Is There Protein in Animal Blood and Is It Safe to Eat?

December 7, 2025 •

4 min read

According to food science research, animal blood contains significant protein, with bovine blood consisting of approximately 17-19% protein by weight. This makes animal blood a valuable and often underutilized byproduct of the meat industry, with various applications in food and animal feed production.

Quick Summary

Animal blood is a highly concentrated source of protein and heme iron, utilized in various food products and animal feeds. Its nutritional profile, including amino acids, makes it a potent supplement when processed safely, but consuming it raw poses significant health risks due to pathogens.

Key Points

Rich Protein Source: Animal blood is a concentrated source of high-quality protein, primarily from plasma proteins and hemoglobin in red blood cells.
High in Heme Iron: Blood is an excellent source of heme iron, which is highly bioavailable and easily absorbed by the body.
Processing Enhances Digestibility: While native blood protein can be resistant to digestion, heat treatment improves its overall digestibility.
Raw Consumption is Dangerous: Eating or drinking raw animal blood is extremely risky due to the potential for bloodborne pathogens and foodborne illness.
Used in Food and Feed Products: Processed blood products, like dried plasma and blood meal, are used as functional ingredients in the food industry and as a protein supplement in animal feed.
Potential for Bioactive Peptides: Modern processing methods can extract bioactive peptides from blood proteins with antioxidant and immunomodulatory properties for potential biomedical use.
Risk of Iron Overload: Excessive consumption of blood or blood products can lead to iron overload, particularly for individuals with a predisposition to hemochromatosis.

The Composition of Animal Blood and Its Protein Content

Animal blood is a complex and viscous fluid comprising several components, including plasma and cellular elements like red and white blood cells. A large portion of its dry matter is protein. The protein content varies slightly by species but consistently remains high. For instance, bovine blood consists of roughly 17% protein, with dried bovine blood products containing upwards of 79%. This protein is primarily divided into two main fractions: plasma proteins and red blood cell (RBC) proteins.

Protein in Blood Plasma vs. Red Blood Cells

The protein in blood is not a single entity but a diverse group of proteins with different functions. Plasma, which makes up about 65-70% of the blood's volume, contains its own set of proteins, including albumins, globulins, and fibrinogen. The cellular fraction, rich in red blood cells, contains hemoglobin, a crucial protein that transports oxygen. The protein concentration is significantly higher in the cellular fraction (e.g., 30% in bovine RBCs) compared to the plasma (e.g., 7-9% in bovine plasma).

Common Blood Proteins

Albumin: A major plasma protein that helps maintain osmotic pressure.
Globulins: A group of plasma proteins involved in immune function and transport of various substances.
Fibrinogen: A plasma protein essential for blood clotting.
Hemoglobin: The primary protein in red blood cells responsible for oxygen transport.

The Nutritional Value of Animal Blood Protein

Protein derived from animal blood is highly digestible and boasts a rich amino acid profile, although it may be low in certain essential amino acids like methionine and isoleucine, depending on the source. This makes it a valuable supplement for enhancing the nutritional content of food and feed products. Beyond protein, animal blood is also an exceptional source of heme iron, a highly bioavailable form of iron that is more readily absorbed by the body compared to non-heme iron found in plant-based sources. This property makes processed blood products effective in combating iron-deficiency anemia.

Traditional and Modern Uses of Animal Blood

Throughout history, various cultures have consumed animal blood in many forms, such as blood sausage (e.g., morcilla, blutwurst), puddings, and soups. Today, its use extends far beyond traditional dishes. Processed blood derivatives, like spray-dried plasma and blood meal, are widely used in the food industry as functional ingredients to improve product texture, and in the animal feed industry as a rich protein source. The potential applications continue to grow, with ongoing research exploring its use in biomedicine for its antioxidant, antibacterial, and immunoregulatory effects.

