Previous experience throughout the world has suggested that certain po
pulations have a genetic predisposition to the development of non-insu
lin dependent diabetes mellitus (NIDDM) in response to a changing envi
ronment. In particular, Native American admixture presents a genetic r
isk for NIDDM and modernization represents an environmental change whi
ch amplifies the risk. This review discusses these factors with respec
t to the situation in Mexico, where a significant portion of the popul
ation is Native American and industrialization is producing rapid envi
ronmental changes. Perhaps, with foresight, the epidemic of NIDDM whic
h has struck Native Americans in the United States and indigenous grou
ps in the South Pacific may be averted in Mexico. Specific aspects of
the traditional Mexican lifestyle which could be retained to protect a
gainst NIDDM are presented.