Research indicates a decrease in mortality rates among women in the 20th century. The life expectancy gap between various races and people has narrowed significantly, with the gender gap becoming wider. This affects sex ratio, and social and demographic factors like marriage and valuation of pension plans (Reijo & Chen 2013, p. 118).
Men are believed to die younger due to stressful lives than women. If this was true, the gap could be decreasing significantly as more women assume jobs that were previously believed to be for men. Also, women get stressed as they work outside the home on top of the stresses at home. However, despite women living longer than men, they are less healthy than men at old age. Biologically, women are considered to be more fit than males due to hormonal and genetic differences (Eskes & Clemens 2007, p. 126).
Theoretically, aging results from the gradual accumulation of tiny faults and damages to cellular components like DNA and protein. Women are believed to have a biological advantage due to their involvement in reproduction. Women are involved in reproduction for longer than males. Also, it is argued that iron may cause early deaths. The only way to lead out the iron is through blood, which is normally an advantage in females as a result of menstrual cycles. High accumulations of iron raise the toxic level as iron is an oxidizing element that has the potential of increasing the heart diseases and risks of cancer (Ginter & Simko 2013, p. 45).
Women have 2 X-chromosomes and men have X and Y chromosomes. The second X chromosome in women acts as a backup after the other gene becomes damaged. Recent hypotheses indicate that the Y gene is normally toxic and acts as a source for other gene products accelerating aging. Specifically, women have microRNA and X chromosomes in their ribonucleic acid. Most microRNA is found in the X chromosome, .and this indicates that the genetic deck is stacked in favor of the women.