Are you also a 3C family? Do you often feel that your eyes are sore and uncomfortable? In the 2020 workplace health survey, vision problems ranked first. Many people will supplement eye care food, and the most familiar one is lutein! However, do you really understand lutein? Commercially available lutein is divided into free type and esterified type. What is the difference between the two? Is the free type really as advertised as being better absorbed?
Lutein will have different structural forms depending on its source. Most of the green vegetables are free lutein. In yellow and orange fruits or flowers, lutein usually contains a fatty acid and Known as "esterified lutein", currently
Because the lutein naturally contained in calendula is esterified, more processing is required to obtain the lutein itself. Many free lutein products are advertised as having undergone a "hydrolysis" step to remove fatty acids. The statement is a bit wrong!
Because free lutein is not obtained by "hydrolysis" to remove fatty acids, but by utilizing the property of fatty acids to be saponified with "strong alkali", potassium hydroxide is added to calendula extract to form "saponins" with fatty acids ” and then removed, lutein will form a free form at this time.
With the trend of less processing in recent years, some consumers will be very concerned about the processing degree of health care ingredients, so if they want to obtain lutein supplements that are closer to the natural form, esterified lutein is the original source of calendula. form.
Wrong! web searchLutein information, found that most of the content pointed out that the molecular weight of free lutein is smaller, so the bioavailability is higher than that of esterified lutein. There are some discrepancies in the content of the road.
There are commercial advertisements citing literature, pointing out that the absorption rate of free lutein is 23% higher than that of esterified lutein, but after reviewing this literature, it is found that this literature is not in the Comparing the availability of free and esterified lutein, but comparing these nutrients after supplementation with different combinations and doses of lutein, zeaxanthin, and meso-zeaxanthin differences in blood levels. Therefore, it is not appropriate to use this literature to prove the absorption rate of different forms of lutein.
The results of studies that are really exploring the absorption rate or utilization rate of lutein are inconsistent! The University of Illinois first conducted a human study in 2002 and published it in the well-known "Journal of Nutrition". It found that subjects who ingested esterified lutein had a blood lutein content of free lutein. 1.61 times that of the esterified form, and the study also showed that the absorption rate of the esterified form was better than that of the free form by about 78% of the subjects!
In 2010, a major nutritional company published a study using free lutein supplied by the company. The results indicated that the blood lutein content of subjects who ingested free lutein was 17% higher than that of those who ingested esterified lutein. However, subsequent studies have not focused onIn terms of the absorption rate of free type and esterified type, which is better and which is worse!
As lutein from lutein esters is bioavailable to an extent similar to the bioavailability of lutein itself in the 2011 European Food Safety Authority document. Therefore,
Wrong! Many articles not only mention that the free form is better retained by the body than the esterified form, but also absorbed faster! But in fact, the results of the 2002 study were the opposite. The data showed that subjects who ingested esterified lutein had a higher rate of increase in blood lutein than free lutein within 24 hours. The claim is just the opposite!
Actually, no matter which form of lutein is taken, it will help the human body, because the human retina needs sufficient lutein content for a long time. therefore!
Yes! If you want to get enough lutein, the stability of the product in the storage environment and whether it can pass the test of gastric acid are the key! At present, the data on the bioavailability of different types of lutein are inconsistent, but in terms of stability, the esterified lutein is slightly better!
Research points out that free lutein is easily damaged by light and heat, especially when exposed to ultraviolet light, the structure of free lutein is more easily degraded,Therefore, special attention should be paid to the storage of free lutein, and it is necessary to avoid close to heat sources, and also be careful with light-transmitting packaging!
Compared with the esterified lutein, the structure is closer to the natural form of calendula, so the structure is more stable, not only heat and light resistance, but also the acid resistance of the esterified lutein is better than Free lutein.
A study in Hungary in 2006 used the in vitro gastric acid test to test the stability of free and esterified lutein to gastric acid. The results showed that after adding a 37°C gastric acid environment for 1 hour, free lutein That is, it was greatly reduced by 66%, but the esterified lutein was only reduced by 1%, indicating that the esterified lutein has the effect of protecting the lutein structure.
Of course, not all commercially available free lutein will be destroyed. If so, the free lutein in it can be protected and released after reaching the intestinal tract smoothly.
If so, make sure that lutein can resist stomach acid and reach the intestines smoothly for absorption by the body!
It's half right! It is said on the Internet that "the content of esterified lutein is half of that of free form". This is because esterified lutein contains both lutein and fatty acid, and the two structures each account for the molecular weight of esterified lutein. 50%, that is, 20 mg of esterified lutein, lutein and fatty acid each account for 10 mg; as for free lutein, because fatty acid has been saponified and removed by strong alkali processing, so 10 mg of free lutein The lutein content is 10 mg.
The emphasis is on the actual content of lutein rather than the additionquantity. What everyone needs to pay attention to the most is the "actual content of lutein", as long as the recommended intake is reached, there will be no gap!
The recommended intake of lutein is between 6 and 30 mg. Taking esterified lutein as an example, if the added amount reaches 12 mg, you can eat the minimum recommended intake of 6 mg. Most of the products on the market are based on the data of the AREDS 2 large-scale study of the US Institute of Health as the basis for the design of the lutein formula. Therefore, the ratio of lutein and zeaxanthin is mostly 10:2, so remember to read before purchasing products. Only by clearing the labeled amount of lutein can you help yourself choose a guaranteed product.
Do you want to buy esterified lutein or free lutein? If we simply compare the absorption rate and human body utilization rate of the two, the current research data is really indistinguishable. Three principles for using lutein are provided:
The real point of purchase should focus on whether the product you eat can meet the "recommended daily intake of lutein (6-30 mg)".
Free lutein is more sensitive to light, heat and stomach acid. The structure of lutein is easily damaged and loses its effect. Therefore, it is recommended to identify acid-resistant capsules when purchasing, and the packaging must also be made of light-proof materials. Keep away from light and heat sources to ensure the lutein content in the product.
Esterified lutein is closer to the form naturally contained in calendula, so consumers who are looking for a low degree of processing can choose esterified lutein. In addition, the structure of the esterified type is quite stable, and it is easy toFor preservation, it is more resistant to gastric acid, so whether it is a product of capsules, beverages, or jelly, esterified lutein can easily withstand the test of gastric acid.
No matter which lutein product you choose, because lutein is a fat-soluble nutrient, please remember to take it after meals for better results.
◎ This article is from / ◎ Written by / Lin Shihang nutritionist ◎ Image source/Provided by Dazhi Image/shutterstock
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