Food Safety and Health Considerations

While nutritionally valuable, consuming animal blood carries significant food safety risks if not properly handled and cooked. Raw blood can harbor pathogens that cause foodborne illnesses, including hepatitis B and C. Proper hygiene, processing, and cooking are paramount to mitigating these risks. Additionally, excessive consumption of blood or blood products can lead to iron overload, a condition known as hemochromatosis, which can be dangerous for individuals with a genetic predisposition.

Comparison Table: Raw vs. Processed Animal Blood


Aspect	Raw Animal Blood	Processed Animal Blood (e.g., blood meal, dried plasma)
Safety	High risk of carrying pathogens and causing foodborne illness if not handled and prepared hygienically.	Low risk due to heat treatment, which eliminates potential pathogens.
Nutritional Profile	Nutrient-rich but difficult to digest due to native proteins being resistant to digestion.	Highly concentrated protein and mineral content, with improved digestibility after processing.
Functional Properties	Limited use due to coagulation and sensory issues (color, odor).	Enhanced functional properties (emulsifying, gelling) for use in food manufacturing.
Application	Traditionally used in certain ethnic dishes (e.g., blood sausages), but consumption of raw blood is not recommended.	Used as a feed ingredient, food additive, and source of bioactive peptides for pharmaceuticals.

Conclusion

In conclusion, the presence of protein in animal blood is undeniable, and its nutritional density, particularly its high content of bioavailable heme iron, makes it a valuable resource. However, its use requires careful consideration of safety and processing. While culturally significant in certain culinary traditions, the modern utilization of animal blood as a sustainable and nutritious ingredient, especially in its processed form, highlights its potential to meet the growing global demand for protein. Adherence to strict hygiene standards and proper cooking methods are essential to unlock its benefits safely. For more information on the processing and potential of slaughterhouse byproducts like blood, see this review: Slaughterhouse blood: A state-of-the-art review on sustainable protein source.

Potential Applications and Future Outlook

The future of animal blood utilization lies in leveraging advanced processing technologies to extract and purify its valuable components. Enzymatic hydrolysis, for instance, can break down blood proteins into bioactive peptides with enhanced antioxidant and immunomodulatory properties, opening new avenues in the nutraceutical and pharmaceutical sectors. By addressing sensory challenges and focusing on safe, sustainable practices, researchers aim to expand the use of blood-derived ingredients across diverse industries, contributing to a more circular and resource-efficient food system. This includes not only human food products but also specialized animal feeds and functional ingredients.

Summary of Safety Measures

For anyone considering the consumption or use of animal blood, the following safety measures are critical:

Source hygienically collected blood: Use blood from healthy animals that has been collected in sanitary conditions to minimize contamination.
Cook thoroughly: Heat treatment is necessary to destroy pathogens that can cause illness.
Avoid raw consumption: The medical community strongly advises against consuming raw blood due to the risk of disease transmission.
Be mindful of iron intake: Individuals, especially those with certain genetic conditions, should be cautious of excessive iron intake from blood-rich foods to avoid complications like hemochromatosis.

Frequently Asked Questions

Yes, but only if it is properly handled, processed, and thoroughly cooked to eliminate pathogens. Consuming raw animal blood is extremely unsafe and can transmit severe foodborne and bloodborne illnesses.

The protein content is very high, with bovine blood being around 17-19% protein by weight. Processed and dried forms, such as blood meal, contain a much higher concentration, often exceeding 80% protein on a dry matter basis.

Animal blood contains a variety of proteins, including plasma proteins like albumin and globulins, and hemoglobin, the primary protein found within red blood cells.

Native blood proteins can be resistant to digestion. However, modern processing methods, particularly heat treatment, are used to improve the digestibility and absorption of these proteins.

This term is used because blood's nutritional composition, especially its high protein content, is similar to that of lean meat. Some cultures have traditionally used it as a meat-like food source.

Blood sausage from a reliable source that is thoroughly cooked is generally safe. The risk comes from poor hygiene during processing or undercooking, which can allow bacterial growth.

Besides the risk of pathogens from raw consumption, the high iron content can pose a risk. Excessive iron intake can lead to hemochromatosis, a condition causing organ damage, especially for those with a genetic predisposition.