Life’s First Molecule: Types Of Proteins By Their Origin

From good old whey and casein to the burgeoning field of plant-based proteins like pea and hemp, to the emerging categories like insect protein and mycoproteins derived from fungi—each comes with its unique set of benefits and limitations. The nuances go beyond just the source; they extend to factors like bioavailability, amino acid composition, and environmental impact. And let’s not forget the novel concept of protein blends, designed to offer the best of multiple worlds.

The Basic Structure of Protein

Proteins are organic compounds formed by a chain of amino acids. They are a vital component in every cell, constituting structures like hair, nails, and muscles. Besides that, proteins help create enzymes, hormones, and other essential biochemical substances.

Unlike fats and carbohydrates, which can be stored in the body, proteins do not have a storage reservoir. This means that a continuous dietary intake is necessary to meet the body’s needs. Proteins are categorized as ‘macronutrients,’ needing to be consumed in relatively large quantities, whereas vitamins and minerals are ‘micronutrients,’ required in much smaller amounts.

Types of Proteins: Breaking It Down

Proteins are made up of 20 different types of amino acids. Some are produced by the body (non-essential), and others need to be obtained through diet (essential).

Classification by Dietary Sources

• Complete Protein Sources: These contain all the essential amino acids and are usually animal-based like meat, poultry, fish, milk, eggs, and cheese.
• Incomplete Protein Sources: Lacking in one or more essential amino acids. Plant-based sources like beans and legumes usually fall under this category.

List of High-Protein Foods

According to the Recommended Dietary Allowances (RDA), the protein needs vary by age, gender, and lifestyle:

Read also: Protein for Cutting and Weight Loss: Which is the Best?

Types of protein in Sports Nutrition

Nutrition and sport are pivotal components for a healthy lifestyle, with protein serving as a crucial macronutrient. Especially in sports, protein supplementation often becomes necessary for optimal athletic performance. The quality of protein is often determined by its content of branched-chain amino acids (BCAAs) like Leucine, Valine, and Isoleucine.

These BCAAs constitute around 33% of skeletal muscle and are unique in being metabolized directly in the muscle tissue, thus serving as a primary energy source during exercise. Specifically, Leucine plays a significant role in promoting insulin secretion, reducing central fatigue, decreasing muscle soreness, and mainly in increasing Muscle Protein Synthesis (MPS) by activating the mammalian target of rapamycin (mTOR) pathway.

The concept of “protein quality” in nutrition focuses on the amino acid composition in a protein source, comparing it to what is considered the highest quality protein. In recent years, traditional protein sources like milk, egg, and meat have dominated the sports nutrition landscape, often considered as high-quality due to their complete amino acid profile. Notably, ovalbumin from egg white serves as a benchmark for evaluating other dietary proteins.

Animal-Based Protein

Milk, Egg, and Meat – traditional protein food sources in sports nutrition. They are high in essential amino acids and BCAAs, particularly useful for muscle protein synthesis (MPS).

Meat-Protein

When most people think of protein, they think of beef protein. But per 100g, whey protein contains almost three times the amount of leucine compared to beef protein. And the higher the leucine content, the more potent the protein is at turning the muscle-building switch back on after a workout.

Dairy Protein: Whey and Casein

Sourced from milk, whey is the ‘fast’ protein that’s easily absorbed and is excellent for post-workout recovery. Casein is the ‘slow’ protein, taking its time to release amino acids, which makes it perfect before bedtime.

Whey Protein is a by-product from cheese and butter production. Whey is the most widely consumed protein supplement in sports nutrition. It is economical and offers various health benefits. It’s rich in essential amino acids and BCAAs. Studies show it’s effective for muscle recovery, strength increment, and various health benefits like antioxidant, anticancer, antidiabetic, anti-obesity, and cardioprotective properties.

