Lutein is an important nutrient that didn’t generate much public fanfare until 2013, the year that the second major clinical trial from the Age-Related Eye Disease Studies (AREDS) was published. Known as AREDS2, this study cemented the role of lutein in eye health, specifically for reducing the risk of age-related macular degeneration (AMD). Researchers and consumers continue to show interest in this powerful antioxidant.
We’ll get into that research in this blog later on. First, for those of you who have heard about lutein, and want to know more, let’s start with some of the basics.
What is Lutein Good For?
Lutein is a carotenoid, the colorful pigments—yellows, oranges, reds—produced and synthesized by plants and algae. While there are hundreds and hundreds of carotenoids—this article says there are more than 600 types—here are three in addition to lutein that you’re probably most familiar with: beta carotene, lycopene and zeaxanthin. That last one will be important as we further explore the benefits of lutein found in AREDS2 and in a follow-up study from that trial.
Another thing that you’ll want to know about carotenoids, lutein included, is that they are potent antioxidants needed to keep free radicals in check. Left to their own devices, free radicals attack your cells and ravage your body, potentially resulting in degenerative eye disease, diabetes, dementia, aging, inflammatory issues, and even potentially cancer. You need antioxidants to prevent free radicals from running amok in your body.
And here’s another tidbit about lutein: there are two major carotenoids that reside in the human eye, specifically in the lens, the retina and even more specifically, in the macula, and one of them is lutein. (The other is zeaxanthin.)
This is a hint of where we’re going when we say that lutein is referred to as “the eye vitamin.” Lutein and zeaxanthin work to protect your eyes from UV rays in sunlight. This article refers to studies that suggest a high level of both of these antioxidants in your eye tissue is associated with better vision, especially when the light is dim or glare is a problem. And a literature review observes that “a large body of evidence shows that lutein has several beneficial effects, especially on eye health.”
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In addition to its impact on AMD, some lutein research, according to the review, associates high lutein plasma concentrations with a low risk for developing cataracts (although AREDS2 did not show an overall cataract benefit). The review also includes study results showing that lutein improves macular pigment optical density (MPOD) levels. Macular pigment helps protect your eyes from absorbing damaging blue light.
Perhaps the strongest scientific research (or perhaps the most visible, thanks to AREDS2) for lutein is in eye health, but research has also uncovered and continues to search for possible lutein benefits beyond eye health. Other studies have associated lutein with heart health benefits, specific cancer risk reduction, and brain health (including children’s cognitive development) and more. In future blogs, we’ll be exploring more about lutein’s other assets when it comes to health.
Which Foods Contain Lutein?
Would it surprise you to know that most of us aren’t getting enough lutein in our diets, despite the fact that it is present in several different foods? According to this article, most people only get about 30% of what research suggests you should get when it comes to lutein.
Here are some of the foods that are richest in lutein.
Spinach is interesting, serving up 8 milligrams (mgs) of lutein in one cup. Unlike some other vegetables where cooking reduces nutrients, when it comes to spinach, cooking the greens just makes them richer in lutein, up to double the amount found in raw spinach.
Kale, on the other hand, starts out with 11 mgs when raw; kale loses about half its lutein content when you cook it, but that still leaves you with a desirable amount.
Another leafy green—romaine lettuce—provides about 4 mgs for every two cups.
These foods, too, contain some lutein, although not in as high quantities as spinach and kale. Corn, bell peppers (especially the green ones), parsley, pistachios and egg yolks, all have some lutein in them, an added bonus if you’re eating them for the other healthy nutrients/health benefits they provide.
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And don’t forget the fruits (well, technically, botanists consider corn and peppers as fruits). Plums, blackberries, and blueberries, as well as kiwis, tomatoes and avocados (yes, tomatoes and avocados are also technically fruit), can pump up your diet with a bunch of lutein and some of the other carotenoids too.
If you’re still not getting enough lutein in your diet, consider adding dietary supplements to fill in the gaps. The options range from multivitamins (including those that are based on the AREDS2 formula) or lutein supplements, or combination lutein and zeaxanthin supplements.
Just How Much Lutein Do You Need?
That’s kind of a trick question although we don’t ask it in a trying-to-trick-you way. The fact is there is currently no established Daily Value (DV) for lutein. Without getting too technical, the government’s Office of Dietary Supplements (ODS) at the National Institutes of Health (NIH) says that “DVs were developed by the U.S. Food and Drug Administration to help consumers determine the level of various nutrients in a standard serving of food in relation to their approximate requirement for it.” (Remember that dietary supplements are regulated as a category of food, so DVs apply there too.)
From a practical standpoint, that simply means that on product, you may see lutein included in the ingredient list, but the column that provides the %DV will be blank, meaning that you won’t see how much the product contributes to meeting a daily value—because one hasn’t been established.
