What is Sialic Acid (N-Acetylneuraminic Acid)?
Sialic acid, also called sialic acid, are a class of -keto acid sugars with nine carbon backbone. The term “sialic acid” (from the Greek for saliva, σίαλον – síalon) was first introduced by the Swedish biochemist Gunnar Blix in 1952. The most common member of this group is N-acetylneuraminic acid (N-acetyl-d-neuraminic acid , Neu5Ac or NANA) found in animals and some prokaryotes.
Sialic acids are widely found in animal tissues and related forms are found to a lesser extent in other organisms, such as in some microalgae, bacteria and archaea. Sialic acids are commonly part of glycoproteins, glycolipids or gangliosides, where they decorate the ends of sugar chains on the surface of cells or soluble proteins. However, sialic acids have also been observed in Drosophila embryos and other insects. In general, plants do not appear to contain or exhibit sialic acids.
In humans, the brain has the highest sialic acid content, with these acids playing an important role in neural transmission and ganglioside structure in synaptogenesis. More than 50 types of sialic acid are known, all of which can be obtained from a molecule of neuraminic acid by replacing the amino group with one of its hydroxyl groups. In general, the amino group carries an acetyl or a glycolyl group, but other modifications have been described. These modifications, along with linkages, have been shown to be tissue-specific and developmentally regulated expressions, so some are only found on certain types of glycoconjugates in specific cells. The hydroxyl substituents can vary considerably; acetyl, lactyl, methyl, sulfate and phosphate groups have been found.
In May 2017, N-acetyl-d-neuraminic acid (Sialic acid) was approved for registration as ‘Authorized Novel Food’ in both China and Europe (by the European Food Safety Authority, EFSA). As a result, sialic acid can be used in baby food, pasta, dairy products and food supplements, among other things
Scientists investigating the functions of sialic acid are trying to determine whether sialic acid is related to rapid brain growth and whether it provides benefits in brain development. Breast milk has been shown to contain high levels of sialic acid glycoconjugates. One study even found that breastfed premature and full-term babies had more salivary acid at five months of age than bottle-fed infants. However, breast milk varies in sialic acid content depending on genetic inheritance, lactation, etc. Studies have focused on comparing the effects of sialic acid on breastfed infants with non-breastfed infants. Brain development is complex, but fast: by the age of two, a child’s brain reaches about 80% of its adult weight. Children are born with a complete set of brain neurons, but the synaptic connections between them will be worked out after birth. Sialic acid plays an essential role in proper brain development and cognition, and it is important that the child has sufficient supplies when it is needed.
The human brain has been shown to contain more sialic acid than the brains of other mammals (2-4 times more). Neural membranes have 20 times more sialic acid than other cell membranes. It is believed that sialic acid plays a critical role in enabling neurotransmission between neurons. The effects of sialic acid supplementation on learning and memory behavior have been studied in rodents, as well as in piglets (whose brain structure and function more closely resemble that of humans).
Rat pups supplemented with sialic acid showed improved learning ability and memory as adults. Newborn piglets were fed a diet rich in sialic acid for five weeks. Next, learning and memory were evaluated using a visual cue in a maze. A link was found between dietary sialic acid supplementation and cognitive function: the piglets that had received high doses of sialic acid learned faster and made fewer mistakes. This suggests that sialic acid has an impact on brain development and learning.
In 2009, scientific advice was requested from the EFSA (European Food Safety Authority) on the substantiation of health claims related to sialic acid and learning and memory. Of the references provided, only one animal study treated piglets fed on milk formula. The EFSA panel concluded that this animal study does not predict the effect of dietary Sialic Acid intake on learning and memory in humans and is therefore of the opinion that no scientific conclusion can be drawn from this reference to substantiate the claim.
Despite the unapproved health claim, Sialic Acid as a relatively new (approved) food is an interesting addition as a Nootropic food supplement.
Next Valley is legally not allowed to make statements about properties and uses of Sialic Acid (Sialic Acid) if they have not been approved as a health claim by the European Commission.
For more information, we refer you to external sources.
- The Sialic Acid wiki at Wikipedia
The optimal dose varies from person to person, but a good guideline is between 100 and 300 mg. Use of Sialic Acid (N-Acetylneuraminic Acid) as a dietary supplement in children under 10 years of age is not recommended.
There are no known side effects of using Sialic Acid. If you do experience side effects due to the use of Sialic Acid, reduce your dose.