Is There a Better Bread?: Wheat vs. Rye Bread

Let's face it. Bread is delicious. And, contrary to the claims of proponents of the low-carb craze, it can also be nutritious — if you choose the right types. Both wheat and rye can be healthy breads, but whether one is better than the other isn't crystal clear.

Both wheat and rye are grains harvested as whole-rye and whole-wheat "berries." In their whole form, they're often used in soups and salads for a boost of vitamins, minerals and fiber. To make bread, the grains are ground and, depending on how they're processed, they may be milled.

Grains that are milled are called "refined grains." The bran and germ have been removed during processing, leaving behind only the starchy endosperm. This results in a finer and softer bread texture, but it also results in a less nutritious bread.

Along with the the bran and germ, many of the vitamins and minerals and much of the fiber have been removed. Refined-grain breads may be enriched with synthetic nutrients, but not with fiber.

One of the reasons whole-grain foods are so good for you is the amount of dietary fiber they contain. Fiber is an indigestible, noncaloric component of all plant foods. After you eat a food rich in fiber, the fiber attracts water in your stomach and intestine, which causes it to swell and become bulkier.

This bulk makes it move more slowly through the digestive system, keeping you feeling full for a longer period of time. Diets higher in fiber lead to improved weight maintenance and weight loss, according to a 2018 study in the journal Nutrition.

Fiber also improves bowel health and helps prevent diseases like diverticulitis and colon cancer, according to the Mayo Clinic. It helps remove some unhealthy cholesterol from your body, and it moderates the effects of carbohydrates on blood sugar. For that reason, the National Academy of Medicine recommends a minimum of 25 grams of fiber daily for women and 38 grams a day for men.

So, whether your choice is wheat or rye, whole-grain varieties are always going to be the better choice. You can typically find many varieties of whole-wheat bread on your grocery store shelves, but whole-grain rye is less common. According to nutrition expert and author Elaine Magee, most grocery store rye breads are made from a combination of refined flour and rye flour.

But that doesn't mean you can't find whole-grain rye breads. Health food stores and online retailers often carry dense dark rye breads that are packed with fiber. One brand of this type of rye bread provides 5 grams per slice.

Read more: What Are the Benefits of Bread Products?

One method used to determine the health value of carbohydrate foods, such as bread, is the glycemic index, or GI. The GI of a food is a measure of how it affects your blood sugar. Knowing this is important, because maintaining steady blood sugar is crucial for controlling diabetes, maintaining or losing weight and overall health.

Foods with a high GI are digested very quickly. They're converted to glucose, which quickly enters the bloodstream, giving you a surge of energy. But once the sugar is ushered into your cells, your energy level crashes, which can lead to fatigue, moodiness and food cravings, according to registered dietitian Joy Bauer.

Low-GI foods, on the other hand, digest more slowly, supplying a steady stream of glucose into the bloodstream. This leads to more stable energy levels, which is crucial for managing diabetes, and makes it easier to control your appetite and calorie intake.

Many factors affect a food's GI rating. According to the Glycemic Index Foundation, these include:

• The extent of processing: More processed and refined carbs digest more quickly.

• A carbohydrate's chemical structure: More complex chemical structures take longer to break down.

• A carbohydrate food's physical structure: Grinding a grain into flour, for example, changes the physical structure of the food.

• The fiber content: Higher-fiber foods digest more slowly.

• The cooking and preparation method: Foods that have been cooked longer typically have a higher GI than less-cooked foods.

• Fat and acid in a food: Fat and acid in a food or in the stomach during digestion slows digestion and the breakdown of carbohydrate to glucose.

Due to the physical structure of bread, most breads have high GI scores. Flour, whether made from whole wheat or refined wheat, digests more quickly than a whole grain because it's been reduced in particle size. This means your body has less work to do to process it.

However, breads higher in fiber, breads that haven't been cooked or processed as long or breads that contain more fat and/or acid may have lower GI scores than other breads. Because of these factors, the GI of commercial and homemade breads will vary. However, according to Oregon State University, the GI rating of white wheat and whole-wheat breads is the same — 71.

According to the American Diabetes Association, any food with a GI over 70 is a high-GI food. Comparatively, the University of Sydney lists the GI of rye bread made with 69 percent whole-grain rye flour as 78. But 100 percent whole-grain rye bread has a GI of 57, making it a medium-GI food.

You may notice that some breads are slightly sweet to the taste. Some of these breads are labeled as "honey wheat bread" or "honey rye," while others, though unlabeled, may still have added sugar or other types of sweetener. Some may even contain high-fructose corn syrup.

Breads containing dried fruit, such as raisin bread, are also high in sugar. Added sugar raises the GI of the bread, which makes it a less healthy choice. Too much added sugar in your diet also increases your risk of obesity, Type 2 diabetes and other chronic illness.

Rather than shunning all types of wheat or rye bread, make your choice based on the label. Look for breads that say they're made with 100 percent whole grain. Breads labeled "multigrain" can be deceiving because they often contain refined grains.

Check the nutrition facts label for fiber and sugar, which are listed next to each other. Look for breads that have at least 2 grams of fiber per slice and less than 1 or 2 grams of sugar per slice — but preferably no sugar. Look for sources of sugar on the ingredients label, such as cane sugar, brown rice syrup, high fructose corn syrup, cane syrup solids, barley malt or other types of sweetener.

According to the University of California San Francisco, there's a minimum of 61 different ways sugar might appear on an ingredients label. If you spot one, put the bread back on the shelf and choose another brand. Better yet, learn how to bake your own bread at home with whole grains and no sugar added.

Read more: Why Isn't White Bread Good for You?