Wheat and barley have been grown by humans for thousands of years and were one of the earliest plants to be domesticated. 

Today, they’re two of the major crops in the world used for food and drink production, as well as animal feed. 

They may look very similar on the surface, but they do have some key differences in terms of how they’re processed and used, their nutrition, and health effects. 

This article tells you all you need to know about the most important differences between the two grains. 

History and characteristics

Wheat and barley were first domesticated in the Middle East approximately 10,000 years ago and have since been a vital part of human and livestock diets (1, 2, 3). 

Both belong to the grasses family (Poaceae), which includes other crops, such as rice, sugarcane, and corn. 

The grains are the fruits, or caryopsis, of the grass plant. These fruits are found on a “spike” or “head,” arranged in vertical rows, similar to an ear of corn (2). 

The grain is made up of three layers. 

The inner germ layer is the nutrient-dense core. Outside of this is the endosperm, which contains mostly carbs and proteins that supply the germ layer with energy. The outer layer is called bran, which is rich in fiber, B vitamins, and trace minerals. 

Since their original domestication, both grains have been cultivated into many different varieties and subspecies (4).

The most commonly cultivated wheat variety is bread wheat (Triticum aestivum). Additional types include durum, einkorn, emmer, and spelt (2, 4).

There are three common types of barley — two-row, six-row, and hull-less. These three types are known under the botanical name Hordeum vulgare L (5). 

Summary

Barley and wheat were some of the earliest domesticated crops.  They both belong to the grass family, and the grain is actually the fruit of the grass, made up of an inner germ, endosperm, and outer bran layer.

Processing and uses

Wheat

Before wheat can be used, it needs to be milled. Milling refers to the process of cracking the grain to separate the bran and germ from the endosperm and crushing the endosperm into a fine flour.

Whole wheat flour contains all parts of the grain, the germ, endosperm, and bran, while regular milled flour contains just the endosperm.  

The milled flour is used for making breads, biscuits, cookies, pasta, noodles, semolina, bulgur, couscous, and breakfast cereals (6). 

Wheat can be fermented to make biofuels, beer, and other alcoholic drinks. It’s also used in smaller amounts for livestock fodder (6). 

Barley

Barley doesn’t need to be milled before use, but it’s usually hulled to remove the outermost layer.  

Hulled barley is a whole grain, as the bran, endosperm, and germ remain intact. For food use, barley is often pearled. This involves removing both the hull and bran, leaving just the germ and endosperm layers (5). 

Although barley was historically an important food source in many parts of the world, it has been largely replaced by other grains, such as wheat and rice over the past 200 years (5). 

Today, barley is primarily used for animal feed or malted for use in alcoholic drinks like beer. However, a small amount of barley is used as a food source for humans as well (5, 7). 

Both hulled and pearled barley can be cooked, similar to rice, and are often used in soups and stews. They’re also found in breakfast cereals, porridge, and baby food (5).

Barley can also be made into flour by milling the pearled grain. The flour is often used with other wheat-based products like bread, noodles, and baked goods to boost their nutritional profile (5, 8). 

Summary

Wheat is milled into flour so it can be used in baked goods like bread. Barley is primarily used as feed for livestock and in alcohol production, but it can also be cooked whole in a similar manner to rice or milled into flour. 

Nutrient breakdown

The nutrient composition of barley and wheat differs depending on the amount of processing each grain has gone through.  

Flour made from wheat usually contains just the endosperm component, while whole wheat flour contains all parts of the grain.

Barley used in cooking generally comes in hulled form, with all parts of the grain intact. It may also come as pearled barley, where the bran has been removed. 

Macronutrients

Here’s how 3.5 ounces (100 grams) of whole wheat flour, refined wheat flour, hulled barley, and pearled barley compare in their macronutrient content (9, 10, 11, 12):

Whole wheat flourWheat flourHulled barleyPearled barley
Calories340361354352
Carbs72.0 grams72.5 grams73.4 grams77.7 grams
Protein13.2 grams12 grams12.5 grams9.9 grams
Fat2.5 grams1.7 grams2.3 grams1.2 grams
Fiber10.7 grams2.4 grams17.3 grams15.6 grams

It’s clear that for calories, carbs, protein, and fats, wheat and barley are quite similar, even after undergoing processing, such as milling or de-hulling. 

However, wheat loses significant amounts of fiber during milling, as the majority of the fiber is found in the bran layer of the grain. In whole wheat flour, the bran is added back into the final product, boosting the fiber content. 

On the other hand, barley is very rich in dietary fiber, providing 60–70% of the 25 grams recommended by the American Heart Association (13).  

Because the fiber is spread throughout the grain, not just in the bran, even when the bran layer is removed in pearled barley, there’s still a significant amount of fiber left. 

Minerals

Here’s how 3.5 ounces (100 grams) of whole wheat flour, refined wheat flour, hulled barley, and pearled barley compare in their mineral content (9, 10, 11, 12):

Whole wheat flourWheat flourHulled barleyPearled barley
Manganese177% of the Daily Value (DV)34% of the DV85% of the DV58% of the DV
Copper46% of the DV20% of the DV55% of the DV47% of the DV
Zinc24% of the DV8% of the DV25% of the DV19% of the DV
Phosphorus29% of the DV8% of the DV21% of the DV18% of the DV
Iron20% of the DV5% of the DV20% of the DV14% of the DV
Magnesium33% of the DV6% of the DV32% of the DV19% of the DV
Potassium8% of the DV2% of the DV10% of the DV6% of the DV

Wheat and barley are rich in minerals. However, both lose significant amounts during processing, particularly in the milling of refined wheat flour. Iron is usually added back to milled wheat flour to match that of the whole grain product.

