The first fact beginning biology students might learn is that if you want to raise a rat's blood pressure and shorten its life, you feed it sugar--not just salt--but sugar (glucose). Now research with human cells has shown how caloric restriction and glucose restriction works to extend human life--at least in the form of cells in a test tube or similar laboratory container.
According to the December 18, 2009 article, "UAB Researchers Link Calorie Intake to Cell Lifespan, Cancer Development," researchers from the University of Alabama at Birmingham (UAB) have discovered that restricting consumption of glucose, the most common dietary sugar, can extend the life of healthy human-lung cells and speed the death of precancerous human-lung cells, reducing cancer's spread and growth rate.
What the general consumer should know is that calorie-intake restriction can benefit longevity and help prevent diseases like cancer that have been linked to aging. To live longer and prevent some diseases, there are potential health benefits of controlling calorie intake. Scientists have found according to their research that calorie reduction extends the lifespan of healthy human cells and aids the body's natural ability to kill off cancer-forming cells. But you don't want to restrict calories so much that you cause a loss of electrolytes or anorexia issues.
The UAB team conducted its tests by growing both healthy human-lung cells and precancerous human-lung cells in laboratory flasks. The flasks were provided either normal levels of glucose or significantly reduced amounts of the sugar compound, and the cells then were allowed to grow for a period of weeks.
Researchers tracked the healthy and the pre-cancerous human lung cells' ability to divide while also monitoring the number of surviving cells. What scientists were looking for focused on patterns.
The pattern revealed showed that restricted glucose levels led the healthy cells to grow longer than is typical and caused the precancerous cells to die off in large numbers. What the scientists looked for were two key genes.
The focused on whether the genes were affected and how the cells responded to less sugar (glucose) consumption.
Telomerase, the first gene studied has the job of encoding an important enzyme that allows cells to divide indefinitely. The second gene, p16, encodes a well known anti-cancer protein.
Cancer-forming cells died off. When you look at healthy cells, you want to see their telomerase rise. But you want to see the p16 gene decrease. You're looking for a boost in healthy cell growth.
When sugar (glucose) was restricted, gene reactions flipped in the precancerous cells with telomerase decreasing and the anti-cancer protein p16 increasing. The result was that the cancer-forming cells died off in large numbers.
What's the purpose of this study? It's to find the links between calorie intake, aging and the onset of diseases related to aging. Fortunately, in this study, human cells were used instead of animals.
The main conclusion of this study is that human longevity can be achieved at the cellular level through caloric restriction. The main problem is to reduce calories, but not so much that you starve yourself of the nutrients you need. More research is needed with human cells of various types. What the researchers are looking for are novel approaches. The goal is to extend the lifespan of humans.
Check out the study, "Glucose Restriction Can Extend Normal Cell Lifespan and Impair Precancerous Cell Growth Through Epigenetic Control of hTERT and p16 Expression" in the current online edition of The Journal of the Federation of American Societies for Experimental Biology, or FASEB Journal. Grants from the National Institutes of Health and the Glenn Foundation for Medical Research funded the scientific study.