Why are proteins so important and what are the best sources?

Read time 5 min

Proteins! For many people, the word protein probably conjures up an image of a muscular man doing a strenuous work-out in the gym. However, the notion that proteins do far more than simply building up muscle tissue as part of a body-building regime is fortunately gaining ground. The fact of the matter is that proteins have a major impact on our physical and mental well-being. At the same time, we are seeing a significant shift away from animal sources of protein to vegetable ones. This article attempts to explain what proteins actually are, why they are essential for a healthy lifestyle, what the differences are between vegetable and animal proteins, and many other issues.

What are proteins and why do we need them?
Proteins, like carbohydrates and fats are macro-nutrients. Simply put, proteins are the fuel that gives us energy. But that’s not all: proteins are made up of different amino acids. These amino acids can be seen as the building blocks of a protein, as links in a chain, each with their own role and function. Our bodies are fashioned from these proteins: they are the bricks on which our house is built. However, as opposed to a house, our bodies need replenishing with new bricks every day. After a certain time, most cells in our bodies are broken down and rebuilt. Take, for example, old cells that have to be repaired and replaced on a daily basis: the renewal of muscles, intestinal cells, the epidermis, the production of red blood cells, enzymes, neurotransmitters and hormones. This constant ‘rejuvenation’ of our bodies is therefore reliant on the presence of sufficient proteins.

Essential and non-essential amino acids

We can differentiate between essential and non-essential amino acids. The former cannot be produced by the body itself and so have to be absorbed via nutrients or suppletion.

• Essential amino acids include isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.
• Arginine and histidine, on the other hand, belong to the group of so-called semi-essential amino acids, which in certain situations have to be absorbed via nutrients.
• Under the right circumstances, the body itself can produce non-essential amino acids, such as alanine, asparagine, asparagine acid, cysteine, glutamine, glutamic acid, glycine, proline, serine and tyrosine.
• Reduced levels of concentration
• Reduced resistance
• Constipation
• Depression
• Slower recovery from cuts and fractures
• Uneasy sensation of hunger
• Problems with the quality of the skin, hair and nails
• Reduced detoxification
• Increased histamine levels
• Decreased production of collagen
• Imbalance in stress management
• Anxiety disorders

A deficiency in (essential) amino acids can bring about problems such as:

In short, a balanced diet is extremely important for taking in the right amino acids. These amino acids (i.e. proteins) are essential for the proper functioning of the system as a whole, inside and out.

Sources of protein

Proteins can be digested from all sorts of different food sources, including meat, fish, dairy products, eggs, nuts, seeds, pulses, soya, and meat substitutes such as seitan. Likewise, products like bread and fruit contain proteins, but you would have to eat an awful lot of these before you took on board all the proteins you need. It’s important to be aware of the biological availability of a protein source. Food sources which, in terms of structure and composition, closely resemble naturally produced proteins are most easily absorbed and therefore have the greatest levels of biological availability. The implication is that these sources contain all the amino acids you need. Animal products have a greater biological availability, for instance, than vegetable products. The fact is that the latter do not always contain all the amino acids we need. For this reason, if you eat next to no meat, it’s additionally important to combine a number of different vegetable sources and to vary your diet in such a way that you take on board as sufficient and comprehensive a range of amino acids as possible.

How much do you need?
When you consider the amount of protein a person needs, you will soon come to the conclusion that we require some protein with every meal in order to meet this need.

An adult with normal levels of activity needs a net quantity of between 0.8 and 1 gram of protein for every kilogram of body weight per day.

There are others, such as vegetarians, vegans, professional athletes, severely ill people and those who have to undergo a major operation, who need high levels of protein (at least 1.2 to 1.8 grams per kilogram of bodyweight).

In practice, for some people this means a shortage of protein is never far away. On the one hand, there are many people who are simply unaware of the importance of taking enough protein on board and, on the other hand, who have no concept of essential sources of protein. In my experience, more and more clients have a desire to supplement their diets with vegetable-based foodstuffs. Of course, this has major benefits for humans, animals and the environment, but it is important that it gives us health advantages too. I was told by one of my clients that she could get enough proteins, for example, by eating oats and whole grain rice. It’s true, these products contain proteins, but because they are vegetable-based, this is too one-sided. One look at her food diary was enough to convince me she wasn’t getting enough.

Breakfast

Oatflakes

Rice coconut milk

Blueberries

Banana

Lunch

4 crackers with peanut butter and hummus

1 slice of bread with chocolate vermicelli

Afternoon snack

1 piece of fruit

Evening meal

Pumpkin soup

2 desert spoons of whole grain rice

2 slices of bread

Late night snack

Piece of chocolate

Client’s protein requirements: 75 g

Total amount of protein for this day: 35 g

My advice to this woman was to combine cereals and pulses more frequently, to use - where possible - meat substitutes, nuts and seeds, with an option to supplement her diet with vegetable protein shakes. Apps like ‘MyFitnessPal’ can help when it comes to information on the intake and share of carbohydrates, proteins and fats. This is a quick and easy way of finding out if you’re getting enough and you will learn about useful sources of (vegetable or animal) supplements.

Vegetable or animal?

When it comes to nutrition, vegetable and animal proteins each have their pros and cons.

Advantages of animal proteins

• They provide the full spectrum of amino acids and so the highest quality proteins.
• They contain easily digested nutrients which are more limited in availability via vegetable proteins, such as iron, B12, various minerals and omega 3.

Disadvantages of animal proteins

• Major environmental impact.
• Adverse effects on animal welfare.
• Processed and red meats have been linked to increased health risks, such as heart disease and (bowel) cancer.
• Non-organic animal proteins may contain traces of endocrine disruptors and antibiotics.

Advantages of vegetable proteins

• Smaller environmental impact.
• No adverse effects on animal welfare.
• All-round, as long as adequately varied in the right combinations.
• Sources are often rich in fibres, anti-oxidants, vitamins and minerals.

Disadvantages of vegetable proteins

• Single sources do not contain the full spectrum of amino acids.
• Sources of vegetable protein can contain ‘antinutrients’. Antinutrients are substances produced by plants to protect themselves, without which a plant would get eaten to extinction. Antinutrients are slightly toxic and not easily digestible, so that the plant’s attacker will hopefully move on to another food source. Small amounts of antinutrients are not harmful, but it is not advisable to eat them in large quantities on a daily basis. Antinutrients can bind minerals and thus make them less easily digestible. For that reason, variation is important, so do not always choose the same sources, but ensure a full range of cereals, nuts, seeds and beans. The soaking, cooking, germination and fermentation of such products can decrease the presence of these antinutrients.

Conclusion

A healthy lifestyle can best be achieved with a diet that is made up of lots of vegetable proteins, no processed meat and small amounts of animal products such as fish, poultry, eggs and grass-fed meat. Since vegetable nutrients often contain proteins whose quality is less, vegetarians and vegans must vary their diet to make sure they take on board all the essential amino acids. What is clear however, is that our consumption of animal proteins exceeds the sustainability levels of the planet and impacts on the environment much more heavily than the consumption of vegetable proteins. By reducing our consumption of animal proteins, we can significantly reduce the demand for water and land use, as well as cut carbon emissions. This choice is being made easier because we now have greater access to vegetable proteins, such as algae, amarant, quinoa, funghi, vegetable protein shakes and pulses of every shape and size. Armed with the knowledge we currently have, it is more than possible to avoid consumption of animal protein and still lead a healthy lifestyle. This in turn helps safeguard the environment and also reduce our reliance on resource-intensive industries producing animal proteins.