Give the gift that helps the aged, possibly including yourself …

Pu-erh Tea Delays Aging
by reversing age-related immunity loss

By Will Block

T ea is the world’s most popular beverage. Its discovery and usage date back four to five thousand years, although the first use of tea is lost in the mists of history and legends. What can generally be confirmed is that tea originated in Yunnan Province, within the southwest of China, an area embraced today by Myanmar and Vietnam. In the villages of Yunnan’s famous MengHai tea mountains, a special variety of tea known as Pu-erh is grown. There are trees over 1,000 years old that produce some of the most prized and collected Pu-erh teas in China and throughout the world. These can be very pricey, with some rare teas (as with a few rare wines) fetching hundreds of thousands of dollars—and for just one pound of tea! But far less costly Pu-erh teas are available, and these have been shown to possess many health benefits, perhaps surpassing all other teas.

Can Pu-erh delay or reverse aging in the elderly?

Of great interest in Chinese Traditional Medicine, Pu-erh tea has long been known for its preventative and curative properties. Among these, it is believed to protect the human body from obesity and from infections. It is also understood to delay aging in the elderly. Where is the evidence?* As our prior articles attest (see footnote), Pu-erh has been scientifically found to induce weight-loss and reduce obesity, to help fend against cancer, to protect kidney function, and possibly to ward off metabolic syndrome (see sidebar, “Pu-erh ideally fit for metabolic syndrome”). But nothing has given support to Pu-erh for anti-infection and delayed aging … until now.


* See “Cocktail of Selected Teas for Better Health and Weight Loss” in the April 2007 issue, “Pu-erh Tea—Exotic, Aged, and Anti-Fat” in the June 2007 issue, “Fighting Fat with Pu-erh Tea” in the July 2007 issue, “Pu-erh Tea Provides Statin Benefits” in the December 2007 issue, “Dramatic Weight-Loss” in the June 2009 issue, “Green Tea Blocks Influenza Reproduction” in the December 2009 issue, “Increase Cellular Energy Output” in the February 2010 issue, “Pu-erh Tea Offers Anti-Cancer Benefits” in the March 2012 issue, and “Pu-erh Tea Could Save Your Kidneys” in the June 2012 issue.



But nothing has given support to
Pu-erh for anti-infection and
delayed aging … until now.


Pu-erh ideally fit for metabolic syndrome

Researchers at the Graduate School of Integration of Chinese and Western Medicine, Beijing Medical University, Beijing set out to explore the regulative efficacy of Pu-erh tea extract on metabolic syndrome.1

Ninety patients with metabolic syndrome were randomly divided into two groups, the intervention group administered with Pu-erh tea extract, and the placebo group with placebo capsules. After 3 months of treatment, body mass index, waist hip ratio, blood lipids, blood sugar, immune and inflammatory index, and oxidation index of the patients with metabolic syndrome were tested and analyzed.

In the intervention group, the body mass index, waist-hip ratio, fasting and 2-hour postprandial blood glucose, serum total cholesterol, triglycerides, low density lipoprotein and apolipoprotein B-100 all decreased in the patients with metabolic syndrome. At the same time, high-density lipoprotein (the good cholesterol) levels increased and apolipoprotein A-1 showed a tendency to increase.

Serum C-reactive protein, tumor necrosis factor-α, and interleukin-6 (all measures of inflammation) were decreased in the intervention group. Interleukin-10 level was increased, malondialdehyde was decreased and superoxide dismutase was increased. These were significant differences.

Pu-erh tea demonstrated excellent potential in improving central obesity, adjusting blood lipid, lowering blood sugar, regulating immunity, and resisting oxidation. Pu-erh was found to adjust the metabolic syndrome of different clinical phenotypes to different degrees, and is ideally fit for early prevention of metabolic syndrome.

Reference

  1. Chu SL, Fu H, Yang JX, Liu GX, Dou P, Zhang L, Tu PF, Wang XM. A randomized double-blind placebo-controlled study of Pu’er tea extract on the regulation of metabolic syndrome. Chin J Integr Med 2011 Jul;17(7):492-8.

