Antioxidants: Ammunition against disease?

Arming with Antioxidants!

When you are looking to boost your immunity in the age of the Coronavirus, start at home. Reach for those brightly colored fruits on your kitchen counter, the vibrant vegetables in your refrigerator, that dark chocolate you had stashed away in your cabinet, the turmeric in your spice drawer and/or that soothing green tea in your pantry to name just a few. You will notice that a common denominator in all of these foods is that all of them have rich, brilliant colors, marking the presence of substances called antioxidants which have substantial disease-fighting potential.

Antioxidants called anthocyanins are found in berries and red wine.© Copyright, 2015-2020, Sangeeta Pradhan, RD, LDN, CDE

I would like to add a disclaimer here. I am not in any way suggesting that antioxidants, beneficial as they are, are the be all and end all in the war against disease producing microbes. There is a whole host of factors that can potentially strengthen your immune system, and antioxidants are only one of the players. However, by combating oxidative damage in your body, their role is an important one, nevertheless, and should not be overlooked.  

When your body is attacked by a “foreign” or alien entity such as a bacterium or a virus, its immune system gets into full gear to combat the invader. Your health and nutrient status are key to ensuring that your immune system is well equipped to vanquish the unwelcome intruder.

Which nutrients may help immune function?

Animal and human studies show that the nutrients  that help your immune system function efficiently include essential amino acids, (break down products of proteins), an essential fatty acid called linoleic acid, vitamin A, folic acid, vitamin B6, vitamin B12, vitamin C, vitamin E, Zinc, Copper, Iron and Selenium. Reviewing each and every one of these would go beyond the scope of this article, hence this post is limited to a few of the commonly found antioxidants and zinc, with a future post devoted to how gut bacteria can help regulate the immune response.

Free radicals and Antioxidants: We have all heard the expression, “eat a rainbow of colors ”, and it’s true! Plant based foods are rich in polyphenols, which are naturally occurring substances in our diet that have been receiving a lot of attention from scientists as a result of their antioxidant properties. Antioxidants may be compounds such as vitamins or enzymes in the human body, or are substances found in foods that can help neutralize free radicals.

What are free radicals? Free radicals are lone oxygen atoms that are unstable as they are missing an electron. These unstable elements then end up attacking and stripping electrons from different compounds in your body, causing wide-spread cellular damage.

Brightly colored fruits and vegetables are one of the richest sources of antioxidants, © Copyright, 2015-2020, Sangeeta Pradhan, RD, LDN, CDE.

The war within: Our bodies are constantly bombarded, as it were, with free radicals, which can lead to oxidative stress and inflammation, the basis of all chronic disease. Antioxidants are like the marines, always standing at bay, ready to fight off the little villains called free radicals. So you want to build a strong arsenal or army of antioxidants from brightly colored fruits and veggies to combat free radicals and prevent disease. Simple, but oh so powerful!!

The promise of polyphenols: Certain antioxidants called polyphenols are found in tea, berries, red grapes, cinnamon, chocolate, coffee, whole grains and legumes.  Yes, whole grains and legumes may seem like unlikely sources of antioxidants because they do not have the same bright colors, but they do belong to a class of polyphenols called lignans.

What’s more, a 2007 study on a class of plant based polyphenols called flavonols has shown that they can down regulate or turn off genes associated with inflammation. This means they might go a long way in helping you fight and overcome the war against the invisible menaces that stalk us such as harmful bacteria and viruses.

Many of the commonly consumed vitamins such as A, C and E have antioxidant properties.

 Vitamin A 

  • A versatile vitamin: We all know that vitamin A is important for vision. But did you also know that it helps support healthy skin, your immune system and bone health?
  • Food sources of vitamin A: There are 2 forms of vitamin A: Preformed vitamin A and pro-vitamin A carotenoids. Preformed vitamin A is derived from animal sources such as milk and milk products, liver, fish oils, butter and eggs.
  • Pro-vitamin A carotenoids, a stronghold of antioxidants: Biologically active, preformed vitamin A is not found in plant foods, however many plants contain pro-vitamin A carotenoids, the red and yellow pigments in plants. While all carotenoids are antioxidants, quenching free radicals and protecting the body from oxidative damage, only a few of the carotenoids in plants have vitamin A activity. The carotenoid with the greatest vitamin A activity is beta carotene1.
  • Beta-carotene: Beta carotene is a rich, deep orange pigment, and  imparts a vibrant color to foods that are abundant in this compound such as carrots, butternut squash, sweet potatoes, and cantaloupe, to name a few.
  • Masked by chlorophyll: Spinach and other leafy greens, including beet greens, (but not beets), also contain beta carotene, however they also contain the green pigment chlorophyll, which masks the carotene they contain.
  • Don’t hold the fat: Since beta-carotene is fat-soluble, it makes sense to consume it with a small amount of fat to enable your body to absorb it in optimal amounts. As noted in this recipe, we used peanut oil, a form of mono-unsaturated fat, to maximize absorption.

Vitamin C: Human beings are one of the few mammals that are unable to synthesize vitamin C, hence we have to obtain this vitamin from our food. The best sources of vitamin C come from papayas, oranges, orange juice, cantaloupe, cauliflower, broccoli, brussel sprouts, peppers, and strawberries.

Two controlled trials found a statistically significant response for the duration of common cold symptoms, with up to 6-8 grams per day of vitamin C. This also showed that the negative findings of some common cold studies could be related to the lower dose of  3-4 grams/day of vitamin C. While three controlled trials found that vitamin C prevented pneumonia,  two controlled trials found a treatment benefit of vitamin C for pneumonia patients. Before we get ahead of ourselves,  I would like to inject a word of caution: The effects of vitamin C against infections must be investigated further before we take this as the gospel truth!

