People who follow a vegan diet may want to check if they are getting enough lysine. According to a 2011 Harris Interactive study, the number of people following a vegan diet in the United States has increased and over 7.5 million U.S. citizens now eat vegan diets that do not include any animal products – no meat, poultry, fish, dairy or eggs.
Vegan Amino Acids Deficiency
The amino acid Lysine is a common deficiency in the diet of a vegetarian, and particularly of vegans, as are amino acids in general. All 22 amino acids come from food; specifically, from proteins.
While chicken and beef provide all 22 amino acids (aminos are the building blocks of proteins), animal meats are not on the vegan/vegetarian diet; however, if one is an ovo-vegetarian (one who eats eggs) or lacto-vegetarian (one who eats dairy products) then some amino acids can be consumed for this purpose. Also, if one is a pesco-vegetarian (one who eats fish) then amino acids can be gotten that way as well. Interestingly, it is lysine that is the one amino acid that is commonly missing from most vegan menus.
High-Lysine Amino Acid Foods for Vegans and Vegetarians
Lysine is an amino acid that can come from food, but is often taken as a supplement. To obtain lysine amino acid from protein one needs 1.0 to 1.1 grams per kilogram of body weight each day (adults), especially if you are over the age of 60.
High-lysine foods include legumes, quinoa, pistachios, and seitan, and need to be eaten daily. Adding enough protein to the diet is important to maintain enough lysine in the body. Legumes, which include soybeans (and products from soybeans such as tofu, tempeh, soy milk, soy meats, and so on), also include beans (pinto, garbanzo, pinto and other dry beans) and their products (falafel, refried beans, and hummus), peas (black-eyed, split, green peas, etc.), lentils, and even peanuts.
There are 9 essential amino acids (EAAs) that the body cannot produce, which must be taken in through food or supplementation. The percentages of EAAs in soy products and animals are close to those in human proteins; however, non-soy plant proteins have at least one amino acid that is lower than soy proteins. Interestingly, legumes and their products are actually fairly close to the percentages in soy.
Other Foods High in the Amino Acid Lysine
Seitan and legumes, per serving, have the highest amount of the amino acid lysine. In particular, it is tempeh and tofu, soy meats, lentils, and seitan, which are highest, with other legumes and their products falling in under that. Lysine is the amino acid that is also found in decent amounts in pistachios and quinoa.
As a general rule of thumb, vegans and vegetarians should try to consume the US RDA recommendations for proteins and lysine, approximately 1g/kg of protein for children, .8g/kg for people 18-59, and up to 1.3g/kg for those over age 60.
Nitrogen balance can also affect how much of the amino acid lysine one needs, as well as amino acids in general. Basically, it is simply recommended that vegans and vegetarians ensure they have more than enough protein to accommodate issues such as nitrogen imbalance. The Vegan Health organization has put together some information on nitrogen balance, as well as a chart for the protein and amino acids in foods in one of their articles on proteins and lysine for vegans.
The bottom line is that vegans and vegetarians should obtain more lysine and other amino acids through diet or supplements to ensure that their health is maintained.