Wheat is particularly high in manganese, and whole grain wheat flour and hulled barley have similar amounts of zinc, iron, magnesium, and potassium. 

Nonetheless, both hulled and pearled barley are better sources of all minerals, compared with refined wheat flour. 

Vitamins

Here’s how 3.5 ounces (100 grams) of whole wheat flour, refined wheat flour, hulled barley, and pearled barley compare in their vitamin content (9, 10, 11, 12):

Whole wheat flourWheat flourHulled barleyPearled barley
Thiamine42% of the DV7% of the DV54% of the DV16% of the DV
Niacin31% of the DV6% of the DV29% of the DV29% of the DV
Vitamin B624% of the DV2% of the DV19% of the DV15% of the DV
Vitamin B512% of the DV9% of the DV6% of the DV6% of the DV
Folate11% of the DV8% of the DV5% of the DV6% of the DV
Riboflavin13% of the DV5% of the DV22% of the DV9% of the DV
Vitamin E5% of the DV3% of the DV4% of the DV0% of the DV

Hulled barley is richer in thiamine and riboflavin than wheat. Conversely, wheat is slightly richer in niacin, vitamin B6, vitamin B5, folate, and vitamin E.  

However, milling wheat to refined flour results in significant losses of all vitamins, and pearling barley results in a significant loss of thiamine, riboflavin, and vitamin E. Thiamine and riboflavin, as well as other B vitamins, are usually added back to refined flour after milling.

Summary

Wheat and barley are very nutrient rich. But wheat milled into refined flour loses a significant amount of fiber, minerals, and certain vitamins. Pearled barley also loses nutritional value. B vitamins are added back to refined flours before processing.

Health effects of wheat and barley

Barley and wheat share some common health effects, as well as some important differences, including how they affect conditions such as celiac disease, wheat allergy, irritable bowel syndrome (IBS), and metabolic syndrome

Celiac disease and non-celiac gluten sensitivity

People with an autoimmune condition known as celiac disease can’t tolerate proteins called gluten, as they damage the lining of the intestine, which can result in bloating, iron deficiency, constipation, diarrhea, weight loss, and even failure to thrive (14).  

Additionally, some people without celiac disease may experience symptoms like bloating, gas, and pain when eating foods that contain gluten (15, 16, 17). 

Barley and wheat both contain types of gluten proteins. Wheat contains glutenins and gliadins, while barley contains hordeins (18).  

Therefore, people who can’t tolerate gluten should avoid both wheat and barley. 

Wheat allergy

Wheat allergy is an immune reaction to various proteins in wheat, some of which are shared by barley (18, 19). 

Allergic reactions include mild symptoms, such as redness, itching, and diarrhea, as well as more severe symptoms, such as asthma and anaphylaxis (19). 

Although they share some similar proteins, many people with a wheat allergy aren’t allergic to barley. In fact, barley allergy is relatively rare and not well studied (20, 21, 22).  

However, if you do have a wheat allergy, it’s best to talk to your healthcare provider if you have concerns about potential reactions to barley (18). 

Irritable bowel syndrome (IBS)

Both barley and wheat contain types of sugars known as fructans and galactooligosaccharides (GOS) (23). 

Fructans are chains of connected fructose sugars commonly found in fruits and vegetables. GOS are chains of galactose sugars. 

Neither of these sugars is broken down during digestion, so they move through to the large intestine where naturally occurring bacteria ferment them, producing gas (23, 24).  

In most people, this doesn’t have any negative effects. Yet, people with IBS can experience bloating, stomach discomfort, diarrhea, or constipation (23, 25). 

Therefore, if you experience IBS symptoms, it may be beneficial to limit the amount of wheat and barley you eat (26). 

Barley, cholesterol, and blood sugar

One big advantage of barley over wheat is that it contains high amounts of the fiber beta-glucan

In fact, barley contains approximately 5–11% beta-glucan, compared with wheat, which contains about 1%. Pearled parley provides even more, as beta-glucan is particularly concentrated in the endosperm layer of the grain (5, 8). 

Beta-glucan has been found to help lower cholesterol and improve blood sugar control (5, 27). 

For example, a review of 34 studies found that including at least 4 grams of beta-glucan per day alongside 30–80 grams of carbs significantly reduced blood sugar levels (28).

Moreover, a review of 58 studies found that 3.5 grams of beta-glucan per day significantly lowered LDL (bad) cholesterol, compared with controls (29).  

Therefore, barley may have some added benefits for health, compared with wheat. 

Summary

Barley and wheat are unsuitable for people with gluten sensitivity. They may also cause problems for people with IBS. Still, many people with wheat allergy can tolerate barley. Barley may help improve cholesterol and blood sugar levels.

The bottom line

Barley and wheat are both important domesticated crops belonging to the grass family. 

Wheat is ground into flour before use in baked goods and other foods, while barley is mostly eaten in whole grain or pearled form.  

Both contain gluten, making them unsuitable for people with celiac disease or gluten sensitivity

While both grains are nutritious, barley is richer in fiber and cholesterol-lowering beta-glucan and loses fewer nutrients during processing than wheat. However, important nutrients are added back to wheat flour that’s milled before using it to create pasta, cereals, and breads.