Zinc (L-OptiZinc®) Clinical Evidence

Annals of Nutrition and Metabolism

Wintergerst ES, Maggini S and Hornig DH. Immune-enhancing role of vitamin C and zinc and effect on clinical conditions. 2006; 50(2): 85-94.

2005 Dec; 16(12):212941.

Topic:

Can vitamin C and zinc improve immune function?

Background:

Levels of vitamin C in plasma and leukocytes (white blood cells) fall rapidly when the body is fighting infection or under stress. Can vitamin C and zinc help the immune system respond more effectively to infections?

Study Type:

Review paper

Dosage:

Up to 1 gram/day

Summary:

Supplementation with vitamin C was found to enhance the function of various components of the immune system, such as antimicrobial cells, natural killer cells, the proliferation of lymphocytes (a kind of white blood cell), chemotaxis (the movement of cells toward or away from a chemical stimulant), and delayed-type hypersensitivity (a kind of immune response in which T cells and T helper cells recognize an antigen and destroy it on contact). Vitamin C also protects cells from free radicals and inflammation.

Conclusion:

“These trials document that adequate intakes of vitamin C and zinc ameliorate symptoms and shorten the duration of respiratory tract infections including the common cold. Furthermore, vitamin C and zinc reduce the incidence and improve the outcome of pneumonia, malaria, and diarrhea infections, especially in children in developing countries.”

American Journal of Clinical Nutrition

Berger MM, et al. Trace element supplementation modulates pulmonary infection rates after major burns: a double-blind, placebo-controlled trial. 1998 Aug;68(2):365-71.

Topic:

Can increased supplementation with trace elements (including copper and zinc) help reduce pulmonary infections in patients with major burns?

Background:

The number one reason people die after major burns is infection. Patients often suffer short-term depletion of trace elements that support the immune system after being badly burned. Would supplementation help?

Study Type:

Human clinical intervention trial

Study Design:

Randomized, placebo-controlled. Subjects consumed either standard trace element intakes plus placebo, or standard trace element intakes plus supplements of trace elements.

Dosage:

For the control group: 20 micromol copper, 0.4 micromol selenium and 100 micromol zinc. For the treatment group: 40.4 micromol copper, 2.9 micromol selenium and 406 micromol zinc, for 8 days.

Subjects:

20 subjects, aged 40 +/- 16 years, with burns on 48 +/- 17% of their bodies.

Results:

Plasma levels of zinc and copper remained below normal in both groups until day 15 for zinc and day 20 for copper. Plasma levels of selenium remained normal in the treatment group, while they fell in the control group. Leukocyte (white blood cell) counts were higher in the treatment group. The number of infections per patient the treatment group (1.9 +/- 0.9) was significantly lower than in the control group (3.1 +/- 1.1).

Conclusion:

“Early trace element supplementation appears beneficial after major burns; it was associated with a significant decrease in the number of bronchopneumonia infections and with a shorter hospital stay when data were normalized for burn size.”

Nihon Rinsho (Japanese Journal of Clinical Medicine)

Kodama H.  Essential trace elements and immunity. 1996 Jan; 54(1): 46-51.

Topic:

What are the effects of trace minerals on the immune system?

Background:

Historically, the immune system has been divided into two parts: humoral and cell-mediated. Humoral immunity was so named because its protective effects were found in the body humor (serum), whereas cell-mediated immunity referred to the protective effects of white blood cells. Trace minerals are known to support immunity—but which kind?

Study Type:

Review paper

Dosage:

Varied by study

Summary:

The author finds that deficiencies in zinc, iron, copper, and selenium can all cause dysfunction of cell-mediated immunity.  However, these deficiencies do not affect B cell function. Additionally, excess supplementation can also impair the immune system.

Conclusion:

“Among essential trace elements in humans, zinc, iron, copper and selenium are essential for the integrity and optimum function of the immunity…A proper balance of these elements is essential for maintenance of immunocompetence.”

Current Opinion in Clinical Nutrition and Metabolic Care

Prasad AS. Zinc: role in immunity, oxidative stress and chronic inflammation. 2009 Nov; 12(6): 646-52.

Topic:

Which conditions can zinc be used to treat?

