Uridine is a naturally occurring substance manufactured by the liver and classified as a nucleoside, meaning that it is a compound containing a nucleic acid with a pyrimidine base that has bonded to the alcohol group of a sugar. Specifically, uridine is a nucleoside of uracil, a primary constituent of ribonucleic acid (RNA), which is involved in the synthesis of protein in the body. This occurs when uracil forms an attachment with ribofuranose, the simple sugar that resides in RNA. This compound is further receptive to the addition of various phosphate groups to form one of three nucleotides, agents involved in regulating metabolism. It may also form deoxyuridine from a bond between uracil and the sugar deoxyribose, but this compound seldom occurs naturally in living organisms.
Researchers have discovered that uridine may have potential benefit in treating a number of medical conditions. For instance, several clinical trials involving cancer patients indicate that supplementation with this compound may help to offset the toxic effects of chemotherapy. There is also evidence to suggest that this substance may help to prevent cellular damage and liver dysfunction associated with a class of anti-HIV medications known collectively as AZT. However, it should be noted that the majority of tests regarding the latter application have been conducted in vitro and not on human subjects.
Other conditions for which therapy with this substance is being considered includes the treatment of Parkinson’s disease, Alzheimer's, bipolar disorder, and depression. In fact, animal-based studies focused on the anti-depressive effects of supplementing with uridine and omega 3 fatty acids combined have shown promising results that are comparable to the efficacy of conventional medications. These studies have prompted at least two US pharmaceutical companies to investigate the future potential of treating these and other disorders with triacetyluridine (TAU), a drug initially dubbed PN401, that converts into uridine in the body.
Additional study and testing includes the use of uridine in combination with omega 3 fatty acids, cytidine, and choline to help prevent age-related dementia. A team of researchers at the Massachusetts Institute of Technology (MIT) has found that these nutrients stimulate the production of phosphatidylcholine and phosphatidylserine. While virtually every cell in the body requires these two phospholipids for normal functioning, they are critical for neurotransmission in the brain. In addition, Turkish scientists have further found that supplementation exhibits these effects without diminishing acetylcholine release, a characteristic associated with age-related dementia.
Natural sources include tomatoes, sugar beets, broccoli, meats, molasses, and Brewer's yeast. It is also a component of human breast milk. Unfortunately, giving exception to breast milk and yeast, the human body does not readily absorb dietary sources of this substance. Beer lovers may be happy to learn, however, that their beverage of choice increases serum levels of uridine, likely due to its yeast content. Attempting to raise available levels of this nutrient by consuming large amounts of beer or yeast may also spike purine levels and increase uric acid output, as well as leading to other health problems associated with alcohol abuse.