Does Milk Have Lysine? A Look at Amounts and Benefits

Lysine is an essential amino acid, a building block of protein that the body cannot produce on its own and must obtain from food. Since it must be sourced from diet, questions often arise about which foods are reliable sources. As milk and dairy products are widely consumed, many wonder about their lysine content and contribution to nutritional needs.

Lysine Content in Various Milk Types

Cow’s milk is a significant source of lysine. A standard 8-ounce (about 245 grams) serving of whole milk contains approximately 750-800 milligrams of lysine. The amounts in 2% and skim milk are very similar, as protein content is not substantially affected by the removal of fat. Goat’s milk offers a comparable amount, containing about 0.37 grams of lysine per 100 grams of milk.

Among plant-based alternatives, soy milk stands out by providing a substantial amount of lysine, though less than dairy milk. An 8-ounce serving of soy milk contains around 500-600 milligrams of the amino acid. Other plant-based milks, such as almond, oat, and coconut milk, naturally contain much lower levels of lysine. While manufacturers may fortify these beverages, their base protein quality and amino acid profile are lower than dairy or soy milk.

Key Functions of Lysine in the Body

Lysine supports the synthesis of proteins necessary for maintaining tissues. It is a component for the production of collagen, a structural protein that provides elasticity to the skin and integrity to bones, tendons, and cartilage. An adequate supply of lysine helps in the repair and maintenance of these connective tissues.

Lysine also aids in metabolic and immune processes. It is a precursor for carnitine, a substance that transports fatty acids into the mitochondria to be converted into energy. Lysine supports the immune system by contributing to the production of antibodies and facilitates the absorption of calcium from the intestine, a mineral important for bone health.

How Milk Helps Meet Your Lysine Needs

Incorporating milk into a daily diet is an effective strategy for meeting lysine requirements. The average adult needs about 38 milligrams of lysine for every kilogram of body weight per day. For a 150-pound (68 kg) person, this translates to roughly 2,584 milligrams daily, and a single glass of cow’s milk can provide nearly a third of this amount.

Since lysine is abundant in animal products, dairy consumers have a straightforward way to obtain this amino acid. Those on plant-based diets must be mindful of lysine sources, as many grains and vegetables are low in it. Including high-lysine plant sources like soy products, lentils, and quinoa is therefore important.