Lifestages - Ageing

Question 1

Ageing

Answer 1

Ageing is a normal biological process which involves some physiological changes and decline. These include:
* Lowered hormone levels, e.g. sex hormones, growth hormone.
* Immunity: dysregulation of innate and adaptive immune function.
* Loss of skin integrity due to ↓production of lipids, ↓desquamation.
* Decreased bone density and muscle mass.
* Heart valves and arteries stiffen (= less flexible).
* Decrease in renal function (GFR (Glomerular Filtration Rate) declines)
* Reduced chest wall compliance and alveolar recoil.
* Neurological function declines (with neuron atrophy).
* GIT: affected by ↓stomach acid, dysphagia and ↓taste sensation.

Question 2

Accelerated ageing

Answer 2

Important to distinguish between normal ageing changes vs changes due todisease.
* E.g. atherosclerosis is becoming more common in teenagers.
* Ageing is normal, accelerated ageing is not.
* Ageing can be accelerated by:
o Lifestyle, poor diet and ↓physical exercise.
o Stress and not having a goal in life.
o The socioeconomics status.
o Diseases and medications.
* Genes contribute about 30% and lifestyle factors 70% to ageing.
* Biological age can differ from one’s chronological age.

Question 3

Ageing: Telomeres

Answer 3

• Telomeres = the specific DNA-protein structures found at both ends of each chromosome. As a normal cellular process, a small portion of telomeric DNA is lost with each cell division.
• When telomere length reaches a critical limit, the cell undergoes senescence (deterioration with age) and/or apoptosis. Telomere length can serve as a biological clock to determine the lifespan of a cell & an organism.
• Certain lifestyle factors such as smoking and poor diet can increase the pace of telomere shortening.
• Studies show that shorter telomeres are a risk factor for cancer.

Question 4

Energetics of Ageing

Answer 4

Mature years are dominated by dryness
* I.e. wrinkles, joint stiffness, decreasing physical strength.
* Increase: soups, stews, smoothies, sweet & high-water content fruit & veg, root vegetables, nut milks, ‘mucilaginous’ okra, chia & linseeds, liquorice, most herbal teas.
Old age is dominated by coldness
* I.e. digestive power weakens, circulation reduces, we feel colder, declining mobility, exhaustion and withdrawal.
* Increase: warm, cooked and mildly spiced food and drinks that increase body temperature, digestive power and circulation (Refer back to your Energetics lecture)