Carotenoids: A Part of Nature’s Rainbow
With a societal push towards healthier eating, you may have heard the phrase “eat the rainbow.” But when it comes to fruits and vegetables, what do those colors actually mean and why are some fruits more colorful than others? Blueberries get their deep blue from anthocyanins, while asparagus gets its green color from chlorophyll. But when you see reds, oranges, and yellows in your grocery store, you’re probably looking at the carotenoids.
What are carotenoids?
Carotenoids are a type antioxidant (i.e. compounds that prevent cell damage from free radicals) that include some familiar power players, like β-carotene, as well as some compounds that probably don’t show up in your everyday vocabulary: lutein (loo-teen), lycopene (lie-co-peen), and zeaxanthin (zee-ah-zan-thin) among others. Deep red tomatoes? That’s lycopene. Vibrant orange carrots? Hello, β-carotene! Bright yellow squash? You’re looking at lutein. Even green vegetables like fresh spinach can pack a variety of these three carotenoids, including up to 31,500 μg of β-carotene per 100 g spinach.[1] That translates to almost 3 times the daily recommended value of Vitamin A, which your body can make using β-carotene.[2, 3]
What can carotenoids do for me?
Carotenoids are a type of antioxidant associated with anti-inflammatory properties and are particularly important for eye health. It’s estimated that lutein and other carotenoids absorb anywhere between 40–90% of blue light that enters your eye. They also reduce light scatter and help decrease damage from light.[4] No, downing extra lutein won’t give you supervision, but it will definitely help keep your eyes in good working order.
Where did the carotenoids go?
Since carotenoids produce distinct colors in your food, depth of color is a great indicator of carotenoid content on your plate. There’s a reason those dull, red tomatoes intuitively don’t seem like they’re great. At least when it comes to carotenoids, they probably aren’t. While TeakOrigin uses lab-grade instruments and robust analytical methods to determine the quantity of carotenoids in fresh produce, the human eye is actually pretty darn good at taking qualitative cues just from color. Carotenoids can be lower than normal for a variety of reasons. Storage conditions (think temperature and exposure to light or oxygen) and cooking methods play a major role in preserving or destroying nutrients in food, and carotenoids are no exception. For example, blanching and freezing spinach preserves around 85% of total carotenoids compared to raw spinach. Boiled spinach that you’ve kept in your fridge for a couple of days may only have 36% of carotenoids left.[1] On top of that, carotenoids degrade over time, so even the best looking older produce may be lacking in carotenoids by the time you are ready to eat it.
Carotenoids are typically highest in fresh, mature, and ripe foods. Carotenoids are fat-soluble, meaning they will dissolve in fat, so drizzling olive oil on your spinach salad is a healthy and tasty way to help get your daily dose of lutein. Better yet, a major fatty acid in avocados (oleic acid) is particularly good at making carotenoids bioavailable, so adding tomato to guacamole may actually help you get more bang for your buck![5]
Eating the rainbow is a great way to stay healthy, but make sure you are doing so while eating high quality, colorful, and fresh foods. It’ll not only add great flavor, but it’ll give your body the nutrients it needs to run, and feel, at its best.
References
- Bunea, A.; Andjelkovic, M.; Socaciu, C.; Bobis, O.; Neacsu, M.; Verhé, R.; Camp, J. V., Total and individual carotenoids and phenolic acids content in fresh, refrigerated and processed spinach (Spinacia oleracea L.). Food Chemistry 2008, 108 (2), 649–656.
- U.S. Department of Health & Human Services, National Institutes of Health, Office of Dietary Supplements, Vitamin A Fact Sheet for Health Professionals. https://ods.od.nih.gov/factsheets/VitaminA-HealthProfessional/.
- Food and Drug Administration, Frequently Asked Questions for Industry on Nutrition Facts Labeling Requirements. https://www.fda.gov/media/99069/download.
- Mares, J., Lutein and Zeaxanthin Isomers in Eye Health and Disease. Annu Rev Nutr. 2016, (36), 571–602.
- Saini, R. K.; Nile, S. H.; Park, S. W., Carotenoids from fruits and vegetables: Chemistry, analysis, occurrence, bioavailability and biological activities. Food Research International 2015, 76, 735–750.
