You may have heard the phrase, “You are what you eat.” It’s no surprise that what you put into your body directly impacts how you feel and other aspects of your health, including cognitive function.
In fact, diets that contain certain amounts of minerals like sodium and potassium could have an effect on brain function, especially in older adults, according to a recent study published in Global Transitions.
Researchers from China found diets higher in sodium were associated with a higher risk of cognitive decline and poor and deteriorated memory. On the other hand, participants in the study who had more potassium intake in their diet were associated with higher cognitive function.
The researchers included more than 4,000 participants in China who were all 50 years or older. Cognitive exams tested the participant’s cognitive function, including verbal memory, executive function, calculation and attention. Participants with lower cognitive scores were considered to have a higher risk of cognitive impairment and vice versa for those with higher cognitive scores.
Given these results and the nutritional situation of the participants, the researchers claim it’s important to focus on identifying the optimal ratio of dietary sodium and potassium in the elderly.
“Our study provides crucial evidence on dietary recommendations of improving the sodium-to-potassium ratio in Chinese diets to lower disease burden caused by cognitive function problems,” Ai Zhao, PhD, corresponding author of the study and assistant professor and researcher at Vanke School of Public Health, Tsinghua University, told Seasons.
Zhao added that because of the irreversible nature of dementia and the lack of effective treatment methods, early prevention and detection of cognitive decline are crucial measures for tackling dementia and other cognitive diseases.
Early prevention and detection of cognitive decline are crucial measures for tackling dementia and other cognitive diseases.
“Lifestyle behaviors, especially dietary factors, are the most important factors to be considered,” she said. “Encouraging higher potassium and lower sodium intake could be served as an easy way to prevent cognitive decline.”
Because there are no medications or treatments for cognitive loss, this study highlights the potential role diet may play in cognitive function and preventing (or slowing) the progression of cognitive decline.
“There is no cure for cognitive loss, so identifying modifiable risk factors such as diet that may help to prevent or delay cognitive decline is important,” Pallini Winnifred, RDN, a registered dietitian nutritionist in New York, told Seasons.
What is the role of sodium and potassium?
Sodium and potassium are both essential minerals that play important roles in maintaining proper body function. Sodium is particularly needed for fluid balance, nerve signal transmission and healthy muscle function, including the heart muscle. Those who have a low intake of sodium may experience symptoms of muscle weakness, confusion, fatigue, seizures and more.
“It’s clear that we need sodium, but having too much can be a problem,” said Megan Wong, RD, a registered dietitian at AlgaeCal. “High sodium intake can increase the risk of dementia by causing high blood pressure, which, over time, damages blood vessels connecting to the brain.”
These vessels not only carry blood, oxygen and nutrients to the brain, but they also take away carbon dioxide and waste products, keeping brain cells clean and healthy.
Potassium also helps maintain proper heart function and muscle function by helping the kidneys get rid of excess sodium, Wong said. She added it also keeps blood vessels more relaxed, “making it easier for blood to flow through and reducing pressure on the walls of blood vessels.” Furthermore, potassium is needed for healthy bones, kidneys, nerves and muscles.
While more studies are needed to understand the effects of sodium intake on cognitive function, Kathryn Piper, RDN, LD, a Missouri-based registered dietitian nutritionist, said that excessive sodium can cause water retention. And that retention causes extra pressure in your blood vessels, which in turn increases your blood pressure and the risk of cardiovascular and cerebrovascular diseases.
“This makes oxygen transport to the brain more difficult and decreases activity and function in the brain,” she said.
However, potassium helps regulate blood pressure by counteracting sodium’s effect, and also opens blood vessels to allow easier blood flow.
Common sources of potassium
- Dried fruits like prunes and raisins
- Cooked spinach
- Leafy greens
How can I get more potassium in my diet?
Try some of these helpful tips to increase the amount of this mineral in your daily diet:
- Read nutrition labels and pay close attention to the sodium content of foods you’re buying and consuming.
- Prepare your own food when you can and avoid using instant products that are packaged, frozen or pre-made.
- Choose fresh and whole foods over processed, prepackaged and frozen foods.
- Aim to eat at least five servings of fruits and vegetables per day.
- Include at least three daily servings of dairy, such as milk, yogurt and cheese.
- Avoid using salt (or seasonings that contain salt) when cooking.
- Use herbs and spices to flavor foods instead of salt.