Aging and Longevity, a Personal Perspective

Antioxidants and You

noreply@blogger.com (Dr. Lou Moretti) — Sun, 31 Aug 2008 18:09:00 +0000

Oxygen is essential for life. It is involved in creating energy rich compounds that drive all the complex chemical reactions that sustain life. In the process, however, molecules called free radicals are produced. These free radicals, if left unchecked, cause damage to DNA and cell membranes. This damage manifests itself as diseases such as Alzheimer’s, Parkinson’s, atherosclerosis and is, in part, responsible for aging. As might be expected, our bodies have developed sophisticated systems to combat this problem. Chemicals called antioxidants are produced which neutralized these free radicals. This whole process of free radical production is referred to as ‘oxidative stress’ and you may run into this term in popular articles discussing diseases and nutrition.

Antioxidants are also plentiful in our diet. Foods such vegetables, fruits and grain are rich in antioxidants. Vitamins C, E and Beta-carotene have strong antioxidative properties. No doubt you have also seen dietary supplements claiming to be rich in antioxidants and therefore promote better health by staving off disease and aging. Unfortunately these claims have been unsubstantiated by research. The only area where antioxidant supplementation has been shown to have benefit is when used as an adjunct for chemotherapy. In this setting the type of antioxidant and the chemotherapeutic agent used are quite specific. Of note, one study demonstrated and actual increase in the incidence of lung cancer in smokers treated with supplemental antioxidants.

The take home message here is clear. Antioxidants are important in maintaining good health. A well balanced diet, rich in fresh fruits, vegetables, legumes and other antioxidant rich foods is essential. With regard to supplements: too much of a good thing may not be a good thing. Keep in mind that we are a product of thousands of years of evolution. Our physiology is sophisticated and precise. Messing around with it is often ill advised. Taking megadoses of nutritional supplements should be avoided

Visible Cellular Senesence

noreply@blogger.com (Dr. Lou Moretti) — Wed, 30 Jul 2008 01:09:00 +0000

The life expectancy of any give species is pretty much determined by its genetic make up. This in turn is the result of evolutionary processes governed by one single imperative: survival of the species. The goal of every species is to reach a prime reproductive age in order to ensure that that species will survive. Living beyond that prime age is just ‘gravy’ for the particular individual. In the case humans, because of unique intellectual and physical abilities, our life expectancy extends well beyond the reproductive years.

Previously I talked about cellular senescence. It is now in these ‘gravy’ years that the ravages of cellular aging become apparent in how we and how different diseases become manifest.

Those cells that loose their ability to divide prematurely have great significance if they happen to be kidney, liver or cells of other vital organs. Organ failure or sub optimal function can have a ripple effect on other crucial physiologic mechanisms. Take, for example, cellular immunity. Elderly individuals have a much more difficult time fighting off infectious disease. Diseases that in a younger person would be far less serious. It is interesting to note that even though one may have a terminal disease such as cancer; it is bacterial infections that most often cause the terminal event.

How each of us age is a product of a lifelong list of decisions. Each decision has impact on the cellular and sub cellular level. There are bad ones: excessive alcohol consumption, smoking, poor nutrition, ultra violet ray exposure, inactivity. These choices lead to increase in cellular free radicals, protein damage, DNA damage and shortened cell life expectancy. What we see is cirrhosis, coronary artery disease, cancer, diabetes, wrinkles, obesity/frailty, poor posture. On the other hand making better choices such as leading a more balanced life, reducing stress and having proper exercise and nutrition can go a long way in reducing the effects of cellular aging and their resulting diseases.
Keep in mind that all these deleterious process are going on while we are still relatively young and, of course, immortal. This is the best time to make positive changes in your lifestyle. Be aware that even with advanced age, programs involving strength and cardiovascular training can slow down and even reverse some diseases of aging. We will discuss this in greater detail next month.

Visable Cellular Senesence

noreply@blogger.com (Dr. Lou Moretti) — Wed, 30 Jul 2008 00:50:00 +0000

Cellular Senescence

noreply@blogger.com (Dr. Lou Moretti) — Mon, 30 Jun 2008 21:16:00 +0000

The human body is thought to be composed of anywhere between 50-100 trillion cells. Some of these cells remain undifferentiated and possess the ability to become any type of tissue. These are the stem cells. Most others develop into specific tissue types such as kidney, liver, etc. The cells of some of these tissues (skeletal and heart muscle, nerve, fat) do not undergo cell division during our lives while others (like skin, gut, hair) do. At about the time of puberty the individual cells begin to age and this process is referred to as cellular senescence. Over the past few decades there has been much research on this topic and scientists are developing a clearer understanding of what causes our cells to age.

