Getting Adequate Protein and Making Healthy Protein Choices
Dr. Louise Gagné

Introduction

Proteins are essential constituents of all our living cells. They are considered the worker molecules in our body that carry out the duties encoded in our genes. Proteins are made from amino acids. They are complex molecules containing carbon, hydrogen, nitrogen, oxygen, usually sulphur, and occasionally other elements.

Proteins are used everywhere in our body for a wide variety of functions, including the growth and repair of tissues and the production of enzymes. They are also used to make our cell receptors, as they are part of our immune response. Multiple important molecules in the body are proteins including albumin, hemoglobin, myoglobin, insulin, collagen and keratin. 

You’ll often hear the term “complete protein.” If a food is to be considered complete protein, it needs to contain all eight of the essential amino acids (10 for children), and it needs to have them in adequate amounts. The essential amino acids are the amino acids that our body requires, but cannot synthesize.

Pros and Cons of Animal Protein 

Pretty well any animal protein that you might name is going to be a complete protein. This includes meat, poultry, fish, shellfish, eggs, milk, cheese, and yogurt. Many animal foods are also rich in a lot of the B vitamins and many minerals. And those minerals are, in general, more bio-available than they are from plant foods. Moreover, meat fat can supply us with monounsaturated fats, which should be our most predominant fat that we eat.

What about the bad side of the fence? Many studies show long term consumption of red meat and processed meat is associated with increased total mortality, and increased cardiovascular disease, type 2 diabetes, and colorectal cancer. The World Health Organization has declared red meat to be a probable carcinogen and processed meat to be carcinogenic.

Plant Proteins

When it comes to plant proteins, soybeans and quinoa provide complete protein, but most individual plants do not. However, plant foods can supply all the needed amino acids when a variety of them are eaten in a single day. To get complete protein in a meal, you need to combine a food from the legume category (e.g. black beans, lentils, kidney beans, peanuts) with a food in the grains, nuts, and seeds category (e.g. wheat, rice, oats, almonds, walnuts, sunflower seeds).  For example, eating rice and beans will give you complete protein. Likewise, hummus provides complete protein because it has a legume (chickpeas) and a seed (tahini).

Plant foods have other important benefits. They provide you with fibre and phytochemicals not found in animal foods, and they contain lower amounts of environmental contaminants. Moreover, plant foods provide monounsaturated fats and polyunsaturated fats and are generally very low in saturated fat. 

How Much Protein Do We Need?

For well, healthy people, 10 to 15 per cent of daily calories should come from protein. If you look at it based on your weight, 0.8 grams of protein per kilogram of your weight is recommended. For example, for a 165 lb. man, this would mean 60 grams of protein per day. Protein needs are higher in the elderly, nursing mothers, children, competitive athletes, and persons recovering from serious illness, or injury. 

Having adequate protein is very important, but eating more protein than your body can make use of, does not benefit you.

Fortunately, most North American diets are not deficient in protein, but elderly persons, those with poor dentition, and those on very low income are more likely to be. Inadequate protein intake can lead to hair loss, impaired immunity, muscle weakness/wasting, and delayed wound-healing.

Protein Quality

It’s extremely important to consider protein quality—the kinds of proteins you are choosing to eat. I recommend minimizing consumption of processed/cured meats with added nitrates/nitrites (e.g. bacon, ham). Unfortunately, when added to meats nitrates and nitrites can combine with amino acids in the meats to form nitrosamines. Nitrosamines are known to cause cancer. The formation of nitrosamines is increased if you cook these meats at higher temperatures. 

It’s important to reduce or avoid deep fried foods and to be careful about your fish selection. Choose fish with low levels of environmental contaminants, such as mercury and PCBs. And choose fish with high levels of omega 3 fats. Wild Alaskan salmon, mackerel, anchovies, sardines, and herring are highly recommended. Unfortunately, our lake fish, which I grew up catching in Saskatchewan, are much higher in mercury and much lower in omega 3s. So is tuna. 

Cooking Methods

We know that charbroiling animal flesh (including fish and poultry) at temperatures over 350º Fahrenheit is going to tend to cause the formation of compounds like heterocyclic amines and polycyclic aromatic hydrocarbons. These are known to be toxic compounds that are associated with increased health risk, and might be one of the reasons why meat consumption in general is linked to some negative health outcomes. It’s for this reason that barbecuing is not a good way to cook your food on a regular basis because of the high temperatures involved. 

High temperature cooking is associated with negative health outcomes when cooking plant foods, too. This is because high temperature cooking also increases the formation of advanced glycation end products. These promote oxidative stress and inflammation which are both recognized as underlying drivers of chronic disease.

What to Do

• Have some meals during the week that are completely vegetarian.
  
• Baking, sauteing, or poaching at lower temperatures is preferable
  
• When cooking meat, adding spices/herbs such as rosemary, basil, thyme, and oregano can help lower the formation of heterocyclic amines. 
  
• Flip meat frequently when cooking.
  
• Marinate meat before you cook it. Acid-based marinades containing vinegar, lemon juice, garlic, etc. can help reduce heterocyclic amine formation by up to 99 per cent.
  
• If you are eating beef, look for grass fed and even grass finished locally raised beef. It will have a better array of fatty acids in it than beef that has been finished with grains at the feedlot. 
  
• About half your meal plate ideally should be made up of fruits and veggies, a quarter with protein and a quarter with some type of healthy choice of carbohydrate.

The material in this article was prepared by Dr. Louise Gagné. She practiced medicine in Saskatoon for over 35 years and completed a Fellowship in Integrative Medicine at the University of Arizona with Dr. Andrew Weil.  She taught nutrition and integrative medicine at the University of Saskatchewan for 15 years. This article was sourced from both her spoken and written words in a presentation she made at the University of Saskatchewan.  Dr. Gagné passed away in 2023, but her exceptional knowledge continues to be shared.