Oxidative stress is one of the most studied mechanisms in the biology of ageing and in the pathogenesis of numerous chronic diseases. And natural antioxidants are currently one of the most sought-after ingredient groups in the global nutraceutical market.
But how exactly do they work, what differentiates them from each other, and which have the most scientific backing as formulation ingredients?
What is oxidative stress?
Cells produce energy through metabolic reactions that generate, as a by-product, highly reactive molecules known as free radicals or reactive oxygen species (ROS). Under normal conditions, the body has its own antioxidant mechanisms to neutralise them.
When the production of free radicals exceeds the body's neutralising capacity, oxidative stress occurs, which can damage lipids, proteins and cellular DNA, contributing to cellular ageing and various pathologies.
Mechanism of action of antioxidants
Antioxidants act by donating electrons to free radicals, stabilising them and breaking the chain of oxidation reactions. Some act directly (primary antioxidants), while others support endogenous antioxidant systems (secondary or indirect antioxidants).
Main natural antioxidants in nutraceutical formulations
- Vitamin C (ascorbic acid)water-soluble, broad-spectrum antioxidant with strong clinical support. Available in multiple forms (calcium ascorbate, sodium ascorbate, C-ester).
- Vitamin E (tocopherols and tocotrienols)Tocotrienols: a fat-soluble antioxidant that protects cell membranes. The less common tocotrienols show superior antioxidant activity in some studies.
- Coenzyme Q10 (ubiquinol/ubiquinone)ubiquinol: involved in the mitochondrial electron transport chain. The ubiquinol (reduced) form is more bioavailable.
- Resveratrol: polyphenol from red wine and other plants, with studies on longevity, cardiovascular function and neuroprotection.
- Curcuminactive ingredient in turmeric, with potent antioxidant and anti-inflammatory activity. Bioavailability is the main challenge: it is solved with lipid formulations (phytosomes, nanoemulsions) or in combination with piperine.
- Grape seed extract (OPC)Proanthocyanidins with high antioxidant activity. Useful in cardiovascular and anti-ageing formulas.
- AstaxanthinCarotenoid of marine origin with one of the highest documented antioxidant capacities. Growing use in skin, sports and eye health formulas.
- Glutathionethe main endogenous antioxidant. Available as a liposomal or S-acetyl-glutathione ingredient to improve its oral bioavailability.
Antioxidant synergies in formulation
Antioxidants work best in a network. Vitamin C regenerates oxidised vitamin E; glutathione regenerates vitamin C; vitamin E and coenzyme Q10 act synergistically in mitochondrial membranes. Designing formulations to take advantage of these synergies allows greater efficacy to be achieved at more reasonable doses.
Considerations for the formulator
The stability of antioxidants in formulation is a critical issue: many are sensitive to light, heat and oxidation. Encapsulation matrices and microencapsulation systems can significantly improve their stability and shelf life.
The choice of the appropriate antioxidant should be based on the intended mechanism of action, compatibility with other ingredients, available chemical form and specific clinical support for the target population.
In a nutshell
Natural antioxidants are versatile ingredients in high market demand. Their correct selection, combination and formulation determine whether an «antioxidant» supplement delivers real results or remains a label promise.
At Sanmart we have a wide range of ingredients in this category, with GMP and ISO certifications and full traceability. Consult our catalogue or contact our technical team for more information.
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