About 20% of the human body is made up of proteins .
Because your body doesn't store protein , it's important to get enough of it each day.
You can get many food sources of protein , including plants and animals.
Some people argue that the protein source , whether animal or vegetable, shouldn't matter.
Others suggest that plant protein is superior to animal protein .
This article compares animal and plant proteins .
Amino acid profile varies between plant and animal proteins
When consumed, protein is broken down into amino acids.
Proteins and amino acids are used for almost all metabolic processes in the body.
However, different proteins can vary greatly in the types of amino acids they contain.
While animal proteins tend to contain a good balance of all the amino acids we need, some plant proteins are low in certain amino acids.
For example, some key plant proteins are often low in methionine, tryptophan, lycine and isoleucine.
Animal proteins are complete, but vegetable proteins are not.
In total, the human body uses about 20 amino acids to build proteins .
These amino acids are classified as essential or non-essential.
Your body can produce non-essential amino acids. However, it cannot produce essential amino acids, which must be obtained through your diet.
For optimal health, your body needs all of the essential amino acids in the right ratios.
Sources of animal protein , such as meat, fish , poultry, eggs and the dairy products , are similar to proteins found in your body.
These are considered as of the complete sources of protein because they contain all the essential amino acids your body needs to function effectively.
On the contrary, vegetable protein sources , such as beans , lentils, and nuts, are considered incomplete because they lack one or more of the essential amino acids your body needs .
Some sources report that soy protein is complete. However, two essential amino acids are only found in small amounts in soy, so it is not comparable to animal protein.
Some Nutrients Are More Abundant in Animal Protein Sources
Of course, proteins are rarely found in isolation. They are usually accompanied by a wide variety of other nutrients.
Foods that contain animal protein tend to be high in several nutrients that often make defect in plant foods .
These include:
- Vitamin B12: Vitamin B12 is mainly found in fish, meat, poultry and dairy products. Many people who avoid animal foods are deficient .
- Vitamin D: Vitamin D is found in fatty fish, eggs and dairy products. Some plants contain it, but the type found in animal foods is better utilized by your body .
- DHA: Docosahexaenoic acid (DHA) is an omega-3 fatty acid essential present in fatty fish. It is important for brain health and difficult to obtain from plant sources .
- Iron heme : The iron heme is found primarily in meat, especially red meat. It is much better absorbed by the body than non-heme iron from plant foods.
- Zinc: Zinc is mainly found in animal protein sources , such as beef, pork, and lamb. It is also more easily absorbed and utilized from animal protein sources .
Of course, there are also many nutrients in plant foods that missing in animal feed . Therefore, eating balanced amounts of both is the best way to get all the nutrients you need.
Certain types of meat can cause disease
Red meat is a source of high quality protein .
Several observational studies have linked red meat consumption to an increased risk of heart disease, stroke, and early death .
However, other research has suggested that the problem is not with all red meats, but rather processed red meats .
In a large observational study of 448,568 people, processed meat was linked to an increased risk of death, with no effect on unprocessed red meat ).
Another study of more than 34,000 women made similar observations. In this case, processed meat was associated with heart failure .
Additionally, a comprehensive review of 20 studies found that processed meat was associated with an increased risk of heart disease and diabetes. Again, no association was found for unprocessed red meat .
Additional studies have confirmed that eating unprocessed red meat is not linked to heart disease .
Despite this, one study found that replacing one serving per day of red meat with one serving of poultry was associated with a 27% lower risk of stroke .
Also, the health risks associated with processed red meat are unrelated to fish and other meats, such as turkey and chicken.
Diets Rich in Plant-Based Protein Are Linked to Many Benefits
Diets high in plant protein , like the vegetarian diet, are linked to numerous health benefits.
Studies suggest that vegetarians tend to have lower body weight, lower cholesterol levels, and lower blood pressure.
They also have a lower risk of stroke, cancer, and death from heart disease than nonvegetarians .
Lower risk of heart disease
One study found that a high-protein diet (about half from plants) lowered blood pressure, cholesterol levels, and heart disease risk more than a standard diet or a healthy carbohydrate-rich diet .
The EcoAtkins study found that a regime low in carbohydrates and high in vegetable protein helped lower cholesterol and blood pressure more than a high-carb, low-fat diet .
Reduced risk of type 2 diabetes
A small study in people with type 2 diabetes found that replacing 2 servings of red meat with legumes 3 days a week improved cholesterol and blood sugar .
However, another small 6-week study in diabetics compared a diet high in plant protein with a diet high in animal protein . No differences were found in blood sugar, cholesterol, and blood pressure .
Protection against weight gain
Diets high in plant protein can also help you control your weight.
An observational study in 120,000 men and women over the age of 20 found that nut consumption was linked to weight loss .
Additionally, eating one serving of beans, chickpeas, lentils, or peas daily can increase satiety and may lead to better weight management and weight loss .
Correlation does not mean causation
It is important to remember that observational studies only report statistical associations. They cannot prove that these benefits were caused by eliminating meat or other sources of animal protein .
One thing to consider is that people on a vegetarian diet tend to be more health conscious than the general population .
Therefore, the health benefits of vegetarian diets are likely due to an overall healthier diet and lifestyle, rather than any inherent difference between plant and animal protein .
Animal Protein Also Has Health Benefits
Animal protein is also associated with positive health effects, although it is often described as unhealthy compared to plant protein .
A study on nurses' health found that poultry, fish, and low-fat dairy products were associated with a lower risk of heart disease .
People who eat fish regularly are also likely to have a lower risk of heart attacks, strokes, and death from heart disease .
A study of over 40,000 men found that those who regularly ate one or more servings of fish per week had a 15% lower risk of heart disease .
In addition, egg consumption has been associated with improved cholesterol levels and weight loss . In one study, women who ate eggs at breakfast - lunch , rather than a bagel, said they felt fuller during the day .
Finally, eating animal protein is linked to increased lean muscle mass and reduced muscle loss that occurs with age .
In conclusion
For optimal health, evidence supports a diet low in processed meat, high in plant protein , with some animal sources such as grass-fed meat, fish, poultry, eggs, and dairy .
Since food sources of plant protein often have lower quality protein, vegetarians and vegans should eat a wide variety of foods to ensure they are getting all the amino acids they need.
For meat eaters, it is important to find the right balance between animal and plant foods.