The chemistry of Pu-erh

Pu-erh tea is produced from the leaves of Camellia sinensis var. assamica, the aforementioned tea variety from Yunnan. This province is especially rich in natural resources and has the largest diversity of plant life in China. The animals, considered as a group, are nearly as diverse. Yunnan Province has less than 4% of the land of China, yet contains about half of China's birds and mammals. Yunnan is home to, most notably, the Indian bison, a giant forest-dwelling ox, the tiger, and the Asian Elephant.


Immunosenescence is defined as
the state of deregulated
immune function that contributes to
the increased susceptibility to
infection, cancer, and
autoimmune disease.


Pu-erh tea reflects the natural diversity of Yunnan. In its creation, it is categorized either as crude Pu-erh tea or ripened Pu-erh tea—dependent on the method of fermentation processes that are unique to this tea. Crude refers to Pu-erh that undergoes a gradual darkening through exposure to the environmental elements, where ripened pu-erh has gone through an accelerated post-fermentation process. Also unique to Pu-erh is that it develops with age, and chemical studies have revealed that its main molecular components are tea polyphenols, flavanols, theabrownin, polyphenols, statins, and tea polysaccharides. In recent years, numerous biomedical studies have shown that Pu-erh tea possesses multiple bioactivities such as the ability to reduce blood lipids and cholesterol as well as body fat, along with antioxidative and anti-inflammatory properties.


Without sufficient naïve T cells,
the body cannot adequately deal with
the threat of new pathogens,
which upon invading the body,
increase susceptibility to infection,
morbidity, and death.


Immunosenescence and aging

There have been no prior Pu-erh studies that have investigated its effects in reducing or limiting infection in the elderly. Nor has its ability to reduce infection been addressed or experimentally confirmed. Nor has there been any clarity regarding the mechanisms associated with these effects. Among the most salient aspects of aging is the decline in immune functions known as immuno­senescence, which is defined as the state of deregulated immune function that contributes to the increased susceptibility to infection, cancer, and autoimmune disease. Although many kinds of cells and factors are involved in the process of immunosenescence, the key point is that the fraction of naïve T lymphocytes in the adaptive immune system declines progressively with aging, while the proportion of memory T lymphocytes (the ones that “think” they know everything) expands.

Naïve T lymphocytes identify and target new pathogens

T lymphocytes belong to a group of white blood cells known as lymphocytes and play a central role in cell-mediated immunity. They can be distinguished from other lymphocytes, such as B cells and natural killer cells (NK cells), by the presence of a T cell receptor on the cell surface. They are called T cells because they mature in the thymus. There are several subsets of T cells, each with a distinct function.

Chinese gifts for happy occasions

In China, the etiquette of gift giving is different than in the U.S. One of the appropriate times to gift is in honor of a visit. When giving a “visiting” gift, it is appropriate to find something the whole family can use, for example, food or tea. In China, tradition dictates that the recipient not appear greedy. Therefore, he or she will often decline a gift one or two times before accepting. If you’re the giver, offer it again until it is accepted. Be aware that in business, your gift may be absolutely refused, so don’t press beyond several refusals. And don’t be offended if the person does not open the gift in front of you. Chinese people do not usually open a gift in front of the giver. It might embarrass them. They will open it later, then call or write to thank the person for the gift. Wrap the gift well, uniquely. Use red colored ribbons to wrap a gift for general and happy occasions.

Of these, the naïve T cells are those T cells that have never been exposed to the antigens to which they are inherently programmed to respond. As naïve T cells become depleted, one of the principal changes in cellular immunity with aging, they can no longer serve their critical and indispensable role in inducing adaptive immunity and antibody production. In effect, naïve T lymphocytes do not allow passage for new pathogens; they must show their IDs. Without sufficient naïve T cells, the body cannot adequately deal with the threat of new pathogens, which upon invading the body, increase susceptibility to infection, morbidity, and death.


