One symptom of the aging process that we all learned about in anatomy and physiology is immune senescence, the breakdown of the immune system and its functioning. There is a reduction of bone marrow production of immune cells, and thus a reduced supply of immune cells; a reduction in their potency and loss of control over inflammation. This increased inflammation also drives aging via increased tissue damage, and is why many people now call aging "inflammaging" (an assignment on this scored me a 95% and I may have taught the teacher a few things). Besides "normal aging", it also raises the risk of age-related diseases such as arthritis, osteoporosis, cardiovascular issues and cancers (Age (Dordr)). Fortunately, there are natural medicines, such as extracts of Pu-erh tea, reishi mushrooms and Cistanche, that can fight immune senescence.
Pu-erh tea, native to China's Yunnan Province and consisting of fermented ripe tea leaves, is better than it sounds. Traditionally prescribed to emperors for longevity, supplementation with Pu-erh tea extract was shown to significantly reduce inflammatory markers in patients with metabolic syndrome. Levels of IL-6 fell by 21%, TNF-alpha fell by 23%, CRP fell by 26% and levels of anti-inflammatory IL-10 rose by 34% over the three-month duration of the study (Chin J Integr Med).
IL-6, written in full as Interleukin-6, increases risk of death by 25% in those aged around 60, but increases it by 118% in people over 80, when its levels are high (Life Extension). Deaths from cardiovascular diseases and obstructive airway disease, as well as the risk of osteoarthritis and macular degeneration, are also increased by elevated IL-6. Another inhibitor of IL-6 is turmeric, which has a high volume of research surrounding its effects. High CRP, or C-reactive protein, increases the risk of death by 158% in people over 80.
Reishi mushrooms, however, lack the bone marrow stimulating properties of Pu-erh tea, but are still able to resurrect the youthful patterns of circulating immune cells. It can also reduce IL-6 and raise IL-10 (Life Extension). Reishi can also enhance numbers and activity of the B lymphocytes. These produce antibodies, assist the macrophages/monocytes and present antigens to other B and T lymphocytes, therefore are indispensable to immune function (Life Extension). In addition, reishi mushrooms also have direct effects against Herpes simplex (cold sores), Herpes zoster (chickenpox and shingles), influenza viruses, Epstein-Barr viruses, and hepatitis B (Life Extension).
Cistanche is a new one for me. A tough desert plant, this has also been traditionally used for longevity. This has been shown to reduce inflammation in animal models of intestinal inflammation, while increasing numbers of immune cells such as macrophages and natural killer cells (Life Extension again). Cistanche also reduces IL-6, IL-4 and TNF-alpha, stimulates bone marrow production of white blood cells, increases numbers of the more versatile "naïve" T cells and reduces allergy markers such as histamine (LE). Interestingly, these effects have been found to lead to an increased life expectancy in mice bred to age faster (Evid Based Complemet Alternat Med). While control mice lived for an average of 325 days, all dead by around 385 days, the mice given Cistanche lived for an average of 375 days - an increase of 15.4%! The last of the mice given low-dose Cistanche lived until about 410 days, but mice in the medium and high dose groups still had survivors at 425 days. Back to the 15.4% increase - if this was applied to humans, someone with an original life expectancy of 81 years (around the average for Australia) would instead have a life expectancy of 93 years. Aside from the evidence suggesting that aging actually stops in the 90s (that would be primarily Michael Rose's research), perhaps amplifying such gains, there is a lot you could do with an extra 12 years of life.