PROTEIN: The Foundation of Life
…and why you should invite bacteria to your next family gathering.
Some scientists date rocks. This is no comment on their social lives, just their area of expertise. On the basis of their work we can give our planet a birthday party to honour its 4.65 billion years.
The Big Bang is a theory about the birth of the universe, which refers to an expansion – not an explosion – about 14 billion years ago. Eventually the sun and later the earth condensed from cosmic dust and gas thanks to the power of gravitational attraction. The contraction of these materials and the radioactivity of some of them created heat. Some elements melted and differentiated into the earth’s crust and core with spectacular volcanic eruptions and other escaping gases. Carbon dioxide, nitrogen and others were held by gravity and formed the primitive atmosphere. Water vapour condensed and our oceans formed.
About 1 billion years later the first life in the form of bacteria developed (possibly seeded by visiting asteroids). Australian fossils show biologically complex versions with cell walls protecting their proteins and DNA. Only from this duo could life develop with ever greater complexity. The universality of DNA’s genetic instructions suggests that all life is descended from one shared ancestor.
Only protein contains nitrogen and there is no growth of any kind without it. Among molecules, proteins are the most complex in structure and sophisticated in function. From bacteria to plants to people: while amazingly diverse, they are all constructed in the same manner from identical protein components. Proteins are made of chains of about 20 different amino acids. Each chain can contain a few or several hundred of these in precise sequence. Technically it is from amino acids, not protein, that human beings produce blood, Hormones, antibodies, enzymes, neurotransmitters, Skin (see related TIPS article), muscle, hair, nails, energy and more. Without amino acids, vitamins and minerals cannot perform properly. You can store carbohydrates and Fats (TIPS) but not protein. Any excess is converted to fat. If insufficient, the body breaks down muscle.
More Important Than What You Eat Is How Well You Digest and Absorb It
Amino acids are basic building blocks. They are linked together by peptides which require digestive enzymes (gastric and pancreatic proteases) to break the bonds between them. The freed amino acids and peptides are absorbed through the small intestine and into the blood courtesy of sodium-dependent transporters. Many head for the master builder the Liver (TIPS) to be assembled into needed structures, used for repairs or burned for fuel. If someone has a food Allergy (TIPS) or sensitivity it is usually to a protein fraction of that food, which for various reasons is poorly broken down. It passes through the Gut (TIPS) wall and is viewed as a dangerous invader. This creates Inflammation (TIPS) and damage, either there or at any site in the brain or body perhaps weakened through genetic or lifestyle factors. Rogue peptides may dock on cellular receptors and alter, stimulate or retard DNA instructions regarding all growth and activity (TIPS: Moods and Foods).
Some amino acids are termed ‘essential’. In the field of nutrition this term means the body cannot produce something and it must be obtained from food. There are 8-10 essential amino acids (opinions vary as to whether some are essential for children only): arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine (or ‘Pvt. Tim Hall’ if you want to remember their first letters). The 10 we can produce are alanine, asparagine, aspartate, cysteine, glutamate, glutamine, glycine, proline, serine and tyrosine. Acids such as taurine (a derivative of sulphur-containing cysteine) lack one of the defining characteristics such as a carboxyl group and so are not technically amino acids but sulphonic acids, or in other cases tri-peptides or other categories.
With protein as in other areas of life, too much of a good thing becomes a bad thing. Excess protein puts particular stress on the liver and kidneys, which have to detoxify and eliminate the waste products of its metabolism. This is implicated with gout; kidney stones; excessive blood clotting and cardiovascular disease; high acidity linked to osteoporosis (TIPS: Bones), arthritis (TIPS: Aches and Pains) and the loss of alkaline Minerals such as Calcium and Magnesium critical for muscle and nerve function, relaxation and Sleep. About 40% of your amino acids are transformed into glucose by the liver and used as fuel. This conversion creates the waste product ammonia. Because it is so toxic – especially to the Brain – the liver turns it into less dangerous urea to be filtered by the Kidneys (TIPS) and urinated out. Insufficient protein is just as nasty and leads ultimately to muscle wasting, lowered immunity, and a protruding abdomen such as seen in starving refugees (and some cancer patients). This is due to an enlarged liver and massive fluid retention since amino acids are not sufficiently present to help with normal osmosis.
Animal Protein Sources are: eggs, dairy products, fish, seafood, poultry and meat.
Plant Protein Sources, roughly in order of quantity are:
1) Legumes (TIPS; peas, beans, lentils, Soy products, peanuts);
2) Nuts and seeds (almond, walnut, brazil, pine nut, pistachio, macadamia, pecan, cashew, hazelnut, sesame/tahini – sesame seed paste, sunflower, pumpkin, coconut);
3) Grains (wheat, rye, oats, barley – TIPS: Gluten; rice, millet, buckwheat, amaranth, quinoa, maize/polenta);
4) Vegetables and fruit (especially bean sprouts, broccoli, potato, spinach, corn) but generally to a lesser extent.
Although plant foods are commonly divided into these 4 groups, most plants – from millet to pumpkin – are technically seeds that can be planted to generate new life. Not only are these 4 groups good sources of protein but also fibre, carbohydrate, antioxidants, vitamins, minerals and hormone-like phytochemicals.