This visual of a Supplement Facts label shows you what we mean—even though this sample label doesn’t include lutein on its list of ingredients. But you get the picture (and see notes #8 and #9 for the explanation).
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Even without a DV for lutein—or for that matter, because they’re related, there’s also no Recommended Dietary Allowance or Adequate Intake (AI)—some experts are making recommendations for how much lutein you need (including for eye health) based on the dose(s) where some of the scientific studies found benefit.
This article says that health benefits for lutein are found in the daily range from 6 mgs to 20 mgs, from your daily diet or dietary supplements. Importantly, 10 mgs daily is the recommendation for eye health. The piece also notes that Americans are falling short, with most only getting around 1-2 mg daily. Although no tolerable Upper Level (UL) of Intake (the amount at which no known adverse effects have been found) has been established for lutein, this published risk assessment “indicates the evidence of safety is strong at intakes up to 20 mg/d for lutein” and points out that higher doses have been studied with no significant resulting adverse effects.
Why is Lutein Good for the Eyes?
Let’s let the science talk. Throughout this blog, we’ve referenced AREDS2, the landmark study, which put lutein on the eye chart (if you think of the chart as a map).
For context, AREDS and AREDS2 are important clinical trials sponsored by the NIH’s National Eye Institute. The studies were developed to understand the natural history and risk factors of cataracts and age-related macular degeneration (AMD), the latter being the most common cause of blindness in older Americans. The researchers wanted to evaluate what impact, if any, vitamins could have on the progression of these eye diseases.
And it turns out there was quite an impact on AMD!
The original AREDS study, published in 2001, found those at high risk of developing advanced stages of AMD, lowered that risk about 25% over five years when treated with a high-dose combination of vitamins C, E, beta-carotene, and zinc.
During the study, two separate studies discovered that smokers who also consumed beta-carotene experienced a significantly higher risk of lung cancer, leading the AREDS researchers to change up the AREDS vitamin formula in AREDS2, adding lutein and zeaxanthin, among other nutrients.
AREDS2 Results: Lutein and Zeaxanthin
In AREDS2, launched in 2006, the study authors enrolled 4203 participants aged 50-85 years at risk for advanced AMD and randomized them to different groups with different nutrients or placebo. In this blog, we’re reporting on the group that received 10 mgs lutein and 2 mgs zeaxanthin (replacing the 15 mgs beta-carotene from the original AREDS formula). In addition, these participants received the remaining nutrients from the original AREDS formula: 500 mgs vitamin C, 400 IU vitamin E, 80 mgs zinc, and 2 mgs copper to avoid zinc-related copper deficiency.
At the conclusion of the five-year AREDS2 study period, the researchers reported that lutein and zeaxanthin were not associated with increased cancer risk, demonstrating safety support for replacing beta-carotene with these carotenoids.
In addition, analysis from the AREDS2 trial suggests that lutein and zeaxanthin offers similar or better protective benefits against advanced AMD compared with beta-carotene. In the trial, participants who took an AREDS formulation containing lutein and zeaxanthin lacking beta-carotene had an 18% lower risk of progressing to advanced AMD compared with those who took AREDS containing beta-carotene (no lutein or zeaxanthin).
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Among participants who had the lowest dietary intake of lutein and zeaxanthin, those who took AREDS with lutein + zeaxanthin had a 26% lower risk of progressing to advanced AMD compared to participants taking the original AREDS formula.
One other benefit in the lutein and zeaxanthin group indicated that the AREDS2 participants with the lowest dietary levels of these carotenoids as measured at enrollment, had on average a 32% reduction in progression to cataract surgery, which appeared to be associated with taking lutein and zeaxanthin.
Further Follow-Up Shows Long-Term Benefits for Lutein and Zeaxanthin
A new epidemiologic follow-up study from AREDS2 published this year monitored 3,883 of the original 4,203 AREDS2 participants for an additional five years beyond AREDS2. Those participants were given the final AREDS2 formulation which included lutein and zeaxanthin.
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At the end of the total ten-year period, the follow-up report showed no increased risk for lung cancer in non-smokers with the lutein/zeaxanthin and the original lutein/zeaxanthin group had an additional 20% reduced risk of progression to late AMD compared to those originally assigned to receive beta-carotene.
“These results confirmed that switching our formula from beta-carotene to lutein and zeaxanthin was the right choice,” said lead study author Emily Y. Chew, M.D.
How Can I Increase My Lutein Levels?
More research, including clinical trials, is needed to further assess other benefits of lutein (with and without zeaxanthin) on eye health and other health-related functions. As more research uncovers more benefits for lutein, don’t be surprised by an increased recommendation from the scientific and public policy communities for FDA to establish a DV and for healthcare practitioners to urge consumers to increase their daily intake of lutein.
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