fortified foods and supplements aren’t the nutritional equivalent of whole foods, says Marion Nestle, PhD, professor of nutrition at New York University and author of What to Eat (North Point Press, 2006). “No single nutrient is likely to work as well as a diet rich in the fruits and vegetables from which that nutrient was isolated.”
A good example is white versus whole-wheat flour. When a whole grain is refined into white flour, up to 90 percent of its nutrients are lost. The government requires that five nutrients be tossed back, but what about the rest? The list of nutrients missing in action includes fiber, magnesium, vitamins E and B6, copper, zinc, and more than one hundred phytochemicals — disease-preventing plant chemicals that are proving to be worth their weight in gold (see “Phyto Power” in the November 2007 archives). And those are just the ones scientists have cataloged thus far.
Whole foods also have beneficial effects downstream — on digestion and metabolism — that refined foods can’t equal. For instance, the fiber from legumes, oats, fruits and vegetables (a.k.a. viscous soluble fiber) inside the gut helps to block the body’s absorption of some dietary cholesterol and bile acids, which are a rich source of cholesterol. With less cholesterol on hand from your food, the body needs to cash in whatever it can filter from the blood to make more bile. That exchange helps keep blood cholesterol levels low.
“We’ve only skimmed the surface of understanding all of the nutritional nuances in whole foods,” says Dave Grotto, RD, LDN, a past spokesperson for the American Dietetic Association and author of 101 Foods That Could Save Your Life (Bantam Books, 2007). “We’ve found a lot of neat stuff, but who knows what we are missing?”
Lost in Translation
When foods are manipulated, something is always sacrificed. But that’s not always a bad thing. For example, squeezing fish oil into a capsule doesn’t leave omega-3s worse for wear. Indeed, studies indicate that fish-oil supplements protect the heart as well as the real deal does. But other manmade nutrients haven’t been as successful.
The biggest flops are antioxidants. Researchers have cataloged more than 8,000 phytochemicals in whole foods, many of which are antioxidants, and they suspect it’s the synergy between these compounds that confer a Kevlar-like protection against cancer. In a scientific review from the European Journal of Cancer Prevention, 128 out of 156 studies showed that a diet rich in fruits and vegetables had a “significant protective effect” against cancer. But antioxidant supplements have yet to deliver on their cancer-prevention promise. And, in some cases and some doses, they can even be harmful.
The most notorious example of an antioxidant supplement gone wrong is beta-carotene. Back in the 1980s, observational studies hinted that the more beta-carotene-laden fruits and vegetables people ate, the less likely they were to suffer from heart disease and certain cancers. So researchers devised two large, double-blind, placebo-controlled studies to see if supplemental beta-carotene could convey the same punch.
The end results made scientific jaws drop. Among those swallowing beta-carotene pills, the odds of cancer went up instead of down. Supplemental beta-carotene is an example of an antioxidant that can disrupt the genetic network in a damaging way, says Spelman.
Another big supplement letdown was fiber. Experts know that people who load their diets with fruit, vegetables and whole grains have a protective edge against colon cancer. Again, researchers set their sites on fiber as the miracle nutrient. They concocted a randomized controlled study to see if fiber supplements were a panacea against colon cancer. Much to their chagrin, the fiber-supplement group saw no added protection.
“Now fiber is thought to simply be a marker for other beneficial nutrients, like phytochemicals, in high-fiber foods,” says Donald Hensrud, MD, an associate professor of nutrition and preventive medicine at the Mayo Clinic in Rochester, Minn. “When it comes to protecting against colon cancer, fiber is probably an innocent bystander.”
All of which means eating fiber-rich whole foods will do things for you that gritty fiber drinks can’t.
The Genetic Connection
So, what the heck is so special about whole foods? For starters, nutrients tell the body what genes to turn on and what genes to turn off. A single nutrient can flip on a single gene, but genes work in clusters. “There is literally a web relationship between genes,” says Spelman.
For example, a vitamin-C supplement will switch on relatively few genes. But an orange will switch on a network of genes that respond to signals from fiber, as well as from the fruit’s various vitamins, minerals and phytochemicals.
“To activate the network, you need the combination of nutrients found in whole foods,” Spelman explains. “A single nutrient just doesn’t have what it takes to stimulate the entire network.” To understand how food interacts with our genes, some experts peer back — way back — to what our Paleolithic ancestors ate. They point out that humans evolved quite nicely for 10 million years without a single dietary supplement, sports drink or breakfast bar.
Do our ancestors have something to teach us about diet? Absolutely, says Hensrud. “Humans evolved eating whole foods, so it’s very likely that the concentration and combination of nutrients in whole foods are what’s best for our bodies.”
If you’re more swayed by your bathroom scale than your club-swinging kin, consider that whole foods also support healthy weight management. Because the fiber is stripped out of most refined grains, they aren’t as filling as the real deal, says Joan Salge Blake, RD, LDN, assistant professor of nutrition at Boston University and author of Nutrition and You (Benjamin Cummings, 2007). “Switching to whole grains such as brown rice and whole-wheat bread will add more fiber to your diet, helping you feel more satisfied with smaller portions, so you’ll eat fewer calories.”
Besides, the human body isn’t designed for a lifetime of dining on refined and functional foods. Remember, most of these foods are chock-full of refined starches and sugars. Make them the centerpiece of your diet, and your blood-sugar levels will be on a nonstop roller-coaster ride. Eventually, the exhausted pancreas burns out and type 2 diabetes enters the picture. “That’s a high price to pay for [the supposed benefits of] refined foods,” notes Spelman.
Still, supplements and fortified foods have their place. People at risk of malnutrition, either from lacking access to whole foods or a health condition that limits their absorption of nutrients, can benefit from these products. For everyone else, experts recommend a case-by-case approach.
For instance, people who hate fish could particularly benefit from fish-oil supplements. Like-wise, people age 50 and older should supplement their diet with vitamin D because the body’s need for the nutrient increases with age. Lactose-intolerant people should seek out either calcium supplements or foods fortified with calcium and vitamin D. And, of course, a good multivitamin is recommended for just about everyone, but especially for women before and during pregnancy.
Just remember, the goal is to view supplements and fortified foods in addition to, not in lieu of, whole foods.
Nutrient-obsessed people like myself, however, don’t benefit from merely whittling our diets down to blueberries and salmon. To gain the most bang from your whole-foods buck, it’s best to build in variety and take advantage of whole-food synergies: Some whole foods partner to help the body absorb nutrients better than if you’d eaten them solo (see “So Happy Together,” below ).
A classic example of food synergy is tomato sauce and olive oil. Tomatoes are rich in lycopene, a powerful phytochemical, but the body needs fat to absorb it. So take a page from Italian Cooking 101 and add a few onions sautéed in olive oil to your favorite tomato sauce. “Consider it the diet working in concert,” says Salge Blake.
It all adds up to some refreshingly simple dietary advice: “All nutrients are needed to make your body work properly,” says Nestle. “And the best place to get them is from whole foods.”
Catherine Guthrie is a Bloomington, Ind.–based writer.