So far, only caloric restriction with adequate nutrition (CRAN) has been shown to retard aging in animals and possibly humans. How many obese elderly people do we see on the street? Only a few and this possibly gives credence to CRAN. In nearly all religions, periodic fasting is recommended and it seems that our wise ancestors were aware of this fact. It is also equally important to remain active by doing regular physical (and mental) exercises. Smoking should be discouraged and 'challenges', such as trauma and infection are to be tackled at the earliest; since the elderly are 'homeostenosed'. The importance of good eating habits can not be overemphasized. We must ensure adequate intake of vitamins by ingesting adequate fruits and vegetables. They not only supply us with vitamins but also the dietary fibers in them ensure regular bowel habits as well as in fighting cancers, such as cancer of the colon. They also contain antioxidants in them, such as lycopene (in tomatoes); apart from vitamins A,C,E and various others. Water intake should be adequate to flush out the toxins of metabolism.
Retarding aging by giving drugs seems fascinating. It has indeed been suggested that the following be taken in a supervised way, in order to live a healthy and long life. Vitamins C, E, B5 (pantothenic acid), carnitine, alpha lipoic acid, coenzyme Q10, deprenyl (eldepryl), flavonoids such as carotene, folic acid, selenium etc has been proposed in this regard. These substances act by scavenging free radicals, fighting oxidation, altering glycation and metabolism and by other factors.
To conclude, it must be remembered that, our motto should be adding lives to years and not merely adding years to lives. Hence the elderly (in fact all of us) should make lifestyle changes and it is our duty to make our senior citizens comfortable, in our society.
Physiology is like software, while anatomy the hardware in human bodies. Physics, including biophysics, can explain many mechanisms of these 'software operations', in physiology and other allied medical disciplines. This blog emphasizes on this analytical approach.
Showing posts with label vitamin. Show all posts
Showing posts with label vitamin. Show all posts
August 25, 2007
August 17, 2007
Aging, Mitochondria and Free Radicals
Molecules comprises of atoms, which have electrons revolving around their nuclei (much like the planets around the sun, a star; though the forces that govern their rotation are entirely different). To the utter vexation of the electrons, Wolfgang Pauli, a great scientist had laid down his 'exclusion principle' which states that no 2 electrons (fermions) can have the same quantum number. Thus, if 2 electrons are occupy an orbital, they must have opposite spins! They (electrons) still do not complain, as long as they stay paired (like husband and wife : opposite spins!) but when they stay single (unpaired), and uncared for (unshared: not contributing to bond formation), they become agitated and highly reactive. Free radicals are molecules that contain unshared electrons and being highly reactive, pounce on nearby molecules and harm them.
Superoxide anion, hydroxyl radicals and nitric oxide free radicals are some examples. They are grouped into a common category called ROS (Reactive Oxygen Species), since all these free radicals contain oxygen in their molecules. To fight against these free radicals our body has developed its own machinery: speroxide dismutase (SOD), catalase (CAT), glutathione peroxidase are some examples. Vitamin C, E, A and some other nutrients assist them in free radical scavenging and serve individually as antioxidants.
Free radicals particularly attack the DNA, both in the nucleus (nDNA) and in the mitochondria (mtDNA), mitochondria being particularly vulnerable due to its inefficient repair mechanism, and also that the mtDNA is not covered by protective histone coverings. As a result of this assault by free radicals, mutations of genes and even deletions occur in the DNA, specially in the mitochondria. Oxidative phosphorylation, the process by which mitochondria produces ATP (the energy currency of the cell; produced in the mitochondria and disposed off to other locations in the cell, for energy utilization, as if portable batteries), is compromised, ATP production diminishes and the cells begin to die. Thus cumulative genetic damage results in aging.
Related Article: Aging: From a General and Evolutionary Perspective
Superoxide anion, hydroxyl radicals and nitric oxide free radicals are some examples. They are grouped into a common category called ROS (Reactive Oxygen Species), since all these free radicals contain oxygen in their molecules. To fight against these free radicals our body has developed its own machinery: speroxide dismutase (SOD), catalase (CAT), glutathione peroxidase are some examples. Vitamin C, E, A and some other nutrients assist them in free radical scavenging and serve individually as antioxidants.
Free radicals particularly attack the DNA, both in the nucleus (nDNA) and in the mitochondria (mtDNA), mitochondria being particularly vulnerable due to its inefficient repair mechanism, and also that the mtDNA is not covered by protective histone coverings. As a result of this assault by free radicals, mutations of genes and even deletions occur in the DNA, specially in the mitochondria. Oxidative phosphorylation, the process by which mitochondria produces ATP (the energy currency of the cell; produced in the mitochondria and disposed off to other locations in the cell, for energy utilization, as if portable batteries), is compromised, ATP production diminishes and the cells begin to die. Thus cumulative genetic damage results in aging.
Related Article: Aging: From a General and Evolutionary Perspective
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