When
my second book “Silica Water the Secret of Healthy Longevity in the Aluminum
Age” was published in the fall of 2018 I had discovered only 5 demographically documented
blue zones. While visiting the Boston
Science Museum’s “Body Worlds” exhibit in the summer of 2019 my wife, Laurie Adamson,
pointed out a display panel of Blue Zones that had two new zones: one in
Pakistan and one in China.
I
quickly checked and found that the Blue Zone in Pakistan has not been
documented due to a lack of birth records.
However, the Blue Zone in West Hetchi, China that is referred to as
“Bama Yao” has been verified by two teams of demographers as having a much
higher centenarian density that neighboring regions. In 2018 this demographic data was
supplemented with two additional studies that led to a remarkably simple
conclusion that the only reason discovered for Bama Yao being a blue zone is
the high silica in drinking water as compared to neighboring regions.
I
have added the following section on West Hetchi, China as a 6th blue
zone to the book and will have a second printing in the fall of 2019. These 2018 studies provide more support
for the conclusion of my second book that OSA rich drinking water is a causal
factor of longevity. Of course I
would be compelled to add this 6th blue zone, even if these studies
did not support this conclusion.
West Hechi, China
Hechi is a prefecture located
in the north of the Guangxi region of China (see Figure 21). This prefecture is
in southern China on the border with Viet Nam. In western Hechi there are three
adjacent counties with much higher centenarian prevalences and longevity
indexes than three adjacent counties to the east in central Hechi. The
longevity counties are: Bama Yao, Fengshan, and Donglan with Bama Yao being a
super blue zone having the highest longevity index. The non-longevity counties
are: Huanjiang, Jinchengjiang, and Nandan. The Duyang Mountains separate the
longevity counties from the non-longevity counties (see Figure 21).
Figure 21 – Location of Hechi and its sampling sites (c) in Gurangxi (b), China (a) 461
Figure 21 – Location of Hechi and its sampling sites (c) in Gurangxi (b), China (a) 461
Bama Yao Blue Zone Verification – In 1992
Yang used data from the 1990 census and from a questionnaire survey conducted
in Bama Yao to analyze the population age 80 and over462. In May to
June of 1994 three Chinese demographers evaluated the quality of Yang’s survey
data by interviewing 67 out of 73 people over age 100 in Bama Yao463. Age records were available from birth
registers and generation rankings. They found that only 3 centenarians still
had spouses and 42 were women and 25 were men.
The people of Bama Yao are comprised of 13 ethnic groups with 17.4%
being Yao. The centenarian prevalence in the Yao population was 79.4 per
100,000 which indicated that Bama Yao is a blue zone. The demographers found
Yang’s survey data to be reliable.
Air Quality in Bama Yao - The centenarian prevalence and the longevity index of 31 regions in China, including Guangxi, were evaluated in 2016 with respect to air quality parameters464. Sulfur dioxide and particulates in the air 10nm or smaller were negatively correlated with centenarian prevalence and the longevity index, respectively. The three longevity counties and three non-longevity counties in Guangxi, including Bama Yao, are located in remote mountainous areas (see Figure 21) and therefore their air quality is well above average. Because all six counties have the same air quality it is not possible that air quality is a factor in the observed longevity in Bama Yao.
Air Quality in Bama Yao - The centenarian prevalence and the longevity index of 31 regions in China, including Guangxi, were evaluated in 2016 with respect to air quality parameters464. Sulfur dioxide and particulates in the air 10nm or smaller were negatively correlated with centenarian prevalence and the longevity index, respectively. The three longevity counties and three non-longevity counties in Guangxi, including Bama Yao, are located in remote mountainous areas (see Figure 21) and therefore their air quality is well above average. Because all six counties have the same air quality it is not possible that air quality is a factor in the observed longevity in Bama Yao.
Natural and Socioeconomic Factors in Bama Yao – Natural factors, such as temperature and altitude, and
socioeconomic factors, such as GDP, economic status, education, local
infrastructure, and health care facilities were evaluated spatially and
geographically with respect to 7 longevity indicators, including centenarian
prevalence and longevity index, in 109 selected counties and districts in
Guangxi465. The results indicated only a weak association with
longevity and natural factors, such as temperature and altitude, and
socioeconomic factors, such as GDP per capita. However, the average GDP in
Hechi was comparatively lower than other regions in Guangxi461. All the longevity and non-longevity counties
in West Hechi have similar topography and temperatures. Therefore, there is no natural of socioeconomic factor that stands out
as being a contributor to the longevity observed in Bama Yao.
