Key Takeaways
- Lutein and zeaxanthin are two molecules that influence many of the same systems that vitamin A does.
- By not overloading on the vitamin-like functions of vitamin A, lutein and zeaxanthin can provide additional beneficial effects to certain organs like the eyes and the brain.
- Both lutein and zeaxanthin are supplements that fall into the category of “should be taken each and every day” unless you eat egg yolks, and it’s good that they’re included in multivitamins specifically for older individuals.
There are essential vitamins and minerals that we all must have in our diets.
Then there are “pseudo-vitamins,” a term that I think I coined but may have stolen from somebody, that refers to things that we don’t need but act like vitamins in our bodies anyways.
Things like CoQ10, PQQ, and creatine are compounds that would be vitamins if we didn’t synthesize them in our bodies.
Essential vitamins all have their own specialized systems for being absorbed and processed in the body. They can be recycled, supported, nurtured, and preserved. This is why it takes months to get scurvy (perhaps even a year)—the body holds on to vitamin C so effectively!
Sometimes, though, molecules that have a similar structure to vitamins are able to borrow these privileges for their own benefit. Sometimes they don’t even need to act like a vitamin, they’re just freeloaders.
This is the case with some structural classes, such as the carotenoids, which are things that sort of look like vitamin A. They can, at times, get the same privileges as vitamin A and access to the same systems in the body just because they look the same.
Pretty racist if you ask me.
However, if they’re otherwise just a snazzy molecule then this means that the body thinks of them as normal compounds and delivers them to where they’re needed, keeps them in the body, and maximizes their potential benefit.
It’s a great profile that many pharmaceutical drugs would love to have, just working with the body rather than having to fight it, and some supplements just get lucky.
Enter, lutein and zeaxanthin, the two big words on the bottom of damn near every multivitamin.
They are carotenoids, they are not vitamin A, and they use their back door entry to actually provide a lot of benefits that vitamin A could otherwise not.
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What Are Lutein and Zeaxanthin?
Lutein and zeaxanthin are part of a group of molecules known as carotenoids that are often found in dark leafy greens, eggs, and other animal products.
Carotenoids are a group of molecules that, structurally, look like vitamin A.
The name comes from the plant form of vitamin A, known as beta-carotene, and as a general rule of thumb carotenoids tend to interact with the same systems that vitamin A does.
The structure of a molecule is what determines their actions after all, and while a very small change can drastically change a molecule this usually is not the case.
Vitamin A is most well known for supporting proper eye health, which is why the animal form is called retinol (named after the retina of the eye). It’s also known for improving skin and brain health. However, the benefits of vitamin A affect the entire body.
This is why many different carotenoids are investigated for these purposes. This extends to atypical sources, like astaxanthin, and more common sources like those found in the humble egg.
What Is Lutein?
Lutein is perhaps the most common carotenoid outside of beta-carotene (pre-vitamin A) itself, being found in a large variety of dark leafy green vegetables and also bright colored veggies like oranges, squash, and corn.
It’s quite literally named after luteus, the latin term for yellow, due to some of the sources it’s found in (the vegetables specifically; egg yolk being yellow is a happy coincidence).
What Is Zeaxanthin?
Zeaxanthin is a carotenoid that, while less researched, is commonly paired with lutein when it comes to supplementation.
This may be due to how lutein, zeaxanthin, and a metabolite of theirs (known as meso-zeaxanthin) are collectively known as “macular pigment” as they build up in the retina where they exert protective effects.
There are many carotenoids in existence, measuring in the hundreds, so zeaxanthin by virtue of being in food sources (most notably the yolk of eggs) and sharing mechanisms with lutein let it hold a note-worthy spot alongside what can be seen as the “main carotenoid” in lutein.
Why Do People Supplement with Lutein and Zeaxanthin?
The main reasons people take lutein and zeaxanthin are:
- Eye health
- Skin health
- Cognitive health
- Cardiovascular health
- Antioxidant properties
They have been researched together in tandem, and have been a very common non-vitamin inclusion in the majority of multivitamins these days. It’s common to see them on the label of many dietary supplements, even those sold in grocery stores.
Supplementation is not mandatory, since even a single egg can raise blood levels of these two carotenoids and daily consumption increases levels in the eyes (a common target tissue), but fears about cholesterol drive some people away from egg consumption.
The reason they’re so widespread, and why people supplement with them, is in part due to how well researched these carotenoids have become in order to try and explain the benefits of egg consumption.
How common is research on these two in particular?
