According to Gram Research analysis, a one-year study of 2,664 older adults with metabolic syndrome found that those who increased their dietary spermidine intake showed significant improvements in liver health and cardiometabolic markers. The group with the highest spermidine intake experienced a 9-point reduction in fatty liver index, a 0.14% improvement in blood sugar control, and a 3.7-centimeter decrease in waist circumference. Spermidine is a natural compound found in aged cheese, mushrooms, whole grains, and legumes.
A new study of 2,664 older adults with metabolic syndrome found that eating more spermidine-rich foods over one year was linked to better liver health and improved heart disease risk factors. Spermidine is a natural compound found in foods like aged cheese, mushrooms, whole grains, and legumes. People who increased their spermidine intake the most showed improvements in fatty liver disease markers, blood sugar control, and body measurements like waist circumference. While the results are promising, researchers emphasize this is an observational study, so eating more spermidine foods may be one helpful piece of managing metabolic syndrome alongside other lifestyle changes.
Key Statistics
A 2026 cohort study of 2,664 older adults with metabolic syndrome found that those who increased dietary spermidine intake over one year experienced a mean reduction of 8.97 points in fatty liver index, a key marker of liver fat accumulation.
Among 2,664 participants in the PREDIMED-Plus trial, those with the highest baseline spermidine intake that increased further showed a 3.72-centimeter reduction in waist circumference and a 0.14% improvement in blood sugar control (glycated hemoglobin) over one year.
A longitudinal analysis of 2,664 older adults found that increased dietary spermidine intake was associated with reductions in liver enzymes alanine aminotransferase (ALT) by 2.93 U/L and aspartate aminotransferase (AST) by 1.11 U/L, suggesting improved liver function.
In a 2026 study of 2,664 participants with metabolic syndrome, those who increased spermidine intake showed a mean body mass index reduction of 1.26 points and hip circumference decrease of 2.33 centimeters over one year.
The Quick Take
- What they studied: Whether eating more spermidine (a natural compound in certain foods) helps improve liver function and heart disease risk factors in older adults with metabolic syndrome
- Who participated: 2,664 overweight and obese older adults who had metabolic syndrome (a cluster of conditions including high blood pressure, blood sugar, and cholesterol). They were tracked for one year as part of a larger nutrition study called PREDIMED-Plus
- Key finding: Adults who increased their spermidine intake the most over one year had meaningful improvements: their fatty liver index dropped by about 9 points, their blood sugar control improved by 0.14%, and their waist circumference shrank by about 3.7 centimeters on average
- What it means for you: Adding more spermidine-rich foods to your diet may help improve liver health and reduce heart disease risk if you have metabolic syndrome. However, this study shows association, not proof that spermidine causes these improvements. Talk to your doctor before making major dietary changes, especially if you take medications
The Research Details
Researchers used data from 2,664 participants in the PREDIMED-Plus trial, a large nutrition study focused on heart health. They measured how much spermidine people ate at the start, at six months, and at one year using a detailed food questionnaire. They then grouped participants into three patterns based on how their spermidine intake changed over the year. The group that started with the highest spermidine intake and increased it further showed the best health improvements.
The researchers used statistical methods to compare changes in liver markers and heart disease risk factors between the three groups. They measured things like fatty liver index (a score that estimates liver fat), liver enzymes (proteins that show liver damage), blood sugar control, and body measurements. They adjusted their analysis to account for other factors that might affect results, like age, exercise, and overall diet quality.
This approach is called a longitudinal cohort study, meaning researchers followed the same people over time and looked at how changes in one thing (spermidine intake) related to changes in other things (liver and heart health markers). This type of study is stronger than a single snapshot but weaker than a controlled experiment where some people are randomly assigned to eat more spermidine.
Following people over a full year gives researchers a realistic picture of how dietary changes work in real life, rather than in a controlled lab setting. By looking at patterns of change rather than just comparing high versus low intake, the study captures how people actually modify their diets gradually. This approach helps answer the practical question: if someone increases their spermidine intake, what health improvements might they see?
This study has several strengths: it included a large number of participants (2,664), followed them for a full year, and used established methods to measure diet and health markers. The study was part of a well-respected nutrition trial (PREDIMED-Plus) with rigorous data collection. However, the study cannot prove that spermidine directly causes the improvements—it only shows that people who ate more spermidine also had better health outcomes. People who increased spermidine intake may have also made other healthy changes. Additionally, the study focused on older adults with metabolic syndrome, so results may not apply to younger or healthier populations
What the Results Show
The group with the highest baseline spermidine intake that increased further over the year (Cluster 3) showed the most impressive improvements. Their fatty liver index—a key measure of liver fat—dropped by about 9 points on average. This is meaningful because fatty liver disease is common in people with metabolic syndrome and increases heart disease risk.
Liver enzyme levels also improved significantly. Alanine aminotransferase (ALT) decreased by about 2.93 units, and aspartate aminotransferase (AST) decreased by about 1.11 units. These enzymes are markers of liver damage, so lower levels suggest the liver was healthier. Blood sugar control improved too, with glycated hemoglobin (a measure of average blood sugar over three months) dropping by 0.14%.
