Focus On: Lysine

WHAT IT IS: Lysine is an amino acid, meaning that our bodies need it as a building block for protein. Furthermore, it’s an essential amino acid, meaning that we need to get it through diet (our bodies cannot manufacture it).

[ Sources ]

The highest concentrations of lysine are in animal proteins. One ounce servings of chicken, turkey, tuna, and ground beef contain 912, 638, 656, and 624 milligrams respectively. Vegan protein sources like nuts and beans are lower: Almonds and pinto beans contain 175 milligrams each per one ounce serving. Low-protein foods have nearly no lysine: One ounce of raw apple has three milligrams.

[ Benefits ]

Lysine helps the body fight viruses (notably cold sores); build connective tissue (collagen); produce hormones, enzymes, and antibodies; lower blood pressure and stroke risk; and absorb calcium. Lysine deficiency has been linked to anxiety and stress. The late great Linus Pauling, PhD, also makes a compelling case for high doses of vitamin C taken with lysine to fight plaque adhesion in arterial walls.

[ Warnings ]

In very large doses—10 to 30 grams per day—lysine increases the toxicity of aminoglycoside antibiotics such as gentamicin, neomycin, and streptomycin.

[ Recommended Dosage ]

The body needs 51 milligrams of lysine for every gram of protein eaten. If you eat 100 grams of protein a day, you’d need over five grams of lysine. Put another way, the lysine needs to be 5.1 percent of the protein eaten. Most vegan protein sources fall short of that mark, whereas most animal-based protein sources meet or exceed it. (One ounce of beef, for example, has 7.6 grams of protein. To reach 5.1 percent lysine concentration, it would need to have 388 milligrams of lysine—it contains 624.) In body weight terms, the World Health Organization suggests 14 milligrams per pound, so a 150 pound person should consume 2,025 milligrams per day.

LYSINE PICKS

TwinLab L-Lysine, 500 mg, $11, 100 capsules, twinlab.com // Solgar L-Lysine, 1000 mg, $28, 250 vegicaps, solgar.com // Source Naturals Free-Form L-Lysine 500 mg, $17, 250 tablets, sourcenaturals.com