01 Oct 2018 — A study has identified the importance of different forms of vitamin E – such as gamma-tocopherol and tocotrienols – over just alpha-tocopherol. The study’s findings show the potential benefits of formulating a vitamin E complete range over common vitamin E supplements that focus solely on alpha-tocopherol.
Alpha-tocopherol transfer protein (ATTP) is commonly thought to be the single transport mechanism for vitamin E, leading many vitamin E supplement suppliers to focus on this tocopherol alone. However, these findings – published in Biology Redox – have identified that ATTP does not regulate vitamin E absorption, nor does it control the intracellular distribution of other vitamin E isoforms.
“Historically, the high affinity and binding of ATTP with alpha-tocopherol was thought to favor alpha-tocopherol and disadvantage the other forms of tocopherol and tocotrienol in the transport and absorption of vitamin E into the plasma. This new finding gives a different view on ATTP’s role that the higher affinity to ATTP doesn’t equate to better cellular uptake and intracellular distribution of tocopherols and tocotrienols,” Diyanah Roslan, Nutritionist at ExcelVite, tells NutritionInsight.
“This study is aligned with our [ExcelVite] message that while ATTP has high affinity to bind to alpha-tocopherol, it does not mean that the other isoforms of vitamin E are not transported into the plasma and intracellular matrix,” she adds.
There are thought to be eight parts of the vitamin E complex. The tocotrienols are potent substances that have anti-inflammatory and anti-cancer actions, reduce cholesterol and help with the metabolism, according to ExcelVite.
However, “most dietary supplement companies in the market carry a standard vitamin E product formed by alpha-tocopherol alone (either synthetic/natural), instead of vitamin E Complete,” says Roslan.
“This is mainly because of the concern of ATTP – the known transport mechanism for vitamin E isoforms. ATTP has a high binding affinity towards alpha-tocopherol but low affinity to tocotrienols and other forms of tocopherol. Hence, it is thought that tocotrienol and other tocopherol forms will not be efficiently absorbed into the plasma, or that tocopherols compete with tocotrienols for the same transfer protein,” she says.
The study was designed to compare the cellular uptake and intracellular distribution of different vitamin E isoforms (tocopherols and tocotrienols), in the presence or absence of ATTP.
“The study reported that the expression ATTP doesn’t impact the cellular uptake and intracellular distribution of different vitamin E isoforms. All four isoforms used in this study (alpha-tocopherol, gamma-tocopherol, alpha-tocotrienol and gamma-tocotrienol) are primarily associated with the lysosomal compartment, endoplasmic reticulum and the plasma membrane – regardless of the presence and absence of ATTP,” Roslan explains.
Although the study does not highlight particular health benefits, it does confirm that other forms of vitamin E are taken up and accumulate in intracellular components.
“Hopefully this will encourage more use of other forms of vitamin E (gamma-tocopherol and tocotrienols) in research and dietary supplements. This would be a good opportunity to formulate and launch a vitamin E Complete as nature produces and to provide the health properties as the key for improved immunity, healthy skin, brain and cardiovascular function,” Roslan concludes.
By Laxmi Haigh
Source: Nutrition Insight
Disclaimer: The statements in the above article have not been evaluated by the Food and Drug Administration. They are not intended to diagnose, treat, cure or prevent any disease.