How May Sensory Changes Affect the Everyday Lives of Older People?

Authors Avatar

How May Sensory Changes Affect the Everyday Lives of Older People?

Our awareness of the world occurs through physiological mechanisms that process afferent, sensory information. Like all physiological mechanisms these are subject to detrimental changes as the body ages. It is essential to understand these changes so that we can meet any extra requirements that may ensue. This is increasingly important as the proportion of the population that is elderly steadily rises. Individuals over the age of 65 now account for 16% of the population (OPCS, 1991a). This essay will identify the problems that arise for the elderly and suggest ways they can be managed.

Gustation shows least age-related decrement because, unlike other neural cells, taste receptors have life spans of only a few days and are continually replaced. Salt and sucrose can easily be identified at all ages, but more complex taste stimuli (eg. carrot) cause difficulties for old people, suggesting that olfaction, rather than gustation, might be impaired (Doty et al., 1984). Olfaction shows marked age-related decline with 25% of 65-80 year-olds, and 50% of people over 80, reporting anosmia (Doty et al., 1984). Possible causes include atrophy of the olfactory bulb (Ordy & Brizzee, 1975), decreased volume of the layers of the bulb (Bhatnagar et al., 1987) and a decreased number of olfactory neurons (Hinds & McNelly, 1981).

Taste and smell are important for the sensory and hedonic experience of eating and if they are impaired the physical and social pleasure of eating is degraded. Fortunately, these sensory losses can be largely offset by using flavour enhancers (Schiffman & Warwick, 1989). However, olfaction also has a warning role in the ability to detect "off" foods, smoke or gas. Therefore food manufacturers should provide large, clearly visible "best-before-end" dates and elderly people should have smoke and gas detectors in their homes. The elderly account for nearly a quarter of deaths due to accidental gas poisonings (OPCS, 1991a), hardly surprising since the ability to detect mercaptans (odorants added to natural gas to aid its detection) deteriorates at the age of about 50 (the ability to detect rose odorants remains high even in the nineties: Gilbert & Wysocki, 1987).

Somatosensory decrements have also been reported. The elderly are less sensitive to temperature and poorer at regulating their own temperature, increasing the risk of hypothermia and frostbite (Fox et al., 1983). People aged over 65 account for 83% of all deaths by hypothermia (OPCS, 1991a) with the social isolation of many old people compounding the problem (Rango, 1985). Therefore it is surprising that the government insists on imposing VAT on fuel. There is also an increase in the thresholds for pain (Ordy & Brizzee, 1975) and touch (Verriollo, 1980) which can cause discomfort by failing to shift position, especially when sleeping. Furthermore the older person will not be as aware of physical disorders so that simple problems progress to advanced stages of complication before medical attention is obtained. Educating elderly people should alert them to these dangers, and they should be encouraged to attend regular medicals. Finally, the vestibular system degenerates leading to an unstable gait, increasing the risk of falling (Ochs et al., 1985). Even small falls are serious, as osteoporosis is more frequent, increasing the risk of fracture. 30% of people aged over 65 fell at least once in the preceding year (Campbell et al., 1981) and 82% of deaths from falls occur in this age group (OPCS, 1991a). Fear of falling can lead to restrictions in physical and social activities, and those who do fall and incur injury may be unable to care for themselves, leading to a dependence on family members or institutionalisation (Bhala et al., 1982). The risk of falling can, however, be reduced, for example not going out when it is icy, gritting pavements, providing priority seating on buses and trains, installing handrails, maintaining pavements to a high standard, providing lifts as well as escalators, and replacing rugs with carpets.

Join now!

More obvious sensory deficits, that the majority of old people encounter, are the declines in vision and audition. Changes in the cornea, lens, and muscles affect vision from the age of 35 (Kline & Schieber, 1985) and changes in the retina and nervous system affect vision from the age of 55 (Keunen et al., 1987). The lens becomes inflexible, leading to problems focusing on near objects (presbyopia), and slowly yellows. The retinal ganglion and receptor cells degenerate, and there is also an increased risk of cataracts, the latter affecting about 25% of 70 year-olds (Corso, 1987).

These changes affect ...

This is a preview of the whole essay