Environmental Factors in Bama Yao – Trace elements in the soil and drinking water of Hechi were
evaluated temporally and spatially with respect to centenarian prevalence and
longevity index from 1982 to 2010461. The trace elements measured in the drinking
water sampled from 40 locations were: Pb, Zn, Cd, SO42-,
Mn, H2SiO3, Ca, Fe, Na, Mg, Li, Mo, and Se. The trace
elements measured in soil were: Sr, K, Mo, Fe, Co, Zn, Cu. The
only trace element in soil and drinking water that showed a significant (0.01 level)
positive correlation with both centenarian prevalence and longevity index is H2SiO3.
This trace element forms a hydrate in water called OSA (H4SiO4). For details see Table 4 at the beginning of
this chapter.
The following paragraph is
taken from the paper linking OSA to longevity in the three longevity counties,
including Bama Yao461: “As many centenarians live in rocky areas466,
most of the members of the longevity population in Hechi use the underground
water source as their primary water supply. These areas do not have much
surface water but do have abundant quantities of underground water from
underground caverns. For example, in 1982, 1990, and 2000, approximately 75% of
the centenarians in Bama County lived in rocky and semi-rocky areas and used
underground water as their main water source, and approximately 30% of the
underground water areas have sustained approximately 70% of the centenarians in
Bama over decades467. It can be inferred that the distinctive
tectonic settings of Hechi might have long-term impacts on longevity in this
region“.
Distinctive Tectonic Setting of West Hechi
The tectonic setting of
western Guangxi has been studied468. The Duyang Mountains that
separate the longevity from the non-longevity counties in Hechi lie along a geological
rift. Rifts occur linearly along the central axis of most mid-ocean ridges
where two tectonic plates are diverging and literally pulling apart the earth’s
crust. The result is a long wide valley to the west of the Duyang Mountains
where the three longevity counties are located called the Danchi Rift Trough468.
This area is distinctive because drinking water in this area is significantly
higher in OSA than the area just to the east of the Duyang Mountains461.
Deep-water ocean sediments
from the late Early Devonian to the late Permian have been uplifted in the
Danchi Rift Trough. The rocks in this area are mostly chert containing greater
than 70% silicon dioxide (SiO2) derived from non-terrigenous (i.e.
marine) sediments468. Sources of these marine sediments can be of
either biogenic or hydrothermal origin. The chert that underlies Bama Yao is
from the Middle Permian period469.
The source of silica in this
cert is predominantly biogenic being derived from siliceous organisms such as
radiolarians, diatoms, and siliceous sponges468. This cert is richer
in SiO2 than modern oceanic siliceous sediment and less rich in SiO2
as compared with the nearly pure SiO2 in chert from terrigenous
sources, such as volcanos468. Enrichment of biogenic SiO2
in chert is hypothesized to occur by a process called diagenetic silicification
that more than doubles the SiO2 in chert470. In this
process water enriched in OSA displaces calcium carbonate in chert making
biogenic SiO2 (a.k.a. opal)471.
Opal is a good source of OSA as
it is the most soluble solid silicate in sediments472. When water
becomes in contact with different types of opal sediments at pore depths
greater than 10cm the equilibrium concentration of OSA in the water is from 9.6
to 72ppm (100 to 750 mcM L-1)472. The unique conditions required for diagenetic silicification resulting
in opal deposits may account for the unique OSA rich well water found in the
Danchi Rift Trough.
References
461. Deng, Q., et al.; Understanding
the association between environmental factors and longevity in Hechi, China: A
drinking water and soil quality perspective; Int. J. Environ. Res. Public
Health; 15:2272:1-17 (2018)
462. Yang, J.; An analysis of the longevous population in Bama; Chin. J.
Popul. Sci.; 4(4):351-6 (1992)
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centenarians in Bama; Chin. J. Popul. Sci.; 8(4):385-94 (1996)
464.Song, W., et al.; Public health
in China: An environmental and socioeconomic perspective; March; 129:9-17
(2016)
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behind regional longevity in Guangxi, China: Is the centenarian ratio a good
enough indicator for assessing the longevity phenomenon?; Int. J. Environ. Res.
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466.Zhang, N,, et al.; Study on regional distribution of longevity and the
hair’s chemical elements content of the crowds in Bama county, Guangxi
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467.Liang, Z.; Understanding the longevity phenomenon in Bama; China Stat.;
(2004)
468.Hu, H., et al.; Depositional chemistry of chert during the late
Paleozoic from western Guangxi and its implication for the tectonic evolution
of the Youjiang Basin; Sci. China Earth Sci.; March; doi:
10.1007/s11430-012-4496-y (2012)
469.Qiu, Z., et al.; Geochemistry and sedimentary background of the
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10.1016/S0070-4571(09)06203-7 (2010)
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