Researchers studied how eating a Western-style diet high in phosphate (a mineral found in processed foods and animal products) affects kidney and heart health. Using mice with a kidney disease similar to human disease, they found that high-phosphate diets caused harmful changes in the heart’s energy-producing structures and increased dangerous hormones in the blood, even in animals without kidney disease. These findings suggest that eating less phosphate might help protect heart and kidney health, especially for people at risk of kidney problems.

The Quick Take

  • What they studied: Whether eating a diet high in phosphate (like many Western processed foods) damages the heart and kidneys, especially in animals with kidney disease
  • Who participated: Laboratory mice genetically modified to have kidney disease similar to human kidney disease (Alport syndrome), plus normal mice for comparison
  • Key finding: Mice eating high-phosphate diets developed harmful changes in heart cell energy production and increased dangerous blood hormones, even without existing kidney disease
  • What it means for you: Eating less phosphate from processed foods and animal products may help protect your heart and kidneys, particularly if you’re at risk for kidney disease. However, this research was done in mice, so more human studies are needed before making major dietary changes. Talk to your doctor before significantly changing your diet.

The Research Details

Scientists created two groups of mice: some with a genetic kidney disease and some that were healthy. Within each group, half ate a high-phosphate diet (similar to typical Western processed foods with lots of meat and additives) and half ate a normal diet with less phosphate. The researchers then measured changes in the mice’s hearts, kidneys, and blood over time as their kidney disease progressed.

This type of study is called a controlled experiment because the scientists carefully controlled what the mice ate and compared the results between groups. By using mice with a specific genetic kidney disease, the researchers could study how diet affects kidney disease progression in a controlled way that would be difficult or unethical to do in humans.

The study examined multiple body systems and measurements, including how well the heart’s energy-producing structures (mitochondria) worked, kidney scarring, blood mineral levels, and hormone changes. This comprehensive approach helped the researchers understand the full impact of the high-phosphate diet.

This research approach is important because it shows how diet affects the body at a cellular level during kidney disease. By studying mice with a disease similar to human kidney disease, scientists can understand mechanisms that might apply to people without putting humans at risk. The findings suggest that dietary changes early on might prevent serious complications, which could change how doctors recommend managing kidney disease.

This study was published in Kidney360, a peer-reviewed scientific journal, meaning other experts reviewed the work before publication. The researchers used a controlled experimental design with comparison groups, which is a strong research method. However, the study was conducted in mice, not humans, so results may not directly apply to people. The sample size of mice was not specified in the abstract, which makes it harder to assess the strength of the findings. More human research would be needed to confirm these results apply to people.

What the Results Show

The high-phosphate diet caused significant problems in both healthy mice and mice with kidney disease. In mice with kidney disease eating the high-phosphate diet, the heart’s energy-producing structures (mitochondria) worked less efficiently. The diet also caused dramatic increases in two important hormones: parathyroid hormone increased 17-fold and a hormone called FGF23 increased 14-fold. Additionally, the kidneys produced 50% less of a protective protein called klotho.

Surprisingly, even healthy mice eating the high-phosphate diet showed similar harmful changes in heart function and hormone levels, though they didn’t have kidney disease. This suggests that high-phosphate diets can damage the body even before kidney problems develop.

The researchers also found that the high-phosphate diet made kidney disease worse in the mice with Alport syndrome, causing more severe changes in the disease markers. The diet affected multiple body systems simultaneously, suggesting phosphate has widespread effects on health beyond just the kidneys.

One interesting finding was that the high-phosphate diet did NOT cause calcium deposits in blood vessels (vascular calcification), which was unexpected based on previous research. This suggests that the harmful effects of high-phosphate diets work through multiple different mechanisms, not just one pathway. The study also showed that kidney scarring (fibrosis) was affected by the diet, indicating damage to kidney tissue structure.

Previous research has shown that high phosphate levels in the blood (hyperphosphatemia) contribute to heart and kidney problems in people with advanced kidney disease. This study extends that knowledge by showing that high-phosphate diets can cause problems even in people with normal kidney function, and that the harmful effects happen at the cellular level in the heart. The findings support earlier research showing that phosphate management is important for kidney disease treatment, but suggest this management should start earlier than currently recommended.

This study was conducted entirely in mice, so the results may not directly apply to humans. The specific sample size of mice used was not provided, making it difficult to assess how reliable the findings are. The study used mice with a specific type of kidney disease (Alport syndrome), which may not represent all types of human kidney disease. Additionally, the study doesn’t tell us exactly how much phosphate reduction would be needed to prevent these problems in humans, or how quickly the benefits would appear. Human clinical trials would be needed to confirm these findings apply to people and to determine safe and practical dietary recommendations.

The Bottom Line

Based on this research, reducing phosphate intake from processed foods and animal products may help protect heart and kidney health, particularly for people at risk of kidney disease. However, this evidence comes from animal studies, so the confidence level is moderate. Current recommendations for people with kidney disease already suggest limiting phosphate, and this research supports starting such management earlier. People should not make major dietary changes without consulting their doctor, especially those with existing kidney disease or heart conditions.

This research is most relevant for people with kidney disease or family history of kidney disease, people with high blood pressure or diabetes (which increase kidney disease risk), and anyone interested in preventing kidney disease through diet. Healthy people without kidney disease risk factors may benefit from moderately reducing processed foods high in phosphate, but this is not urgent. People with advanced kidney disease should definitely work with their doctor on phosphate management. This research is less relevant for people with normal kidney function and no risk factors.

Based on this research, changes in blood hormone levels and heart function occurred over the course of the study as kidney disease progressed, suggesting weeks to months of dietary changes might be needed to see benefits. However, the exact timeline for humans is unknown. Some benefits might appear relatively quickly (weeks to months), while protection against long-term heart and kidney damage would take longer to measure (months to years). Consistent dietary changes over time are likely more important than immediate results.

Want to Apply This Research?

  • Track daily phosphate intake by logging processed foods, meat portions, and dairy products consumed. Users can set a target phosphate limit (discuss with doctor) and monitor whether they stay below it daily. Weekly summaries can show trends in phosphate consumption.
  • Users can replace high-phosphate processed foods with fresh vegetables, fruits, and whole grains. Specific actions include: choosing fresh meat over processed varieties, reducing soda and energy drinks (high in phosphate additives), limiting cheese and dairy, and reading food labels for phosphate additives. The app can suggest low-phosphate meal ideas and track progress toward dietary goals.
  • Set up monthly check-ins to review phosphate intake trends and adjust goals. Users should also track any health markers their doctor recommends (like blood phosphate levels if they have kidney disease). The app can send reminders about high-phosphate foods to avoid and celebrate consistent adherence to lower-phosphate eating patterns over time.

This research was conducted in mice with a specific genetic kidney disease and has not been tested in humans. The findings suggest potential benefits of reducing dietary phosphate, but individual results may vary. This information is not a substitute for professional medical advice. People with kidney disease, heart disease, or those taking medications should consult their doctor before making significant dietary changes. Do not stop or change any prescribed treatments based on this research. Always work with your healthcare provider to develop a safe, personalized nutrition plan appropriate for your individual health status and medical conditions.