Vitamin E is another important antioxidant. Plant foods, especially plant oils, wheat germ and nuts  are the primary source of vitamin E in the diet, with smaller amounts in leafy vegetables and some fruits.

Where is lycopene lurking?:  Yet another member of the large family of plant pigments called carotenoids mentioned earlier, is lycopene.

Many studies suggest that the consumption of lycopene or lycopene-containing foods reduces the risk for developing certain forms of cancer including prostate cancer, along with the risk of cardiovascular disease

Tomatoes and tomato products are by far one of the richest sources of lycopene, with a mere 1/2 cup of canned tomato puree providing a whopping 27,000 + micrograms of lycopene, and 1 tbsp of tomato paste providing a hefty 3000+ micrograms. Not to be outdone, 1 slice of watermelon does provide 12,000 + micrograms, and 1/2 a pink grapefruit, 7000 + micrograms.

What is interesting about lycopene is that it is a heat stable antioxidant that becomes more bio-available (more easily absorbed by your body) after you cook it.  This is in sharp contrast to some of the water-soluble B vitamins that are often depleted after cooking. It is also fat soluble, hence tomatoes cooked in an oil rich medium (as featured in this recipe), have a higher lycopene content than raw tomatoes. 

Zinc: Foods with the highest zinc concentration include red meat, some shellfish, legumes, fortified cereals, and whole grains.  

Low levels of zinc are associated with an impaired immune system and poor prognosis in conditions such as sepsis. Zinc has been shown to inhibit replication of the virus causing the common cold. Administering zinc via lozenges at concentrations of ≥75 mg/day reduced the duration of common cold symptoms in healthy individuals. When using zinc lozenges, bear in mind that side effects may include a bad taste and nausea. Currently, there is inadequate data on whether prophylactic (for prevention of the common cold), zinc supplementation might be effective. Thus, more research is needed to investigate and understand the therapeutic potential of zinc for infectious diseases.

Flip side of the coin: All the nutrients discussed here come primarily from whole and unprocessed foods. As you may have guessed, processed foods and foods with added sugar or high fructose corn syrup have been shown to increase the production of free radicals in the body. This is a double whammy as they certainly do not provide any antioxidants, but in addition, are bombarding you with those vicious, free radicals that you want to avoid. 

Moral behind the story: Get all the colors of the rainbow on your plate, (not from M and Ms!), and dig in while sipping on a cup of hot green, tea (or your favorite dark red wine-in limited amounts of course)! 

Check out my recipe index to get some quick ideas that tap into the amazing, antioxidant power of foods.

(This is not an all-encompassing list, please stay tuned for more on other immune boosters and the role of gut bacteria in future posts). Stay healthy!

Disclaimer:  This blog is strictly for informational purposes only and should not be construed as medical advice. Please consult your physician or registered dietitian for recommendations tailored to your specific needs. In addition, please consult your physician before taking any antioxidant or vitamin supplements.


About Sangeeta Pradhan RD, CDE

Hi there! Welcome to my blog! If you are confused with all the conflicting messages you get bombarded with every day on carbs, fats, proteins, gluten and anything you can think of related to nutrition, look no further! The purpose of my blog is to cut through all this clutter, utilizing scientific, evidence based guidelines to help you, the consumer, navigate the complex, dietary landscape, and thus empower you to make informed decisions.
This entry was posted in Antioxidants, Fiber, Probiotics, Uncategorized. Bookmark the permalink.

9 Responses to Antioxidants: Ammunition against disease?

  1. sandomina says:

    Very informative. Thanks.


  2. Very informative and interesting post. Thank you, Sangeeta


  3. Fully agree, the brighter our food the healthier it is…. 🙂 I have been using some of my frozen fruit raspberries and redcurrants to make pies … My waist line might be protesting.. But isn’t it funny how our bodies often instinctively know what they want to eat… I have also been eating lots of celery.. As I have been craving it eat it…. Do you know what that is good for… My Gran always told us it cleared the blood??? but do not know….
    Also been taking my Vit C intake … with fruit and vitamins.. 🙂
    Thank you for this post loaded full of information…
    ❤ Take care also Sangeeta.

    Liked by 1 person

  4. Thank you so much for the feedback and for stopping by. Stay healthy!


  5. Thank you so much for taking the time to provide feedback. Stay safe and healthy!


  6. Hi Sue,

    Thank you so much-great feedback-celery has Vitamin A, Vitamin K ( helps blood clot), smaller amounts of potassium, Vitamin C and Manganese. Also contains another anti-oxidant called quercetin that can help combat inflammation in the body. In addition, it also supports gut health like many fibrous foods do. It has a high water content, so very filling for those trying to lose weight. Again, important to include a variety of all different foods to harvest all the nutrients each has to offer, but celery can certainly be one of those various foods. Hope this helps. Stay healthy and safe, my friend:))

    Liked by 1 person

  7. Thank you So much that is very helpful.. My monthly acupuncture has had to stop so maybe I am drawn to celery for the help with inflammation with my muscles, I have been overdoing the gardening recently Lol… Many thanks for this information… Truly appreciate it.. ❤

    Liked by 1 person

  8. Always, welcome, Sue. I hope your inflammation completely resolves very soon!

    Liked by 1 person

  9. 💙🙏 thank you 😊

    Liked by 1 person

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