Interviewer: Doctor, you talk quite a bit about longevity. You have a couple of books dedicated to that as well. Can you talk about how realistic an extension of life expectancy is in the near future and maybe how that's changed even in recent years?
Dr. Terry Grossman: Well, we know that just in the last century, life expectancy has increased from...people were only living 46, 48 years in 1900, and now average life expectancy is in the mid 70', and closer to 80 for women. That's just in the United States. In some countries, it's greater than that. Right now we're adding five hours per day to our life expectancy. Every day that we live, we can expect to live five hours more. If we multiply this out, this corresponds to about two or two and a half months per year. Every year, we're adding about two, two and a half months to our expected life expectancy. Things are improving in time.
I think there'll be a major paradigm shift in the not-too-distant future; some time in the first half of this century. Right now, the maximum life expectancy for humans seems to be a little bit more than 120 years, perhaps 124 years. This is a result of the telomeres at the end of our chromosomes. We have enough telomere length at the end of our chromosomes that it essentially just runs out after 120, 124 years. But with the new therapies that are being available now, there are some telomerase activating medications, it seems as though we can solve this telomere problem so that maximum life expectancy may increase this century, 150 to 200 years or beyond.
Interviewer: Talk about telomeres again a little bit and explain what those are. They're on the ends of chromosomes, and they shrink over time, and they're a good indication of life expectancy, aren't they?
Dr. Terry Grossman: Yes, exactly. Telomeres, the most common analogy used for them is, if you look at a shoelace, the tip of the shoelace, that little plastic tip keeps it from unraveling. Well, the same way with our DNA, with our chromosomes. It's a double strand of DNA and at the tip, to keep it from unraveling, we have these things that are called telomeres. You can just think of them as small beads. They keep the double strands of DNA from unraveling. Every time the cell divides, a small piece of the telomere length comes off, and it gets shorter and shorter. And when the telomeres reach a certain critical length, they've lost so much of their length, at that point it generates a signal to the cell that it's now time for it to die. There is a process called apoptosis, which essentially is programmed cell death, and the cell says "OK. It's time," and it dies.
The good news is we now have some nutritional strategies to increase telomere length. There's a couple that are on the market today. There'll be some more available in the years ahead. These should be able to increase telomere length, and we do know that longer telomere length is associated with not just increased longevity, but with increased vigor and increased health. There's a lot to be said for increasing our telomere length, and we can do that now with certain supplements, and we can also do that by our lifestyle choices. For instance, vigorous physical exercise, deep sleep; getting enough deep sleep every night, not exposing yourself to excess stress. These are some of the things that we've found that will increase telomere length.