Tag: Quercetin

Antioxidants support the body from oxidative stress. They help the fight against an overabundance of free radicals, unstable molecules that can damage cells and contribute to extra sick days. A balanced diet rich in antioxidants can support your immune system, promote skin health, and even reduce the risk of some chronic diseases. But what are antioxidants, and where can we find them in our diets?

Antioxidants, An overview

Antioxidants are substances that help neutralize free radicals, preventing them from causing cellular damage in the body. Free radicals are produced in the body through normal metabolic processes, but external factors such as pollution, smoking, UV radiation, and certain chemicals can increase their production. While free radicals do play a role in immune defence, an overproduction can lead to oxidative stress, which is associated with numerous health issues, including inflammation, cancer, and cardiovascular diseases.

There are several types of antioxidants, categorized based on their chemical nature and sources. The two major classes are:

1. Endogenous Antioxidants – These are produced by the body, such as glutathione and superoxide dismutase.

2. Exogenous Antioxidants – These come from the diet, primarily from fruits, vegetables, and other plant-based foods.

Among the most well-known dietary antioxidants are vitamins (like A, C, and E), minerals (such as selenium), and phytochemicals (like flavonoids, polyphenols, and carotenoids). Each type of antioxidant has unique properties and functions.

Types of Antioxidants and Their Benefits

1. Vitamin C (Ascorbic Acid)

One of the most abundant water-soluble antioxidants, vitamin C, is essential for maintaining a healthy immune system, protecting skin from oxidative damage, and aiding in collagen production. Vitamin C is also crucial for regenerating other antioxidants like vitamin E. Studies suggest that consuming foods rich in vitamin C can lower the risk of chronic diseases and support the body’s defence system against infections and inflammation.

Foods Rich in Vitamin C:

– Citrus fruits (oranges, lemons, limes)

– Berries (strawberries, blueberries, raspberries)

– Bell peppers

– Broccoli

– Kiwi

2. Vitamin E (Tocopherol)

Vitamin E is a fat-soluble antioxidant that protects cell membranes from oxidative damage. It’s particularly effective in guarding skin cells against damage caused by UV radiation and environmental toxins. Vitamin E also supports immune function and has anti-inflammatory properties, which can help reduce the risk of heart disease and certain cancers.

Foods Rich in Vitamin E:

– Nuts and seeds (almonds, sunflower seeds, hazelnuts)

– Vegetable oils (sunflower oil, safflower oil)

– Leafy greens (spinach, kale)

– Avocados

3. Beta-Carotene (vitamin A)

Beta-carotene is a type of carotenoid that the body converts into vitamin A, a powerful antioxidant. It plays a critical role in maintaining good vision, skin health, and immune system function. Beta-carotene also helps prevent oxidative damage in cells, reducing the risk of certain cancers and age-related macular degeneration.

Foods Rich in Beta-Carotene:

– Carrots

– Sweet potatoes

– Pumpkins

– Dark leafy greens (spinach, kale)

– Apricots

4. Selenium

Selenium is a trace mineral that works synergistically with other antioxidants like vitamin E to help protect the body from oxidative stress. It is essential for thyroid health and immune function. Selenium deficiency can lead to an increased risk of cancer, cardiovascular diseases, and cognitive decline.

Foods Rich in Selenium:

– Brazil nuts

– Tuna and other fatty fish

– Chicken and turkey

– Eggs

– Whole grains

5. Flavonoids and Polyphenols

Flavonoids are a diverse group of plant-based antioxidants found in many fruits, vegetables, and beverages. They have strong anti-inflammatory and immune-boosting properties. Polyphenols, a type of flavonoid, have been studied for their role in reducing the risk of cardiovascular diseases, promoting brain health, and potentially preventing cancer. These antioxidants help neutralize free radicals and reduce inflammation, contributing to improved overall health.

Foods Rich in Flavonoids and Polyphenols:

– Berries (blueberries, blackberries)

– Dark chocolate (with at least 70% cocoa)

– Green tea and black tea

– Red wine

– Apples

6. Lycopene

Lycopene, a carotenoid found in tomatoes and other red-coloured fruits, has been linked to a lower risk of prostate cancer and heart disease. Its antioxidant properties help protect cells from damage and reduce inflammation. Interestingly, lycopene is better absorbed by the body when tomatoes are cooked, making tomato-based sauces a great source of this antioxidant.

Foods Rich in Lycopene:

– Tomatoes (especially cooked)

– Watermelon

– Pink grapefruit

– Red peppers

– Papaya

Antioxidants usually taken in supplement form

Quercetin

Quercetin is a flavonoid found in apples, onions, tomatoes, tea, and brassica vegetables. It offers antioxidant, antiviral, anti-inflammatory, anti-diabetic, and anti-carcinogenic benefits. Quercetin has been studied for promoting mitochondrial biogenesis, stabilizing mast cells, and supporting the gut’s tight junctions.

CoQ10

CoQ10 is concentrated in mitochondria, where it helps produce energy, making it vital for energy-intensive processes like immune function. It also has antioxidant and anti-inflammatory properties, and research indicates that it helps reduce oxidative stress caused by intense exercise.

