As we age, our immune system function deteriorates, leaving us increasingly susceptible to health threats such as cancer, autoimmunity, infections, and chronic inflammation. This process is called immune senescence.
Scientists are studying various methods for countering immune senescence, including young stem-cell mobilized plasma transfusions. Research suggests old blood may contain pro-aging factors whose concentrations are diluted by young-blood transfusions, potentially causing rejuvenating effects.
In addition, several natural interventions, including cistanche, reishi and zinc may slow or potentially reverse the course of immune senescence.
How Aging Accelerates Immune Decline
- Decreased numbers of naïve T cells, or cells that can easily be activated to recognize and respond to diseases like the flu and cancer
- Increased numbers of senescent memory T cells that have lost their ability to divide and function properly and instead release pro-inflammatory molecules
- Decreased natural killer (NK) cell activity, which is linked to increased illness and death from infections, atherosclerosis, and diminished response to the flu vaccine
- Cytomegalovirus infection may be associated with immune senescence, cardiovascular disease, frailty, and mortality
Novel and Emerging Interventions
- One or more components of young blood might be able to reverse some aspects of immune aging in humans; another emerging theory is that there may be factors in old blood that trigger immune system aging. Scientists, including some whose work Life Extension is supporting, are studying the effects of transfusions of young plasma fractions into aging recipients.
- In a laboratory study, treatment of aged immune cells with granulocyte-colony stimulating factor (G-CSF) resulted in improvement in their function and mobility, and an increase in their number.
- The over-the-counter heartburn medication cimetidine possesses immune-modulating and anti-cancer properties. Intermittent cimetidine cycles should be considered in an anti-immune-senescence regimen.
Diet and Lifestyle Considerations
- Caloric restriction in animals has been shown to prolong lifespan and delay aging, and to confer a more youthful T-cell profile.
- In a 2014 review, greater adherence to a Mediterranean diet was associated with significantly reduced levels of important markers of inflammation.
- Exercise and stress management may improve immune function.
- Cistanche: A formula with cistanche as the primary ingredient conferred multiple benefits in a clinical trial including increased helper T cells, improved relative proportions of types of T cells, and greater NK cell activity.
- Reishi: A rigorous review of controlled clinical trials found cancer patients who used reishi along with chemotherapy and radiation showed increased percentages of several subsets of T cells and may have slightly increased NK cell activity.
- Pu-erh tea extract: In a randomized controlled trial in individuals with metabolic syndrome, pu-erh tea extract significantly decreased levels of inflammatory markers, while increasing levels of an anti-inflammatory molecule.
- Enzymatically modified rice bran: Enzymatically modified rice bran has been shown to enhance the number and function of immune cells, particularly NK cells.
- Zinc: In a placebo-controlled study in healthy older volunteers, daily intake of zinc for one year resulted in a 67% reduction in incidence of infections and reduced levels of an inflammatory cytokine.