We all age. From the moment we are conceived we start aging, and we continue to change throughout our lives. Aging is therefore really about the accumulative changes that occur throughout our lives. If we didn't change, then we wouldn't age (an embryo that is frozen doesn't age for example). The major change that occurs from the time we are conceived is cell division (mitosis and meiosis) and specification for acquistion of functions (differentiation) as we develop into an organism. These same events occur during adulhood to maintain our tissues, but as we get older, cell division becomes disrupted, leading to cell death and eventually the dysfunction of one or more bodily organs leads to the development of a disease. When an organ fails so severely than we can on longer maintain function, we die.
If we could prevent the disruption in cell division when we get older, then we could live longer. But what causes cells to start dividing aberrantly? This is caused by changes in our reproductive hormones. These hormones belong to the hypothalamic-pituitary-gonadal axis (our reproductive hormones) and include sex steroids (e.g. estrogens, androgens, progestagens), gonadotropins (follicle-stimulating hormone, luteinizng hormone), activins (inhibins and activins) and other hormones. All these hormones change dramatically as we age in both women (Fig. 1
) and men (Fig. 2
) as illustrated below. From an evolutionary perspective, since we are no longer reproductive, we are no longer needed by the species.Figure 1: Hormonal Changes in Women at MenopauseFigure 2: Hormonal Changes in Men During Andropause
Therefore, if we could keep out HPG axis in balalnce for longer, we could live a longer, healthier life. This is the goal of the Live Longer Foundation, to find strategies to keep our reproductive hormone axis in balance for longer.
For more information on the theory behind how we age click here
For an update on how the theory explains our age-related diseases please click here
To see a slide presentation of the theory and strategies to maintain hormonal balance click here