These data suggested that the Pu-erh
tea reversed the immunosenescence
by restoring the immune deficiency
and decreasing inflammation.


Additionally, the activated lymphocytes such as CD8 T cells (CD8+CD28+ cells) and NK cells—which are the front line of immune cells attacking and destroying the virus hosted cells, cancer cells, and various pathological microorganisms—also decline with aging.

Pu-erh’s gift to its users: enhanced immunity

In a new study, just published this month in the journal Food Chemistry, Chinese researchers employed a strain of the senescence-accelerated mouse (SAM-P8), which has a shorter life span than the senescence-accelerated mouse resistant sub-strain (SAM-R1), which has a normal aging process and life span.1 Because of their early onset of aging, SAM-P8 mice illustrate immunological deregulated alterations and neurological senescence in the hippocampus. This part of the brain belongs to the limbic system and is important for the consolidation of information from short-term memory to long-term memory, along with spatial navigation. The SAM-P8 strain of mouse is widely used as a naturally developed animal model to study aging and anti-aging therapeutics.


† Curiously, testosterone can improve a senescent hypothalamus in some instances.


In the Chinese study, the researchers examined the effects of aqueous extracts of ripened and crude Pu-erh tea on SAM. After oral administration of either Pu-erh tea extract for 4 weeks, the proportions of naïve T lymphocytes in the peripheral blood or spleen were analyzed. In addition, activated CD8 T cells, NKs, and cytokine interleukin-6 (IL-6) in SAM-P8 were measured.


The depleted CD8 T lymphocytes
activated effect in the aged mice
was replenished remarkably.


The senility-prone SAM-P8 mice were administered individually with crude or ripened Pu-erh tea at 125, 250, or 500 mg/kg. Both versions of Pu-erh tea significantly increased the fractions of naïve T lymphocytes, CD8 T cells, and NK cells in the peripheral blood, but decreased the levels of IL-6 in aged mice. IL-6 is an inflammation marker for clinical infection. These data suggested that the Pu-erh tea reversed immunosenescence by restoring the immune deficiency and decreasing inflammation. Thus, long term drinking of Pu-erh tea may be beneficial for the aged population in terms of increasing the body’s resistance to infection and cancer.


‡ The 500 mg/kg dose is the equivalent of about 3 g for a 165-lb human.


First to show anti-aging benefits in aged mouse model

This study is the first to demonstrate beneficial effects of oral administration of aqueous Pu-erh tea extract in an aged mouse model. It indicates that Pu-erh tea is able to increase the proportions of naïve T lymphocytes significantly in the peripheral lymphocyte pool. In addition, the depleted CD8 T cells activated effect in the aged mice was replenished remarkably. For the innate immune system, NKs in the peripheral blood and spleen pool was also noticeably restored, and the level of inflammation indicator IL-6 was reduced significantly.

In summary …

Infectious diseases, malignancies, inflammatory, and autoimmune disorders are major causes of morbidity and mortality in the aged population. Increased susceptibility to these aging-related diseases may stem from underlying dysfunctions of the aged immune system. Aging of the immune system involves the progressive alterations in both humoral (antibodies secretion) and cellular-mediated immunity.

The principal changes in cellular immunity with aging are the depletion of naïve T lymphocytes, which plays a critical and indispensable role in inducing adaptive immunity and antibody production. Therefore, the lack of naïve T cells will pose the aged organisms with the threat of new pathogen’s invading and increased susceptibility to infection. Other research has shown that interventions such as calorie restriction and vitamin E supplementation can increase the peripheral proportion of naïve T cells, which consequently decrease the frequency of infection, tumors, and inflammatory illnesses, as well as prolonging life span.


Infectious diseases, malignancies,
inflammatory and autoimmune
disorders are major causes of
morbidity and mortality in
the aged population.


In the present experiment, SAM-P8 showed significant reduction of naïve T lymphocytes compared with the younger counterpart, SAM-R1 mice. After administration of Pu-erh tea, the naïve T cells both in peripheral blood and spleen were restored to strengthen the aged immune function against infection and cancer.

