Continuing the macromolecule series, the next myth busting I’ll do involves protein. Vegetarians get this comment all the time: “But where do you get your protein?” This comment comes from the erroneous belief that protein only originates from animal sources. Actually, ALL foods contain protein; vegetables and fruit too. What’s more important to consider is the balance of amino acids (which make up protein) in our diet.
Remember that all fresh unprocessed foods are made up of 6 basic constituents; protein, carbohydrates, fat, vitamins, minerals and water. This is true of both animal and plant foods. Animals are made up of similar proteins to us and so give us similar proportions of amino acids. But we also get more fat, cholesterol and calories along with it. Plants are dissimilar to us, so we have to eat a greater variety of plant-based foods to accumulate all the amino acids we need. Plant food sources have the benefit of supplying cancer-fighting phytochemicals, probiotic-supporting fiber, many essential vitamins and minerals, and generally, fewer calories per serving. (It also takes less energy, water, and releases less waste to create plant-based food than animal-based food. But that’s a whole ‘nuther post.)
Protein is used in our bodies as source of both building blocks and energy. If we consume more protein than we need, we store it in our energy reserves, also known as fat deposits. Sorry. On the other hand, if we don’t eat enough, our metabolism will mine our muscle to get it. This seems to be more important with aging.
Let’s drill down to understand protein. Proteins are made of up of chains of repeating units called amino acids or peptides. Think of 20 different styles of beads creating a polypeptide necklace. There are many combinations and lengths.
When we eat food, we masticate it into smaller pieces, then swallow it. The stomach finishes the deconstruction job by hitting food particles with digestive enzymes (trypsin) and hydrochloric acid. The smaller pieces of protein are disassembled into free-floating amino acids which pass into the small intestine for absorption into the blood stream. The amino acids are then taken up from the blood by every cell of our body.
Once amino acids are absorbed into cells, they are used for construction of particular cellular proteins. The 20 different amino acid beads have slightly different terminals, giving them slightly different electronic properties. When the whole string of beads is assembled, it twists and turns, balancing the positive and negative charges along it’s length to find a final resting conformation. The pockets created in the folded protein string determines it’s function. It could be a digestive enzyme, an antibody, insulin receptor, or hemoglobin among many others.
Back to the macro-world of food choices, how much protein do we need and where do we get it? The answer seems to depend on a number of factors, including age, gender, activity level, and goals. For the average sedentary US’er, the recommendation is about 5 oz/day for women and 6 oz/day for men. If you are working out hard, add a few ounces, being mindful that if you don’t use it, you store it. And if you stop working out, you have to reduce your intake accordingly (don’t stop working out.) You have lots of choices - remember that all foods contain protein. If you make vegetarian or vegan choices, eat a large variety, and complement your legumes with grains within 24 hours to complete your amino acid array. Other complete plant amino acid sources include soy, hemp, and quinoa.
The ultimate answer? Eat a variety of fresh delicious foods; more plant-based than animal-based, stay hydrated, get good sleep and Move move move. It’s not rocket science, and you certainly don’t need to buy special dietary products to maintain good health. Your bank account and your health span will reflect these good choices.
