Some recent results published in the premier science journal Nature: Cell Biology indicates that a simple chemical compound found in grapefruit and also exchanged during sex can prolong the lifespan of mice. The chemical, known as spermidine (its name indicates where it can be found in humans) is a simple molecule consisting of three nitrogens and a handful of carbons and hydrogens. It plays a vital role in the cycle of cell growth. Every cell in our body has a natural lifetime, which can range from very short periods to very long periods, but once that time is up, the cell dies. We survive because our bodies continuously produce new cells. However, some cells cannot be freshly produced, and some cell types are only replenished very slowly. A patient suffering from radiation poisoning or some diseases dies as a result of insufficient white blood cells, which are needed to fight off infection. It has long been theorized that extending the lifetime (the expiration date, so to speak) of cells would increase the lifespan of the host organism. This has now been shown to be true.
When the Austrian scientists took a yeast culture and grew the yeast in an environment that was rich in spermidine, the cells were seen to live four times longer than cells that grew up without exposure to the polyamine. Fruit flies (which are a common target animal for genetic testing, as they have short lifetimes and their genome has been sequenced) lived for about 30 percent longer when spermidine was added to their food supply. Mice who ate food rich in spermidine exhibited a large decrease in the amount of damage to their bodily proteins, irrepairable damage that is associated with the aging process.
The scientists theorize that spermidine has this life-prolonging effect by changing the way that cells respond to damage. Any cell – all cells – can become damaged as a result of a wide number of outside sources. UV radiation can cause genetic damage, causing the cell to spiral into an uncontrollable growth spurt and produces a cancerous skin tumor. The food that we eat, if not rich with antioxidants, can cause electrochemical changes to parts of the cell and cause them to become unresponsive and useless. As parts of the cell begin to break and are discarded, the cell has to initiate a “Spring cleaning” of sorts to clean out all of the garbage that is piling up. This scientific name for this cleaning mechanism is autophagy. Like any overworked housekeeper, eventually the autophagy process begins to slow down and the garbage begins to pile up. Eventually the cell can’t take it anymore, and commits its own version of suicide – cell death, initiated by biochemical triggers within the cell. The cells lifetime is therefore cut short by the pileup of molecular refuse.
Spermidine enters the equation by preventing molecules in the cell from triggering the “I give up” signal which initiates the cells suicide. The cell continues to battle on, like the impossibly overworked but extremely motivated WALL-E robot from the Pixar film. As a result, despite the mountains of rubbish, the cell continues to live.
Humans can benefit from this research as it’s one of the clearest indications scientists have of the influence of our diet on the amount of time each of us has to live. A lifestyle that is rich in spermidine, which human skin is exposed to during sex and our diets intake through foods like grapefruit, may be a lifestyle that leads to a longer lifetime. So go on, enjoy some fresh fruit and make some time to be with your partner. It’s medicinal.
The source of this information may be found at: http://www.nature.com/ncb/journal/v11/n11/abs/ncb1975.html