Resists infection and tumors

Besides the lymphocyte quantities, the body’s resistance against infection or tumors also seems to rely on the activation status of lymphocytes. Some studies have shown that obstruction of T lymphocyte activation may contribute to the immunity defects associated with aging. The Chinese data demonstrate that the activated effector CD8 T cells were decreased in the senescence-prone SAM-P8. This sub-group of effector T lymphocytes plays an important role in mediating the immune destruction of virus infected or cancer cells. However, when given Pu-erh tea, the aged mice were able to augment the percentage of CD8 T cells, indicating that this effect may be another pathway for inhibiting infection and cancer in the elderly.


The principal changes in
cellular immunity with aging
are the depletion of naïve T
lymphocytes, which plays a
critical and indispensable role in
inducing adaptive immunity and
antibody production.


Immune surveillance

In addition to adaptive immunity, NKs have been confirmed to exert immune surveillance on invaded virus and emerged cancer cells. In the Chinese study, the NKs in the aged mice declined dramatically, but after administration of Pu-erh tea to the SAM-P8 groups, the NKs were remarkably regained in the peripheral pool. Pu-erh tea demonstrated restorative effects by replenishing the NKs and resuming the naïve T and activation T cells in the aged adaptive immune system.

The improvement of bone-marrow function

Multiple studies show that the hematopoietic stem cells (multipotent stem cells that give rise to all the blood cell types) and progenitors in the bone marrow may suffer from the endogenous and microenvironment insults, undergoing gradual decline of function in self-renewal, differentiation, and proliferation. This leads to the shrinking output of various cells including T lymphocytes and NKs. The Chinese researchers used one of the main markers of hematopoietic stem cells and progenitors in mice, to observe the new output cells in the blood from bone marrow.

The results show that the marker in the blood of SAM-P8 mice was reduced, compared with SAM-R1 mice. This change is in parallel with alterations of naïve T lymphocytes and NKs in the peripheral pool, suggesting that improving bone marrow function may be one of the underlying reasons that Pu-erh tea can rebuild the peripheral immune cellular components.


Improving bone marrow function may
be one of the underlying reasons that
Pu-erh tea can rebuild the peripheral
immune cellular components.


Pu-erh protects against cancer and limits its progression

As previously mentioned, numerous studies have reported that Pu-erh tea, along with other types of tea, has been demonstrated to have beneficial effects in protecting against cancer and limiting its progression. Tea polyphenols have also been shown to inhibit oxidative stress-induced cancerous mutations, far more so for green tea than black tea, because of the high contents of EGCG and EGC in green tea. However, studies have shown that ripened Pu-erh tea has demonstrated similar activity as crude Pu-erh tea, despite significant differences of the tea’s polyphenol contents. Thus, there must be other active compounds in Pu-erh tea with respect to the developing immunity of the elderly.

Aging by immune deficiency and chronic inflammation

Accumulating studies show that aging is not only manifested as immune deficiency, but chronic inflammation as well. With aging, the pro-inflammatory cytokines, such as IL- 6, TNF-a, IL-1b and C-reactive protein increase significantly. These changes are further aggravated in the age related diseases such as Alzheimer’s disease, Parkinson’s disease, amyotrophic lateral sclerosis, and atherosclerosis. This phenomenon is consequently known as “Inflamm-aging.”

Thus, an agent that can reverse immunodeficiency and decrease chronic inflammation in the elderly is much to be desired. Ring the bell for Pu-erh. And don’t forget its hypolipidemic and weight slimming effects. Make your tea time, Pu-erh time, and reap the benefits.

Reference

  1. Zhang L, Shao WF, Yuan LF, Tu PF, Ma ZZ. Decreasing pro-inflammatory cytokine and reversing the immunosenescence with extracts of Pu-erh tea in senescence accelerated mouse (SAM). Food Chem 2012 Dec 15;135(4):2222-8. doi: 10.1016/j.foodchem.2012.07.033. Epub 2012 Jul 15.


Will Block is the publisher and editorial director of Life Enhancement magazine.

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