are certain signs or signals in our body that change or appear as we age. They can be proteins, genes, chemical substances, or even external changes like wrinkles. These biomarkers help scientists understand how aging occurs and what processes it involves. They also assist in assessing how healthy we are and how much time we may have left.

are substances that help protect the body from the harmful effects of free radicals and oxidative stress. They neutralize free radicals, preventing damage to cells and tissues.

Examples of antioxidants include:

Vitamin C (ascorbic acid) - found in citrus fruits, strawberries, and other fruits and vegetables.

Vitamin E (tocopherol) - found in nuts, seeds, and oils.

Selenium - a mineral that can be obtained from fish, meat, and nuts.

Carotenoids, such as beta-carotene, which is converted to vitamin A in the body - found in carrots, sweet potatoes, and spinach.

Flavonoids - found in fruits and vegetables, such as berries, red wine, and tea.

Antioxidants help maintain health and can reduce the risk of various diseases, such as cancer and cardiovascular diseases.

Factors of aging are the core components directly influencing the aging process. These factors encompass genetic traits, biochemical changes within the body, environmental factors, lifestyle choices, and other aspects contributing to aging.

Aging cofactors, on the other hand, are additional elements that can either amplify or mitigate the impacts of the primary aging factors on the aging processes. Cofactors may involve risk factors for age-related diseases (e.g., smoking as a cofactor in cancer development), protective factors (e.g., healthy nutrition as a cofactor in maintaining health), or other conditions that interact with the aging factors.

In essence, factors of aging are the primary drivers of aging, while cofactors are supplementary factors that can influence how these primary factors affect the aging process.

are unstable molecules containing unpaired electrons and can be highly reactive. They seek to stabilize themselves by capturing electrons from other molecules, which can lead to cell and tissue damage in the body.

An example of a free radical is the oxygen free radical, denoted as "O2." It can be generated as a result of metabolic processes in the body and participate in oxidative reactions. It can cause damage to cells and contribute to aging processes and the development of various diseases, such as cancer and cardiovascular diseases.

is an experimental procedure in which two animals of different ages, typically a young one and an old one, are surgically connected in a way that their circulatory systems become interconnected. This procedure allows for the exchange of blood, cells, and biological signals between the two animals.

HCP is used in research on aging and longevity to understand how youthfulness or factors associated with youth can influence the aging processes. It can help identify potential biological mechanisms that contribute to aging or its deceleration.

This method enables scientists to study the impact of young blood or young cells on aging tissues and organs, as well as investigate various aspects of aging biology, such as tissue regeneration, inflammation, and many others. HCP has generated interest in the field of longevity research and may have the potential to develop methods for improving the quality of life in old age.

is a chemical process in which molecules of hydrogen peroxide (H2O2) interact with other molecules within the body. This reaction can occur both inside and outside of cells.

In the context of aging, hydrogen peroxide oxidation plays a role in causing damage at the cellular level. The byproducts of hydrogen peroxide oxidation, such as free radicals, can harm cellular structures, including proteins, lipids, and DNA. This process is referred to as oxidative stress.

means abnormal or unusual changes, alterations, or mutations in a biological entity, such as a protein, gene, cell, or organism. This change can deviate from the typical or normal characteristics or functions of that entity.

In a biological context, aberrant modifications can manifest in various forms. For example, aberrant modification of a protein can lead to its abnormal structure or function, which can impact normal biological processes in the organism. Aberrant modification of a gene can result in a mutation, which can lead to the development of genetic diseases.

This protein is a major component of amyloid plaques that form in the brains of Alzheimer's disease patients. Beta-amyloid originates from a larger protein called beta-amyloid precursor protein, or APP. In Alzheimer's disease, fragments of APP are improperly processed and aggregate into plaques in the space between neurons. These plaques can interfere with neuron communication and contribute to their death.

Tau protein typically functions to maintain the structure of neurons, providing stability to microtubules within cells. However, in Alzheimer's disease, tau protein undergoes aberrant modification and begins to form accumulations known as neurofibrillary tangles or tau tangles. These tangles disrupt the normal function of neurons and lead to their degeneration.

is a condition in which there is an imbalance in the body between the production of free radicals and the antioxidant systems designed to neutralize them. This can lead to an accumulation of free radicals and damage to cells and tissues.

An example of oxidative stress includes situations where the body is exposed to harmful environmental factors such as air pollution, excessive ultraviolet radiation from the sun, or smoking. As a result of such exposure, there is an increase in the level of free radicals, which can damage cells and contribute to the development of diseases, such as sunburn, premature skin aging, and even cancer.