Glycation and aging
Glycation refers to the oxidation of protein by glucose. In chemistry (and cooking), these are called “browning” reactions, and, in fact, they are seen when meats are “browned” by frying. The result is a cross-linking of glucose or another sugar molecule to the protein, an action which effectively prevents the protein from acting properly.
Glycation is a major cause of the aging process and especially devastating to diabetics.
The human body is mostly made up of proteins. Proteins are responsible for the daily functioning of your body, which is why anything that causes protein deterioration to have a dramatic impact on the body's function and appearance.
Thanks largely to the destructive effect of sugar and aldehydes (compounds formed by the oxidation of alcohol), the protein in our bodies tends to undergo destructive changes as we age. This destruction is a prime factor, not only in the aging process itself, but also in the familiar signs of aging such as wrinkling skin, cataracts, and the destruction of our nervous system, particularly our brains.
Glycations occur mainly in the bloodstream to a small proportion of the absorbed simple sugars: glucose, fructose, and the milk sugar galactose. Fructose and galactose have approximately ten times the glycation activity of glucose, the primary body fuel, making it a less desirable carb source.
Glycation is the first step in the evolution of these molecules through a complex series of very slow reactions in the body, which lead to advanced glycation endproducts (AGEs)
Some AGEs are benign, but others are more reactive than the sugars they are derived from, and are implicated in many age-related chronic diseases such as cardiovascular diseases, Alzheimer's disease, cancer, neuropathy and other sensory losses such as deafness. This range of diseases is the result of the very basic level at which glycations interfere with molecular and cellular functioning throughout the body and the release of highly oxidizing side-products such as hydrogen peroxide.
Long-lived cells (such as nerves and different types of brain cell), long-lasting proteins (such as crystallins of the lens and cornea), and DNA may accumulate substantial damage over time. Cells such as the retina cells in the eyes, and beta cells (insulin-producing) in the pancreas are also at high risk of damage.
Damage by glycation results in stiffening of the collagen in the blood vessel walls, leading to high blood pressure, especially in diabetes.
Glycations also cause weakening of the collagen in the blood vessel walls,which may lead to micro- or macro-aneurisms; this may cause strokes if in the brain.
One of the easiest to spot signs of the damage from AGEs is aging of the skin and formation of pigments where they inflame the skin.
Another method is to measure HbA1C level in the blood, which measures glycated hemoglobin and allows you to monitor blood sugar levels over a period of about 3-4 months as this is the lifespan of red blood cells.
Carnosine and glycation
It appears carnosine boosts the cell's ability to clear out damaged proteins once they're formed. One of the problems with damaged proteins is that their mangled structures often don't give easy access to the enzymes that normally digest worn-out cellular components, making it difficult for the cell to remove them. Experimental studies have found that carnosine reacts with proteins which have already been damaged by glycation and other assaults on their structural/functional integrity, forming "carnosylated" complexes which appear to be more easily removed than the original, warped protein.
Carnosine has been proven to reduce or completely prevent cell damage caused by beta-amyloids. The presence of beta-amyloid leads to damage of the nerves and arteries of the brain. Carnosine blocks and inactivates beta-amyloid.
The key is that carnosine not only prevents damaging cross-links from forming in proteins, it eliminates cross-links that have previously formed in those proteins, thus restoring normal membrane function in cells. This is true not only in the brain, but in all the organs of our body -- our skin included. The damage you see in the skin is not just a cosmetic question. That damage is absolutely an indicator of the kinds of damage happening to every other organ in your body -- including your eyes and your brain.
Carnosine has the remarkable ability to throttle down bodily processes that are in a state of excess, and to ramp up those that are under expressed. For example, carnosine thins the blood of people whose blood tends to clot too much and increases the clotting tendency in those with a low clotting index.
Carnosine positively impacts the activity of sympathetic and parasympathetic nerves that supply energy to the adrenal glands, liver, kidney, pancreas, stomach, and white and brown fat tissues, thereby causing beneficial changes in blood pressure, blood glucose, appetite, lipolysis, and the thermogenic burning of fat.
Two facts lend more credence to the idea that supplemental carnosine is beneficial to your brain. First, it has been known for some time that brain tissue naturally contains high levels of carnosine, which are capable of reducing the oxidative and glycemic stresses to which the brain is especially vulnerable.
Carnosine in brain tissue reduces inflammation, a harmful factor in and of itself,and reduces the accumulation of beta-amyloid plaque in the brain, a probable key factor in the onset of Alzheimer's.
More recent studies have shown that carnosine levels are actually significantly lower in patients with Alzheimer's and other neurodegenerative disorders such as Parkinson's disease than in people without those problems. This might indicate either a carnosine deficiency that allows for the onset of the diseases (carnosine levels are dramatically lower in pre-diabetics, diabetics, and the elderly) or that the diseases themselves exhaust the carnosine supplies in the brain.
Numerous studies now point to the role carnosine might play in both protecting the brain from Alzheimer's disease.
L-carnosine still ranks as one of the most important anti-aging supplements available to us today. It is probably the single supplement most likely to produce a visible "youthening" of your appearance in the shortest possible time.