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The basis for this news account, the recent paper by Morris et al.
(1) is the latest in a series of papers linking fish consumption to
reduced risk of Alzheimer's disease (AD). The first report on the topic
was based on an ecologic approach using AD prevalence and dietary supply
data for 11 countries (2). In addition to the finding on fish, cereals
were also identified as a risk reduction factor, while total fat and total
energy consumption were identified as major risk factors. While the use
of the ecologic approach was questioned, the ecologic approach was
recently vindicated for two fundamental ecologic findings from the 1970s,
fiber as a risk reduction factor for colon cancer and animal fat as a risk
factor for breast cancer (3). Thus, there is no good reason to dismiss an
epidemiologic study simply because it employs the ecologic approach. In
the case of (2), it was on the mark on all five major findings.
A number of papers have been published discussing fish as a risk
reduction factor for AD (4-9). The likely roles of fish, derived from the
n-3 oils, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA),
include better nutritional support for brain development and function, and
reduction of inflammation (10). However, as is well known, consumption of
fish does have its problems, not only due to other substances found in
fish such as mercury, pesticides, etc., but also due to global over
fishing and depletion of fish stocks (11). Nonetheless, the studies
regarding fish and AD not only offer clues into the etiology of AD but
provide a method of reducing the risk of developing this dread disease.
References
1. Morris MC, Evans DA, Bienias JL, Tangney CC, Bennett DA, Wilson RS,
Aggarwal N, Schneider J. Consumption of fish and n-3 fatty acids and risk
of incident Alzheimer disease. Arch Neurol. 2003;60:940-6.
4. Grant WB. Fish consumption, cancer, and Alzheimer disease. Am J
Clin Nutr. 2000;71:599-600.
5. Otsuka M. [Analysis of dietary factors in Alzheimer's disease:
clinical use of nutritional intervention for prevention and treatment of
dementia] Nippon Ronen Igakkai Zasshi. 2000;37:970-3. Japanese.
6. Otsuka M, Yamaguchi K, Ueki A. Similarities and differences
between Alzheimer's disease and vascular dementia from the viewpoint of
nutrition. Ann N Y Acad Sci. 2002;977:155-61.
7. Barberger-Gateau P, Letenneur L, Deschamps V, Pérès K, Jean-
François Dartigues JF, Renaud S. Fish, meat, and risk of dementia: cohort
study. BMJ 2002;325:932-3.
History of fish and Alzheimer's disease
The basis for this news account, the recent paper by Morris et al.
(1) is the latest in a series of papers linking fish consumption to
reduced risk of Alzheimer's disease (AD). The first report on the topic
was based on an ecologic approach using AD prevalence and dietary supply
data for 11 countries (2). In addition to the finding on fish, cereals
were also identified as a risk reduction factor, while total fat and total
energy consumption were identified as major risk factors. While the use
of the ecologic approach was questioned, the ecologic approach was
recently vindicated for two fundamental ecologic findings from the 1970s,
fiber as a risk reduction factor for colon cancer and animal fat as a risk
factor for breast cancer (3). Thus, there is no good reason to dismiss an
epidemiologic study simply because it employs the ecologic approach. In
the case of (2), it was on the mark on all five major findings.
A number of papers have been published discussing fish as a risk
reduction factor for AD (4-9). The likely roles of fish, derived from the
n-3 oils, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA),
include better nutritional support for brain development and function, and
reduction of inflammation (10). However, as is well known, consumption of
fish does have its problems, not only due to other substances found in
fish such as mercury, pesticides, etc., but also due to global over
fishing and depletion of fish stocks (11). Nonetheless, the studies
regarding fish and AD not only offer clues into the etiology of AD but
provide a method of reducing the risk of developing this dread disease.
References
1. Morris MC, Evans DA, Bienias JL, Tangney CC, Bennett DA, Wilson RS,
Aggarwal N, Schneider J. Consumption of fish and n-3 fatty acids and risk
of incident Alzheimer disease. Arch Neurol. 2003;60:940-6.
2. Grant WB. Dietary links to Alzheimer's disease. Alz Dis Rev.
1997;2:42-55
http://www.mc.uky.edu/adreview/Vol2/Grant/grant.pdf
3. Grant WB. Vindication for the ecologic approach, BMJ Rapid
Response, 26 July 2003, http://bmj.com/cgi/eletters/327/7408/181#34924
4. Grant WB. Fish consumption, cancer, and Alzheimer disease. Am J
Clin Nutr. 2000;71:599-600.
5. Otsuka M. [Analysis of dietary factors in Alzheimer's disease:
clinical use of nutritional intervention for prevention and treatment of
dementia] Nippon Ronen Igakkai Zasshi. 2000;37:970-3. Japanese.
6. Otsuka M, Yamaguchi K, Ueki A. Similarities and differences
between Alzheimer's disease and vascular dementia from the viewpoint of
nutrition. Ann N Y Acad Sci. 2002;977:155-61.
7. Barberger-Gateau P, Letenneur L, Deschamps V, Pérès K, Jean-
François Dartigues JF, Renaud S. Fish, meat, and risk of dementia: cohort
study. BMJ 2002;325:932-3.
8. Grant WB. Dietary links to dementia (fish). BMJ, 26 Oct 2002.
http://bmj.com/cgi/eletters/325/7370/932#26525
9. Berrino F. [Western diet and Alzheimer's disease] Epidemiol Prev.
2002;26:107-15. Review. Italian.
10. Grant WB. Reducing the risk of Alzheimer's disease: NSAIDs, fish
oils, and diet, BMJ electronic response, 31 July 2003.
http://bmj.com/cgi/eletters/327/7407/128#35160
11. Myers RA, Worm B. Rapid worldwide depletion of predatory fish
communities. Nature 2003;423:280-3.
Competing interests:
None declared
Competing interests: No competing interests