Plant proteins: definition, sources, recipes and supplements

The plant kingdom is packed with high-quality proteins

Like all living organisms, plants contain proteins. They fulfilll in plants the same type of function as they do in animals: enzymatic (they catalyze reactions), structural, mobility, cell communication, etc.

It’s proteins, for example, which determine when trees shed their leaves and how plants defend themselves against attack, as well as facilitating absorption of nutrients essential to the growth of the plant or its fruit, etc. (1-3)

For anyone keen to increase their daily protein intake, or reduce their consumption of animal-source protein (for ethical or environmental reasons), it’s thus important to know which foods are high in plant proteins.

As a reminder, daily protein intake, depending on age, objectives and level of physical activity, should be between 0.8g per kilo of bodyweight and 2g per kilo of bodyweight (the latter when building muscle mass for example) (4).

The best dietary sources of plant proteins

Given that plant proteins play a fundamental role in the development, growth and death of plants, the highest amounts are usually found in seeds (with a few exceptions: spirulina, klamath algae, moringa leaves ...)

The best plant protein sources are: (5-8)

• spirulina, which contains 65g of protein per 100g and is particularly popular with vegetarians and vegans as a source of plant proteins. It’s usually consumed in tablet form, which is also good for energy and immunity (one option being the supplement Spirulina) ;
• Klamath blue-green algae (AFA), with 63g of protein per 100g and which importantly, is the only plant source of vitamin B12, making it invaluable for vegans. With a high content of PEA, it’s also popular for its positive effects on mood (it’s the substance in the supplement Klamath AFA) ;
• soya, containing 36g per 100g, which can be consumed in the form of tofu and sprouted seeds, etc.;
• moringa, which contains 27g per 100g, but which is hard to find in Europe in the form of leaves for use in cooking. However, many people choose to consume it in supplement form to help control their blood sugar levels (Organic Moringa leaf extract, for example) ;
• hemp seeds, lentils, pumpkin seeds, peanuts, kidney beans, broad beans, split peas, chickpeas, etc. which contain between 20g and 26g of protein per 100g and which should really form the basis of a vegetarian diet rich in protein, fibre, minerals and trace-elements;
• oats, which contain an average 16g of protein per 100g and which offer the additional advantage of having a low glycaemic index whilst being very fortifying, making them the perfect choice for a vegan breakfast high in plant proteins;
• spelt and buckwheat, which contain between 13g and 15g of protein per 100g;
• quinoa, which contains 14g of protein per 100g;

The aim is to vary your plant protein sources over a week to create balanced meals from a variety of seeds, nuts, grains and pulses.

Vegetarian recipes to ensure a good intake of essential amino acids

Above all, however, we need to obtain specific amino acids from the protein we consume. Amino acids are actually the building blocks of proteins. While the body is able to produce 11 of them itself, 9 have to be obtained from the diet: tryptophan, lysine, methionine, phenylalanine, threonine, valine, leucine, isoleucine and histidine (9).

The problem is that these essential amino acids are not uniformly present in all plant proteins. That’s why it’s always best to combine cereals with pulses. Apart from being more digestible, this combination delivers a balanced intake of essential amino acids: the pulses offer amino acids not provided by the cereals, and vice versa.

Here are some very simple vegetarian or vegan combinations/recipes: rice (cereal) with lentils (pulses) ; corn (cereal) with kidney beans (pulses); oats (cereal) with soya (pulses)... all of which you can mix with sauteed pumpkin seeds or chopped peanuts (seeds), or sprinkle with chopped pistachios, almonds or walnuts (nuts).

Vegetarians, though not vegans, also have the option of taking a daily dose of whey protein (such as Undenatured Whey Protein Isolate), whey being a by-product of cheese production. Whey protein contains all the essential amino acids in sufficient quantities to meet the body’s needs (10).