Can You Get Peptides Naturally From Food?

Peptides have become a popular topic in health and wellness, particularly with the growing interest in collagen supplements, skincare ingredients and products marketed for muscle recovery and anti-ageing.

But while peptides are often associated with supplements and specialised treatments, they're not necessarily something you need to purchase separately. In fact, peptides can be found in certain foods or produced naturally when your body digests the proteins you eat.

What are food-derived peptides?

Peptides are short chains of amino acids, the building blocks that make up proteins.

When amino acids join together through chemical bonds, they form chains of different lengths. Shorter chains are generally described as peptides, while larger, more complex chains are usually classified as proteins.

Food-derived peptides are peptide fragments that occur naturally in foods or are released when food proteins are broken down.

This can happen through several processes, including:

• Digestion: Enzymes in your stomach and small intestine break dietary proteins into smaller peptides and amino acids.

• Fermentation: Microorganisms involved in producing foods such as yoghurt and cheese can break down proteins and release peptides.

• Food processing: Processes such as enzymatic hydrolysis can break proteins into smaller fragments, as seen in some protein and collagen supplements.

Some food-derived peptides are described as bioactive peptides because researchers have identified biological activities they may perform under certain conditions. However, this doesn't necessarily mean consuming the food containing them will produce the same effects in the human body.

Which foods are natural sources of peptides?

Many protein-rich foods can provide peptides or the proteins needed to produce them during digestion.

Here are some common examples.

1. Milk, yoghurt and cheese

Dairy products are among the most extensively studied sources of food-derived peptides.

Milk contains two main groups of proteins: casein and whey. When these proteins are broken down during digestion or fermentation, they can release a variety of peptide fragments.

Fermented dairy products, including yoghurt and certain cheeses, are particularly interesting because the microorganisms used in production can help break down milk proteins.

Researchers have investigated some dairy-derived peptides for their potential effects on blood pressure regulation and other biological processes. For example, certain peptides released from casein have been studied for their ability to inhibit angiotensin-converting enzyme (ACE), which is involved in regulating blood pressure.

2. Eggs

Eggs are another source of high-quality dietary protein, containing all nine essential amino acids.

Proteins found in egg whites and yolks can release peptide fragments during digestion or processing. Some egg-derived peptides have attracted research interest for their potential antioxidant, antimicrobial and blood pressure-related activities.

Most of these proposed benefits are still being investigated, with much of the evidence coming from laboratory or animal studies rather than large human clinical trials. Nevertheless, eggs remain a useful source of dietary protein and other important nutrients.

3. Meat and poultry

Meat and poultry contain proteins that are broken down into amino acids and peptides during digestion.

Foods such as beef, chicken and pork also contain naturally occurring muscle proteins and collagen-rich connective tissues.

Researchers have identified various peptides formed during meat processing, ageing, cooking and digestion, with some showing potential antioxidant activity. A 2013 study published in Food Chemistry examined peptides found in Spanish dry-cured ham. Researchers identified 27 peptides in extracts showing antioxidant activity and found that some of these peptides could help neutralise free radicals in laboratory tests.

Another 2017 study published in Food Research International investigated peptides from dry-cured ham bones. Researchers found that cooking influenced their antioxidant activity and identified hundreds of peptide fragments after simulated digestion.

However, the types and amounts of peptides present in meat can vary depending on several factors, including:

• Cut of meat: Lean muscle cuts, such as chicken breast or beef steak, contain different proportions of muscle and connective tissue compared with collagen-rich cuts such as beef shank, brisket or pork hock.

• Cooking method: Boiling, slow cooking, roasting and grilling expose meat to different temperatures and cooking conditions, which can affect protein structure and peptide formation.

• Processing conditions: Methods such as dry-curing, fermentation and ageing can encourage proteins to break down into smaller peptides. Factors such as salt concentration, temperature and processing time can also influence the peptides produced.

Most research into the antioxidant properties of meat-derived peptides has been conducted in laboratory settings, which means more human research is needed to determine whether these peptides provide meaningful health benefits when consumed as part of a normal diet.

4. Fish and seafood

Fish and other seafood contain proteins that can be broken down into smaller peptide fragments.

Marine-derived peptides have attracted interest for their potential antioxidant and other biological properties. Fish skin, scales and other collagen-rich tissues are also commonly used to produce marine collagen peptides for nutritional supplements.

Some studies have explored marine protein hydrolysates and collagen peptides for potential effects on skin and joint health. However, eating fish and taking a concentrated marine collagen supplement are not necessarily equivalent, as the peptide composition and amounts can differ considerably.

Fish also provides other valuable nutrients, including omega-3 fatty acids in oily varieties.

5. Soybeans, legumes and other plant proteins

Peptides aren't exclusive to animal-based foods.

