Antioxidant action which consists of enzymatic antioxidants and non-enzymatic antioxidants, counteracts oxidative stress that produces cellular damage. Free radicals, pathological inflammatory processes, reactive nitrogen species and reactive oxygen species are responsible for the ageing process and many diseases caused by oxidation.

Components that exert antioxidant action: some examples. 

• Vitamin C. A powerful antioxidant that protects cells from free radical damage.
• Vitamin E. Helps protect cell membranes from oxidative stress.
• Beta-carotene. A precursor of vitamin A with antioxidant properties.
• Selenium. A mineral that acts as a cofactor for antioxidant enzymes.
• Polyphenols. Found in fruits, vegetables, tea, and wine, they have strong antioxidant properties.
• Flavonoids. A group of polyphenols known for their antioxidant activity.
• Lutein and zeaxanthin. Antioxidants found in green leafy vegetables that protect eye health.
• Coenzyme Q10. Helps protect cells from oxidative damage and plays a role in cellular energy production.

These components are essential for neutralizing free radicals and protecting the body from oxidative stress, contributing to the prevention of chronic diseases.

Several components can contribute to or exacerbate oxidation-related diseases. These include:

• Free radicals. Unstable molecules that can damage cells and contribute to the development of chronic diseases.
• Cigarette smoke. Contains chemicals that generate free radicals and increase oxidative stress.
• Environmental pollutants. Such as heavy metals and toxins, can induce oxidative damage to cells.
• Foods high in saturated and trans fats. Can increase levels of oxidative stress in the body.

• Alcohol. Its metabolism produces free radicals that can damage cells.
• UV radiation. Can cause oxidative damage to the skin and increase the risk of skin cancer.
• Stress. Can increase the production of free radicals and oxidative stress.
• Diet low in antioxidants. A diet with low levels of antioxidant vitamins and minerals can reduce the body's ability to combat oxidative stress.

These factors can increase the risk of developing oxidation-related diseases, such as cardiovascular diseases, certain types of cancer, and neurodegenerative diseases.

Antioxidants studies

Melini F, Melini V, Luziatelli F, Ficca AG, Ruzzi M. Health-Promoting Components in Fermented Foods: An Up-to-Date Systematic Review. Nutrients. 2019 May 27;11(5):1189. doi: 10.3390/nu11051189.

Abstract. Fermented foods have long been produced according to knowledge passed down from generation to generation and with no understanding of the potential role of the microorganism(s) involved in the process. However, the scientific and technological revolution in Western countries made fermentation turn from a household to a controlled process suitable for industrial scale production systems intended for the mass marketplace. The aim of this paper is to provide an up-to-date review of the latest studies which investigated the health-promoting components forming upon fermentation of the main food matrices, in order to contribute to understanding their important role in healthy diets and relevance in national dietary recommendations worldwide. Formation of antioxidant, bioactive, anti-hypertensive, anti-diabetic, and FODMAP-reducing components in fermented foods are mainly presented and discussed. Fermentation was found to increase antioxidant activity of milks, cereals, fruit and vegetables, meat and fish. Anti-hypertensive peptides are detected in fermented milk and cereals. Changes in vitamin content are mainly observed in fermented milk and fruits. Fermented milk and fruit juice were found to have probiotic activity. Other effects such as anti-diabetic properties, FODMAP reduction, and changes in fatty acid profile are peculiar of specific food categories.

Giampieri F, Alvarez-Suarez JM, Battino M. Strawberry and human health: effects beyond antioxidant activity. J Agric Food Chem. 2014 May 7;62(18):3867-76. doi: 10.1021/jf405455n.

Abstract. The usefulness of a diet rich in vegetables and fruits on human health has been widely recognized: a high intake of antioxidant and bioactive compounds may in fact play a crucial role in the prevention of several diseases, such as cancer, cardiovascular, neurodegenerative, and other chronic pathologies. The strawberry (Fragaria × ananassa Duch.) possesses a remarkable nutritional composition in terms of micronutrients, such as minerals, vitamin C, and folates, and non-nutrient elements, such as phenolic compounds, that are essential for human health. Although strawberry phenolics are known mainly for their anti-inflammatory and antioxidant actions, recent studies have demonstrated that their biological activities also spread to other pathways involved in cellular metabolism and cellular survival. This paper has the main objective of reviewing current information about the potential mechanisms involved in the effects elicited by strawberry polyphenols on human health, devoting special attention to the latest findings.