Alpha-Lipoic Acid (ALA)

ALA helps regenerate other antioxidants like vitamins C and E and increases essential antioxidant enzymes like catalase and superoxide dismutase. ALA can cross the blood-brain barrier, reducing neuroinflammation and pro-inflammatory cytokines. It also supports immune modulation and has been studied for its role in preventing SARS-COV-2 entry into cells. ALA is found in foods like broccoli, spinach, red meat, and tomatoes.

Glutathione

Glutathione, the body’s “master antioxidant,” is crucial for immune function and protecting cells from oxidative stress. Synthesized from cysteine, glycine, and glutamic acid, glutathione supports mitochondrial function, DNA maintenance, and the immune system, including lymphocyte and NK cell activity. It also regenerates vitamins C and E.

N-Acetyl Cysteine (NAC)

NAC is a precursor to glutathione, boosting its levels and acting as an antiviral, antioxidant agent. It helps protect cells from damage, reduces inflammatory cytokines, and restores natural killer (NK) cells, supporting overall immune health.

Resveratrol

Resveratrol is a polyphenol found in grapes, red wine, mulberries, and rhubarb. It provides antioxidant, anti-inflammatory, and immune-regulating benefits by targeting enzymes involved in eicosanoid production, inhibiting NF-kB, and reducing inflammatory cytokines. Resveratrol also promotes mitochondrial biogenesis and activates sirtuins, proteins associated with metabolism and aging.

Antioxidants and Immune Health

A growing body of evidence suggests that antioxidants can boost immune function. antioxidants, particularly those derived from plant-based sources, play an essential role in supporting immune health by neutralizing free radicals and reducing inflammation. Chronic oxidative stress can impair the immune system, making the body more susceptible to infections and diseases. By consuming antioxidant-rich foods, you can reduce oxidative stress and help the immune system function more efficiently.

For instance, vitamin C is known for its immune-boosting properties, helping white blood cells function more effectively and protecting them from oxidative damage. Flavonoids and polyphenols, found in fruits like berries and beverages like green tea, also contribute to a healthy immune response by reducing inflammation and supporting the production of immune cells.

How to Incorporate Antioxidant-Rich Foods into Your Diet

Incorporating foods rich in antioxidants into your daily diet is easier than you might think. Here are a few tips:

1. Eat the Rainbow: Include a variety of colourful fruits and vegetables in your meals. The different pigments in plants are often linked to specific antioxidants. For example, orange and yellow fruits are rich in carotenoids like beta-carotene, while dark purple and blue fruits are high in anthocyanins, another type of antioxidant.

2. Swap Snacks: Choose nuts, seeds, and berries as snacks instead of processed foods. Almonds and sunflower seeds provide vitamin E, while blueberries offer a good dose of flavonoids.

3. Cuppa: Green tea is rich in catechins, a type of flavonoid known for its antioxidant effects. Similarly, red wine in moderation can provide polyphenols, particularly resveratrol, which is linked to heart health benefits.

4. Use Antioxidant-Rich Oils: When cooking, use olive oil or avocado oil, both rich in vitamin E and other antioxidants. These oils can protect cells and help fight inflammation.

conclusion

Antioxidants support good health. By eating a variety of antioxidant-rich foods, you can help your body’s defence against oxidative stress, promote immune health, and potentially lower your risk of developing age-related diseases. From vitamin C-rich citrus fruits to selenium-packed Brazil nuts, the key is to diversify your food choices to ensure you’re getting a broad range of antioxidants.

References:

_{A Review of Dietary (Phyto)Nutrients for Glutathione Support, Deanna M. Minich, and Benjamin I. Brown https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6770193/}

_{Review: Free radicals, antioxidants, and the immune system, J A Knight https://pubmed.ncbi.nlm.nih.gov/10807157/}

_{Huang, Z., Liu, Y., Qi, G., Brand, D. and Zheng, S. (2018). Role of Vitamin A in the Immune System. Journal of Clinical Medicine, 7(9), p.258. doi:https://doi.org/10.3390/jcm7090258 Manthena, S. (2015).}

_{Effectiveness of CoQ10 Oral Supplements as an Adjunct to Scaling and Root Planing in Improving Periodontal Health. JOURNAL OF CLINICAL AND DIAGNOSTIC RESEARCH. doi:https://doi.org/10.7860/jcdr/2015/13486.6291.}

_{Sinha, R., Sinha, I., Calcagnotto, A., Trushin, N., Haley, J.S., Schell, T.D. and Richie, J.P. (2018). Oral supplementation with liposomal glutathione elevates body stores of glutathione and markers of immune function. European Journal of Clinical Nutrition, [online] 72(1), pp.105–111. doi:https://doi.org/10.1038/ejcn.2017.132}

_{Rizwan, M., Rodriguez-Blanco, I., Harbottle, A., Birch-Machin, M.A., Watson, R.E.B. and Rhodes, L.E. (2011). Tomato paste rich in lycopene protects against cutaneous photodamage in humans in vivo: a randomized controlled trial. The British Journal of Dermatology, [online] 164(1), pp.154–162. doi:https://doi.org/10.1111/j.1365-2133.2010.10057}

_{Harvard Health. (n.d.). Understanding Antioxidants. https://www.health.harvard.edu/staying-healthy/understanding-antioxidants}