Egg White Protein

Remember the Rocky movies where Sylvester Stallone gulps down raw eggs? Well, he was onto something. Egg whites are packed with high-quality protein and essential amino acids, minus the cholesterol found in the yolk.

Plant-Based Protein

Emerging as an alternative due to sustainability, ethics, and allergy concerns. They contain fewer essential amino acids and BCAAs than animal protein but are rich in antioxidants and anti-inflammatory compounds. Pea and Soy Protein almost match WHO’s recommended levels of essential amino acids. They are effective for muscle maintenance and strength but are slightly less bioavailable than animal proteins.

Legume and Grain Protein: though usually lacking one or two essential amino acids, when combined they offer a full amino acid profile.

Novel Sources: Insects and Mycoproteins

Emerging Contenders: Hydrolysates, Peptides, and Amino Acids As sports nutrition evolves, the focus is gradually shifting towards more specialized forms of protein like hydrolysates and peptides. These are essentially ‘pre-digested’ forms of protein that are rapidly absorbed, providing quicker muscle recovery. Individual amino acids, such as leucine, are also gaining traction for their role in stimulating muscle protein synthesis.

Mycoproteins

Sourced from fungi and are environmentally friendly. They are high in dietary fiber and possess a high digestibility similar to milk. The new rockstars in the protein world have got a low carbon footprint and are growing in popularity for their health benefits, including the support of muscle adaptation and cardiometabolic health.

Insect Proteins

Due to increasing global population and limited resources, there’s a growing need for alternative protein sources. Insects have emerged as an environmentally friendly option, with a low carbon and water footprint. As icky as it may sound, insect proteins like those from crickets are gaining acceptance. They are not only sustainable but also packed with essential amino acids. A good option for the adventurous eaters among us.

Coleoptera, Lepidoptera, Hymenoptera, and Orthoptera: Insect orders commonly used for food, rich in chitin, vitamins, and minerals. Their protein content ranges from 40-60%, making them comparable to traditional animal sources.

However, the scientific verdict is still pending; most existing studies are in vitro, and comprehensive human trials are needed to confirm the efficacy and safety of these alternative protein sources.

Protein Hydrolysates and Bioactive Peptides

Emerging forms like hydrolysates and peptides bring new options to the table. Hydrolyzed proteins and bioactive peptides could offer multi-functional benefits, including improved sports performance, lessened complications associated with athletic activities, and promotion of healthy aging.

These are essentially ‘pre-digested’ forms of protein that are rapidly absorbed, providing quicker muscle recovery. Individual amino acids, such as leucine, are also gaining traction for their role in stimulating muscle protein synthesis.

Protein Blends

Combinations of different protein sources to maximize ergogenic effects and balance out the deficiencies in essential amino acids found in individual sources. For instance, a blend of vegetable and dairy proteins could provide both the muscle protein synthesis benefits from whey and the antioxidant advantages from plant proteins.

Soy-Dairy or Vegetable-Dairy Blends: These mixes aim to combine the MPS-enhancing capacity of whey with the antioxidant and anti-inflammatory activities of plant-based proteins.

As athletes and researchers continue to explore the optimal synergy of protein forms and sources, one thing is clear: the world of sports nutrition is as multifaceted as it is fascinating.

Final Thoughts

Whether you’re an elite athlete, a fitness aficionado, as one navigates through the multitude of choices, it becomes increasingly evident that the “best” protein source is highly individualistic, shaped by factors ranging from nutritional needs and ethical considerations to environmental impact. The future of protein, thus, promises to be as diverse as the needs it seeks to serve.

While the traditional view has often tilted in favor of animal-based proteins due to their complete amino acid profile, the landscape is changing rapidly. Sustainability concerns, health implications, and ethical considerations are pushing people to explore alternative sources. Whether it’s plant-based proteins offering antioxidant properties, insects providing a sustainable complete protein, or mycoproteins (fungi-derived proteins) with their unique nutrient profile—new research is continually broadening our understanding and options in sports nutrition.