We are now living longer than we ever have in history. Between 1940 and 2040 the population above the age of 85 will increase 40-fold. In fact, one of the fastest growing segments of the US population is people over the age of 85. They accounted for about 12% of all elderly people in 2000 and are expected to grow to 20% by the year 2040 (1).

Because of this meteoric rise in the number of elderly people, geriatric problems are on a steep and steady rise. Dehydration, falls, fractures, cognition, attention deficits and sensory disorders are now becoming much more commonplace.

The latest information on the subject was presented last week at the 20th annual meeting of the Society for the Study of Ingestive Behavior held in Zurich, Switzerland. In a presentation entitled, “Salt appetite across generations: aged and middle-aged,” researchers Khadeja Hendi and Micah Leshem of the Department of Psychology, University of Haifa, confirm that, in the elderly, impaired thirst results in a greatly increased the risk of dehydration. However, salt appetite does not diminish with age. In light of the risks to cardiovascular health and longevity from consuming any less than 6.5 g or more than 15 g of salt per day, increasing intake in the elderly prone to dehydration should be examined (2). Their findings show that the healthy salt appetite in most aged may be harnessed to sustain hydration status. This should serve as an additional reminder to assisted living care givers to be very cautions before recommending a ‘low-salt’ diet for the elderly.

Furthermore, in older people, mild hyponatremia is the most common form of electrolyte imbalance and has been shown to be associated with walking impairment, attention deficits and a much higher frequency of falls. Indeed, there have recently been a number of publications that found a direct relationship between mild hyponatremia and falls, bone fractures, unsteadiness and attention deficits (3, 4). Falls are a major socioeconomic problem in the elderly. About 30% of people over 65 fall every year (5, 6). Fall-related injury in the elderly is associated with numerous psychological and physical consequences and is a leading cause of death and disability. Falls are also associated with bone fracture in 4–6% of cases and death occurs from complication of fall in around 2% of cases mostly in patients with hip fracture (7). Almost 5.3% of all hospitalizations in people aged 65 years or older are due to fall related injuries (8).

Mild hyponatremia in the elderly is no longer considered as an asymptomatic condition. Evidence clearly points to significantly increased attention deficits, loss of cognitive function, increased falls and fractures – a cascade of conditions resulting in a highly diminished quality of life and a reduced life span. It is a significant threat that can be treated by simply adding salt to the diet.

The elderly should very carefully consider any broad, sweeping recommendations to go on a low salt diet. A well balanced diet, replete with salads, vegetables and fruit is the best approach to enjoying a healthy, active retirement.

References

1) www.merck.com/mkgr/mmg/contents.jsp also CDC figures

2) Alderman, MH, and Cohen, HW, Dietary Sodium Intake and Cardiovascular Mortality: Controversy Resolved? Am J Hypertens, 25 (7), 727-734, (2012).

3) Gankam Kengne, F., Andres, C., Sattar, L., Melot, C., and Decaux, G., “Mild hyponatremia and risk of fracture in the ambulatory elderly,” QJ Med, 101, 583–588, (2008).

4) Renneboog, B., Musch, W., Vandemergel, X., and Manto, M. U., “Mild Chronic Hyponatremia is Associated with Falls, Unsteadiness, and Attention Deficits,” The American Journal of Medicine, 119, 71.e1-71.e8, (2006).

5) Graafmans, W.C., Ooms, M.E., Hofstee, H.M., Bezemer, P.D., Bouter, L.M., Lips, P., “Falls in the elderly: a prospective study of risk factors and risk profiles,” Am J Epidemiol, 143, 1129–36, (1996).

6) Sattin, R.W., “Falls among older persons: A public health perspective,” Ann Rev Public Health, 13, 489–508, (1992).

7) Sattin, R.W., Lambert, D.A., DeVito, C.A., Rodriguez, J.G., Ros, A., Bacchelli, S., et al, “The incidence of fall injury events among the elderly in a defined population,” Am J Epidemiol, 131, 1028–37, (1990).

8) Alexander, B.H., Rivara, F.P., Wolf, M.E., “The cost and frequency of hospitalization for fall-related injuries in older adults,” Am J Public Health, 82, 1020–23, (1992).