Is There A Longevity Gene? Sort Of

Back in February researchers with DeCode Genetics announced the discovery of what the media called a “Methuselah gene” — a gene that seems to confer on those born with it a relatively longer life span than the rest of us.

Those researchers compared a group of 1,200 long-lived people in Iceland with a group that lived the average age, and found that the 1,200 long-lived people had more family connections with each other than did the control group of average-lived people.

They hen began looking at those long-lived people and claim to have found “a simple, single gene” that predisposes those folks to living a very long time. “Somehow this gene is making a protein in the body that is helping people live to ripe old ages,” said DeCode CEO Karl Stefansson.

Well, that all depends on what they were looking for and what this gene, assuming their discovery holds up, actually does. There are, after all, two separate but closely related issues with aging. First, there are diseases and other problems that occur more frequently as we grow older (such as the risk of a heart attack), and, second, there are those age-related problems that occur even when we remain relatively healthy, such as the changes that occur in our skin, the decline in the quality of muscle tissue, etc.

Most likely, this gene governs the former sort of problems. There are a number of known genes and variants where people who end up with a gene variant end up having a much lower risk of certain diseases. Science is already aware of genes that cause people to have increased risk of developing diseases such as breast cancer, heart disease, etc. Finding and compensating for these genes will, of course, extend our lifespan. If I have a gene that makes it likely I will die of a heart attack before I am 50, and somebody figures out a way to neutralize that — either with a fancy cure or just an optimal diet — then they are extending my life span.

But figuring out how to reduce those other age-related problems is a much bigger problem. The bottom line there is that there was simply no evolutionary pressure for humans to live past 80 or 90 and so our bodies lack systems to preserve the integrity of our biological systems into advanced ages. Not that that cannot be overcome, but it is a lot harder than simply lowering the risk of heart attacks or cancer that our genes have conferred on us. After all, even if we avoid major diseases well into our 80s or 90s, the other aging problems eventually will catch up to us and cause our bodies to fail.

It is very unlikely that phenomenon is controlled by a single gene. Rather it is the complete absence of types of genes (i.e. those that would be responsible for long-term maintenance) across all of our body’s systems that guarantees we will succumb to death.

Source:

Discovery of ‘Methuselah gene’ unlocks secret of long life. Robin McKie, Observer, February 23, 2002.

The Longevity Game

How long do you have left to live? Northwestern Mutual has a very well done longevity calculator — you tell it your age, weight, and answer a few lifestyle questions and it will tell you your expected life expectancy.

The magic 8 ball says my life expectancy is about 91 (the short version is if you don’t drink, don’t smoke and aren’t accident prone, you should live a very long time).

Nature on Aging

Speaking of aging, Nature has an article on the topic at its web site, The times of our lives, which looks at current theories about aging.

A good article, for the most part, until the last couple paragraphs which detail why we might not get to immortality as quickly as we’d like — politics.

Most human beings are not so blessed. According to figures from the World Health Organization, people born today in Sierra Leone will be lucky to reach their 40th birthday. Life expectancy in Africa and countries such as Russia are declining for a variety of reasons, ranging from AIDS to economic hardship. The leading cause of death among young black men in the United States is gunshot wounds.

One might argue that before we seek to find ways to increase the maximum possible human life span from Jeanne Calment’s current record of 122 years, we should ensure that more people get the chance to enjoy even that allotted span.

I’m not quite sure how stopping basic research into aging would keep black men in urban areas from killing each other in such large numbers nor how biologists, or anybody for that matter, will be able to stop the real scourge that plagues Africa: non-responsive, corrupt regimes (how can South Africa stop its AIDS problem when its president recently denied outright that HIV causes AIDS).

Fortunately there is a huge profit to be made from any breakthrough that might extend longevity, so I’m confident research will continue.