Over time, the connection between humans and the food we consume has transformed significantly. Early changes involved the transition from hunting and gathering to agriculture, culminating in our latest shift driven by technology.

With pressing issues like factory farming and climate change now at the forefront of our concerns, it's essential to reassess our food choices and their impact on animals.

Recently, while resting after an intense workout with a friend, we engaged in a thoughtful discussion that meandered from light topics to deeper philosophical questions. One key area of focus was our contrasting lifestyles and dietary habits, leading us to explore our shared disconnect from our food sources and how we might bridge that gap.

Understanding Protein

Protein is a vital macronutrient that forms the enzymes crucial for metabolic processes. It plays a key role in producing enzymes, hormones, and hemoglobin, and serves as the main structural element in muscles and various bodily tissues. Proteins consist of polypeptide chains made from 20 different amino acids.

Among these, essential amino acids are the nine that humans cannot produce on their own, making it necessary to obtain them through food. A helpful mnemonic to remember these is VH MILK WTF (Valine, Histidine, Methionine, Isoleucine, Leucine, Lysine, Tryptophan, Threonine, Phenylalanine).

A "complete protein," which can be derived from both plants and animals, contains all the essential amino acids. While animal products are commonly recognized as complete proteins, certain plants like soy, amaranth, and quinoa also meet these criteria.

Although complete proteins can enhance any diet, they are not strictly necessary for obtaining essential amino acids. A diverse vegan diet, rich in lentils and whole grains, can sufficiently meet the needs of a vegan individual.

Debates around protein quantity often arise, yet research indicates that the amount of protein consumed does not correlate with specific mortality causes. A Harvard study tracking over 130,000 participants for up to 32 years found no link between total protein intake and overall mortality. However, the source of protein does impact health; higher animal protein intake was associated with increased cardiovascular disease and overall mortality risks, while plant protein intake correlated with lower risks.

The National Academy of Medicine recommends a daily protein intake of 0.8g per kg of body weight, equating to about 7g per 20lbs. This implies that sourcing adequate protein from plants is entirely feasible. While vegetarians and vegans may consume less protein than omnivores, studies show they still meet or exceed the recommended daily intake.

Protein deficiency, although rare in the U.S., can occur, typically presenting as edema, hair loss, and muscle mass reduction, often accompanied by other nutritional deficiencies.

Comparing Bioavailability of Animal and Plant Proteins

Despite the numerous advantages of plant proteins, there's a common belief that they may not be as effective as animal proteins due to lower anabolic effects and essential amino acid content. This concern, while valid, can be addressed through a well-rounded plant-based diet.

The Protein Digestibility Corrected Amino Acid Score (PDCAAS) indicates that many plant proteins fall below the 100% threshold necessary to fully meet essential amino acid requirements. Similarly, the Digestible Indispensable Amino Acid Score (DIAAS) has identified limitations in plant proteins, with legume proteins often lacking sulfur amino acids and cereals lacking lysine.

Digestibility issues in plant proteins can be attributed to their secondary structures, which may hinder absorption. However, cooking and processing methods can enhance digestibility significantly. For instance, heat treatment has been shown to improve digestibility by 18%, while treatments used in commercial legume protein production can deactivate up to 80% of trypsin inhibitors, making them more comparable to animal protein sources.

Exceeding the daily protein recommendation can also help address deficiencies in a plant-based diet. Research comparing omnivorous and vegetarian diets during resistance training revealed that higher protein intake (1.1g/kg/d) effectively closed the muscle mass gap observed at lower intake levels (0.78g/kg/d).

Ultimately, the research suggests that the perceived shortcomings of plant protein bioavailability can be effectively managed through increased intake from diverse sources, particularly when combining grains and legumes. Being mindful of limiting amino acids and seeking foods rich in these nutrients can further enhance protein digestibility.

The Impact of Protein on Global Health

Animal-sourced proteins generally have a more detrimental effect on global health and the environment compared to plant-based options. The subsidies for animal products misrepresent their true economic and environmental costs, contributing to alarming forecasts of global crises.

For instance, the U.S. government allocates approximately $38 billion annually to subsidize the meat and dairy industries, while less than 1% supports fruits and vegetables. This spending disproportionately favors livestock and major crops like corn and soy, which are predominantly used as animal feed. In 2013, over 70% of U.S. soybeans were used for this purpose.

These subsidies have a ripple effect on international markets, where they drive down prices and force local farmers in poorer nations into poverty. As animal-derived products rank among the top sources of greenhouse gas emissions globally, the consequences are felt most acutely by disadvantaged populations who are least equipped to cope with environmental changes.

The environmental costs of animal protein production are staggering, leading to extensive greenhouse gas emissions, resource depletion, and habitat destruction. For instance, producing a pound of lamb generates 30 times more greenhouse gases than a pound of lentils, with beef accounting for 36% of food industry emissions in the U.S.

Research indicates that shifting to plant-based protein can yield significant environmental benefits. Life cycle assessments show that producing 1kg of beef results in 45-640kg of CO2 equivalents, while producing 1kg of tofu generates only around 10kg CO2 equivalents. Generally, plant-based protein production requires less land, energy, and water than animal sources.

The inefficiency of animal protein production is a crucial factor in its environmental impact. The energy conversion rates for animal-sourced foods are notably low, with dairy and eggs yielding only 17% efficiency and beef as low as 3%. By prioritizing plant-based proteins, we can enhance overall efficiency, leading to environmental gains.

Looking Ahead

As we contemplate the changes our world has undergone, it becomes clear that past generations have adapted to and overcome their challenges. Today's realities present us with extraordinary hurdles.

Progress may feel slow or daunting, and we may recognize flaws in ourselves and our surroundings, even as we strive for change. This reflects our humanity, as does the support we can offer one another during difficult times. My friend and I resolved to push ourselves further, learn more, and take meaningful action.

Ultimately, it's essential to work toward the world we wish to see in the future.