Aging
How and why it happens.
by Khalid Mahmud, M.D., F.A.C.P.
Nature protects us through sexual maturity to ensure that we can reproduce for the survival and progress of our species. After that, nature loses interest. Protective mechanisms begin to fade, and we are on our own. Many internal and external factors begin to erode our youth and health and we age at variable rates depending upon how we influence various aging factors:
Genes
We may be born with some good genes and some bad ones; but, we can alter the final effects of these genes on our bodies. Good genes cannot protect us from a pack of cigarettes a day. A healthy lifestyle and nutrition, on the other hand, can overcome the effects of our weaker genes. The genes we are born with are not set in stone. They change (mutate) as we age depending on internal and external factors, and cause multiple health problems.
Hormones
Hormones have a pronounced influence over almost all important body functions. They do so by controlling enzymes that drive thousands of chemical reactions inside our cells. The production of several important (good) hormones such as melatonin, HGH (human growth hormone), thyroid hormones, DHEA, testosterone, estrogen, and progesterone begins to decline after we have attained sexual maturity. Some decline as early as age 15 (melatonin), others decline as late as age 45 (estrogen). These hormones are essential for a young and vigorous mind and body. They maintain our lean body mass, prevent fat accumulation, and keep our skin young and firm and our bones strong. They sustain our hearts, our minds, our immune systems, our social functions, our productivity, our sexual desires, and performance. It has been suggested that it is not because we age that our hormones decline... rather it is because our hormones decline that we age.
Oxidative Stress (Free Radicals)
The energy to carry on all life functions is created within tiny power-generating furnaces (mitochondria) inside our cells. In order to do that, electrons travel through a chain of proteins in a tightly controlled manner. Almost all of this goes without a hitch; but unfortunately a few electrons leak out. They immediately combine with other molecules to create "free radicals," such as "super oxide" - oxygen with an extra electron. These free radicals are extremely reactive and steal electrons from other important molecules such as DNA, RNA, proteins, enzymes and lipids. Such damage leads to aging and age-related diseases such as Alzheimer's disease, heart attacks, strokes, and cancer. As we age, our mitochondria become leakier and create more and more free radicals. Oxidative stress can be increased by smoking, radiation, infections, inflammation, and even physical exercise. Unfortunately, oxygen gives us life, but it also takes life! Up to 3 percent of the oxygen we breathe turns into free radicals. To counter oxidative stress, nature has created several powerful anti-oxidants in our cells. Others we must acquire through our diets (vitamins E, C, etc.). In addition, nature has created several repair enzymes that are critical, especially those that repair DNA. We can affect most of these processes to reduce the overall damage from oxidative stress.
Glycation of Proteins
Extra sugar in the system can attach to proteins and render them non-functional by cross-linking them. The buildup of such glycated proteins leads to chronic degenerative diseases and is considered to be an important cause of aging.
Inflammation
Our cells produce important hormones called "eicosanoids." Some of these cause inflammation, which is necessary to fight invaders like bacteria and viruses, and others prevent inflammation. Ideally, there is a balance between our inflammatory and anti-inflammatory tendencies. As we age, several factors, including diet, allergies, and auto-immune states, tip the balance towards inflammation. Such inflammation is damaging to the body and is partly responsible for many aspects of aging and age-related diseases.
Cortisol (the "stress hormone")
Unlike the other "good hormones," cortisol levels tend to increase as we age, and are related to the stresses of modern day living. This is a "catabolic" hormone that breaks down muscle, increases body fat, kills nerve cells, impairs immune responses, and contributes to aging and diseases of aging.
Insulin
The modern American diet, especially since the development of the Government's food pyramid, has created havoc with obesity and diabetes in this country. Sixty percent of Americans are overweight. As many as 50 percent may be walking around with high insulin levels and insulin resistance, which is caused by carbohydrate excess. Suppose a child's entire bloodstream contains only 20 grams of sugar. Imagine the shock to his or her body after drinking a soda containing 40 grams of sugar in a just a few minutes! Let's not forget about the hundreds of grams of other carbohydrates in pizza, pasta, chips, cookies, and candy. All of this leads to a state called insulin resistance that is directly related to aging and many diseases of aging such as obesity, hypertension, high cholesterol, heart attacks, strokes, and cancer.
Heavy Metals and Other Toxins
We are constantly exposed to toxic metals such as mercury, lead, aluminum, cadmium, and arsenic in our environment. These toxic elements can interfere with enzymatic reactions, disrupt cellular function, and can lead to multiple problems including behavioral disorders, neurological disorders, cardiovascular diseases, and even cancer.
Sedentary Lifestyle
It has been estimated that being sedentary is equivalent to smoking a package of cigarettes per day. It will shorten life just that much. The good news is that more and more Americans are taking up exercise; the bad news is that most are still inactive. Those who do exercise frequently don't know how to do it correctly and how to maximize its benefits. Exercise has numerous benefits including cardiovascular conditioning, improved lean body mass and bone density, improved mood and mental status, reduced stress and depression, and an overall improved quality of life. It delays the aging process.
Gastro-intestinal factors
As we age, our gastrointestinal system comes under attack. Chlorine in the water kills friendly bacteria in the gut, leaving room for harmful bacteria take hold. Numerous toxic substances and drugs damage the intestinal mucosa. We become allergic to certain foods. We begin to lose hydrochloric acid in the stomach and essential digestive enzymes in the intestine. Our gut lining becomes leaky and loses important immune defenses. As a result, incompletely digested proteins get absorbed into the bloodstream and create numerous problems including auto-immune inflammatory conditions. Much can be done to prevent and control these processes.
Immune System Decline
Our thymus gland is responsible for the programming and maturation of various immune cells. It begins to atrophy at an early age - a natural process. As we get older, our immune systems becomes weaker. We have less NK (natural killer) cells. Our immune cells start to mistake our own tissues as foreign invaders and start attacking these tissues (auto-immune diseases). We can do things to keep our immune systems healthy.
The Sun
While the sun sustains life on earth, it also causes aging of the skin. Almost 90% of skin aging is directly related to UV light exposure. UV radiation breaks down collagen, prevents new collagen formation, and inflicts oxidative damage to skin structures including sweat glands, oil glands, and fat cells. It creates age spots and dilated vessels. The dermis (inner skin layer) gets thinner, loses elasticity and does not hold moisture. Our skin becomes loose, leathery, and wrinkled. Finally, superficial cells with damaged DNA begin to replicate and turn into different kinds of cancer. Much can be done to prevent and reverse UV-related aging.
