08 Jul 2022 Article

In this article I am talking about the amino acid lysine. Of the twenty amino acids that we need every day, this one is perhaps one of the most important. Read why below. In this article I also share the best vegetarian sources of lysine.

Lysine is one of the essential amino acids. Well, what are these, essential amino acids? Amino acids are chemical units, often called “building blocks” of proteins. All proteins are made of amino acids. The proteins in the human body are made of twenty amino acids. Nine of these are essential. A substance is called “essential” when our body cannot make it itself. Such a substance must therefore come from outside, by eating or drinking it.

The functions of lysine

The main role of lysine is to participate in protein synthesis. Lysine is known to be necessary for the growth and development of children. Children’s need for lysine is in fact twice that of adults. Furthermore, this amino acid promotes the absorption of calcium. Lysine also plays a role in collagen production and tissue repair.

The Dutch health authorities advise against taking individual amino acids in the form of supplements. The reasoning is that too much of one or more amino acids can be toxic to our body. However, lysine has been used for decades as a natural remedy for cold sores (Herpes Simplex). If you ask the scientists, lysine has not been proven to cure cold sores. But many people from real life say that it does help them. It could be a placebo effect. I’d say: as long as it works!

How much lysine do we actually need?

For adults, the World Health Organization recommends taking 30 mg lysine/kg body weight/day. If you weigh 60 kg, then you need: 30 mg X 60 kg = 1800 mg lysine per day.

As for supplements, science says that a daily dose of up to 3 g of lysine per day is not harmful to health. However, I wouldn’t keep taking lysine (or any other supplement for that matter) continuously.

In which foods do we find lysine? The best vegan and vegetarian sources of lysine

The foods richest in lysine are meat (products) and some types of fish. If you are a vegetarian/vegan, you run the risk of not getting enough lysine. The fact is that plant foods contain little lysine. This is why it is useful to know which vegetarian and vegan foods do contain lysine. You can find many tables online. Unfortunately, the numbers in the tables are often made up. I can’t say it any other way. The data I share in this article comes from the Food Data Central of the U.S. Department of Agriculture. In my opinion, this is the most reliable source of food nutrient profiles.

Lysine is a so-called “limiting” amino acid. Which means it’s only found in small amounts in some food categories, grains being the most notorious example. So, if you are a vegetarian and if your diet is based on grains, you can develop a structural lysine deficiency. Quinoa is often mentioned as an exception. I checked: quinoa contains 776 mg of lysine per 100 g. Most grains contain three times less lysine.

Legumes contain a lot of lysine.

  • Lentils contain an average of 1700 mg g lysine per 100 g.
  • Beans contain an average of 1500 mg lysine per 100 g.
  • Chickpeas contain 1400 mg lysine per 100 g.

All soy products (soy is a legume) contain a relatively high amount of lysine.

  • Soy flour contains 3127 mg lysine per 100 g or 200 mg per tablespoon (7 g).
  • Tofu contains 1120 mg lysine per 100 g.
  • Tempeh contains 908 mg lysine per 100 g.
  • Soy milk contains 200 mg lysine per 100 ml.

Other good sources of lysine include:

  • Cottage cheese: 1200 mg lysine per 100 g.
  • Egg: 418 mg lysine per egg (50 g).
  • Parmesan cheese: 384 mg lysine per 10 g (2 tbsp).
  • Pecorino romano cheese: 300 mg lysine per 10 g.
  • Pistachios: 277 mg lysine per 25 g (other nuts contain significantly less lysine).
  • Sunflower seeds: 246 mg lysine per 25 g.
  • Spirulina: 212 mg lysine per 7 g (1 tbsp).

As you can see, in theory it should not be difficult to meet your daily lysine requirement, even if you are a strict vegetarian. Eating legumes very regularly is the best strategy. And a handful of pistachios and sunflower seeds now and then also helps.