We've all heard the advice to eat more whole grains, and cut back on refined starches.
And there's good reason. Compared with a diet heavy on refined grains, like white flour, a diet rich in whole grains — which includes everything from brown rice to steel-cut oats to farro — is linked to lower rates of heart disease, certain cancers and Type 2 diabetes.
So when it comes to choosing bread, experts say, you want to move away from the white loaves in the grocery aisle. That's because white flour is a high-glycemic food — like sugar.
"That white bread is going to digest much more quickly, leading to a surge and crash in blood sugar that may stimulate hunger later in the meal, but also raise risk for diabetes and heart disease," says physician David Ludwig of Boston Children's Hospital. (As I reported in a recent series on fat, refined carbohydrates like white flour can worsen blood cholesterol levels compared with saturated fat.)
But when you start looking for alternatives, it's worth noting that not all loaves labeled "whole grain" or "whole wheat" are created equal. And that's because wheat is milled in different ways.
Most wheat is processed into refined flour. That means its three main components are separated out. The starchy endosperm ends up as the flour. The germ and bran are discarded and used for other things.
Many whole wheat and whole grain breads are made from this kind of flour — with some or all of the bran and wheat germ added back. Technically, as long as the three parts are present in the flour in the same relative proportions as in the intact grain, it's considered a whole grain. (Here's the official guidance from the Food and Drug Administration.)
But wheat can also be milled in a way that leaves fragments of the whole grain intact — think traditional grinding stones. And there's a difference between how your body metabolizes grains that are still intact, and grains that have been refined and reassembled.
Experts say it's certainly better to opt for any kind of whole grain loaf over white bread. But if bread lovers want to put the brakes on the rise and fall in blood sugar, perhaps the best options are loaves that contain chunks of grain still intact — like bits of wheat kernel, rye or millet.
Often, when it comes to processing foods, "less is more," Ludwig tells us.
"Whole foods, minimally processed foods, certainly whole grains, take awhile to digest. They have to travel down the intestinal tract, and the sugars are slowly absorbed out of that whole grain so that blood sugar and insulin levels rise only modestly," he says.
He points to one small study published back in the late 1980s where researchers found that increasing the proportion of whole grains or coarse cracked wheat in breads led to a more favorable glucose response in people with diabetes.
And over the long term, eating whole grains instead of highly refined grains may help reduce the risk of Type 2 diabetes.
Artisanal bakers like Dan Gottfredson, who operates a Great Harvest Bread Co. bakery in Rockville, Md., is well aware of the trend toward more whole foods. And, he says, bread fits into this trend.
So it's not a surprise that his best-selling breads of the day are crunchy, high-fiber loaves, such as his whole wheat Dakota bread, which is loaded with sunflower seeds, pumpkin seeds and whole-grain millet.
If you listen to my story, you'll hear that increasingly there are more whole grain options in the grocery aisle, too. Examples include 12-grain breads, rye breads or loaves topped with cracked oats.
DAVID GREENE, HOST:
It's Tuesday morning and it's MORNING EDITION, from NPR News. I'm David Greene.
KELLY MCEVERS, HOST:
And I'm Kelly McEvers. If you're paying attention to what you eat, you've probably been told to eat more whole grains. But then maybe you go to the grocery store, see all the choices and get confused. NPR's Allison Aubrey reports that to know how to pick a good whole grain bread, you first have to know why it's better than the white stuff.
ALLISON AUBREY, BYLINE: Dan Gottfredson is of the generation that grew up with Wonder Bread. But the kind of breads he makes today at his small bakery in Rockville, Md., is entirely different. As he cranks up his stone mill, he dumps in whole kernels of wheat.
DAN GOTTFREDSON: So we fill the hopper up with 150 pounds worth of wheat seed.
AUBREY: Holding out a handful of these seeds, also called wheat berries, which are harvested from the top of wheat stalks, he shows me that inside each one is what's called the wheat germ, which is chock full of minerals and vitamins. And there's also the wheat bran, the source of all the fiber.
GOTTFREDSON: The wheat bran is the skin of the wheat kernel.
AUBREY: Now, to make white bread, most of the bran and germ are tossed out. But to make his whole wheat bread, Gottfredson uses flour made from the whole kernel. What he shows me next is how he grinds it using a stone mill.
GOTTFREDSON: The stones are inside the machine. One stone stays stationary. The other one spins really, really fast. They're so close together that it crushes the wheat.
AUBREY: And what comes out the other side is, of course, nutty smelling flour that still has larger bits of wheat germ and bran intact. And within a few hours the flour is baked into a high fiber chunky bread that smells divine.
GOTTFREDSON: It smells so much better, so much richer.
AUBREY: So why is bread made with whole grains so much better for you? Well, physician David Ludwig of Boston Children's Hospital says consider what happens to your body when you eat white bread. It's almost like eating sugar.
DAVID LUDWIG: That white bread is going to digest much more quickly, leading to a surge and crash in blood sugar that may stimulate hunger later in the meal, but also raise risk for diabetes and heart disease.
AUBREY: By comparison, he says whole grains work a lot differently.
LUDWIG: Whole foods, minimally processed foods, certainly whole grains, take a while to digest. They have to travel down the intestinal tract and the sugars are slowly absorbed out of that whole grain so that blood sugar and insulin levels rise only modestly.
AUBREY: Which is a good thing. Now, not everyone's going to shop for fancy bakery bread every week, but what people can do, Ludwig says, is to look in the grocery store bread aisle for loaves that have bits of grain and seeds still intact.
LUDWIG: Best is grains that have been minimally processed, either into breads where you can still see pieces of the kernel intact, or better yet, even the flourless breads, like pumpernickels that are consumed in Europe.
AUBREY: Now, all this explanation makes good sense to my colleague and fellow health reporter, Julie Rovner. But as we walk down the bread aisle of the local grocery store, we find you really do have to look carefully to find a good option. Julie picks up a brownish honey wheat loaf.
JULIE ROVNER, BYLINE: This might well be a winner.
AUBREY: But when we look at the nutrition label, it's hardly whole grain. Only some of the flour is whole wheat. It doesn't have much more fiber than white bread, and it's got a fair amount of sugar.
ROVNER: That's not so good. This one is kind of not going there for me.
AUBREY: But then we find a loaf that's covered in chunks of flax seeds and millet, and the bread itself is kind of speckled with intact grains. It looks like this might be the best option, but Julie's not so sure she wants to eat it.
ROVNER: Well, this one, I think, might be a little bit too far over for me. This is the whole grain healthy multigrain bread, which is, you know, looks like something a bird would eat.
AUBREY: But then she reads the label.
ROVNER: It's got all this stuff. It does say good source of fiber, no high fructose corn syrup, 18 grams of whole grains per slice. Actually, it's only got 110 calories per slice.
AUBREY: Actually, maybe that's not a bad choice.
ROVNER: Yeah, it actually may not be. I'm coming around on this one.
AUBREY: She's prepared to give it a try, but certainly Julie's not the only one who feels these kinds of breads might take some getting used to. Now, the bread industry says the shift towards whole grains has been happening slowly. It wasn't long ago that sales of white bread dominated. Now loaves containing whole wheat flour have overtaken white and increasingly there are more whole grain options on the shelves of mainstream grocery stores. Allison Aubrey, NPR News. Transcript provided by NPR, Copyright NPR.