In recent years, with an advancement of digital technology and the rise of new media, people spend more time online than ever before at home, work and school. A trend survey released by the Specialist Medical Association in 2019 indicated that Taiwanese have been found to spend about 10.7 hours a day on digital device, approximately 2/3 of the day. Therefore, vision and eye health has become an unignorable national issue. Several studies have demonstrated that lutein supplementation can provide high-potency support to improve visual acuity and vision longevity, optimize the overall eye health.
WHAT DOES LUTEIN DO FOR THE BODY?
Lutein and zeaxanthin are the main pigments in the key parts of the body. Most research results showed that these two nutrients offer powerhouse support for vision health. They can effectively filter blue light, enhance acuity and help reduce negative effects of excessive digital screen time and blue light exposure.
There are many lutein supplementations on the market, how to choose?
1. Lutein is available in two forms – "lutein esters", and "free lutein".
Lutein is a carotenoid, a source of fat-soluble nutrients. The human body cannot synthesize lutein on its own, which means we must obtain this important nutrient from our diets or dietary supplements to meet the daily requirement. Common food sources include spinach, kale, cauliflower, peas, lettuce, bell peppers, and egg yolks.
Lutein is available in two forms – lutein esters, and free lutein. Esterified lutein is mainly found in yellow-colored fruits or flowers, and the free form is mostly found in green leafy vegetables. A lutein ester has two extra fatty acid molecules. Naturally derived lutein is commercially extracted from marigold flowers. Upon saponification of the marigold extract, the lutein fatty acid esters are converted to free lutein.
2. The "free form" is better absorbed than the "esterified form"? Is it because the molecular weight of the free form is smaller?
Compared with "free lutein", "lutein esters" have 50% more fatty acids in structure, so the molecular weight is larger than that of the "free form". "Lutein esters" must be decomposed by digestive enzymes before it can be absorbed and utilized, whereas "free lutein" does not need to go through the process of human digestion; therefore, is better absorbed by our body.
Based on clinical studies, the effect of "free lutein" used in supplements on the absorption/bioavailability has been 5 times higher than "esterified lutein" (Edward P Norkus, 2010). However, there is still no consistent result between the absorbable efficiency of the two forms of lutein. The 2011 European Food Safety Authority report and the Japanese study showed that both forms of lutein can effectively increase the concentration of lutein in the body (Hiroko Yoshizako, 2016).
Generally speaking, when it comes to choose a lutein supplement, you should first pay attention to the information of the supplement facts. Supposelly it contains 20 mg of "esterified lutein", which means 10 mg of it is "lutein ester", and the other 10 mg is fatty acid. So the lutein content is actually only half. If you choose the product contains 20 mg of "free lutein", because "free lutein" has been processed to remove fatty acids, the content of lutein would be exactly 20 mg.
3. How to take lutein for better absorption?
Most studies have shown that dietary fat can enhance the absorption of carotenoids, and lutein is in fact one type of carotenoid. Studies have found that taking lutein with fat simultaneously can increase the absorption rate. Therefore, whether it is esterified or free lutein, it is recommended to supplement after meals (Nuray Z. Unlu, 2005).
4. The proper dosage of lutein supplements. Are there any side effects from taking too much?
Internationally, there is no recommended daily intake for lutein supplementation currently, but nutritionists have advised consuming at least 6 mg daily. In 2013, the AREDS-2 Phase II clinical study published by the National Institutes of Health (NIH) showed daily doses of 10 mg of lutein and 2 mg of zeaxanthin can be beneficial for our health. This study also became the golden ratio used in many subsequent formulations.
It is clinically observed that when a person takes too much of lutein, the skin will turn slightly yellow. Once reducing the dose, the yellowish condition will subside and recover after a period of time, and there is no adverse effect on health (Katherine M. Ranard, 2017).
According to the researches that long-term supplementation of lutein does not produce toxicity or teratogenicity, and is highly safe. The US FDA also recognizes it as a safe product (GRAS).
Therefore, the recommended daily intake of lutein is 6~20 mg/day. Even though currently there is no recommended daily intake in Taiwan, the Ministry of Health and Welfare has recommended an upper limit of 30 mg/day. No matter what kind of supplemental form, long-term and continuous lutein supplementation can effectively maintain visual health!
5. The compound formulations with lutein can effectively improve visual performance.
Zeaxanthin is commonly pair with lutein, the two ingredients absorb different wavelengths of blue light, they can complement with each other to provide double protection. Besides, ingredients such as astaxanthin, bilberry, fish oil, etc., also have been scientifically and clinically proven to be very beneficial to eye health. In particular, choosing clinically-proven astaxanthin and bilberry should be the guarantee of the potency.
6. What can't lutein be taken with? Are there any contraindications?
Lutein is generally suggested to be separated from carotenoids, because both are members of carotenoids and are fat-soluble nutrients with similar routes of absorption in the gastrointestinal tract; therefore, there may be a problem of competitive absorption. Clinical studies have also found that if high doses of lutein combined with β-carotene, an inhibitory effect of β-carotene on lutein absorption would occured.
If additional high doses of lutein and β-carotene need to be supplemented simultaneously, it is recommended to extend the time interval of the two nutrients or take them with meals, which could reduce the problem of competitive absorption. Moderate intake of carrots, sweet potatoes, etc. in the diet has little effect against the absorption of lutein. Only when a large amount of β-carotene is taken at the same time (such as carotene-containing multi-vitamins) will affect the potency of lutein. Therefore, among the vegetables and fruits from natural source, there is little chance to cause the problem of competitive absorption. There is no need to worry.
7. The guidelines for picking the right lutein supplements:
1). Form Matters! Choose the right form. There are many types of lutein products on the market according to consumers' eating habits, such as capsules, lozenges, drinks, foam tablets, jelly bars, etc. However, it should be noted that when the finished products are in the form of beverages, tablets and jelly bars, in order to adjust the taste and texture, unnecessary preservatives and artificial flavors may be added, which creating a body burden. It is recommended to choose plant-based, transparent capsules, so that the active ingredients can be completely retained in the capsule, and there is no need to add preservatives, artificial colors and titanium dioxide or other banned ingredients in the EU.
2). Pay attention to the actual content, not the added amount. Assuming that each lutein capsule contains 100 mg of marigold extract, which contains 20% lutein and 4% zeaxanthin, it can be calculated as each capsule contains 20 mg of lutein and 4 mg of zeaxanthin. This is the real actual content!
3). Choose the compound lutein formulation, such as combining high-concentration bilberry, astaxanthin or other formulas, so the better result can be achieved. Supplementing fish oil at the same time is good as well. However, it should be noted that the concentration of astaxanthin and bilberry should not be too low, otherwise the effect wouldn’t be visible. By clinical research, astaxanthin should be at least 4 mg per day and bilberry should be at least 80 mg per day are the ideal.
4). No matter what lutein supplement brand you choose in the end, one thing you must keep in mind – take it after meals regularly. In the long run, continuous supplementation will eventually lead to a better level of eye performance.