Background:

Zinc serves as a signal molecule for immune cells and can thus be expected to affect a wide variety of immune-related conditions.

Study Type:

Review paper

Dosage:

Varied by study

Summary:

    The authors found that zinc has been successfully used to treat:

    • Diarrhea in children
    • Chronic hepatitis C
    • Shigellosis
    • Leprosy
    • Tuberculosis
    • Pneumonia
    • Acute lower respiratory tract infection
    • Common cold
    • Leishmaniasis (a disease caused by parasites)

    Zinc has also been successfully used to decrease the incidence of:

    • Respiratory tract infections in children
    • Infections, oxidative stress, and inflammation in the elderly and in patients with sickle cell disease
    • Blindness in elderly individuals with dry type age-related macular degeneration

    Conclusion:

    “Zinc supplementation has been successfully used as a therapeutic and preventative agent for many conditions.”

     

    BMC: Public Health

    Yakoob MY, et al. Preventative zinc supplementation in developing countries: impact on mortality and morbidity due to diarrhea, pneumonia and malaria. 2011 Apr 13; 11 Suppl 3: S23.

    Topic:

    Can preventative zinc supplementation among children under five in developing countries prevent deaths from diarrhea, pneumonia and malaria?

    Background:

    Zinc deficiency is widespread among children in the developing world and places them at increased risk of infection due to decreased immune response.

    Study Type:

    Review paper

    Dosage: 

    Varied by study

    Results:

      The authors found zinc supplementation reduced deaths from diarrhea and pneumonia, but not from malaria.

      Conclusion:

      “We, therefore, conclude that zinc supplementation in children is associated with a reduction in diarrhea mortality of 13% and pneumonia mortality of 15%.”

      Biogerontology

      Kahmann L, et al. Effect of improved zinc status on T helper cell activation and TH1/TH2 ratio in healthy elderly individuals. 2006 Oct-Dec; 7(5-6): 429-35.

      Topic:

      Can supplementation with zinc help strengthen immunity in the elderly?

      Background:

      Mild zinc deficiency is common among the elderly and can lead to decreased cell-mediated immunity.

      Study Type:

      Human clinical intervention trial

      Dosage: 

      Not stated in abstract

      Subjects:

      19 healthy subjects, aged 69.8 +/- 5.1 years

      Results:

      Subjects were mildly deficient in zinc at the beginning of the study. Over the course of the study, their blood levels of zinc rose and their levels of activated T-helper cells (white blood cells that direct the activities of other immune cells) were significantly reduced, indicating that the immune system was less threatened. The ratio of TH1/TH2 (two different kinds of T helper cells) was unchanged.

      Conclusion:

      “These findings suggest that elderly individuals may benefit from moderate zinc supplementation due to improved immune response leading to reduced incidences of autoimmune diseases and infections.”

      Journal of Translational Medicine

      John E, et al. Zinc in innate and adaptive tumor immunity. 2010; 8: 118.

      Topic:

      How does zinc impact immunity?

      Background:

      Zinc affects both innate and adaptive immunity. In other words, it affects the body’s ability to respond to new and previously encountered threats.

      Study Type:

      Review paper

      Dosage: 

      Varied by study

      Summary:

      The authors find that zinc deficiency:

      • Increases rates and duration of infection
      • Plays a role in weakened immune systems in the elderly
      • Places stress on the immune system

      Meanwhile, supplementation with zinc:

      • Improves immunity
      • Decreases inflammation

      Conclusion:

      “These general findings suggest that zinc is critical for normal immune cell function, whereby zinc depletion causes immune cell dysfunction, and zinc supplementation can either restore function in the setting of dysfunction or improve normal immune cell function.”

      Mechanism of Action

      Zinc deficiency damages both innate and adaptive (learned) immunity, and can lead to atrophy of the thymus (a gland where T cells develop and differentiate), changes in thymic hormones and lymphopenia (a condition characterized by low levels of lymphocytes in the blood). These changes lead directly to increased rates of infection and longer-lasting infections. When zinc stores are low, DNA repair enzymes and signaling molecules also suffer. Supplementation with zinc improves immune reponse and down-regulates mechanisms that lead to chronic inflammation.