Animal vs. Plant Protein : Understanding the Differences, Benefits, and Sources

Animal and plant proteins both have their own pros and cons. However, many of you may be wondering about the difference between these two. In this article, we will discuss the differences between animal protein and plant protein.

It is important to consume sufficient amount of protein daily for better health. Protein is needed for vital functions, such as cellular processes, immune function, cell structure, and growth etc. So, it is extremely important to consume the right amount of protein on a daily basis for optimum health.^(1,2)

There are many food sources for protein which consist of animals and plants. There are some who claim it does not matter where the protein comes from, whether animal or plant, protein is protein. Whereas, according to others, one type of protein is better than another.

In this article, we will compare both the proteins, from animals as well as plant proteins.

Amino acids are the building blocks of proteins. The human body needs about 20 different amino acids in order to build proteins.^(3,4)

There are some amino acids which are manufactured by the body itself; however, one needs have nine of them, which are known as essential amino acids via diet. The sources of protein can differ depending on the type of amino acids it has.

Mostly, animal proteins are referred to as complete protein, which means they have all the nine essential amino acids. However, there are some plant proteins, such as soybeans and pea protein, which are also complete sources of protein; whereas other plant foods are thought to be incomplete proteins.⁽⁵⁾ Which brings us to the fact that there are some plant protein sources, such as peanuts, beans and wheat that have increased total protein; however, do not have one or more of the essential amino acids. However, one can easily incorporate other type of food with these sources of incomplete plant protein for meeting the protein requirement of the body.

A good example would be using a peanut butter sandwich, which is not only good in taste, but also is a good example of a combination which gives you a complete protein source. The wheat in the bread is low in the lysine, which is an amino acid, so to counter that, the peanuts are rich in it, which gives you complete protein snack or meal.⁽⁶⁾

It is important that vegetarians or vegans also get sufficient protein in their diet from different plant protein sources, so all the essential amino acids are covered.

Some of the excellent sources of animal proteins are: fish and seafood; eggs, poultry, lean meat, wild game, dairy products, such as yogurt, milk and cheese.⁽⁷⁾

Animal protein sources also contain other important nutrients, such as vitamin B12 and a form of iron known as heme-iron. This form of iron is easily absorbed when compared to the iron present in the plant foods, which are referred to as non-heme iron.⁽⁸⁾

It is also important to remember that some animal proteins are not as nutritious as others, such as ultra-processed animal food products like chicken nuggets and hot dogs have a high sodium and unhealthy fat content and are not recommended for overall good health. It is recommended to choose nutritious sources of animal protein, such as salmon, whole eggs, shellfish, turkey and chicken.

Some of the excellent sources of plant proteins are: nuts, chia seeds, quinoa, beans, wild rice, Ezekiel bread, legumes, buckwheat, wheat, spirulina, nutritional yeast, hemp seeds and soybean products like edamame, tofu and tempeh.⁽⁹⁾

Quinoa, Ezekiel bread, spirulina, soybeans, buckwheat, nutritional yeast, hemp seeds and chia seeds have all the nine essential amino acids, which means that they are complete vegetarian protein sources.⁽¹⁰⁾

Other plant protein sources, such as nuts, beans, wheat, legumes and wild rice have either less of or do not have one or more essential amino acids. However, as plant foods have different quantities of different amino acids, so it is still possible to get all the essential amino acids from an exclusively plant-based diet.

This can be done by consuming a varied diet along with complementary plant proteins, to ensure that vegetarians or vegans are also getting all the essential amino acids from their diet. Some of the examples of complete protein combinations include pita bread and hummus; beans and rice; and kidney beans with pasta salad.

According to research following plant-based diets have benefits such as reduction in blood pressure when compared to animal protein based diets.⁽¹¹⁾

Studies also show that individuals following vegetarian diet tend to have decreased body weight, reduced levels of cholesterol, and reduced risk of cancer, stroke and death from heart disease when compared to individuals who consume non-vegetarian food.⁽¹²⁾

However, it does not mean that each and every plant-based diet is great for heart health. A study linked with plant-based diets, which was rich in nutritious plant foods such as vegetables, whole grains, seeds and nuts showed lower risk of heart disease.⁽¹³⁾

On the other hand, plant-based diets which have less nutritious options like refined grains and fried vegetables were linked with an increased risk of heart disease.⁽¹³⁾

Plant-based diets also seem to be beneficial in managing the blood sugar levels. There were many studies which have shown that vegetarian diets are good for treating as well as preventing type-2 diabetes.⁽¹⁴⁾

Diet which consists of nutrient-dense plant foods like fruits, whole grains, nuts, vegetables, vegetable oils and legumes are especially linked with a substantially decreased risk of developing type-2 diabetes.⁽¹⁵⁾

Even though these are promising results, there is no proof that these health benefits can be achieved from eliminating animal protein sources. These health benefits can also result from increased consumption of plant foods that are high in nutrition.

Some sources of animal protein have lot of positive health effects,⁽¹⁶⁾ such as regular consumption of fish is known to have lot of health benefits, such as reducing the risk of heart disease and lowering the risk of cognitive decline.^{(17, 18, 19)} Consumption of animal protein is also associated with increased lean muscle mass and decrease in muscle loss which happens with aging.^{(20, 21)}

Red meat is considered a complete protein source, whereas many observational studies have associated consumption of red meat to an increased risk of stroke and heart disease.^(22,23,24) There is mixed research regarding this.

Some experts say that these adverse health effects may not be linked with all the types of red meat, instead it has more to do with processed red meat. According to a recent review, if consumed within recommended portions, red meat does not increase the risk of heart disease.⁽²⁵⁾

Another study showed that consumption of increased quantities of unprocessed red meat was linked with a 9% increase in relative risk of heart disease, whereas consumption of eating increased amounts of processed meat was related with an 18% increase of heart disease.⁽²⁶⁾

The point to be noted here is that these health risks are not associated with consumption of fish and lean meats, such as chicken and turkey.⁽²⁶⁾

There are many factors to think of before labeling any form of protein good or bad or before choosing between animal and plant protein sources. Both of them have many beneficial qualities along with their own drawbacks.

Instead of thinking about exclusively following a single form of protein diet, it is better to concentrate on eating a varied diet, which is rich in both lean animal proteins and nutrient-dense plant proteins. For those who are vegetarians or vegans, they need to consult their dietitian to figure out the groups or pairing of food items, which can give them the complete amount of protein from a plant based diet.

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