The Right Chemistry: Muscle building is not routine, it's triggered by protein
Protein, protein everywhere…with plenty of drops to drink! You can guzzle protein shakes, drink protein pop, or even protein water. Then there are the protein-fortified foods. Protein cereal, protein bread, protein Pop Tarts, protein popcorn, protein gummies and protein bars galore. The protein craze is off and running.
To get a grip on this race to down more and more protein, let’s go back to the starting blocks. Exactly what are proteins and why are they looking to step up to the top of the podium?
Chemistry is defined as the study of matter and the changes that matter undergoes. But what is matter actually made of? That question occupied the minds of chemists in the early 19th Century and led to Dutch chemist Gerardus Johannes Mulder to investigate some common substances such as egg whites, milk and blood. From these he managed to isolate some constituents that shared a feature in that they were composed of carbon, hydrogen, oxygen and nitrogen.
Excitedly, Mulder wrote to noted Swedish chemist Jons Jacob Berzelius that he may have found one of the prime building blocks of life since eggs, milk and blood all originate from a living source. Berzelius suggested that these substances be named “proteins” from the Greek term meaning “of first importance.”
Some 60 years later, German chemist Emil Fischer would determine that proteins consist of fundamental units called amino acids joined together in a long chain. Mulder’s isolates later turned out to be the proteins we know as albumin, casein and fibrin. It wasn’t long before scientists discovered that there are some 20 amino acids that can join together in numerous ways to form a variety of proteins that are not only the building blocks of muscles but also serve as enzymes, hormones and clotting factors. Indeed, proteins are of “primary” importance to life.
It is the connection of proteins to muscles that has generated the greatest interest. Long before proteins were identified, the ancient Greeks urged the eating of meat to improve athletic performance. “Muscle to muscle” was their cry as they downed the muscular flesh of animals in the hope of gaining strength.
Today, there is still a common belief that protein builds muscle. The “pre-game steak” was a regimen that many athletes followed until research revealed that carbohydrates are the key to energy and should make up 50 to 60 per cent of pre-game calories, with only 25 per cent devoted to protein for muscle maintenance.
Muscle maintenance is not the same as muscle building. Muscle proteins are constructed from amino acids that are supplied by the digestion of dietary proteins. However, to “build” muscles, you have to do more than supply the required amino acids. You have to sweat it at the gym. But no matter how hard you train, you cannot build more than a few grams of muscle a day. The amino acids needed to do this are easily supplied by proteins in the diet.
Muscles, though, are also in a state of flux, constantly breaking down and in need of repair. This repair requires amino acids provided in the diet. Consider also that our hair, nails, skin, connective tissues, organs and the inner structure of bones are all made of proteins, as are enzymes, many hormones and blood components such as hemoglobin and fibrin. The neurotransmitters dopamine, serotonin, norepinephrine and gamma-amino-butanoic acid are all made from amino acids released when proteins are digested.
Clearly, protein intake is important. That then leads us to the pivotal question of the amount of protein that should be consumed a day to meet the body’s needs.
Since protein is the only macronutrient that supplies nitrogen, it is possible to determine the nitrogen content of different amounts of protein fed to volunteers and then measure the amount of nitrogen excreted in their urine, sweat and fecal matter.
From the difference of nitrogen ingested and excreted, it is possible to determine the amount of nitrogen retained by the body and from that calculate the daily protein requirement. It is in this fashion that 0.8 grams per kilogram of body weight was determined to be the minimum amount needed daily to prevent deficiency. This dose will prevent the loss of lean tissue and supply enough amino acids for basic physiological functions, but does not maximize muscle mass or optimize athletic performance.
There is some controversy about optimal intake, but 1.1 to 1.5 g/kg of body weight is a reasonable goal. Older adults exhibit “anabolic resistance,” meaning they require higher protein doses to stimulate the same muscle-building response seen in younger individuals and should therefore aim for a dose of around 1.2g/kg, meaning 80 to 90 grams of protein a day for a person who weighs 70 kilograms.
Although protein intake is usually associated with animal foods, it is certainly possible to meet daily needs from vegetable sources. That may even be preferable. An American study that followed over 400,000 people for 16 years found that swapping just 18 grams of meat protein, but not dairy or fish protein, for plant protein daily was associated with a 12–14 per cent lower risk of dying prematurely. This difference seems to disappear after the age of 75.
So how does one get 80 to 90 grams of protein a day? A single 10-ounce steak will do it, but that comes with the baggage of fat and cholesterol. A chicken breast will furnish about 50 grams with much less fat. A cup of tofu or a 100-gram serving of salmon will deliver 20 grams of protein. A serving of Greek yogurt has about 15 grams while two eggs, half a cup of cottage cheese or a bowl of lentil soup will provide about 13 grams. You can get about 10 grams from a peanut butter and jelly sandwich, eight grams from a glass of milk and double that from the “ultrafiltered” version.
As far as supplements go, a scoop of Whey powder has about 25 grams and protein bars contain around 20, the same as the “protein pop” that has jumped on the bandwagon. Your homework now is to calculate whether you are getting enough protein each day. It is a worthwhile effort.
Remember though that another kind of effort is needed if you want to use that protein to build muscle. Reaching for those dumbbells is far from dumb.
Joe Schwarcz is director of McGill University’s Office for Science & Society (mcgill.ca/oss). He hosts The Dr. Joe Show on CJAD Radio 800 AM every Sunday from 3 to 4 p.m.