On Life Span Differences Between Primates
Via ScienceDaily, an interesting theory: "In spite of their genetic similarity to humans, chimpanzees and great apes have maximum lifespans that rarely exceed 50 years. The difference, explains USC Davis School of Gerontology Professor Caleb Finch, is that as humans evolved genes that enabled them to better adjust to levels of infection and inflammation and to the high cholesterol levels of their meat rich diets. ... these evolutionary genetic advantages, caused by slight differences in DNA sequencing and improvements in diet, make humans uniquely susceptible to diseases of aging such as cancer, heart disease and dementia when compared to other primates. ... Over time, ingestion of red meat, particularly raw meat infected with parasites in the era before cooking, stimulates chronic inflammation that leads to some of the common diseases of aging. ... ApoE3 is unique to humans and may be what Finch calls 'a meat-adaptive gene' that has increased the human lifespan.
However, the minor allele, apoE4, when expressed in humans, can impair neuronal development, as well as shorten human lifespan by about four years and increase the risk of heart disease and Alzheimer disease by several-fold. ApoE4 carriers have higher totals of blood cholesterol, more oxidized blood lipids and early onset of coronary heart disease and Alzheimer's disease."
Link: http://www.sciencedaily.com/releases/2009/12/091202153802.htm