According to research, as humans and animals age, they find it harder to control their sodium and water retention, thirst, and urine concentration. Data from an article published in the American Journal of Physiology—Regulatory, Integrative and Comparative Physiology determined that age can greatly hinder the capacity of rats to eliminate excess sodium when fed a high-salt diet.
The results of this study can be used to analyze how salt consumption can affect the elderly since it implied that older people might have a higher chance of experiencing negative side effects when following a diet with a high salt content.
The researchers said that changes in how sodium and water balance is controlled was one of the main characteristics of the normal human aging process, which also includes "a decrease in thirst, urinary concentrating ability and capacity to excrete water and electrolytes."
The body usually reacts to a diet with an increased salt content by producing more urine to eliminate the excess sodium. However, this particular response isn't as effective among the elderly.
The researchers continued that any changes in older people's electrolyte and fluid levels may increase their risk of developing disorders like hyponatremia (caused by water retention) or hypernatremia (caused by sodium retention). These health problems may result in central nervous system dysfunction. The disorders can even reduce the effectiveness of medication, which might jeopardize the health of older patients and any surgical outcomes, among other health concerns.
Dr. Hong Ji and his colleagues from Georgetown University worked with a team of researchers from St. Louis University and Nova Southeastern University to study aldosterone, a steroid hormone produced by the adrenal gland.
Aldosterone helps to manage the fluid and electrolytes in the body. Electrolytes, which includes minerals like calcium, potassium, and sodium in the blood, help control various bodily functions and processes.
Aldosterone production is managed by angiotensin type 1 (AT1) receptors that are activated once it binds with angiotensin II, the peptide hormone. Earlier studies have shown that aldosterone levels decrease with age and it becomes less responsive to environmental changes. (Related: Natural remedies treat adrenal fatigue.)
The researchers studied the effects of aldosterone and animal response to dietary sodium by administering a low-sodium diet to young and old rats. At the start of the study, old rats had lower aldosterone levels and they consumed less food and drank less water than the young rats.
After a two-week period, all of the rats were fed a high-salt diet for six days. While on the high-salt diet, the rats had a lower level of plasma aldosterone. However, the decrease was relatively lower among the old rats.
The young rats drank and urinated more frequently. Even though the old rats also drank more water, it took a while for them to increase their water intake and they still drank less compared to the younger rats.
While the older rats slightly increased their liquid intake, it didn't help them produce more urine or dilute their urine. This implies that they had trouble eliminated the excess sodium they consumed.
The researchers commented that the study findings showed that aging affects adrenal AT1 receptor response in male Fischer rats fed a high-sodium diet. They concluded, "The number of adrenal AT1 receptors were not reduced as rapidly in response to a high salt diet compared to the young animals. These age-associated effects on adrenal AT1 receptors correlated with reduced water intake and plasma aldosterone with little change in urine volume, urine osmolality or plasma AVP (antidiuretic hormone)."
Tips for a low-salt diet
Here are some tips to help you get started on a low-salt diet:
- Add more fresh fruit and vegetables to your diet.
- Always check food labels to verify a product's sodium content.
- Eat fresh meats instead of packaged products. Even though fresh cuts of beef, chicken, or pork contain natural sodium, this isn't as high as the salt content of processed meats like bacon.
- If you're dining out, check the restaurant's website for the sodium content of their dishes. If you're already at the restaurant, ask for your dish to be served without any salt.
- While salt preference is an acquired taste, it can be unlearned. After at least six to eight weeks of following a low-salt diet, you'll have an easier time avoiding salty food.
You can read more articles about healthy low-salt diets at Longevity.news.
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