Aging successfully: a genetic perspective

Healthy human aging: intrinsic and environmental factors

Abstract This review is an attempt to compile current knowledge on concepts and transformations that occur naturally in the human body and that characterize what is defined today as biological aging with quality of life and longevity. Many authors define natural aging as a continuous and uninterrupted process, which occurs in the human body causing structural and functional changes, classified as: cumulative, progressive, intrinsic and deleterious (CUPID). Usually these changes begin early in life and culminate in physical death. Genetic, chemical and biochemical changes lead to progressive degeneration of cells, tissues and organs, body systems and the organism as a whole, leading to loss of structures and functions due to aging. All these changes were discussed in some detail in the review here presented. We concluded that aging is not genetically determined, resulting in the accumulation of cellular and tissue damage, particularly in chromatin and DNA within cells, in addition to structural and bioactive proteins that command the general metabolism. Environmental factors such as feeding (nutrition) and lifestyle were also discussed.

Distribution of apolipoprotein E alleles in the Omani population

OBJECTIVE

To estimate the apolipoprotein E (apo E) allele distribution in the Omani population and to compare them with those of other populations.

SUBJECTS AND METHODS

One hundred and sixty-two healthy Omanis of Arab Bedouin origin were genotyped by polymerase chain reaction followed by restriction fragment length polymorphism.

RESULTS

The apo E allele frequencies were: epsilon2, 0.052; epsilon3, 0.886; epsilon4, 0.062. This pattern of distribution, characterized by the lowest epsilon4 and among the highest epsilon3 allele frequencies in the world, was very similar to that of Arabs, Southern Europeans of the Mediterranean basin, Indians, and Japanese populations.

CONCLUSION

The results indicate that the allelic distribution of apo E in healthy Omanis is characterized by low Apo epsilon4 and high epsilon3 allele frequencies similar to those of other Arab, Southern European, Japanese and Indian populations. The homogeneous distribution of apo E alleles in this group of populations might have been influenced by diet and/or genetic admixture.

Iron as the malignant spirit in successful ageing

Iron enhances the production of the highly reactive and toxic hydroxyl radical, thus stimulating oxidative damage. Iron has been associated with a number of oxidative injury-dependent, age-related conditions and diseases. Indeed, oxidative injury is a major factor of (accelerated) ageing. This commentary reviews part of the existing literature on iron's deleterious effects, particularly in the context of ischemia-reperfusion injury and cardiovascular, brain and muscle diseases as well as skin ageing. Furthermore, the advantages of iron chelation are presented. Indeed, iron chelation or deprivation has been shown to act as a potent anti-oxidant in a variety of animal models of human diseases, preventing oxidative stress to tissues and organs. Iron chelators favor successful ageing in general, and when applied topically, successful skin ageing. It has also been proposed that gender-related differences in iron status are responsible for the increased longevity of women as compared to men. Despite this evidence, the role of iron in ageing and the possibilities of pharmacologically targeting iron have remained essentially unexplored. Iron thus appears as the "malignant spirit" in successful ageing.