In animal studies, Carnosine has been shown to reduce mortality, and to prevent much of the brain damage and loss of mental function, after a simulated stroke. Animals receiving Carnosine before blocking the blood vessels that feed their brains are less than half as likely to die, and the memory function and the activity of key brain enzymes is better preserved in Carnosine-supplemented survivors than in survivors who did not receive the supplement. In fact, rodent “stroke” survivors who get Carnosine perform as well on many memory tests as they did before the “stroke!”
While performing their astounding cell-rejuvenation experiments, Holliday and MacFarland happened to find that one of their cell cultures had become contaminated with cancer cells, which quickly began to choke out the healthy ones. But when Carnosine was added to samples of this contaminated population, it was found that the cell cultures became free of cancer cells. The same results followed when Carnosine was tested against seven human cancer cell lines. The researchers found that they could add cancerous cells to a culture of healthy ones, bathe the warring tribes in Carnosine – and sit back and watch as the cancer cells slowly disappeared from the pool, even as the healthy cells thrived.
When Japanese researchers implanted cancer cells into laboratory mice, and then administered a daily injection of Carnosine two centimeters away from the implant site, Carnosine-treated animals showed reduced tumor growth and mortality compared to animals not receiving the dipeptide. In some cases, tumors regressed. The effects were further enhanced when Carnosine was combined with an immune-enhancing drug.
But if we try to pin down just how it is that Carnosine can exert its other, wide-ranging anti-aging effects, we'll have a hard time choosing among all the options. The protective properties of Carnosine have been described as "pluripotent" – that is, "many-powered." Carnosine is a highly versatile antioxidant, and also has indirect antioxidant powers through the chelation of pro-oxidant metals and the prevention of the destruction of the antioxidant enzyme superoxide dismutase (SOD) normally seen in cells exposed to hydrogen peroxide.
The power of these combined antioxidant actions was shown in experiments in which cells were exposed to toxic levels of oxygen. Carnosine treatment preserved healthy cell structure and reduced damage to the cells' DNA even though no other tested antioxidant could do so: not vitamin C, not vitamin E, not N-acetylcysteine (NAC), and not the potent synthetic antioxidant ethoxyquin.
Carnosine protects against the formation of Advanced Glycation Endproducts (AGEs), warped cellular proteins that have been damaged by sugar. Preliminary studies in animals fed a high-fructose diet suggest that Carnosine’s AGE-fighting ability helps preserve the flexibility of blood vessels, preventing some of the increase in blood pressure that is otherwise suffered under such circumstances. As well, Carnosine also maintains more youthful levels of proteolysis (the ability to tear down old, defective cellular proteins) in cells, – a process which slows down in old cells, interfering with cellular function. And Carnosine has been shown to react with certain abnormal proteins in a way which some research suggests may make them more readily broken up and disposed by the cell’s “garbage disposal” systems.
Carnosine changes gene expression in cells exposed to it, including increasing the expression of vimentin, a protein involved in maintaining the integrity and complex internal structure of the cell. Carnosine enhances various aspects of immunity, and protects cells against damage from a variety of toxins produced in the body as a part of normal metabolism. Test-tube studies have found that Carnosine also prevents amyloid beta-peptide, which forms the seed of the plaques associated with Alzheimer's disease. The list of protective functions goes on and on.