Plant proteins found in soybeans, lentils, chickpeas, beans and other legumes can also release peptides during digestion or food processing. Soy proteins, in particular, have been studied for their potential to produce bioactive peptides.

Fermented soy foods such as tempeh and miso may contain peptide fragments produced as microorganisms break down proteins during fermentation.

Researchers have investigated plant-derived peptides for antioxidant activity, ACE inhibition and other potential effects.

How does your body get peptides from food?

When you eat protein-rich foods, your digestive system begins breaking their proteins down into smaller components.

This process starts in the stomach, where stomach acid helps unfold proteins and digestive enzymes begin breaking them apart.

As food moves into the small intestine, additional enzymes continue breaking proteins into shorter peptides and individual amino acids.

Your intestinal cells can absorb amino acids as well as certain small peptides, particularly dipeptides and tripeptides, which contain two or three amino acids.

Most of these small peptides are then broken down further into individual amino acids within intestinal cells before entering the bloodstream.

These amino acids can be used for important functions such as:

• Building and repairing body tissues.

• Producing enzymes and hormones.

• Supporting normal immune function.

• Maintaining muscles and other protein-containing structures.

• Producing new proteins required by the body.

Some specific food-derived peptides may survive digestion and be absorbed in small amounts, but this depends on their structure and other factors.

This is an important distinction: eating a food that contains a biologically active peptide doesn't guarantee that the peptide will reach the bloodstream intact or produce the effects observed in laboratory experiments.

Does cooking or fermentation affect peptides in food?

Food preparation and processing can influence which peptides are present in food. However, these changes aren't necessarily good or bad. They simply affect how proteins are structured and broken down.

Cooking

Heat can change the structure of proteins, a process known as denaturation. This can make some proteins more accessible to digestive enzymes, although the effects vary depending on the food and cooking conditions.

Cooking can also alter or break down certain peptides. For this reason, the peptide composition of a food may differ before and after cooking.

Fermentation

Fermentation is particularly interesting in peptide research.

During fermentation, microorganisms produce enzymes that can break down proteins into smaller fragments. This process can release peptides that weren't present in the same amounts in the original food.

Examples of fermented foods include:

• Yoghurt and kefir

• Certain cheeses

• Tempeh

• Miso

• Natto

Researchers have identified various peptides in fermented foods and investigated their potential biological activities. However, the peptide content can vary significantly between products depending on the microorganisms used, fermentation time and production methods.

Protein hydrolysis

Hydrolysis is the process of breaking proteins into smaller fragments, often using enzymes. It's commonly used to produce ingredients such as hydrolysed collagen peptides and certain protein powders.

This process creates smaller protein fragments, but it doesn't automatically make a supplement more beneficial than an ordinary protein-rich food.

An example of protein powder to know is the Chief Nutrition's Collagen Protein Powders. They are made using Australian grass-fed bovine collagen that has undergone hydrolysis to produce smaller collagen peptides. Containing Type I and Type III collagen, these powders offer a convenient way to incorporate collagen protein into your daily diet.

If you're looking to incorporate collagen peptides into your routine, explore the Chief Nutrition Collagen Protein Powder range at Aussie Pharma Direct.

Are food-derived peptides the same as peptide supplements?

Although both involve chains of amino acids, there are important differences between peptides obtained through food, nutritional peptide supplements and synthetic peptides developed for medical or experimental use.

 

One important difference is that dietary peptides are generally processed through the digestive system. Prescription peptide medicines, on the other hand, are specifically formulated and administered to produce particular therapeutic effects.

Likewise, experimental synthetic peptides promoted online for muscle recovery or anti-ageing shouldn't be confused with the peptides naturally produced when you digest food.

Being derived from amino acids doesn't automatically make every peptide safe, effective or interchangeable.

Do you need peptide supplements if you eat enough protein?

For most healthy adults, a varied diet that provides sufficient protein can supply the amino acids needed for normal body functions.

You don't generally need a specialised peptide supplement simply to obtain peptides, as your digestive system naturally produces peptide fragments when it breaks down dietary proteins.

However, some people choose to use protein or collagen supplements for convenience, dietary preferences or particular nutritional goals.

Whether a supplement is useful depends on factors such as:

• Your overall protein intake: Are you already meeting your daily protein requirements through food?

• Your dietary preferences: Do you have restrictions that make it difficult to consume certain protein sources?

• Your individual nutritional needs: Protein requirements can vary with age, activity levels and health circumstances.

• The specific supplement: Different peptide products contain different ingredients and have different levels of supporting evidence.

• Your expectations: A supplement shouldn't be assumed to provide a particular health benefit simply because it contains peptides.

Ultimately, you don't need to seek out special peptide-containing products simply to obtain peptides from your diet.

Eating a variety of nutritious, protein-rich foods is a practical way to provide your body with the amino acids it needs, while supplements may serve specific nutritional purposes depending on your circumstances.