To put it into perspective, a cursory search of lutein and zeaxanthin in Pubmed (a collection of online scientific data) result in 5,000 and 3,000 hits respectively—340 and 180 clinical trials each.
While not as well researched as common staples like creatine, fish oil, and vitamin C this is far more than the majority of herbal supplements that are lucky to get 10 clinical trials. Bacopa monnieri, which we use in Ascend, is glad to have 18 good ones.
As far as dietary supplements go lutein and zeaxanthin are pretty lucky.
So we reach a point where these two are technically not vitamins, but they’re a common compound in the human diet (through eggs) and may explain the benefits of eating egg yolks. Furthermore, due to a combination of eye and brain health they may hold a special place for aging individuals.
Do these benefits come to fruition in scientific studies?
What Are the Benefits of Lutein and Zeaxanthin?
The major benefits of lutein and zeaxanthin are mostly related to systems vitamin A acts on.
This includes:
- The eyes, specifically the retina
- The brain, fairly ubiquitously
- The skin, to a degree
Let’s start with the most common reason people supplement with these compounds.
Lutein and Zeaxanthin and Eye Health
When it comes to the vitamin A systems, the eyes are the first thing to think of.
While vitamin A is vital to proper eye health, we can’t simply just plop more into the body. After all, excess of any vitamin will cause harm to the system rather than support it—much like a doting mother with your email password, too much love can be oppressive.
So things that gain access to these areas, but don’t act like a vitamin but just provide other benefits, can hold a lot of promise. This is what we see with lutein and zeaxanthin.
Both of these carotenoids are able to reach the eye after oral supplementation, where they act as antioxidants—in a way that many other antioxidants can’t since the eyes don’t tend to absorb just anything from the blood.
It’s because they’re carotenoids that they can exert protective effects both in rats and humans.
These two carotenoids, also known as the “macular pigments” or “macular carotenoids,” are associated with vision quality and less age-related macular degeneration (AMD.)
In fact, consuming these carotenoids from both supplements and eggs seems to help mitigate the progression of this disease state. However, it seems to take a long time to occur as even eight weeks of supplementation is too short in duration.
It seems best to be something taken each and every day, which is perhaps why it’s included in multivitamins, but it seems effective for aging individuals who are starting to get eye problems.
Lutein and zeaxanthin, the macular pigments, are important for eye health. You can get them through the diet or through supplements, but they can reduce the rate of which you lose eyesight during aging.
Lutein and Zeaxanthin and Brain Health
Lutein and zeaxanthin can be measured in the eyes, and their density is associated with Alzheimer’s disease and cognitive decline.
Based on this association, studies were conducted to see how lutein and zeaxanthin affect the brain itself. Most studies right now focus on lutein alone as it seems to be surprisingly nootropic, but some studies still assess both collectively.
It should also be mentioned that, since lutein is present in many vegetables including dark leafy greens, it’s one of many factors behind why veggies can slow cognitive aging alongside stuff like nitrates and potassium.
These carotenoids are present in the brain, to a high degree in white matter as well (the connective part between the two sides of the brain) and lutein is thought to be protective by virtue of its antioxidant properties preventing DHA from being oxidized.
Along with EPA, DHA is the primary fatty acid found in fish oil and in human brain tissue. Both DHA and EPA can be oxidized, and lutein may very well prevent this.
That’s the theory right now, at least, but regardless of how it works it’s known that supplementation of these carotenoids (12 mg a day) is able to improve cognition when supplemented for one year in elderly individuals.
It’s uncertain if this applies to youth since they normally have pretty good levels of lutein and zeaxanthin, but these levels are reduced in the elderly. The benefits may be more related to replenishment rather than inherent.
The benefits are widespread though, being associated with better overall cognition and specifically both memory and executive function. In the case of lutein, at least, it’s even associated with improved crystallized intelligence, which is the ability to use stuff you already know.
Lutein and zeaxanthin are supplements that already have a reason to be recommended to aging individuals (eye health) and now have a very beneficial one-two punch to support their inclusion in many multivitamins.
What Do Lutein and Zeaxanthin Not Do?
Similar to most staples that have nice, subtle, hype there’s nothing we can really smack down here. No major claims that are outright false.
However, some claims are simply lacklustre and are in this section by virtue of being “meh.”
Lutein and Zeaxanthin and Skin
Vitamin A is also known for its effects on the skin, mostly because the pharmaceutical that has vitamin A-like properties known as Accutane is bloody potent.
