What Really Causes Alzheimer's Disease - Soil and Health Library

techniques, medical researchers must still rely on such problematic
diagnosis by exclusion “until the characteristic lesions
of Alzheimer’s disease can be documented on pathological examination
of the brain.” 26 Since so few autopsies are conducted
on the elderly, it is very difficult to obtain accurate data capable
of establishing variations in the incidence of Alzheimer’s
disease over time. As a result, it is hard to determine how
much, if any, the risk of developing the disease has changed in
specific age groups since it was first recognized in the early
20 th century by Alzheimer. 27
This problem of diagnosis without autopsy does not mean that
there have been few surveys of the demented. Indeed, in 1998,
Ineichen 28 identified over 100 epidemiological surveys of dementia
published from a wide variety of countries. What can
all this information tell us about the age-adjusted incidence of
Alzheimer’s disease? Is it increasing? This is still a very difficult
question to answer with any certainty. There can be no
doubt, for example, that the age-adjusted mortality rates for
Alzheimer’s disease have risen over the past decade in both
Arizona 29 and Missouri. 30 However, how much this is the result
of a true increase in incidence of the disease in particular age
groups, and how much it simply reflects improved diagnosis,
changes in public and physician attitudes towards Alzheimer’s
disease, alterations in the coding and classification of dementia,
and decreases in other leading causes of death is very
unclear. 31
Studies of temporal change in dementia incidence really require
repeated surveys of the health of large populations. As a
consequence, they tend to be rare because they are complex,
costly, and involve extended fieldwork over long periods of
time. The most robust such study comes from the Swedish
Island of Lundby 32 whose entire population of approximately
2,500 was examined several times between 1947 and 1972.
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