Opinions vary but a conventional estimate is that an adult requires 0.8 grams of protein per kilo of bodyweight. So a 70 kilo person would need about 56 grams of protein daily (more if pregnant, breast-feeding or recovering from trauma such as an operation). Children and infants need 2-3 times this amount respectively. The greater your activity and muscle mass, the greater your need. Simply adding up the protein in individual foods to get your needed total though can be misleading. Plants are usually low in at least one amino acid. The overall value of how much protein is available is only as good as its weakest link. Animal foods have a more balanced profile, with the egg rated as having the greatest usability. But if different plant protein families are combined in one meal, the weak link in one can be compensated for by the strength of that amino acid in its partner.
An example is a serving of chickpeas (11 grams of protein) and rice (5 grams). By serving them together their total value becomes not 16 but 23 grams. Also helpful is to combine plant foods with just a small amount of animal food to maximise their collective worth. As a stand alone plant food, soybeans (and products such as tofu) have the most balanced levels of amino acids. Check out the chart below. You can also benefit from adding high protein-powered extras such as spirulina, or flaky savoury yeast (see my yummy Dynamite spread recipe in The Shape Diet).
A particularly efficient protein combination found in most traditional cuisines around the world is to pair legumes (high in lysine) with grains (low in lysine). Classic examples are:
• Beans on toast;
• Peanut butter sandwich;
• Kidney beans in tacos or tortillas;
• Falafel or hummus in pita bread;
• Dhal curry with rice.
Your own imaginative combinations can simultaneously increase visual appeal, taste and protein levels. For lunch or dinner combine several vegetables plus 2 or more other plant families. Try:
• Vegetable soup with lentils (legume) + multigrain seed bread (grain + seed);
• Baked potato with tahini or macadamia butter (seed/nut) + salad with chickpeas (legume) and croutons (grain);
• Stir-fried or simmered vegetables with mung sprouts (legume) + cashews (nut) + noodles (grain);
• Vegetable curry with coconut cream (seed), tofu or lentil (legume) + rice (grain).
Human beings spent about 500,000 years as hunter gatherers (high animal protein, low starchy carbohydrate; suits ENTHUSIAST/ANALYSER body-type) and less than 10,000 years as cultivators (low animal protein, high starchy carbohydrate; suits DRIVER/SENSUALIST). Fortunately your appearance and health issues provide indicators as to what suits you best today. See the questionnaire in The Shape Diet to determine your metabolic body-type and the particular foods that tend to work for you or against you.
PROTEIN CONTENT per 100 grams (raw or cooked as commonly consumed ie raw nuts and fruit; cooked legumes, grains, meat and vegetables)
|Animal Sources Legumes/Pulses|
|beef, lean 27.6 miso 32.48|
|lamb, lean 27.6 peanuts 25.87|
|pork, lean 27.5 tofu 15|
|snapper 26.3 lentils 9|
|chicken 23 chickpeas 8.8|
|tuna 23.4 kidney beans 8.67|
|prawns 20.9 hummus 6|
|salmon 20 baked beans 5.4|
|cheese 20 carob 4.7|
|mussels 16 alfalfa sprouts, raw 3.99|
|milk 3.2 soy milk 3.75|
|Nuts and Seeds Grains/Cereals|
|walnuts 23.24 oats 16|
|sunflower 22.77 amaranth 14.45|
|almonds 21.26 quinoa 14|
|pistachio 20.61 rye flour 14|
|sesame 20.33 rice bran 11.86|
|linseed 19.50 bread, mixed grain 10|
|tahini 17.64 corn meal/polenta 8.12|
|hazelnuts 14.80 pasta 4.77|
|cashews 14.70 millet 3.51|
|brazils 13.93 buckwheat 3.38|
|macadamia 7.73 rice, white 2.69|
|coconut 6.88 rice, brown 2.58|
|coconut cream 2.65 barley, pearl 2.26|
|oat bran 2.3|
|rice noodles 0.91|
|peas 5.36 currants, dried 4.01|
|spinach 2.97 figs, dried 3.32|
|broccoli 2.92 prunes 3.32|
|Brussels sprouts 2.55 raisins 3.20|
|potato 2.50 avocado 2.05|
|corn 2.38 apricot 1.40|
|asparagus 2.38 kiwifruit 1.14|
|kumara/sweet potato 2.32 feijoa 1.11|
|tomato 2.28 banana 1.09|
|beans, green 1.89 nectarine 1.06|
|cauliflower 1.84 cherry 1.06|
|beetroot 1.68 olives, pickled 1.03|
|onion 1.36 rhubarb 0.90|
|lettuce 1.35 blueberries 0.75|
|peppers 0.92 pawpaw/papaya 0.61|
|carrot 0.76 pineapple 0.54|
|spirulina 43.79 nori (seaweed) 4.52|
|flaky savoury yeast 40.02 parsley 2.97|
|garlic 6.16 wakame (seaweed) 2.60|
|wasabi 4.80 mushrooms 2.17|
NZ Food Composition Table; USDA Nutrient Database