Accutane has both amazing success stories associated with it as well as horrible stories of side-effects, both of which speak to the power of combining vitamin-like properties with pharmaceuticals. What about things that have access to these systems but without the vitamin-like functions though?
Well, lutein and zeaxanthin are indeed present in the skin but believe it or not there’s very limited evidence on this topic. It has been studied and oral supplementation improved antioxidant defenses while lightening the skin (basically helping smooth out complexion so you have a more even skin tone) but beyond that studies are limited.
This may be due to how, in assessing what carotenoids would be best for the skin, many researchers like to lean towards astaxanthin which has a wide range of benefits.
Lutein and zeaxanthin may be good for the skin, but not only are they understudied they’re also outperformed by the salmon carotenoid known as astaxanthin. While not enough evidence to seek out lutein and zeaxanthin for skin health, they might be a nice additional benefit.
Lutein and Zeaxanthin and Cardiovascular Health
Lutein and zeaxanthin are recommended for cardiovascular health at times, and their effects are quite … well … lacklustre.
This stems from the fact that, due to being in veggies that are all around good, lutein intake is at times associated with less cardiovascular problems compared to people who eat less veggies (and thus, get less lutein.)
However, studies assessing these carotenoids themselves or in combination with fish oil fail to see appreciable reductions in cardiovascular disease risk.
This isn’t to say they are wholly worthless, as they may have anti-inflammatory effects in people who already have coronary artery disease, but the claim that they are “heart healthy” should be taken with an ironic grain of salt.
Right now, lutein and zeaxanthin could be argued to be a tad heart healthy but it isn’t a strong enough reality to make it a selling point of these carotenoids. May very well be a happy little side-effect, or not, but at least it isn’t negative.
What Is the Clinically Effective Dose of Lutein and Zeaxanthin?
Studies on these carotenoids tend to float around in a pretty well established range of 12 to 20 mg combined carotenoids.
Usually the lower end is used when there are other antioxidants also present, like in studies assessing “multivitamins” that also use vitamins C and E, while the 20 mg dose is used in studies using these carotenoids by themselves.
The dose is either split evenly between the two or, more commonly, there’s a relatively higher proportion of lutein due to it having more studies on it—for example, a supplement with 12 mg lutein paired with 6 mg zeaxanthin.
These doses, taken once a day with a meal, seem to be sufficient to get all clinical benefits from these carotenoids.
What Types of Results Should I Expect with Lutein and Zeaxanthin?
As all benefits of these carotenoids only occur after supplementing with them for a few months, it’s doubtful that you’ll perceive any benefits from them.
Even in people who would benefit from them the most, which are individuals who due to age are having their cognition and eye sight go away hand in hand, the benefits occurring over the course of two months minimum (six months up to a year being better estimates for efficacy) make it so it’s hard to see day to day differences.
However, there are also no known acute side-effects with lutein and zeaxanthin so you may quite literally feel nothing from these supplements until your next family gathering where somebody comments on how you seem more “on your game” with your wit.
Do Lutein and Zeaxanthin Have Any Side Effects?
At this moment in time, supplementation of lutein and zeaxanthin in otherwise healthy subjects (youth or elderly) is not associated with any known side-effects.
The only potential side-effect of these carotenoids is similar to that of vitamin C and E. By virtue of them being antioxidants, if given to heavy smokers it may be possible that lutein actually ends up doing a bit more harm than good.
This is because any antioxidant that serves a “moderating” role may have the potential to be a pro-oxidant, on an as needed basis, and the act of heavy smoking can force these antioxidants to be harmful when they should instead be helpful.
It isn’t fully proven to be harmful, yet, but it’s a well known enough phenomena to be cautious about taking high dose lutein while smoking heavily. (Or, you know, just stop smoking? Might be the better option.)
The Bottom Line on Lutein and Zeaxanthin
At the end of the day, these two molecules are a great example of what I believe pseudo vitamins should be known for—despite not being among them.
This refers to things that, if they end up being put in your mouth, you smile and move on with your day. Beneficial effects that interest you, but a magnitude that usually doesn’t drive a purchasing decision.
However, if you are an older individual who is reaching the age where cognition and eye health are starting to go away hand-in-hand, then these two become things to seek out immediately due to their benefits.
The ability to potentially preserve proper cognitive function during aging paired with the ability to prevent the decline in eyesight that come with aging are enough, but a potential cardiovascular and skin benefit are just icing on the cake.
Thankfully, you might already be taking them. Pushing back the inevitable aging process is pretty easy when the multivitamin you’re taking already has your back, ain’t it?
