Too much and too little salt - both can affect the cognitive functions

If too little salt consumption favors dementia?

More and more older people suffer from dementia. The illness is a heavy burden for those affected and their relatives and causes huge costs in the health system. Researchers now found that lower levels of sodium in the blood are associated with a decline in cognitive function in old age. The deficiency could thus promote dementia. A major source of nutrition for sodium is salt.

Researchers at the University of Colorado's Anschutz Medical campus found in their study that in a so-called hyponatraemia, a decline in cognitive function in old age is the result. The physicians published the results of their study in the journal "Clinical Journal of the American Society of Nephrology" (CJASN).

Dietary guidelines advise against high salt intake. Researchers now found that not only too much salt, but also too low salt intake has a negative impact on cognitive function in old age. (Image: HandmadePictures / fotolia.com)

Even mild hyponatraemia has a negative impact on health

Hyponatraemia occurs when sodium levels in the blood drop below 135 mmol / L, experts say. Although mild hyponatremia has previously been considered asymptomatic, recent studies suggest that it may be associated with higher risks of attention deficit, movement disorders, falls, cardiovascular events, and even premature death.

Effects of severe hyponatremia

Severe hyponatremia has previously been associated with cognitive and neurological disorders, but the association between serum sodium levels and cognitive decline in older adults has been uncertain. The results of the current study show that the treatment of sodium levels could help to maintain cognition in old age, the researchers explain.

Over 5,400 subjects were studied for the study

In the study, data from more than 5,400 live men over the age of 65 were reviewed by Drs. Kristen Nowak and her colleagues from the University of Colorado. Subjects were medically monitored for an average of 4.6 years. Of the participants, a total of 100 men had a serum sodium level, which indicated a hyponatremia.

Effects of a low sodium level in the blood

The researchers found that even a slightly lower sodium level in the blood was associated with both cognitive impairment and diminishing cognitive function over time. Compared to men with sodium levels of 141 to 142 mmol / L, men at levels of 126 to 140 mmol / L were 30 percent more likely to be affected by cognitive impairment. The increased risk of probable cognitive decline over time was 37 percent.

The physicians also found an association between a high serum sodium level (143-153 mmol / L) and a cognitive decline over time. In other words, both too much and too little salt in the diet could negatively impact cognitive function.

Further research is needed

A slightly lower level of sodium in the blood is likely to go unnoticed in clinical practice, explains study author Dr. Nowak. Since serum sodium levels as well as slight changes in cognitive functions often occur with age, further research on this topic is very important in the future. Physicians should then be able to answer the question of whether correction of lower sodium levels affects cognitive function through further investigation. (As)