Does an ear of corn have protein? Unpacking the nutritional facts

November 5, 2025 •

4 min read

A single medium ear of sweet corn contains approximately 3 grams of protein, contrary to the common belief that it is only a source of carbohydrates. So, does an ear of corn have protein? Yes, it does, but understanding its role within a balanced diet is key to maximizing its nutritional benefits.

Quick Summary

An ear of corn provides a moderate amount of protein, although it is not a complete protein source. It is primarily a carbohydrate and fiber source, rich in various vitamins and antioxidants, and contributes to overall dietary intake.

Key Points

Protein Content: A medium ear of corn has approximately 3 grams of protein, contributing to daily intake but not functioning as a primary source.
Incomplete Protein: Corn protein lacks certain essential amino acids, making it an incomplete protein source that should be paired with other foods for a full profile.
Rich in Fiber: Corn provides a good amount of both soluble and insoluble dietary fiber, which supports healthy digestion and blood sugar regulation.
Antioxidant Powerhouse: Yellow corn is rich in antioxidants like lutein and zeaxanthin, which are crucial for maintaining eye health.
Mineral and Vitamin Benefits: Corn offers a variety of vitamins and minerals, including B vitamins, vitamin C, magnesium, and potassium.
Smart Pairing: To create a complete protein, combine corn with legumes like beans or other whole grains within the same meal or day.

Understanding Corn's Macronutrient Profile

Corn, or maize, is a staple crop enjoyed globally in many forms, from fresh on the cob to milled flour and popcorn. When considering its nutritional value, most people focus on its carbohydrate content. However, a deeper look reveals a more complex profile that includes a moderate amount of protein. A typical medium ear of sweet corn provides about 3 grams of protein, which, while not as high as animal products or legumes, is a notable contribution for a starchy vegetable. The quantity of protein can vary slightly depending on the variety of corn and how it is prepared.

The Quality of Corn Protein

It is important to differentiate between the quantity and quality of protein. The protein found in corn is considered 'incomplete'. This means it lacks sufficient amounts of certain essential amino acids, particularly lysine and tryptophan, that the human body cannot produce on its own. To compensate for this, a person on a plant-based diet should practice protein complementation—the process of combining different incomplete protein sources throughout the day to form a complete amino acid profile. Pairing corn with legumes like black beans or peanuts is an excellent way to achieve this.

Corn: More Than Just Carbohydrates and Protein

Beyond its protein content, corn offers a wealth of other nutrients essential for health. It is a good source of dietary fiber, with about 2 to 3 grams per medium ear. This fiber is beneficial for digestive health and helps regulate blood sugar levels.

Moreover, corn is rich in various vitamins and minerals:

B Vitamins: It provides B vitamins, including folate and thiamine, which are crucial for converting food into energy.
Vitamin C: An antioxidant that supports the immune system and protects cells from damage.
Magnesium and Potassium: These minerals play a role in numerous body processes, including blood pressure regulation and nerve function.
Antioxidants: Yellow corn is an excellent source of the antioxidants lutein and zeaxanthin, which are vital for promoting eye health and protecting against age-related macular degeneration.

Corn in a Balanced Diet: Considerations

For those managing conditions like diabetes, it's important to recognize that corn is a starchy vegetable and should be accounted for as a carbohydrate source. The good news is that its fiber content helps slow down the absorption of its natural sugars, preventing a rapid spike in blood sugar. Portion control is key. While high-fructose corn syrup is derived from corn, it is a highly processed product with none of the nutritional benefits of whole corn kernels. Opting for whole grain corn, such as eating it fresh or as popcorn, is the healthiest approach.

Corn vs. Common Protein Sources

To put corn's protein contribution into perspective, here is a comparison with other food items. This table highlights how corn, while containing protein, is best used as a complementary rather than primary protein source in a diet.


Food Item (Approx. 100g)	Protein (g)	Key Macronutrient	Complete Protein?	Complementary Pairing
Sweet Corn (Boiled)	3.4	Carbohydrate	No	Legumes, Rice
Chicken Breast	31 [Source: USDA]	Protein	Yes	N/A
Black Beans (Cooked)	8.9 [Source: USDA]	Carbohydrate/Fiber	No	Rice, Corn
Lentils (Cooked)	9 [Source: USDA]	Carbohydrate/Fiber	No	Whole grains, Nuts
Quinoa (Cooked)	4.1 [Source: USDA]	Carbohydrate	Yes	N/A

How to Enjoy Corn's Nutritional Value

Corn's versatility makes it easy to incorporate into your diet in numerous healthy ways. Instead of adding excessive butter and salt, consider these healthier options:

Grilled Corn: A simple spritz of olive oil and a dash of chili powder adds flavor without heavy fats.
Corn Salad: Combine fresh corn kernels with black beans, diced tomatoes, cilantro, and a lime vinaigrette for a refreshing and complete-protein dish.
Soup and Chili: Add corn to your favorite soups and stews for extra fiber, texture, and flavor.
Popcorn: Air-popped popcorn made at home is a healthy, whole-grain snack. Top it with nutritional yeast for a cheesy flavor and some extra nutrients.
Salsa: A corn and mango salsa can be a vibrant and healthy addition to grilled chicken or fish.

Conclusion

In summary, yes, an ear of corn does contain protein, but its nutritional role extends far beyond this single macronutrient. While its protein is incomplete, it serves as a valuable source of fiber, vitamins, and powerful antioxidants that support eye and digestive health. By incorporating corn into a balanced eating plan, especially alongside complementary protein sources, you can fully enjoy its flavor and a wide array of health benefits. To learn more about corn's health benefits, a great resource is the article from Johns Hopkins Medicine.

Resources

Johns Hopkins Medicine - Health Benefits of Corn

Frequently Asked Questions

A medium-sized ear of sweet corn provides about 3 grams of protein. The amount can vary slightly based on the corn variety and size.

No, the protein in corn is not a complete protein. It is deficient in certain essential amino acids, primarily lysine and tryptophan, that the body cannot produce on its own.

You can achieve a complete protein by practicing protein complementation, which means pairing corn with other foods that supply the missing amino acids. Combining corn with legumes like black beans or other whole grains works well.

In addition to protein, corn is a good source of fiber, B vitamins (thiamine, folate), vitamin C, magnesium, potassium, and vision-supporting antioxidants like lutein and zeaxanthin.

Corn can be classified as either a vegetable or a whole grain, depending on when it is harvested and how it is prepared. Both forms offer nutritional benefits. Whole grain corn, like popcorn or dried corn, is particularly high in fiber.

Despite being a starchy vegetable, sweet corn generally ranks low to medium on the glycemic index. Its fiber content helps to slow the absorption of carbohydrates, preventing sudden blood sugar spikes.

For healthier preparations, try grilling or boiling corn and topping it with herbs and spices instead of butter. Other great options include adding corn kernels to salads, soups, or making your own air-popped popcorn.