The term oxidative stress refers to a metabolic state that corresponds to an increase in free radicals within the body. Under normal conditions, free radicals are neutralised by antioxidants. However, when the antioxidants available are insufficient for the purpose, an excessive increase in free radicals occurs which can cause severe, often irreversible damage to cells. Since it compromises cell regeneration, oxidative stress is one of the primary factors involved in the ageing process. Signs and symptoms may include premature ageing, fatigue, memory disorders and inflammatory conditions. Oxidative stress is also associated with numerous pathologies such as hypertension, cardiovascular diseases, arteriosclerosis and neurodegenerative diseases (e.g. Parkinson's disease). According to scientific studies, antioxidant intake can protect against oxidative stress, which confirms the importance of adopting a balanced diet. Other factors that can contribute to oxidative homeostasis include healthy physical exercise, stopping smoking and reducing stress.