Uridine 

The chemical structure of uridine

Uridine is a molecule (known as a nucleoside) that is formed when uracil is attached to a ribose ring (also known as a ribofuranose) via a β-N1-glycosidic bond.

If uracil is attached to a deoxyribose ring, it is known as a deoxyuridine.

Harvard researchers report that supplementation in rats with a combination of uridine and EPA/DHA omega-3 fatty acids has antidepressant activity equivalent to that of commonly prescribed antidepressant medications, such as Prozac and other SSRIs. 1

Dietary sources of uridine

Uridine is found is a variety of foods. Sugarcane extract is rich in nucleosides, especially uridine.2 Tomatoes also (about 500-1000 mg. of uridine per kilogram of dry matter).3

Brewer's yeast is also a good source of uridine, as yeast is high in RNA (ribonucleic acid), which after digestion is broken down into ribosyl pyrimidines (uridine and cytidine), which are absorbed intact 4. About 3 percent of yeast (dry weight) results in digestion uridine products. This assumes the usual 9% RNA content found in Brewer's yeast. Alternatively, drinking beer also results in increased plasma uridine 5. The ingestion of one liter of beer results in increased plasma uridine at a level that is comparable to those reached after ingestion of CDP-choline (citicoline) (as in 6, the increase is measured as a percent change relative to baseline plasma uridine). Alternative uridine/cytidine sources include other high RNA foods such as organ meats (liver, pancreas, etc) or broccoli 7. High RNA foods may result in high blood purine levels, which may increase uric acid production in humans, which may aggravate conditions such as gout. Because of this, it has been suggested that the RNA content of yeast products should be chemically reduced if these products are to be consumed in high amounts as a source of protein (50 grams or more per day). However, such processing is expensive, and as of today (2008), it seems that commonly available Brewer's yeast products are not RNA-reduced. Consumption of moderate amounts of yeast (5 grams per day) should provide enough uridine for improved health, while minimizing possible side effects such as increased uric acid production.

References

  1. ^ http://cat.inist.fr/?aModele=afficheN&cpsidt=16548265
  2. ^ http://www.thebody.com/content/art30244.html
  3. ^ http://www.aseanfood.info/Articles/11018411.pdf
  4. ^ http://content.karger.com/ProdukteDB/produkte.asp?Doi=46734
  5. ^ http://cat.inist.fr/?aModele=afficheN&cpsidt=13973855
  6. ^ http://www.ncbi.nlm.nih.gov/pubmed/10974208
  7. ^ http://content.karger.com/ProdukteDB/produkte.asp?Doi=46734


v • d • e
Nucleobases, nucleosides, and nucleotides
Nucleobases
Nucleosides/
(NB+pentose)
Nucleotides/
(NS+phosphate)
monophosphates (AMP, GMP, UMP, CMP) | diphosphates (ADP, GDP, UDP, CDP) | triphosphates (ATP, GTP, UTP, CTP)
monophosphates (dAMP, dGMP, dUMP, TMP, dCMP) | diphosphates (dADP, dGDP, TDP, dCDP) | triphosphates (dATP, dGTP, TTP, dCTP)
Major families of biochemicals
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Alkaloids · Nucleobases · Nucleic acids ·  · Enzyme cofactors · Flavonoids · Polyketides · Tetrapyrroles
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