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  • Writer's pictureChristina Seibold

Functional Foods, What the What??

Updated: Jun 21, 2023

Do you ever wonder what that phrase “functional food” means? It’s likely that if you’ve been to the grocery store or read the news lately, you’ve seen the phrase. But what does it mean? Is it any different from any other health claims found on beverages and packaged foods?

Health claims (think “good source of…” or "high in ….”) found on beverages and packaged foods can be completely overwhelming to the consumer. And, let’s be honest, grocery shopping is tedious enough without spending time trying to decipher all the lingo on food packaging. So, in the interest of saving you time in the future, let me break down exactly what a functional food is, what these foods do for human health, what food sources are considered functional foods, and some of my favorite functional foods. Hopefully, the next time you are at the store you’ll be able to easily spot some of these “functional” foods that tout amazing health benefits.

So, what exactly is a functional food? Simply put, they are foods or ingredients in foods that improve physical health and/or lower the risk for disease or chronic health conditions. Functional foods have properties “beyond basic nutrition” that may improve gastrointestinal (gut) function, boost immune function, lower cancer and cardiovascular (heart) disease risk, and improve mental health (1), (2). These foods may also positively affect aging, stress, and inflammation (1), (2). There are four basic categories of functional foods that include whole foods, modified foods, probiotics, and prebiotics (1).

Whole foods (fruits, vegetables, whole grains, seafood, meat and dairy) are the rock stars of functional foods. These are filled with vitamins, minerals, fiber, phytonutrients and other nutrients that work with your body's systems to support optimal function (no modifications necessary). This is why eating a whole foods diet leads to better long-term health outcomes. By this logic, it’s probably no surprise that in the eyes of your nutritionist, whole foods are the best choice. But, what about all the other choices at the store? The convenient pre-packaged foods and beverages that people gravitate towards to get their daily dose of vitamins, minerals or immune boosting nutrients?

Cue in functional beverages (think vitamin water, Kombucha, juiced vegetable drinks, probiotic drinks, and even some caffeinated energy drinks). These are often classified as modified foods because they are “enriched” (nutrients are added back in that were lost during processing) or “fortified” (added nutrients that were not in the original food) with vitamins, minerals, antioxidants, fatty acids, electrolytes, probiotics, phytochemicals (plant-based chemicals), botanicals, or adaptogenic herbs that may boost your immune system. Sounds pretty great that you could boost your immune system with that next trip to the convenience store right? But are these super ingredients all they are cracked out to be?

Honestly, it depends on the person. Adaptogens like Ashwagandha and Panax Ginseng have gained popularity as ingredients in functional foods with claims that they can decrease stress, increase your energy, and potentially regulate your immune system (3). Although that sounds like a great idea, especially in a world where our stress levels are off the charts, not everyone is able to tolerate these types of herbs. An important point to consider when choosing a product with herbs or botanicals is that some herbs can interact with medications. If you are considering a new product that touts some serious health benefits, take a minute to do a little research to see if there are any potential interactions or side effects. Especially if you use medications or have a chronic health condition. Secondly, keep in mind that some of the popular functional foods and beverages can have quite high sugar and caffeine content. Both of which can negate some, if not all, positive effects of vitamins, minerals, antioxidants, and other phytochemicals.

So, lastly, what about probiotics and prebiotics? What do they bring to the table in terms of “functional foods?” Simply put, probiotics are the live bacteria that provide us health benefits by keeping harmful bacteria in check in our gut, while prebiotics are non-digestible nutrients (fibers) that feed the beneficial bacteria in the colon (5). But what do they do for our health? Turns out, they do quite a lot. Some probiotic strains can positively influence the health of our gastrointestinal tract and may have a positive effect on stress and anxiety (4), while some prebiotics are known to have anti-cancer effects, increase immunity, and increase the absorption of minerals (6).

So all that said, would I pick up a minimally processed food or beverage that claims to have functional health benefits? Maybe. What I would choose is a beverage like green tea (zero sugar) or Kombucha that has less than 12 grams of sugar per container. Container is a key word because some beverages on the market have a serving size of 2 or 2.5 per container, something that most people aren’t checking before downing the whole bottle or can.

Personally, I am more apt to choose unprocessed functional foods and beverages that contain vitamins, minerals, fiber, omega-3 fatty acids, antioxidants, and prebiotic foods that provide fuel or energy to the bacteria that reside in our gut.