Oxygen is utilized by all living organisms to produce energy. This is done in small structures within the cell called mitochondria. As with everything that has a plus side, there is also a downside. These oxidative reactions produce by products called free radicals which in turn can cause damage to DNA. We are now all familiar with the fact that our chromosomes are composed of DNA and are found in the nucleus of the cell. Mitochondria also have DNA but their DNA is more sensitive to the damaging free radicals. This is because of the structure of the DNA itself and the fact that it is present near the production site of the free radicals.

Our body produces chemical substances called antioxidants that help neutralize these free radicals. With time this process becomes less effective. The end result is thought to be one of the major causes of aging. The rapidity with which an animal can repair this damage correlates to the life expectancy of that particular species.

The most interesting aspect of cellular senescence relates to changes in chromosomal telomeres. Telomeres are the end caps of individual chromosomes. You may recall that chromosomes (46 in humans) occur in pairs and are ribbon like structures. These end caps function like the plastic tip of a shoe lace. They prevent the DNA of the chromosome from unraveling when the DNA replicates during cell division. If this protective device was not present the results would be catastrophic for the organism. It is estimated that cells can undergo about 60 cell divisions during their lifetime. The interesting point is that each time the cell divides the telomere loses some of its substance (which is made of DNA and protein). Once it reaches a critical size an adjacent gene is activated and further cell divisions are prevented. Certain cells, however, produce an enzyme called telomerase which permits the rebuilding of these lost molecular structures and thus the cell can continue to divide. Cells that possess this enzyme can divide indefinitely and are in a sense ‘immortal’. Sperm and certain cells in the immune system are examples. Cancer cells possess telomerase and this is, of course, detrimental.
Next month we will examine how cellular aging manifests itself at the tissue level and in ways that are visible to the naked eye.

Overview

noreply@blogger.com (Dr. Lou Moretti) — Tue, 27 May 2008 02:11:00 +0000

Aging is a process we are all familiar with and although we usually think of it in relation to living things, it also applies to more abstract entities such as populations and planets, stars etc. For our purposes we will focus on humans and maybe a few experimental animals.

Life is continuum from birth until death. We can divide it into stages such as youth, middle and old age; indeed different societies may use any number of terms to describe the same process. For uniformity, division into years works best (that is, until the numbers get so large that you would prefer to just use the term ‘mature’).

Now, one might say that John is 55 years old. We all have some notion of what that means. However, someone else might state further that he looks much older than his stated age. And another observer might note that John acts like an adolescent. Hmmm.
What we have done here is define three types of aging: 1) chronological (years), 2) physiological, and 3) psycho-social.

The physiological processes of aging start to become more visible at about age 30. It is interesting to note that when you look at a young population there are much fewer differences between individuals than you will observe in an older group. Genes and environment play a profound role in how we age. We have no control over our genetic make up and initially no control over where we are born and into which socio economic class. Thereafter, however, we are faced with an infinite number of daily choices. For instance:
Should I drink alcohol?
Should I use drugs?
Which kind?
Do I exercise?
Do I overeat?
Should I smoke?
Should I engage in unsafe sex?
Should I get married?
Have children?

The list goes on and by now you can see that at age 55 years John is the product of many choices; some wise and some not so smart. Each having an effect on how aging will progress and how some of the genes will manifest themselves.

Next time we will examine aging at the cellular level.

Welcome

noreply@blogger.com (Dr. Lou Moretti) — Mon, 14 Apr 2008 22:11:00 +0000

Welcome to the first installment of my blog dealing with aging and longevity. Let me introduce myself. My name is Dr.Lou Moretti and for the past 30 years I have practiced full time emergency medicine in the Chicago metropolitan area. During that tenure I have had the unique opportunity to see first hand (and attempt to correct), the consequences of the aging process. Also, the cumulative effects of physical neglect and abuse to the human body.
The human lifespan is ever increasing due to advances in modern medicine and ongoing research in the area of aging.
It is my intent, over the ensuing months and years, to discuss with you what I have learned in my personal and professional life with regard to aging. I will also present current research that has practical relevance to this topic. If we are lucky, we will all have the luxury of growing old. Let's develop a strategy.

If you live in Chicago and are a man or woman over 50 years of age and thinking about starting a fitness program, I invite you to view my website: www.personallybest.com.