How probable is all this? More probable than you think. We all know that life is getting longer, that the new "real old age" starts at 80 and not 60, and we've all heard of amazingly old villagers in Italy, in Calabria and Sardinia. Scientists here in Italy have engaged now for years in systematic research to try and uncover the "secret" of old age. Add to that other research in other parts of the world, in Switzerland, in Ecuador, in the United States, and you get an interesting, if complex, picture of where Science stands on this question.
To begin with, this new research is putting dents into some convictions like the one about the benefits to be derived from a restricted diet based on mainly fruits and vegetables. While centenarians from rural areas in Italy often ate that way, it's basically because they were poor and had nothing else to eat when they were young and continued to eat the same way out of habit even when their economic circumstances improved.
And that's one more reason why the question of longevity is treated in genetic terms.
First, it's a question of having the right genes to avoid early death from major life-threatening diseases like cancer. For example, there have surprising results from research among men suffering from a recessive mutation in a single gene that causes the so-called "Laron syndrome", a form of dwarfism that is prevalent in many families in El Oro province. It would appear that the "little people" as they are known locally, are (relatively) immune to cancer and diabetes. Such conclusions are based on serious epidemiological research that started in 1987 and has identified about 100 people suffering from Laron syndrome. Moreover the results are comforted by a set of complementary experiments carried out in the laboratory on mouses. In 1996 Andrzej Bartke, a scientist at Southern Illinois University, shut down the growth hormone pathway which resulted in smaller mice but also, surprisingly, produced longer-living mice by a noticeable margin: some 40 percent longer than normal mice.
This suggests that there might be a link between genes that govern growth and cancer which is, as everyone knows, a condition where cells are multiplying in disorder, as if growth had run amok.
Second, the question arises whether there is a gene responsible for longevity. In Italy, since 1994, scientists at the University of Calabria have carried out solid demographic surveys of families with centenarians to try and figure out how much of longevity is determined by genetics, how much by the environment and how these factors interact to contribute to longevity. The scope of this research has recently turned up an astonishing finding: contrary to accepted wisdom that women live longer than men, a 2011 paper reported that the genetic factors involved seemed to benefit males more than females. While the genetic component of longevity appears to be stronger in males, women may take better advantage of non-genetic factors such as diet and medical care.
So women should not despair, with diet and medical care, the chances of enjoying a life as long as men can even out!
Clearly the question is far more complex than just having a gene that you engineer for longevity and you're done. Calabrian researchers have shown that there are at least five or six pathways that influence longevity, and they include response to stress, the metabolism of nutrients and metabolism in general, i.e. the storage and use of energy. Anything really can influence how long you live, from childhood diet to how long a person attends school.
In America, research is going in another direction at the Albert Einstein College of Medicine, with studies of brain function and mobility in the elderly. Plus a particularly interesting study of 500 centenarians, all Ashkenazi Jews who were found to have exceptionally high levels of HDL (the good form of cholesterol). This was apparently caused by a variant of a gene known as CETP (cholesteryl ester transfer protein) which protects against cardiovascular disease.
You can easily imagine how this finding has sent off pharmaceutical companies on a frantic search for drugs that would replicate the action of the centenarian variant of CEPT!
The search for genes with key metabolic responsibility in the mitochondria of centenarians also goes on at a fast clip. Think of the mitochondria as the cell’s power plants, with their own DNA and genes. Several mitochondrial proteins have been identified by Einstein College scientists, the so-called "mitochines" associated with people who live into their 90s and 100s. One molecule in particular, dubbed the "humanin" has been shown to have surprising effects in experiments on rats: it was found to normalize glucose levels and essentially erase diabetic symptoms in a few hours. It also prevents arteriosclerosis and Alzheimer’s in mice prone to these diseases and helps limit coronary damage when attacks in the experimental animals are induced.
In short, human genetics research is currently focused on seeking "protective genes". One of the most promising is called FOXO3 (I love the name!), which has been found in long-lived Japanese-American men on the island of Oahu. This gene is similar to the one identified in the Laron population in southern Ecuador. Other scientists, at Einstein, are studying stem cells, suspecting that there might be influences on the fetus that affect genetic mechanisms at the beginning of life that somehow set the rate of aging.
Recently, scientists in Switwerland have treated worms with antibiotics and expanded their life span by 60 percent (see article below).
So are we close to identifying a sure path to longevity? Not really, not yet, but we're on our way, no doubt about it.
Question: Will living long make you happy?
It depends. Just imagine for a moment that science gives us the option - I expect this could happen in about 80 years or so - to choose, assuming you have the means, to join an Age Prevention Program that will guarantee youthful looks till the day you drop dead. Because die you must: it seems we are genetically programmed to last some 130-140 years and not more.
So you look young and you feel good all your life. Is that a blessing or a curse?
Two years ago, I asked myself that question and came up with an answer in fictional form, a short-short story, flash fiction really, to try and move you and make you think. Curious? Here it is, on Read Wave, a cool new site for readers:
This is the original story which was the starting point of the serial level I am currently writing, 2213:Forever Young. Part One and Part Two of Forever Young are just published, I'm currently working on Part Three and it will be soon available.
Do let me know in the comments: do you believe longevity is pure gold, particularly if the problems of aging have been solved, or is there something not quite right about it?