Physics of the Future: How Science Will Shape Human Destiny and Our Daily Lives by the Year 2100

to scan the genomes of millions of people by computer to isolate the genes that partially control our life span.
    Furthermore, these computer studies may be able to locate precisely where aging primarily takes place. In a car, we know that aging takes place mainly in the engine, where gasoline is oxidized and burned. Likewise, genetic analysis shows that aging is concentrated in the “engine” of the cell, the mitochondria, or the cell’s power plant. This has allowed scientists to narrow the search for “age genes” and look for ways to accelerate the gene repair inside the mitochondria to reverse the effects of aging.
    By 2050, it might be possible to slow down the aging process via a varietyof therapies, for example, stem cells, the human body shop, and gene therapy to fix aging genes. We could live to be 150 or older. By 2100, it might be possible to reverse the effects of aging by accelerating cell repair mechanisms to live well beyond that.
    CALORIC RESTRICTION
    This theory may also explain the strange fact that caloric restriction (that is, lowering the calories we eat by 30 percent or more) increases the life span by 30 percent. Every organism studied so far—from yeast cells, spiders, and insects to rabbits, dogs, and now monkeys—exhibits this strange phenomenon. Animals given this restricted diet have fewer tumors, less heart disease, a lower incidence of diabetes, and fewer diseases related to aging. In fact, caloric restriction is the
only
known mechanism guaranteed to increase the life span that has been tested repeatedly, over almost the entire animal kingdom, and it works every time. Until recently, the only major species that still eluded researchers of caloric restriction were the primates, of which humans are a member, because they live so long.
    Scientists were especially anxious to see the results of caloric restriction on rhesus monkeys. Finally, in 2009, the long-awaited results came in. The University of Wisconsin study showed that, after twenty years of caloric restriction, monkeys on the restricted diet suffered less disease across the board: less diabetes, cancer, heart disease. In general, these monkeys were in better health than their cousins who were fed a normal diet.
    There is a theory that might explain this: Nature gives animals two “choices” concerning how they use their energy. During times of plenty, energy is used to reproduce. During times of famine, the body shuts down reproduction, conserves energy, and tries to ride out the famine. In the animal kingdom, the state of near starvation is a common one, and hence animals frequently make the “choice” of shutting down reproduction, slowing metabolism, living longer, and hoping for better days in the future.
    The Holy Grail of aging research is to somehow preserve the benefits of caloric restriction without the downside (starving yourself). The natural tendency of humans apparently is to gain weight, not lose it. In fact, living on a calorically restricted diet is no fun; you are fed a diet that would make a hermit gag. Also, animals fed a particularly severe, restricted diet becomelethargic, sluggish, and lose all interest in sex. What motivates scientists is the search for a gene that controls this mechanism, whereby we can reap the benefits of caloric restriction without the downside.
    An important clue to this was found in 1991 by MIT researcher Leonard P. Guarente and others, who were looking for a gene that might lengthen the life span of yeast cells. Guarente, David Sinclair of Harvard, and coworkers discovered the gene SIR2, which is involved in bringing on the effects of caloric restriction. This gene is responsible for detecting the energy reserves of a cell. When the energy reserves are low, as during a famine, the gene is activated. This is precisely what you might expect in a gene that controls the effects of caloric restriction. They also found that the SIR2 gene has a counterpart in mice and in people, called the SIRT genes, which produce proteins called sirtuins. They then looked for chemicals that activate the sirtuins, and found the chemical resveratrol.
    This was intriguing, because scientists also believe that resveratrol may be responsible for the benefits of red wine and may explain the “French paradox.” French cooking is famous for its rich sauces, which are high in fats and oils, yet the French seem to have a normal life span. Perhaps this mystery can be explained because the French consume