I’ll leave you with a few of my favorite functional foods:

  • Chia Seeds which contain fiber (great prebiotic), Omega-3 fatty acids, vitamin E, phenolic acid, vitamins, and antioxidants (7).

  • Chicory root which tastes similar to coffee and has inulin fiber that feeds beneficial bacteria in your gut. It may also have glucose regulating properties, a plus for improving glucose regulation (8).

  • Kombucha, a fermented tea that contains probiotics and antioxidants.

  • Tomatoes, a rich source of the antioxidant lycopene (1).

  • Berries: of all kinds! The antioxidant content in berries (especially dark blue) is fantastic.

  • Broccoli, rich in fiber and sulfur containing compounds that are essential for glutathione production, the most abundant intracellular antioxidant that we have (1).

  • Green tea, rich in antioxidants.

  • Spinach, rich in fiber, folate, calcium, and lutein, a carotenoid that is beneficial for eye health (1).

  • Fresh fish, full of essential fatty acids that help inflammation, and play a role in the health of our cell membranes.

  • Mushrooms, a rich source of Vitamin D which is important in immune health.

  • Kimchi, a fermented food source of probiotics consisting of baechu cabbage, radish, cucumber and leek, is a rich source of plant-derived lactic acid bacteria that may have functional health benefits as an antioxidant, antidiabetic and might be beneficial in cases of obesity (9).

  • Last, but not least are prebiotic foods such as: onions, garlic, leeks, asparagus, green bananas, and Jerusalem artichokes. These guys are feeding all that good bacteria in your gut that is keeping you healthy!

So the next time you are perusing the functional foods section of the grocery store, I hope you will use the information provided in this article to help you make informed decisions to better your health.


  1. Musthafa, Mohamed Essa & Bishir, Muhammed & Bhat, Abid & Chidambaram, Saravana Babu & Al-Balushi, Buthaina & Hamdan, Hamdan & Govindarajan, Nagamaniammai & Freidland, Robert & Qoronfleh, M.. (2021). Functional foods and their impact on health. Journal of Food Science and Technology. 60. 10.1007/s13197-021-05193-3.

  2. Altintas, Zeynep & Tolun, Aysu. (2019). Medicinal Properties and Functional Components of Beverages. 10.1016/B978-0-12-816397-9.00007-8.

  3. Ratan ZA, Youn SH, Kwak YS, Han CK, Haidere MF, Kim JK, Min H, Jung YJ, Hosseinzadeh H, Hyun SH, Cho JY. Adaptogenic effects of Panax ginseng on modulation of immune functions. J Ginseng Res. 2021 Jan;45(1):32-40. doi: 10.1016/j.jgr.2020.09.004. Epub 2020 Sep 17. PMID: 33437154; PMCID: PMC7790873.

  4. Lew, L., Hor, Y., Yusoff, N. A. A., Choi, S., Yusoff, M. S. B., Roslan, N. S., . . . Liong, M. (2019). Probiotic lactobacillus plantarum P8 alleviated stress and anxiety while enhancing memory and cognition in stressed adults: A randomised, double-blind, placebo-controlled study. Clinical Nutrition, 38(5), 2053-2064.

  5. George Kerry, R., Patra, J. K., Gouda, S., Park, Y., Shin, H., & Das, G. (2018). Benefaction of probiotics for human health: A review. Journal of Food and Drug Analysis, 26(3), 927-939.

  6. Mohanty, D., Misra, S., Mohapatra, S., & Sahu, P. S. (2018). Prebiotics and synbiotics: Recent concepts in nutrition.

  7. Tak Y, Kaur M, Kumar R, Gautam C, Singh P, Kaur H, Kaur A, Bhatia S, Jha NK, Gupta PK, Amarowicz R. Repurposing chia seed oil: A versatile novel functional food. J Food Sci. 2022 Jul;87(7):2798-2819. doi: 10.1111/1750-3841.16211. Epub 2022 Jun 16. PMID: 35708201.

  8. Nishimura M, Ohkawara T, Kanayama T, Kitagawa K, Nishimura H, Nishihira J. Effects of the extract from roasted chicory (Cichorium intybus L.) root containing inulin-type fructans on blood glucose, lipid metabolism, and fecal properties. J Tradit Complement Med. 2015 Jan 20;5(3):161-7. doi: 10.1016/j.jtcme.2014.11.016. PMID: 26151029; PMCID: PMC4488567.

  9. Song, E., Ang, L., Lee, H.W. et al. Effects of kimchi on human health: a scoping review of randomized controlled trials. J. Ethn. Food 10, 7 (2023).


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