Researchers looked at 31 studies about the Paleolithic diet—a way of eating based on foods our ancestors ate thousands of years ago, like meat, fish, vegetables, and nuts. They found that people who followed this diet had improvements in important heart health markers like blood sugar control and fat levels in their blood. The diet also appeared to lower the risk of heart disease by about 16% in people who stuck with it closely. While these results are promising, scientists say more research is needed to understand if these benefits last over many years.

The Quick Take

  • What they studied: Whether eating a Paleolithic diet (foods like meat, fish, vegetables, fruits, and nuts without grains or processed foods) helps prevent heart disease and improves heart health markers
  • Who participated: 31 different research studies involving thousands of people total—some studies tracked people over time, while others had people try the diet for a set period and measured changes
  • Key finding: People following the Paleolithic diet showed better blood sugar control, lower triglycerides (a type of fat in blood), and about 16% lower risk of heart disease compared to people eating typical diets
  • What it means for you: The Paleolithic diet may help your heart health, but it’s not a guaranteed cure. Results were strongest in people who followed the diet very closely. Talk to your doctor before making major diet changes, especially if you have existing health conditions

The Research Details

Scientists conducted a systematic review and meta-analysis, which means they searched for all high-quality studies about the Paleolithic diet and combined the results to see the big picture. They included 19 studies where people were randomly assigned to either eat the Paleolithic diet or a regular diet (the gold standard for testing diets), and 12 studies that followed people’s eating habits over time to see what happened. They used statistical methods to combine results from all these studies and look for patterns. They also examined whether eating more strictly (higher adherence) made a bigger difference in results.

By combining results from many studies instead of looking at just one, researchers can see if findings are consistent and reliable. This approach is stronger than any single study because it reduces the chance that one unusual result will mislead us. The researchers used careful methods to make sure they were comparing similar studies fairly.

This analysis included both controlled experiments (where researchers control what people eat) and real-world observations (where researchers watch what people naturally eat). The controlled studies are generally more reliable for proving cause-and-effect. The researchers used established quality standards (GRADE assessment) to evaluate how confident we should be in their findings. However, the studies varied in length, quality, and how strictly people followed the diet, which can affect the overall conclusions.

What the Results Show

When researchers combined results from controlled diet studies, they found three main improvements in people eating the Paleolithic diet: First, fasting insulin (a hormone that controls blood sugar) dropped by about 1 unit on average, which suggests better blood sugar control. Second, triglycerides (unhealthy fats in blood) decreased by 0.16 units. Third, people who stuck very closely to the Paleolithic diet had about 16% lower risk of heart disease compared to people eating standard diets. These improvements were statistically significant, meaning they’re unlikely to have happened by chance. The improvements were strongest in people who followed the diet most strictly, suggesting that commitment to the diet matters.

The research also showed improvements in other heart health markers, though the details weren’t fully specified in the summary. The dose-response analysis (looking at whether stricter adherence meant better results) suggested that people who followed the diet more closely got better benefits. This pattern is important because it suggests the diet itself causes the improvements rather than other factors.

These findings support previous research suggesting that diets emphasizing whole foods and avoiding processed foods can benefit heart health. The Paleolithic diet’s benefits appear similar to other healthy eating patterns like the Mediterranean diet, though direct comparisons weren’t made in this analysis. The 16% reduction in heart disease risk is meaningful but modest compared to some other lifestyle interventions.

The studies analyzed varied significantly in how long people followed the diet (from weeks to years), making it hard to know if benefits last long-term. Most studies were relatively short-term. The research couldn’t prove the diet works for everyone—results depended heavily on how strictly people followed it. Different studies measured different outcomes, and some had small numbers of participants. The analysis couldn’t separate the diet’s effects from other healthy lifestyle changes people might have made. Most participants were from developed countries, so results may not apply equally to everyone worldwide.

The Bottom Line

If you’re interested in heart health, the Paleolithic diet appears to be a reasonable option worth discussing with your doctor, especially if you have risk factors for heart disease. The evidence is moderate-strength—promising but not definitive. Focus on the core principles: eat whole foods like vegetables, fruits, lean meats, and nuts while limiting processed foods, grains, and added sugars. Don’t expect overnight results; give any diet change at least 8-12 weeks to see effects. This shouldn’t replace medical treatment if you have existing heart disease.

People concerned about heart disease risk, those with high blood sugar or triglycerides, and anyone looking to improve their diet should pay attention to these findings. People with certain medical conditions (like kidney disease) should check with their doctor first, as the diet is high in protein. This research is less relevant for people already eating very healthy diets or those with specific medical reasons to avoid certain foods.

Most studies showed improvements in blood sugar and triglycerides within 4-12 weeks. Heart disease risk reduction likely takes longer to develop—probably months to years of consistent eating. Don’t expect dramatic changes immediately; think of this as a long-term investment in your health.

Want to Apply This Research?

  • Track daily adherence to Paleolithic diet principles (percentage of meals containing only whole foods without grains or processed items) and measure weekly fasting blood sugar or triglyceride levels if possible through your doctor
  • Start by replacing one meal per day with Paleolithic-friendly foods: a plate with grilled chicken, roasted vegetables, and a side salad instead of your usual meal. Gradually expand to more meals as it becomes comfortable
  • Weekly check-ins on how many Paleolithic-compliant meals you ate, monthly tracking of energy levels and digestion, and quarterly blood work (with your doctor) to measure fasting insulin, triglycerides, and other heart health markers

This research summary is for educational purposes only and should not replace professional medical advice. The Paleolithic diet may not be appropriate for everyone, particularly those with kidney disease, certain allergies, or specific medical conditions. Before making significant dietary changes, especially if you have existing health conditions, take medications, or are pregnant or breastfeeding, consult with your healthcare provider or registered dietitian. While this meta-analysis shows promising results, individual responses to dietary changes vary considerably. This summary represents current research but should not be considered definitive medical guidance.