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A​ recent study shows that consuming high levels of sodium is associated with cognitive decline while a diet high in potassium is linked to improved cognitive function. Gillian Vann/Stocksy
  • Sodium and potassium are minerals that the human body needs at specific levels.
  • A​ recent study shows that consuming high levels of sodium in the diet is associated with cognitive decline.
  • On the flip side, the study suggests that diets high in potassium are associated with higher levels of cognitive function.
  • Decreasing sodium intake and increasing potassium intake could help boost brain health.

Diet is a key aspect of overall health.

While the body produces some components of these minerals, you can also get vital nutrients from food sources. Making healthy food choices affects multiple areas of health, including brain function.

A​ recent study published in Global Transitions examined how sodium and potassium intake impact the risk of cognitive decline in older people.

The results show that high dietary sodium intake is associated with cognitive decline and higher levels of dietary potassium are associated with improved cognitive function.

Both sodium and potassium are minerals the human body has to maintain at specific levels.

Both minerals impact blood pressure and fluid volume, which means their levels can impact cardiovascular health.

Typically, consuming too much sodium can contribute to high blood pressure and put people at risk for more severe heart problems in the future.

N​on-study author and registered nutritionist Beata Rydyger, BSc, a clinical advisor at Zen Nutrients, explained to Medical News Today:

“Sodium and potassium are vital minerals that act as charged particles to carry electrical current across cells. This electrical current is essential for nerve stimulation, muscle contraction, and fluid regularity. A deficiency can lead to lack of energy, fatigue, muscle soreness, and blood pressure irregularity. Research shows that it is often a deficiency of potassium rather than sodium that promotes symptoms like high blood pressure, and restoring potassium levels can restore balance.”

In addition, there are other areas of health that sodium and potassium may impact that researchers are still working to understand.

For the current study, researchers looked at how dietary potassium and sodium impacted cognitive functioning among older adults in China.

The prospective cohort study included over 4,000 participants, all aged 50 or older, in their analysis.

T​he researchers collected information on participants’ dietary intake via self-reporting over a 3-day period.

They then evaluated participants’ cognitive status by asking questions that involved memory recall and mental math. They also asked participants questions about their memory and recent changes they had experienced in their memory.

In general, researchers found that higher potassium intake was associated with a positive impact on cognitive function. But higher sodium intake was associated with negative effects on cognitive function, including memory deterioration.

Study author Ai Zhao, Ph.D., assistant professor at the Vanke School of Public Health at Tsinghua University in Beijing, noted the key findings of the team’s research to MNT:

“In this prospective study, we found that lower dietary sodium, lower sodium to potassium ratio, and higher dietary potassium might benefit cognitive function in the elderly, while salt intake was not directly associated with cognitive function. In addition, we extended previous studies by demonstrating that the effects of dietary sodium, sodium-to-potassium ratio, and potassium on cognitive function might be mediated by the status of cardiovascular and cerebrovascular diseases (CCVD).”

The study had several limitations that are important to note.

First, researchers only collected data pertaining to three consecutive days. This means the data may not reflect participants’ long-term eating habits. In addition, the methods used in the study could not quantify sodium intake from all sources, such as processed foods and restaurant dishes.

In addition, the researchers’ data methods may have missed other nutrients that could have influenced cognitive function. Since they used phone interviews to assess cognitive function, they could not completely screen or diagnose cognitive impairment.

And because of the nature of the study, it cannot determine cause. Instead, researchers relied on participant self-reporting, which increases the risk of errors in data collection.

“Further randomized controlled trials targeted to the elderly are needed to confirm our conclusions, and studies should also be conducted in other countries and populations,” Dr. Zhao noted.

Finally, since the study was done in a specific population, the results cannot be generalized to all populations.

It is worth noting, however, that the United States population consumes more than the recommended daily amount of sodium, so examining the implications of this study may be helpful for Americans.

The study serves as a reminder that diet can impact many areas of health, including cognitive function.

People can consume healthy levels of potassium and sodium in their diets. They can work with their doctors and nutrition specialists to plan diets that fit their nutritional needs.

“Our findings suggested decreasing sodium intake and properly increasing potassium intake are beneficial to cognitive function,” Dr. Zhao explained.

“Increasing potassium intake while reducing sodium intake involves a conscious effort to look at the nutritional content of foods. People can then take steps to choose foods high in potassium and foods that are lower in sodium.”

Potassium-rich whole-food sources include:

  • bananas
  • avocados
  • dried fruits
  • leafy greens
  • potatoes

Rydyger noted the following dietary recommendations to MNT:

“Both sodium and potassium work in tandem to support health, so it is important to include both in the diet. It is far more common, however, to consume more sodium than potassium, so making sure to reach optimal potassium levels through a healthy, balanced diet is essential. Processed carbohydrates deplete the body of potassium, so paying attention to the quality of food intake is also important.”