Why It Matters
The neutrophil-to-lymphocyte ratio (NLR) reflects the relationship between innate and adaptive immune response during illness or other pathological state. (source, source)
NLR has emerged as a cost-effective, readily available biomarker that captures the balance between pro-inflammatory neutrophil activity and immune-regulatory lymphocyte function. An elevated NLR reflects systemic physiological stress and chronic inflammation, while a suppressed NLR may indicate immunosuppression or impaired innate defense. (source)
Low Neutrophil/Lymphocyte Ratio: Suppressed Innate Immunity
A low neutrophil/lymphocyte ratio can be influenced by physiological factors involving the immune system, where bone marrow, spleen, and lymph nodes play essential roles in producing and regulating these blood cells. Nutritionally, factors such as nutrient deficiencies or inadequate intake of essential vitamins and minerals can impact immune cell production and function. (source, source, source)
Potential Performance Impact
- Weakened innate immune defense that increases susceptibility to infection during heavy training periods
- Impaired neutrophil-mediated tissue repair following exercise-induced muscle damage
- Reduced first-line inflammatory response that slows the initial phase of recovery
- Compromised pathogen clearance that may lead to prolonged illness and missed training days
Optimization
Prioritize selenium-rich foods. Selenium has been shown to raise neutrophil levels. (source, source) Selenium acts as a cofactor for an enzyme that protects neutrophils from oxidative damage, which supports neutrophil function and normalizes levels in the body. (source, source)
Protocol: Eat at least one serving of selenium-rich foods three times per week. One serving examples: Brazilian Nuts (1 oz), Yellowfin Tuna (3 oz), Sardines (3 oz), Beef (3 oz), Chicken (3 oz)
Aerobic training. Aerobic exercise has been shown to elicit a neutrophil response. (source) Aerobic exercise triggers the release of specific hormones, including cortisol and catecholamines, which stimulate the bone marrow to release neutrophils into the blood to combat inflammation. (source)
Protocol: Follow a structured program that ensures at least 150 minutes of moderate intensity (50 to 70% max heart rate) or 75 minutes of high intensity (75% max heart rate or greater) a week.
Supplement with selenium. Selenium has been shown to raise neutrophil levels. (source, source) Selenium acts as a cofactor for an enzyme that protects neutrophils from oxidative damage, which supports neutrophil function and normalizes levels in the body. (source, source) Supplementation with selenium improves neutrophil health and function.
Protocol: Supplement with at least 50 mcg of selenium.
Prioritize fatty fish. Consumption of omega-3 fatty acids has been shown to reduce IL-6 and work to normalize lymphocyte levels. (source, source, source)
Protocol: Eat at least two servings of fatty fish a week. One serving examples: Salmon (3 oz), Herring (3 oz), Bluefin Tuna (3 oz), Anchovies (3 oz), Mackerel (3 oz)
Supplement with omega-3 fatty acids. Omega-3 fatty acid supplementation has been shown to reduce IL-6 and work to normalize lymphocyte levels. (source, source, source)
Protocol: Consume at least 3 g of total omega-3 fatty acids (EPA and DHA) daily.
High Neutrophil/Lymphocyte Ratio: Systemic Immune Stress
A high neutrophil/lymphocyte ratio can be influenced by physiological factors such as inflammation and stress, which may stimulate an increase in neutrophils and a decrease in lymphocytes. From a nutritional perspective, diets high in processed foods, sugar, and unhealthy fats can contribute to chronic inflammation, affecting the balance of neutrophils and lymphocytes. (source, source, source, source)
Potential Performance Impact
- Chronic systemic inflammation that impairs recovery and blunts training adaptation
- Suppressed adaptive immune function that increases vulnerability to illness
- Elevated physiological stress that disrupts hormonal balance and sleep quality
- Impaired lymphocyte-mediated immune surveillance that compromises long-term health
Optimization
Prioritize zinc-rich foods. Zinc consumption has been shown to reduce neutrophil activity. (source) Zinc has anti-inflammatory properties that reduce the recruitment and activity of neutrophils, thereby decreasing neutrophil concentrations in the body. (source, source)
Protocol: Consume at least two servings of zinc-rich food a day. One serving examples: Oysters (3 oz), Beef (lean cuts) (3.5 oz), Crab (3 oz), Pumpkin Seeds (1/4 cup), Lamb (3 oz)
Prioritize glutamine-rich foods. Consumption of glutamine has been shown to increase lymphocytes. (source) Glutamine is the primary source of energy for lymphocytes to increase in number. (source)
Protocol: Consume at least one serving of foods high in glutamine at each meal daily. One serving examples: Beef (lean cuts) (3.5 oz), Chicken (3.5 oz), Pork (3.5 oz), Eggs (3 large eggs), Walnuts (1 oz)
Prioritize sleep. Sleep is associated with increased lymphocytes. (source) Sleep allows the body to recover, helping to reduce oxidative stress and cellular death which negatively affect lymphocyte levels. (source, source)
Protocol: Strive to get 8 to 10 hours of sleep for optimal recovery and adaptation.
Supplement with zinc. Supplementation with zinc has been shown to reduce neutrophil activity. (source) Zinc has anti-inflammatory properties that reduce the recruitment and activity of neutrophils, thereby decreasing neutrophil concentrations in the body. (source, source)
Protocol: Supplement with at least 5 mg of zinc daily.
Supplement with glutamine. Supplementation with glutamine has been shown to increase lymphocytes. (source) Glutamine is the primary source of energy for lymphocytes to increase in number. (source)
Protocol: Consume two to three 5 g servings of glutamine daily.
