All About Aging
What is the 'aging process'?
There's no real aging process, there are aging processes. You age at the level of your molecules. You age at the level of your cells. You age at the level of your organs. And then, your whole body ages. So it depends on what we're talking about. Aging is not really caused by any one thing. Aging is probably the sum of a number of processes coming together. Let me give you an example. Aging probably has environmental causes, for example sunlight causing the aging of your skin. Aging also has a genetic component. For example, we live, on average humans, about 75, 80 years in developed countries, but other mammals, like the mouse, lives an average of two to three years. So obviously the genes' difference between mice and us account for this huge difference between mice and us in life expectancy.
Why are we considered senior citizens at the age of 65?
Age 65 was actually first defined in 1888 by Otta Van Bismack, who was the prime minister of Germany at that time. He was a little bit annoyed at all these legislations being stopped by people above him. All these bureaucrats. So he decided to come up with the idea of retiring them all, and so he defined 65 as the retirement age in Germany and that has been picked up universally.
What does 'life expectancy' mean?
Life expectancy can be defined in many ways. What most people think about of life expectancy is life expectancy at birth, which in the United States right now is on average about 78 to 79 years, but you can also have a life expectancy at age 65, 75, 85. It depends on the age you're defining it at.
What is considered 'normal aging'?
Normal aging is in the eye of the beholder. A biologist would say, "normal aging is aging devoid of disease," for example, with a minimum amount of disease. A sociologist might say, "normal aging is aging successfully in the community." A psychologist could say, "normal aging is aging in a way that is psychologically effective for you, and psychologically functioning well."
What is 'usual aging'?
Usual aging would be aging without serious setbacks, without serious diseases. Developing, for example, the usual amount of osteo arthritis as you got older. The usual loss of your near vision as you get older. Your greying of your hair would be usual aging. So this would be considered usual aging. Unusual aging would be developing a devastating condition. A severe heart attack in your 40's or 50's. It would not be unusual to get a heart attack in your 80's.
What is 'successful aging'?
I was part of the McArthur Foundation, and our title was "The Foundation Study of Successful Aging." Successful aging was defined by the different specialists in the group. The psychologists considered successful aging as aging successfully in terms of your psychological functioning, without serious depression, without serious anxiety - doing well in a psychic way. A sociologist would define successful aging as functioning well in the community; being happily married, having good relationships with your family, having many friends, and having a good, strong, robust social network. The biologist would define successful aging as having very few of the devastating diseases of aging - aging without, for example, Alzheimer's disease, without problems with balance, or without a serious depression. It's the eye of the beholder.
Can I slow down the aging process?
Absolutely. You can absolutely slow down the Aging by exercising, by eating right, by getting a good night's sleep, and by having a good attitude.
Which genetic factors affect aging?
A number of genetic factors affect aging. For example, whether you are born with the wrong genes, born with genes for premature diabetes, born with genes for premature heart disease, or born with genes that affect your immune system. These would in fact be devastating to your aging process. On the other hand, are you born from parents who lived a long time or grand parents who survived for a great time. These are positive things that you have, positive genetic influences.
Which environmental factors affect aging?
In all likelihood, the environment is much more important than your genes. Let me give you an example. Your big environmental issue is exercise. Are you sedentary or do you exercise? No factor can affect the aging process more than this issue. If you exercise, you can really impact on the aging process. If you're sedentary you can die earlier with many more conditions and diseases, and possibly be disabled much earlier. The other thing that can affect it is nutrition - what do you eat?
What cellular changes are associated with aging?
At the cellular level we have many things happening. What the biggest is that every day our cells are bombarded by free radicals. What are free radicals? These are highly reactive bio chemicals that are made when we take in air - when we breath in oxygen and when we eat our foods to make energy and the bad products are billions, millions, trillions, quadrillions of free radicals and they attack your inside membrane, your inside proteins, your inside DNA and cause damage. Now our body has antioxidant protection; we have normal antioxidants inside that are then evoked to help detoxify ourselves but the process may not be hundred percent successful and free radical damage can accumulate and in fact be one of the things contributing to ageing. A second factor is cross linking and that is your proteins contain amino acids that can cross link to each other and cause these proteins to become stiff. The best example of cross linking is the colour gene in your skin when you're young your skin is very, very flexible and pliable as you get aged it gets much less pliable and that is because of the colour gene cross linking in your skin, the same thing happens in your eyes the colour gene and cross linking in your eye can result in cataracts. So cross linking and free radicals are two very important processes that go with ageing environmentally.
Which bodily changes are associated with aging?
With aging there are a number of changes, normal changes with aging. Let's start with your eyes, you get to be 40 or 45 you have to move that newspaper further and further and further away from your eyes and then you need reading glasses. That happens to about 95% of the population. As you get older too the lens of your eyes starts to get opacified and eventually you will develop a cataract, and that's a normal change with aging. Also glare becomes much more difficult to deal with as you get older. Colours aren't as vivid as they used to be. The amount of light coming into your eye decreases with aging. That's just examples of five changes that occur just in your eyes. Your hearing decreases with aging; you lose the high-pitched sounds with aging. You also lose the intensity of sound with aging. It's a normal change with aging. Smell decreases by almost three or four logs, which means almost by ten thousand times less, as you get older. So you can detect odours one ten thousandth as well as you could do before. Taste decreases with aging, taste for many things. And older people sometimes need more spicy foods for that. Then we'll move down to our lungs, our lungs are not as efficient as they used to be. I diaphragm doesn't move as much as it used to and therefore we're unable to run up and down the basketball court as much as we can. That results in players having to retire in their early thirties. The heart is affected by aging. The heart can't beat as rapidly as it could when you were younger in response to stress. Another factor for retirement of athletics as they get older is that your joints become less flexible. Your muscles decrease slightly in size with aging. We can help that by exercise and weight training, which are very important. But they do decrease somewhat with aging. Your kidney doesn't function as affectively at secreting waste as it used to, as you get older. And there are probably a dozen or more things that I haven't listed that do change with aging.
