In a special issue titled “The Science of Staying Young,” Scientific American reports on exciting anti-aging research projects, including many that address the role of antioxidants in slowing age-related disease. In the opening narrative, Scientific American states that by 2050, there will be five times more people in the world over the age of 80 than there were in 2000. The United Nations predicts that people over 80 will be the fastest-growing segment of the world’s population. While some economists view this trend with alarm, Scientific American optimistically predicts that medical advances will reduce the “degradation that time imposes on our bodies and minds.” The role of free radicals in accelerating aging processes is discussed throughout this special issue of Scientific American. One of the articles sought to determine why certain people reach the advanced age of 95 and older while maintaining good health. One explanation is that these healthy oldest humans appear to have longevity genes that combat free radical damage, and thus slow aging by reducing oxygen damage to cellular DNA.
While growing numbers of Americans are taking antioxidant supplements, the fact is that nothing has worked as well to date as the natural antioxidants—such as glutathione and superoxide dismutase—that are produced in our cells. While some of us have genes that continue producing natural antioxidants in advanced age, most people need help. The good news is that science is developing “super antioxidants” that quench destructive free radicals much more effectively than common supplements like alpha tocopherol.
Deadly Role of Oxygen Radicals
Scientific American’s special issue provides abundant information on the destructive force of free radicals and how this relates to aging. The magazine described how oxygen radicals damage almost every critical component of cells, including DNA, proteins, and membranes.
Researchers interviewed by Scientific American describe how they were able to double the life span of insects by programming their genes to produce more natural antioxidants such as superoxide dismutase. They note that pigeons live 35 years, or about 12 times longer than rats of approximately the same weight—with the difference being that pigeons produce half as many free radicals as rodents do.
According to Scientific American, oxidants bombard the DNA inside our cells roughly 10,000 times each day, but many of the free radicals generated are intercepted and neutralized by antioxidants. They note, however, that free radical damage adds up over time and “the result just may be an older, frailer you.”
Encouragingly, researchers interviewed by Scientific American describe studies in which old rats looked and functioned like younger rats following oral administration of antioxidants. The researchers cautioned, however, that humans cannot expect the same benefits from most conventional supplements, as these do not supply the full spectrum of nutrients found in fruits and vegetables, and their nutrients may not be adequately disseminated throughout the body. Exceptions were nutrients like lipoic acid, which is uniquely able to boost antioxidant activity within the cell and protect against mitochondrial decay.
Critical Need to Keep Sugar Out
Of the various approaches to slowing aging, calorie restriction is considered the gold standard.15-31 The problem, of course, is that few people can adhere to a lifelong low-calorie diet.
Scientific American considered the beneficial bodily effects induced by calorie restriction, such as increased levels of the hormone DHEA and reduced blood levels of insulin and artery-clogging lipids. But one of the magazine’s most profound findings concerns calorie restriction’s effect of lowering glucose, which results in diminished cellular metabolic activity and fewer free radicals being generated.37 Scientific American produced a brilliant molecular drawing of how excess glucose may accelerate aging and how calorie-restriction mimetics could slow aging by blocking the ability of cells to use excess glucose.
Reasons for Optimism
For those who think there is a limit to life span, Scientific American cites studies showing how the manipulation of genes in worms increased their life span to the human equivalent of 500 years. Scientific American goes on to point out how researchers can now make normal human cells live forever in a petri dish—something that scientists have long ridiculed as an impossibility.