Researchers looked at 11 large studies involving over 450,000 people to see how healthy eating patterns affect heart failure risk. They found that people who closely followed three popular healthy diets—DASH, Mediterranean, and AHEI—had about 25% lower chances of developing heart failure compared to those who didn’t follow these diets. The good news is that all three diets worked similarly well, and the more closely people stuck to any of these eating patterns, the better their heart protection. This suggests that choosing any of these healthy eating approaches and following it consistently could be a powerful way to protect your heart.

The Quick Take

  • What they studied: Whether eating according to three specific healthy diet plans (DASH, Mediterranean, and AHEI) could lower the chances of developing heart failure
  • Who participated: Over 450,000 adults from 11 different research studies around the world, with at least 18,877 people who developed heart failure during the studies
  • Key finding: People who followed any of these three healthy eating patterns most closely had a 25% lower risk of heart failure compared to those who followed them least closely. All three diets showed similar protective benefits.
  • What it means for you: If you’re concerned about heart health, adopting any of these three eating patterns and sticking with it consistently may significantly reduce your heart failure risk. However, this research shows association, not that diet alone prevents heart failure—talk to your doctor about your individual risk factors.

The Research Details

This was a meta-analysis, which means researchers combined results from 11 separate long-term studies that followed people over time to see who developed heart failure. Each study tracked thousands of people and recorded what they ate and whether they developed heart failure. The researchers used a special statistical method to combine all these studies together, looking at how closely people followed each of the three diets and comparing heart failure rates between those who followed the diets most closely versus those who followed them least closely.

The researchers also looked at whether there was a dose-response relationship—basically, whether following the diet more closely led to even better protection. They used advanced statistical techniques to map out this relationship, similar to how a doctor might look at whether taking more of a medicine provides more benefit (up to a safe level).

All the studies they included were prospective cohort studies, which means they followed healthy people forward in time to see who got sick, rather than looking backward at people who already had the disease. This type of study is considered stronger evidence than some other research designs.

This research approach is important because it combines evidence from many studies, which gives us a much clearer picture than any single study could provide. By looking at 11 different studies with over 450,000 people total, the researchers could see patterns that might not show up in smaller studies. The dose-response analysis is particularly valuable because it shows that the benefit isn’t just an all-or-nothing thing—the more closely you follow these diets, the more protection you appear to get.

This study has several strengths: it included a very large number of people (450,000+), looked at multiple studies from different populations, and used rigorous statistical methods. The studies included were all prospective (following people forward in time), which is stronger than retrospective studies. However, all the included studies were observational, meaning researchers watched what people ate naturally rather than randomly assigning people to different diets. This means we can’t be completely certain that the diet itself caused the lower heart failure risk—other healthy habits of people who eat well might also play a role. The researchers did try to account for this in their analysis, but it’s still a limitation.

What the Results Show

When researchers combined all 11 studies, they found that people with the highest adherence to healthy eating patterns had a 25% lower risk of heart failure compared to those with the lowest adherence. To put this in perspective, if 100 people with low diet adherence developed heart failure, only about 75 people with high adherence would be expected to develop it.

When looking at each diet separately, all three showed protective effects. The Mediterranean diet showed the strongest association with a 26% lower risk, followed by the AHEI diet with a 25% lower risk, and the DASH diet with a 19% lower risk. Importantly, the differences between the three diets were not statistically significant, meaning they all performed similarly well.

The dose-response analysis revealed that the protection increased steadily as people followed the diets more closely. This wasn’t a situation where you had to be perfect to see benefits—even moderate improvements in diet adherence appeared to provide meaningful protection. The relationship was linear, meaning each step up in diet adherence corresponded to a step down in heart failure risk.

The researchers also looked at whether the effects were different for different groups of people. While they didn’t find major differences based on factors like age or sex in the available data, this is an area where more research could be helpful. The consistency of findings across three different dietary patterns is itself an important secondary finding—it suggests that the common features of these diets (lots of vegetables, fruits, whole grains, and healthy fats; less processed food and salt) are what matter most, rather than the specific details of any one diet.

This research aligns with and strengthens previous findings about healthy eating and heart health. Earlier studies had suggested these diets were good for the heart, but this meta-analysis provides stronger evidence by combining many studies. The finding that all three diets work similarly well is consistent with other research showing that the general principles of healthy eating matter more than following one specific diet perfectly. This research also fits with what we know about how diet affects heart disease risk factors like blood pressure, cholesterol, and inflammation.

The main limitation is that all included studies were observational—researchers watched what people naturally ate rather than randomly assigning people to different diets. This means we can’t be completely certain the diet caused the lower heart failure risk; people who eat healthily might also exercise more, manage stress better, or have other healthy habits. Additionally, most studies relied on people remembering and reporting what they ate, which can be inaccurate. The studies also mostly included people of European descent, so we’re less certain how well these findings apply to other populations. Finally, the studies measured diet at one point in time, but people’s eating habits change over years, which could affect the results.

The Bottom Line

If you’re interested in reducing your heart failure risk, adopting and consistently following any of these three eating patterns—DASH, Mediterranean, or AHEI—appears to be beneficial. Start by gradually increasing vegetables, fruits, whole grains, and healthy fats while reducing processed foods and salt. You don’t need to be perfect; even moderate improvements in diet quality appear to provide meaningful protection. Confidence level: Moderate to High (based on large sample size and multiple studies, though observational design limits certainty).

Anyone concerned about heart health should pay attention to this research, especially people with family history of heart disease, high blood pressure, high cholesterol, or other heart disease risk factors. People already diagnosed with heart disease or heart failure should definitely discuss dietary changes with their cardiologist. This research is less directly applicable to people with certain medical conditions that restrict what they can eat—they should work with their healthcare team on personalized recommendations.

Don’t expect overnight results. Research suggests that dietary changes typically take weeks to months to noticeably affect blood pressure and cholesterol levels, which are key factors in heart failure risk. Some benefits like reduced inflammation might appear within weeks, but the major protective effects likely develop over months to years of consistent healthy eating. Think of this as a long-term investment in your heart health rather than a quick fix.

Want to Apply This Research?

  • Track daily adherence to one of the three diets using a simple scoring system (0-10 scale) based on how closely you followed the diet that day. Record specific foods eaten from each food group (vegetables, fruits, whole grains, healthy fats, lean proteins) to monitor patterns over weeks and months.
  • Start with one small change: add one extra serving of vegetables or fruits to your daily meals. Once that becomes routine (usually 2-3 weeks), add another change like switching to whole grains or reducing processed foods. This gradual approach is more sustainable than trying to overhaul your entire diet at once.
  • Use the app to track your diet adherence score weekly and monthly, looking for trends over time rather than daily perfection. Set reminders for grocery shopping focused on diet-friendly foods, and periodically review your food logs to identify which dietary changes have been easiest to maintain and which need more support.

This research shows an association between healthy eating patterns and lower heart failure risk, but does not prove that diet alone prevents heart failure. Heart failure is a complex condition with many contributing factors including genetics, age, high blood pressure, diabetes, and other medical conditions. This information is for educational purposes and should not replace professional medical advice. If you have concerns about heart health or are considering significant dietary changes, especially if you have existing heart conditions or take medications, please consult with your doctor or a registered dietitian before making major changes to your diet. Individual results may vary based on your specific health situation.