Researchers studied over 17,000 American adults to understand how inflammatory foods affect heart, kidney, and metabolic health. They found that people who ate more inflammatory foods—like processed items and sugary drinks—had worse heart and kidney problems and higher death rates over time. The study tracked people for nearly 10 years and discovered that each point increase in a diet inflammation score raised the risk of serious disease by 6%. This suggests that choosing less inflammatory foods might help prevent or slow down these serious health conditions.

The Quick Take

  • What they studied: Whether eating foods that cause inflammation in the body is connected to developing serious heart, kidney, and metabolic problems, and whether it affects how long people live.
  • Who participated: 17,412 American adults of various ages, races, and backgrounds who participated in national health surveys between 1999 and 2018. Researchers looked at what they ate and tracked their health for about 10 years.
  • Key finding: People who ate the most inflammatory foods were 36% more likely to develop advanced heart and kidney disease compared to those who ate the least inflammatory foods. For every one-point increase in the inflammation score, the risk of serious disease went up by 6%.
  • What it means for you: Choosing less inflammatory foods—like fresh fruits, vegetables, whole grains, and fish instead of processed foods and sugary items—may help protect your heart and kidneys. However, this study shows a connection, not proof that changing your diet will definitely prevent disease. Talk to your doctor about your specific diet needs.

The Research Details

Researchers used information from a large national health survey that tracked American adults over nearly 20 years. They calculated a “dietary inflammation score” based on what people reported eating in a single day, then grouped people by how inflammatory their diets were. They compared people with different diet inflammation scores to see who developed heart and kidney problems and who died during the follow-up period.

The researchers used statistical methods to account for other factors that might affect health, like age, smoking, exercise, and income. They also looked at whether the relationship between inflammatory foods and disease was consistent across different groups of people, like men versus women or smokers versus non-smokers.

This approach allowed them to study a very large group of real people over a long time, which is stronger than smaller studies but not as definitive as experiments where researchers control everything.

This study design is important because it uses real-world data from thousands of people followed over many years, making the results more relevant to everyday life than laboratory studies. By tracking people’s actual eating habits and health outcomes, researchers can see patterns that might not show up in shorter studies. However, because people chose their own diets rather than being assigned to eat certain foods, we can’t be 100% sure that the inflammatory foods caused the disease.

This study is fairly reliable because it included a very large number of people (over 17,000), used standardized methods to measure diet and disease, and followed people for a long time. The researchers also adjusted their analysis to account for other health factors that might affect the results. However, the study relied on people remembering what they ate, which can be inaccurate. Also, the study shows association (connection) rather than causation (proof that one thing causes another).

What the Results Show

People who ate the most inflammatory foods had significantly worse health outcomes. Those in the highest group of inflammatory eating had a 36% greater chance of developing advanced heart and kidney disease compared to those in the lowest group. The relationship was consistent and dose-dependent, meaning that as inflammatory food consumption increased, so did disease risk.

Over the nearly 10-year follow-up period, people with higher dietary inflammation scores had higher death rates from all causes and specifically from heart disease. For every one-point increase in the inflammation score, the risk of dying from any cause increased by about 7%, and the risk of dying from heart disease increased by about 7% as well.

The relationship between inflammatory foods and disease appeared to be linear, meaning it didn’t level off at higher levels—the more inflammatory the diet, the greater the risk. This suggests there may not be a safe threshold for inflammatory eating patterns.

The study found that certain groups of people were more affected by inflammatory diets. Women showed particularly strong connections between inflammatory eating and advanced heart-kidney disease. Former smokers and people without high blood pressure showed stronger connections between inflammatory diets and overall death risk. People with higher education levels showed stronger connections between inflammatory diets and death from heart disease.

This study builds on previous research showing that diet inflammation is linked to various chronic diseases. It extends that knowledge by specifically examining heart-kidney-metabolic syndrome, which is a cluster of conditions that often occur together. The findings align with other research suggesting that anti-inflammatory diets may be protective for heart and kidney health. This is one of the larger studies to examine these connections over such a long time period.

The study has several important limitations. First, people reported what they ate based on memory, which can be inaccurate. Second, the study only measured diet at one point in time, so it doesn’t account for changes in eating habits over the years. Third, while the study shows a connection between inflammatory foods and disease, it cannot prove that the foods caused the disease—other unmeasured factors could be responsible. Finally, the study included mostly American adults, so results may not apply to other populations.

The Bottom Line

Based on this research, consider reducing inflammatory foods like processed items, sugary drinks, and fried foods, and increase anti-inflammatory foods like fruits, vegetables, whole grains, fish, and nuts. This recommendation has moderate confidence because the study shows a strong connection, but it’s not definitive proof. Talk to your doctor or a dietitian about what diet changes make sense for your specific health situation.

This research is most relevant for people concerned about heart and kidney health, those with family histories of these conditions, and anyone interested in disease prevention through diet. It’s particularly important for women and people with metabolic concerns. However, if you have existing heart or kidney disease, work with your healthcare provider rather than making major diet changes on your own.

You likely won’t notice dramatic changes immediately. The study tracked people over nearly 10 years, suggesting that dietary changes work gradually over time. You might notice improved energy, better blood pressure, or improved blood sugar within weeks to months, but protection against serious disease develops over years of consistent healthy eating.

Want to Apply This Research?

  • Track your daily intake of inflammatory foods (processed foods, sugary drinks, fried items) versus anti-inflammatory foods (fruits, vegetables, whole grains, fish). Aim to reduce inflammatory foods by 10-20% each week and increase anti-inflammatory foods by the same amount. Monitor changes in energy levels and any health markers your doctor tracks.
  • Start by identifying your top three inflammatory foods and replace them with healthier alternatives. For example, swap sugary drinks for water or unsweetened tea, replace white bread with whole grain, or choose grilled chicken instead of fried. Make one change per week to avoid feeling overwhelmed.
  • Use the app to log meals weekly and track the ratio of inflammatory to anti-inflammatory foods. Set a goal to gradually shift toward more anti-inflammatory choices over 8-12 weeks. If you have regular doctor visits, ask your healthcare provider to track relevant health markers like blood pressure, cholesterol, or blood sugar to see if dietary changes are helping.

This research shows a connection between inflammatory foods and heart-kidney disease, but it does not prove that changing your diet will prevent these conditions. Individual results vary based on genetics, overall lifestyle, and other health factors. Before making significant dietary changes, especially if you have existing health conditions or take medications, consult with your doctor or a registered dietitian. This information is for educational purposes and should not replace professional medical advice.