How is age a risk factor for disease?
Age is a major risk factor for a wide range of diseases for several reasons:
Accumulation of cellular damage: As we age, our cells and tissues undergo cumulative damage from various sources, including oxidative stress, free radicals, and metabolic byproducts. This damage can lead to cellular dysfunction, mutations, and eventually age-related diseases.
Weaker immune system: The immune system plays a crucial role in defending against infections and diseases. However, as we age, the immune system becomes less efficient in recognizing and eliminating pathogens, making older individuals more susceptible to infections, certain types of cancer, and other diseases.
Reduced organ function: With advancing age, there is a gradual decline in the function of major organs, including the heart, lungs, kidneys, and liver. This decline in organ function can lead to an increased susceptibility to various age-related diseases.
Genetic factors: Aging is influenced by both genetic and environmental factors. Some genetic variations and mutations that occur during our lifetime can increase the risk of certain age-related diseases, such as cardiovascular diseases, neurodegenerative disorders, and specific types of cancer.
Cellular senescence: Cellular senescence is a process in which cells lose their ability to divide and function properly. Senescent cells accumulate in tissues over time and can contribute to age-related diseases by disrupting normal tissue function and promoting inflammation.
Reduced resilience: As we age, our bodies become less adaptable to stress and environmental challenges. This reduced resilience can make older individuals more susceptible to various health problems and slower in recovering from illnesses or injuries.
Therefore, advancing age increases the likelihood of developing various diseases and conditions due to a combination of factors related to cellular damage, immune function decline, organ dysfunction, genetic factors, cellular senescence, and reduced resilience.