Chronic kidney disease, often called CKD, is a long-term condition in which the kidneys slowly lose their ability to filter waste and extra fluid from the blood.
The kidneys play a vital role in keeping the body healthy by balancing minerals, controlling blood pressure, and removing toxins. When they do not work properly, harmful substances can build up in the body.
CKD affects millions of people worldwide, especially older adults and those with diabetes or high blood pressure. While many people know CKD can lead to heart problems and kidney failure, fewer realize that it may also affect the brain.
A new study has found that people with more severe kidney disease are more likely to develop problems with memory, attention, and thinking.
The research was published in JAMA Network Open and was led by scientists from the Tulane University School of Public Health and Tropical Medicine. The team followed 5,607 adults who were already living with CKD to see how their kidney health related to changes in their brain function over time.
Doctors measure kidney health using two main tests. One test is called the estimated glomerular filtration rate, or eGFR. This number shows how well the kidneys are filtering blood. A lower number means worse kidney function.
The other test measures protein in the urine, known as the urinary protein-to-creatinine ratio, or UPCR. Healthy kidneys usually prevent protein from leaking into urine, so high protein levels can signal damage.
The researchers discovered that people with higher levels of protein in their urine were more likely to develop problems with attention, thinking speed, and decision-making skills.
These mental abilities are important for everyday tasks such as driving, managing money, following conversations, and staying safe at home. The study also found that people with lower eGFR, meaning poorer kidney function, had a higher risk of slower thinking and reduced attention.
When both problems were present at the same time—low eGFR and high protein in urine—the risk of overall cognitive decline was even greater.
People in this group were significantly more likely to experience memory loss and reduced mental sharpness compared to those with milder kidney disease. This suggests that worsening kidney damage may have a direct impact on brain health.
Scientists believe there are several reasons why kidney disease might harm the brain. Poor kidney function can lead to inflammation, buildup of toxins in the blood, and damage to blood vessels.
These changes can reduce blood flow to the brain and affect how brain cells communicate. CKD is also closely linked to high blood pressure and diabetes, both of which are known to increase the risk of dementia and stroke.
An important finding from the study was that protein in the urine appeared to explain much of the connection between kidney disease and cognitive problems.
In other words, leakage of protein may be a key warning sign that the disease is affecting not only the kidneys but also the brain. This means that testing urine protein levels could help doctors identify patients who are at higher risk of mental decline.
The study highlights the need for regular monitoring of both kidney function and cognitive health in people with CKD. Early detection of memory or thinking problems may allow patients and families to plan ahead and take steps to protect brain function.
Lifestyle changes such as controlling blood pressure, managing blood sugar, eating a balanced diet, staying physically active, and avoiding smoking may help slow both kidney and brain damage.
In reviewing the findings, this research provides strong evidence that chronic kidney disease is not only a kidney problem but also a brain health issue. The large number of participants strengthens the reliability of the results, and the use of two different kidney measurements offers a clearer picture of risk factors.
However, the study shows associations rather than direct cause, meaning more research is needed to understand exactly how kidney damage leads to cognitive decline. Future studies may explore whether treating protein leakage or improving kidney function can help protect memory and thinking abilities.
Overall, the study sends an important message: caring for kidney health may also protect the brain. Patients with CKD and their doctors should pay attention to early signs of cognitive changes and work together to reduce risk factors.
As the global population ages, understanding this connection could help prevent disability and improve quality of life for millions of people.
If you care about dementia, please read studies that eating apples and tea could keep dementia at bay, and Olive oil: a daily dose for better brain health.
For more health information, please see recent studies what you eat together may affect your dementia risk, and time-restricted eating: a simple way to fight aging and cancer.
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