ANTI AGING

BY: CHERYL MAY CHONG130110113038

Rate of Living Theory

Aging is caused by the rate of metabolism because the mechanisms of metabolism cause damage.

Basal Metabolic Rate (BMR)

Basal Metabolic Rate (BMR) Basal Metabolic Intensity (BMI) = body mass

BMI rapid ageing shorter lifespan

The greater an organism’s basal metabolic rate, the shorter the life span.

Free radicals or other metabolic by-products play a role in senescence.

ExampleAnimals with the most rapid metabolisms tend to have the shortest lifespans, i.e, birds have a shorter lifespan than humans.

Studies examining the relationship between metabolic rates and longevity have produced inconsistent results, limiting the usefulness of this theory.

LIVE FAST DIE YOUNG!

Free Radical TheoryWhat is a Free Radical (FR) ? FRs are atoms or molecules with an unpaired electron

e.g. 02 + e = *O2-

(superoxide radical)

Small FRs in the body include:

hydroxyl radical (*OH)nitric oxide radical (*NO)

Larger FRs contain an organic molecule, R:

alkoxyl radical (*RO) peroxyl radical (*ROO)

Reactive Oxygen Species (ROS)

ROSs are not FRs but are highly reactive substances:

e.g. Hydrogen peroxide (H2O2)Peroxynitrite (ONOO-)

Peroxynitrite is the fastest acting and most toxic to the body.

Damage caused by FRs is the main reason for aging and age related diseases.

There is no clear idea as to which, if any, of the the many types of FR are the most important in promoting ageing.The theory is based upon several observations

+ve correlations:

metabolic rate vs FR production age vs “

cataracts vs “

-ve correlations:

mean Longevity vs FR production

FRs damage body molecules by taking electrons from molecules - oxidation

Oxidation alters the shape of molecules which often leads to malfunction.

FRs appear to cause damage to DNA, lipids & proteins

FR damage can cause:

- inflammation- excess blood clotting- cataracts- atherosclerosis

To defend against the effects of FRs the body has mechanisms to eliminate them and to remove and repair molecules damaged by them.

Substances called ANTI-OXIDANTS destroy FRs by helping to create pairs of electrons.

Examples of anti-oxidants:

- vitamin E- vitamin C- beta carotene

The body also makes its own anti-oxidants:

- melatonin- albumin- uric acid

The body also makes enzymes to prevent FR Production and speed up FR elimination.

Selenium is a vital dietary component as it helps an enzyme (glutathione peroxidase) remove H2 O2.

Not all free radicals cause damage. You use free radicals as part of your

immunological response system. Macrophages engulf bacteria Free radical reactions produced inside the

macrophage oxidize and kill bacteria.

Question: Does it make any biological sense to try to eliminate all free radicals in your body by taking supplements?

But…

Can you delay or stop aging by taking vitamins and other free radical

scavengers?

There is no evidence-based proof that dietary supplements delay or stop aging. This is a big area of nutrition quackery. BEWARE!

Remember, there is a lot of evidence-based proof that taking some supplements INCREASES cancer rate, for example lung cancer. Smokers who take beta-carotene supplements have higher lung cancer rates than smokers not taking these supplements.

Therefore, the risk/benefit ratio is in favor of NOT taking SUPPLEMENTS to retard aging.