From the Guidelines
Vitamin E is the most effective immunostimulant, with a recommended daily dose of 200 IU for optimal immune enhancement in older adults. This recommendation is based on the strongest and most recent evidence from studies such as Meydani et al. 1, which demonstrated that vitamin E supplementation improved T cell-mediated functions, including lymphocyte proliferation, IL-2 production, and delayed-type hypersensitivity response, in older adults.
Key Findings
- Vitamin E supplementation has been shown to improve immune function in older adults by enhancing T cell-mediated responses and reducing inflammatory markers such as PGE2 1.
- A daily dose of 200 IU vitamin E was found to be the most effective in improving T cell-mediated functions, compared to lower or higher doses 1.
- Vitamin E supplementation has also been shown to improve vaccine response, reduce susceptibility to infections, and decrease mortality from lower respiratory infections 1.
Mechanisms of Action
- Vitamin E enhances T cell function by inhibiting PGE2 production and improving membrane-associated signaling molecules 1.
- Vitamin E also reduces the production of other inflammatory markers such as TNF-α and IL-6 in older adults 1.
Clinical Implications
- Vitamin E supplementation should be considered as a potential adjunct therapy to improve immune function in older adults, particularly those with compromised immune systems 1.
- A daily dose of 200 IU vitamin E is recommended for optimal immune enhancement in older adults, based on the available evidence 1.
From the Research
Immunostimulants
The most effective immunostimulants are still being researched, but several studies suggest that certain nutrients and natural products can enhance immune function.
- Foods rich in vitamins C, D, and E, as well as minerals like zinc and magnesium, have been shown to support immune function 2, 3, 4, 5
- Omega-3 polyunsaturated fatty acids, found in foods like fish and olive oil, have anti-inflammatory properties and may promote immunomodulatory properties 3, 5
- Probiotics and prebiotics can help reduce intestinal inflammation and downregulate hypersensitivity reactions 4
- Certain phytoconstituents, such as polyphenols and terpenoids, have been found to have immunomodulatory properties and can augment the immune response 6, 4
Natural Products
Several natural products have been found to have immunomodulatory properties, including:
- Plant-derived probiotics or micronutrients 6
- Melatonin, a multifunctional molecule with anti-inflammatory and immunomodulatory properties 4
- Bioactive compounds from plants, fungi, animals, microorganisms, and other natural sources 4
Dietary Recommendations
While there is no single most effective immunostimulant, a well-balanced diet that includes a variety of whole foods, such as fruits, vegetables, whole grains, and lean proteins, can help support immune function.