Chronic disease spectrum in indigenous peoples
Ring and Brown are incorrect in generalising that “indigenous peoples
tend to have higher mortality right across the disease spectrum, including
“circulatory conditions”,  as this does not apply to coronary heart
American Indians have lower age-adjusted mortality rates for
cardiovascular disease than the US population as a whole; Alaska
Indians and Eskimos have lower cardiovascular mortality and less severe
and extensive coronary and aortic atherosclerosis than Alaska whites;
and CHD is relatively uncommon in South Africa’s black population.
An explanation offered for this reverse disparity is that, in
comparison with non-indigenous people in a population, a low prevalence of
persistent lactase activity in adulthood and an associated lower intake of
lactose from milk are protective. This does not apply to hypertension
and its complications, so the term “circulatory conditions” conceals the
reverse disparity with CHD.
A single report on Australian Aborigines gives a prevalence of
persistent high lactase activity of 16%. We need to know their mortality
rate, not from “circulatory conditions”, but from CHD separately to that
of hypertension and consequential heart failure, stroke and renal failure.
1. Ring I, Brown N. The health status of indigenous peoples and
others. BMJ 2003;327:404-05.
2. Segall JJ. Digestive and nutritional factors may explain lower
prevalence of coronary disease in indigenous peoples. BMJ 2003;327:449-50.
3. Lee ET, Welty TK, Fabsitz R, Cowan LD, Le N-A, et al. The Strong Heart
Study. Am J Epidemiol 1990;132:1141-55.
4. Newman WP, Middaugh JP, Propst MT, Rogers DR. Atherosclerosis in Alaska
non-natives. Lancet 1993;341:1056-57.
5. Seftel HC. The rarity of coronary heart disease in South Africa
Blacks. S Afr Med J 1978;54:99-104.
Competing interests: No competing interests