Impact of aging on the body and mind

What are the 12 hallmarks of aging?

Primary

• Genomic instability

• Telomere attrition

• Epigenetic alterations

• Loss of proteostasis

• Disabled macroautophagy

Antagonistic

• Deregulated nutrient-sensing

• Mitochondrial dysfunction

• Cellular senescence

Integrative

• Stem cell exhaustion

• Altered intercellular communication

• Chronic inflammation

• Dysbiosis

Genomic instability

DNA accumulates damage and mutations, increasing cellular dysfunction and disease risk

Telomere attrition

The protective caps at the ends of chromosomes shorten, limiting cells’ ability to divide

Epigenetic alterations

Changes in how genes are switched on and off disrupt normal cellular function

Loss of proteostasis

Cells become less effective at maintaining, folding, and removing proteins, allowing damaged proteins to accumulate

Disabled macroautophagy

Cells lose efficiency in recycling damaged components ad clearing cellular waste

Deregulated nutrient-sensing

Pathways such as mTOR, AMPK, and insulin/IGF-1 signalling become dysregulated, affecting metabolism and repair

Mitochondrial dysfunction

The cells energy producing structures become less efficient and can generate harmful stress signals

Cellular senescence

Damaged cells stop dividing but remain metabolically active, often releasing inflammatory molecules

Stem cell exhaustion

Stem cells decline in number or function, reducing the body’s ability to regenerate tissue

Altered intercellular communication

Cells and organs communicate less effectively, disrupting coordination and repair

Chronic inflammation (inflammaging)

Persistent, low grade inflammation damages tissues and increases susceptibility to age-related diseases

Dysbiosis

Changes in the gut microbiome and other microbial communities negatively affect immunity, metabolism, and inflammation

What are the categories roles and key ideas?

• Primary→ causes of cellular damage→ what initiates aging

• Antagonistic→ responses to damage→ how the body tries to compensate

• Integrative→ consequences of accumulated damage and dysfunction→ how aging ultimately affects tissues and organs

What are health conditions associated with aging?

• Cataracts and refractive errors

• Back and neck pain

• Osteoarthritis chronic obstructive pulmonary disease

• Diabetes

• Depression

• Dementia

What physically declines with age?

• Heart capacity

• Resting energy expenditure

• Maximum energy expenditure

• Lung volume

• Normal vision

• Identifying smells

• Identifying spoken words

Distinguish crystallised and fluid abilities

• Crystallised are the cumulative skills and memories that result from cognitive processing that occurred in the past, typically in the form of acquired knowledge tested with general knowledge

• Fluid abilities require cognitive processing at the time of assessment and reflect manipulation and transformation of information to complete the test quantified with tests that require the subject to attend to ones environment and process new information to quickly problem solve

How good are these cognitive abilities with age?

• Crystallised abilities improve until approx 60 followed by plateau until 80

• Steady decline in fluid abilities from 20 to 80

What are the types of memories (how can they be probed with different tests)?

• Immediate memory

• Short term memory→ digit span test

• Working memory→ backwards digit span test

• Long-term memory→ recall tests

What is age-associated memory impairment?

Memory loss that is considered normal in light of a persons age and education level

What is Mild Cognitive Impairment?

• The stage between age associated cognitive impairment and the more serious decline of dementia

• May include problems with memory, language or judgement

• Associated with brain shrinkage

• Can be tested by the Montreal Cognitive Assessment (MoCA) → pen and paper test administered by clinician

What is dementia (distinguish it from MCI)?

• Dementia is a term used to describe a group of symptoms that occur when brain cells stop working properly

• MCI means that the cognitive declines dont affect the persons ability to carry out everyday tasks while dementia indicates they are

• Common causes of dementia AND MCI are alzheimer’s disease, vascular disease, frontotemporal degeneration and lewybody disease

What area of the brain has to do with memory?

Hippocampus and is decreases in size in MCI and dementia which can be checked for using an MRI to see if theres changes

How and what do PET scans do?

• Inject or swallow safe radioactive dyes which bind to molecules in the brain (in this case glucose) and the scanner produces an image of where the target molecules are

• So they can see how much glucose is present in the brain to check for brain activity or abnormal build up of proteins which causes diseases like alzheimer’s