Elias RJ, Kellerby SS, Decker EA. Antioxidant activity of proteins and peptides. Crit Rev Food Sci Nutr. 2008 May;48(5):430-41. doi: 10.1080/10408390701425615. 

Abstract. Proteins can inhibit lipid oxidation by biologically designed mechanisms (e.g. antioxidant enzymes and iron-binding proteins) or by nonspecific mechanisms. Both of these types of antioxidative proteins contribute to the endogenous antioxidant capacity of foods. Proteins also have excellent potential as antioxidant additives in foods because they can inhibit lipid oxidation through multiple pathways including inactivation of reactive oxygen species, scavenging free radicals, chelation of prooxidative transition metals, reduction of hydroperoxides, and alteration of the physical properties of food systems. A protein's overall antioxidant activity can be increased by disruption of its tertiary structure to increase the solvent accessibility of amino acid residues that can scavenge free radicals and chelate prooxidative metals. The production of peptides through hydrolytic reactions seems to be the most promising technique to form proteinaceous antioxidants since peptides have substantially higher antioxidant activity than intact proteins. While proteins and peptides have excellent potential as food antioxidants, issues such as allergenicity and bitter off-flavors as well as their ability to alter food texture and color need to be addressed.

Huang D, Ou B, Prior RL. The chemistry behind antioxidant capacity assays. J Agric Food Chem. 2005 Mar 23;53(6):1841-56. doi: 10.1021/jf030723c. 

Abstract. This review summarizes the multifaceted aspects of antioxidants and the basic kinetic models of inhibited autoxidation and analyzes the chemical principles of antioxidant capacity assays. Depending upon the reactions involved, these assays can roughly be classified into two types: assays based on hydrogen atom transfer (HAT) reactions and assays based on electron transfer (ET). The majority of HAT-based assays apply a competitive reaction scheme, in which antioxidant and substrate compete for thermally generated peroxyl radicals through the decomposition of azo compounds. These assays include inhibition of induced low-density lipoprotein autoxidation, oxygen radical absorbance capacity (ORAC), total radical trapping antioxidant parameter (TRAP), and crocin bleaching assays. ET-based assays measure the capacity of an antioxidant in the reduction of an oxidant, which changes color when reduced. The degree of color change is correlated with the sample's antioxidant concentrations. ET-based assays include the total phenols assay by Folin-Ciocalteu reagent (FCR), Trolox equivalence antioxidant capacity (TEAC), ferric ion reducing antioxidant power (FRAP), "total antioxidant potential" assay using a Cu(II) complex as an oxidant, and DPPH. In addition, other assays intended to measure a sample's scavenging capacity of biologically relevant oxidants such as singlet oxygen, superoxide anion, peroxynitrite, and hydroxyl radical are also summarized. On the basis of this analysis, it is suggested that the total phenols assay by FCR be used to quantify an antioxidant's reducing capacity and the ORAC assay to quantify peroxyl radical scavenging capacity. To comprehensively study different aspects of antioxidants, validated and specific assays are needed in addition to these two commonly accepted assays.

Ozawa H, Miyazawa T, Burdeos GC, Miyazawa T. Biological Functions of Antioxidant Dipeptides. J Nutr Sci Vitaminol (Tokyo). 2022;68(3):162-171. doi: 10.3177/jnsv.68.162. 

Abstract. In the history of modern nutritional science, understanding antioxidants is one of the major topics. In many cases, food-derived antioxidants have π conjugate or thiol group in their molecular structures because π conjugate stabilizes radical by its delocalization and two thiol groups form a disulfide bond in its antioxidative process. In recent years, antioxidant peptides have received much attention because for their ability to scavenge free radicals, inhibition of lipid peroxidation, chelation of transition metal ions, as well as their additional nutritional value. Among them, dipeptides are attracting much interest as post-amino acids, which have residues in common with amino acids, but also have different physiological properties and functions from those of amino acids. Especially, dipeptides containing moieties of several amino acid (tryptophan, tyrosine, histidine, cysteine, and methionine) possess potent antioxidant activity. This review summarizes previous details of structural property, radical scavenging activity, and biological activity of antioxidant dipeptide. Hopefully, this review will help provide a new insight into the study of the biological functions of antioxidant dipeptides.

The reports  provided on Tiiips website are for informational purposes only and should not replace medical advice. Always consult a healthcare professional before making health-related decisions.