The Flavonoid Fighter - The Anticancer Potential of Quercetin Revealed

There’s a reason an apple a day keeps the doctor away… behold quercetin, the unsung hero of the nutrient world that's been quietly fighting cellular villains (better known as free radicals) for years. This tiny yellow molecule, also known as sophoretin, meletin, or quercetol, is donning a cape made of antioxidants and ready to swoop in and save the day!

From anti-allergic to anti-inflammatory properties, quercetin has shown major potential in being just the thing to make spring a less sneezy season and to extinguish the inflammatory processes that put your body in alarm mode. More importantly, scientists have been able to watch quercetin suppress cancer development in tumour cells grown in Petri dishes and in animals designed to replicate human cancers. They observed this for breast, lung, liver, ovarian,
and prostate cancers!

So what, you might ask?
The stage has been set for quercetin to show promising results in your body, as a powerful anticancer fighter keeping your cells in check. From combatting oxidative stress to directly suppressing cancer cell growth, quercetin might take the spotlight as an important emerging cancer-preventative nutrient to watch out for.

Is Quercetin In My Kitchen? Where!?

Where can you find this caped crusader, you might ask? Well, it turns out that quercetin has been masquerading as the bitter taste in some of your favourite foods – so you might want to think twice before turning away from a bitter plate. Capers are its secret lair, containing a whopping 234 mg per 100 grams. Quercetin also hangs out in more palatable hideouts like red onions, apples, and blueberries.

Let’s take a look at a list of other common sources of quercetin:

1. Red onions: 32 mg per 100g – that guacamole you made your friends is more than just a tasty dip; it’s a health superfood. Red onions also provide the most bioavailable form of quercetin (AKA ingesting quercetin from red onions would yield the most benefits!)
2. Kale: 23 mg per 100g – as bitter as kale is, your body sure won’t be when you nourish it with this anticancer superfood.
3. Blueberries: 8 mg per 100g - that $8 berry smoothie you’re treating yourself to at the end of a long day may just be the investment you need to protect your body against the threat of cancer.
4. Apples: 4 mg per 100g – an apple a day surely will keep the doc away!

However, it is worth noting that the crop of food and its storage form will impact how much quercetin you will get out of it. Onions contain the most bioavailable form, whereas other food sources might be less efficient at supplying you with quercetin capable of acting on your cells.

Superpowers: More Than Meets the Eye

What exactly does quercetin do? Let’s walk through the various benefits associated with consuming a diet high in quercetin.

1. Antioxidant Extraordinaire: Quercetin is like that friend who always has your back. It scavenges harmful free radicals, protecting your cells from oxidative stress (which could otherwise lead to cancer development). In scientific terms, it's been shown to increase plasma levels of superoxide dismutase, catalase, and glutathione – your body's natural antioxidant defence squad.
2. Inflammation Fighter: This flavonoid isn't afraid to take on chronic inflammation. Studies have shown it can reduce levels of inflammatory markers like C-reactive protein(CRP) and interleukin-6 (IL-6). It's like having a tiny firefighter constantly dousing flames in your body!
3. Allergy Alleviator: Quercetin fights allergies by inhibiting the release of histamine from mast cells. It's like having a bouncer at the door of your immune system, keeping those pesky allergens in check. Getting through spring will be a breeze with this nutrient in hand.
4. Cancer Cell Nemesis: Now, this is where quercetin really flexes its superhero muscles. In lab studies, it's been shown to give cancer cells the old one-two punch. But remember, while quercetin is impressive in the petri dish, it hasn't quite made it to the human boxing ring yet for cancer treatment.
   
   It’s important to note, however, that these benefits have mostly been found in petri dish cells and animal models. To fully apply these findings to humans (like you!), more studies done on humans are needed.

Mechanisms of Anticancer Action: The Science Behind the Superpowers

So... how exactly does quercetin put the brakes on cancer development?

• Apoptosis Activator: Quercetin is like the strict parent of the cellular world. When it spots misbehaving cancer cells, it activates their self-destruct sequence (apoptosis). It does this by triggering the release of cytochrome c and activating caspase enzymes, the executioners of the cellular world. This means that when a cell is damaged in a way that puts it at risk of becoming a cancer cell, quercetin will activate its programmed death, effectively eliminating it from your body!

• Cell Cycle Arrest: This flavonoid knows how to put cancer cells in time-out. It halts them at the G2/M phase of the cell cycle, essentially telling them, "You shall not pass!" to the division stage. Why is this useful? Cancers are characterized by unregulated growth. Quercetin essentially keeps the precancerous cell at the checkpoint just before it can divide, preventing it from producing more damaged cells.

• Antioxidant Gene Booster: Quercetin doesn't just fight free radicals itself; it's also a great coach. It boosts the expression of your body's own antioxidant enzymes, creating a stronger defence team against oxidative stress. Oxidative stress interacts with every stage of cancer progression, producing DNA damage and enabling inflammation, so antioxidants play a critical role in countering this stress and preventing cancer from progressing at various stages.

• Synergist Extraordinaire: Here's where quercetin really shines. When it teams up with certain cancer-fighting drugs, it's like the dynamic duo of the medical world. It's been known to enhance the effects of drugs like cisplatin and doxorubicin, showing cancer cells who's boss. It also makes drug-resistant cancers more sensitive to these chemotherapy drugs and radiotherapy via several molecular pathways.

The Balancing Act: Even Superheroes Have Limits

Before you go chugging quercetin by the gallon, remember that even superheroes have their limits. While generally safe, high doses (over 1 gram per day) might cause kidney issues in some people. It's always best to get your dose from a variety of fruits and veggies rather than going overboard with supplements. It’s also not the most stable and soluble nutrient, making it more difficult for it to make the fully journey from your plate to your cells. Nonetheless, a plate of
fruit and veggies a day will make your body thank you, and the onions that make you cry will have your cells jumping with joy.

In conclusion, quercetin might not wear a cape in real life, but in the world of nutrition and cellular biology, it's definitely a superstar. From its antioxidant powers to its cancer-fighting potential, this flavonoid is proof that sometimes the best things come in small, molecular packages. So next time you're munching on an apple or adding some red onions to your salad, give a little nod to quercetin – the tiny but mighty nutrient that's been looking out for you all along!

Want to get started? Here’s an easy recipe involving quercetin: Berry Blast Smoothie

(Recipe credits: Dinner At The Zoo, https://www.dinneratthezoo.com/mixed-berry-smoothie/)

Ingredients:

• 1 1/2 cups apple juice
• 1 banana, sliced
• 1 1/2 cups frozen mixed berries
  - Use blueberries & blackberries to secure quercetin in your smoothie!
• 3/4 cup vanilla Greek yogurt
• 1 tablespoon honey optional
• Optional garnish: fresh berries and mint sprigs
  
  Instructions:

1. Simply add the apple juice, banana, berries and yogurt to a blender, and blend until smooth. If the smoothie seems too thick, add a little more liquid (1/4 cup).
2. Taste and add honey if desired. Pour into two glasses and garnish with fresh berries and mint sprigs if desired.

Want to learn more?

Quercetin is only one player in the fight against cancer. For more info on other anticancer nutrients and lifestyle tips, take a look around Anticancer.ca. You would be doing your health a massive favour!

This article is based on peer-reviewed information. Read the full article about quercetin for comprehensive scientific evidence, clinical trial information, and citations:
https://anticancer.ca/docs/quercetin

Written by Adriana Goraieb
Photographer: @genipicache.photography (Instagram)
Model: @moiracosgriffe (Instagram)