Antioxidant
Antioxidant – definition and facts in our glossary. Important antioxidants include vitamin C, E, selenium, glutathione, and CoQ10.
What is an Antioxidant?
Common antioxidants include vitamin C, vitamin E, selenium, glutathione, and CoQ10.
How does it work in the body?
Free radicals naturally arise in the body as by-products of metabolism and can also come from external sources such as pollution, smoking, and UV radiation. When free radicals exceed the body's ability to neutralise them, this can lead to oxidative stress, which is linked to several chronic diseases, including cancer, cardiovascular diseases, and neurodegenerative disorders.
Scientific benefits
Several studies have investigated the potential health benefits of antioxidants. Here are some of the most prominent findings:
Dosage and recommendations
The recommended dosage of antioxidants can vary depending on the specific antioxidant and individual needs. Here are some general guidelines:
- Vitamin C: 75-90 mg per day for adults.
- Vitamin E: 15 mg per day for adults.
- Selenium: 55 mcg per day for adults.
- Glutathione: There is no established recommendation, but supplements typically range between 250-500 mg per day.
- CoQ10: 100-200 mg per day is a common dose for adults.
Before starting supplements, it is important to consult a doctor or nutritionist to determine what is best suited for your needs.
Best sources and forms
Antioxidants are found in a variety of foods and supplements. Here are some of the best sources:
- Vitamin C: Citrus fruits, berries, peppers, and vegetables such as broccoli.
- Vitamin E: Nuts, seeds, spinach, and avocado.
- Selenium: Brazil nuts, fish, eggs, and whole grain products.
- Glutathione: Found in foods such as avocado, asparagus, and broccoli, but can also be taken as a supplement.
- CoQ10: Found in meat, fish, and whole grain products, as well as in supplements.
Side effects and warnings
Although antioxidants are important for our health, higher doses of certain supplements can cause side effects. Here are some examples:
- Vitamin C: Large doses can cause stomach discomfort and diarrhoea.
- Vitamin E: Higher doses may increase the risk of bleeding, especially if you are taking blood-thinning medications.
- Selenium: Overdose can lead to selenium toxicity, causing symptoms such as hair loss and stomach discomfort.
- Glutathione: Supplements are generally safe, but there is limited research on long-term effects.
- CoQ10: May cause mild side effects such as stomach discomfort and nausea.
It is always best to consult a doctor before starting supplements, especially if you have underlying health conditions or are taking medications.
Frequently asked questions
What is the difference between natural and synthetic antioxidants?
Natural antioxidants come from foods and plants, while synthetic antioxidants are chemically produced. Research suggests that natural antioxidants may be more effective and better absorbed by the body.
Can I get enough antioxidants through diet?
Yes, a balanced diet rich in fruits, vegetables, nuts, and whole grains usually provides sufficient antioxidants for most people. Supplements are generally not necessary if you have a varied diet.
How do antioxidants affect ageing?
Is it safe to take antioxidants during pregnancy?
It is important to consult a doctor before taking any supplements during pregnancy, including antioxidants, to ensure they are safe and appropriate for your situation.
Products containing Antioxidant
Show all 5 →Related entries
Vitamin C
Vitamin C (ascorbic acid) is a water-soluble vitamin and a powerful antioxidant.
Vitamin E
Vitamin E – definition and facts in our glossary.
Glutathione
Glutathion – definition and facts in our glossary. The body's master antioxidant 2D a tripeptide of cysteine, glycine, and glutamate.
CoQ10
CoQ10 – definition and facts in our glossary. Levels decrease with age and statin treatment.
Astaxanthin
Astaxanthin is a carotenoid from the alga Haematococcus pluvialis. 6000x stronger antioxidant than vitamin C. Gives salmon its pink colour.