Body measurements showed consistent improvements across the group that increased spermidine intake. Body mass index (BMI) decreased by about 1.26 points, waist circumference shrank by 3.72 centimeters, and hip circumference decreased by 2.33 centimeters. These changes are clinically meaningful—a 3.7 centimeter reduction in waist circumference is associated with real health benefits.
All of these improvements were statistically significant, meaning they were unlikely to have occurred by chance. The improvements were consistent across multiple health markers, suggesting spermidine intake may have broad benefits for people with metabolic syndrome.
The study identified three distinct patterns of spermidine intake change over the year. Cluster 1 had low baseline intake that stayed low. Cluster 2 had moderate intake that remained stable. Cluster 3, the focus group, had high baseline intake that increased further. Only Cluster 3 showed significant health improvements, suggesting that both starting with adequate spermidine intake and increasing it further may be important. The other two clusters showed minimal changes in health markers, indicating that modest spermidine intake may not provide the same benefits as higher intake levels.
Previous animal studies (in mice and rats) had shown that spermidine supplements could reduce fatty liver disease and improve metabolic health. This human study provides the first strong evidence that these benefits may translate to real people eating spermidine-rich foods. The findings align with what we know about spermidine’s biological effects—it appears to reduce inflammation and support cellular health. However, this is one of the first human studies examining dietary spermidine (not supplements) in a large population, so the results add important new evidence to a growing field
The biggest limitation is that this study shows association, not causation. People who increased spermidine intake may have also exercised more, reduced stress, or made other dietary improvements that caused the health benefits. The study cannot isolate spermidine’s specific effect. Additionally, the study included only older adults with metabolic syndrome, mostly from Mediterranean regions, so results may not apply to younger people or those without metabolic syndrome. The study relied on participants’ memory of what they ate (food frequency questionnaires), which can be inaccurate. Finally, researchers did not measure spermidine intake directly in blood or urine, so the estimates are based on food composition databases that may have errors
The Bottom Line
If you have metabolic syndrome or fatty liver disease, consider adding more spermidine-rich foods to your diet as part of a comprehensive approach to health. Good sources include aged cheeses, mushrooms, whole grains, legumes (beans and lentils), nuts, and fermented foods. This recommendation has moderate confidence because the research shows strong associations but cannot prove causation. Combine dietary changes with exercise, weight loss if needed, and regular medical checkups. Always consult your doctor before making major dietary changes, especially if you take medications for blood sugar or cholesterol
This research is most relevant for older adults with metabolic syndrome, fatty liver disease, or multiple heart disease risk factors. It may also interest anyone trying to improve liver health or reduce metabolic disease risk. The findings are less relevant for young, healthy people without metabolic syndrome. If you’re pregnant, nursing, or have liver disease, talk to your doctor before significantly changing your diet
Based on this study, meaningful improvements in liver markers and body measurements appeared over a one-year period. You might notice changes in waist circumference within a few months, but liver function improvements typically take longer—expect to see meaningful changes in liver markers after 6-12 months of consistent dietary changes. Results depend on how much you increase spermidine intake and whether you make other healthy lifestyle changes
Frequently Asked Questions
What foods have spermidine in them?
Spermidine is found in aged cheeses, mushrooms (especially button and shiitake), whole grains, legumes (beans and lentils), nuts, seeds, and fermented foods like soy sauce and tempeh. Mushrooms and aged cheese are among the richest sources.
Can spermidine supplements work as well as food sources?
This study examined dietary spermidine from foods, not supplements. While animal studies suggest supplements may work, we don’t yet have strong human evidence comparing supplements to food sources. Food sources provide additional nutrients and fiber that may contribute to health benefits.
How much spermidine do I need to eat daily?
The study didn’t specify an exact daily amount, but the group with the best results had high baseline intake that increased further. Most nutrition experts suggest aiming for at least one serving of spermidine-rich foods daily, such as a handful of nuts, a serving of legumes, or mushrooms with a meal.
Will eating more spermidine help if I don’t have metabolic syndrome?
This study focused on older adults with metabolic syndrome, so we don’t know if benefits apply to healthier people. However, spermidine-rich foods like whole grains, legumes, and mushrooms are nutritious and beneficial for everyone, so including them in your diet is a good idea regardless.
How long does it take to see improvements from eating more spermidine?
This study tracked changes over one year. You might notice changes in waist circumference within a few months, but improvements in liver function markers typically take 6-12 months of consistent dietary changes. Results vary based on how much you increase intake and other lifestyle factors.
Want to Apply This Research?
- Log spermidine-rich foods daily (aged cheese, mushrooms, whole grains, legumes, nuts) and track weekly waist circumference measurements. Set a goal to include at least one spermidine source at two meals per day
- Replace refined grains with whole grains, add mushrooms to meals 3-4 times weekly, include legumes in at least two meals per week, and add aged cheese or nuts as snacks. Start with one change and add others gradually over 2-3 weeks
- Track weekly waist circumference and monthly weight. If possible, work with your doctor to monitor liver enzymes (ALT, AST) and blood sugar (HbA1c) every 3-6 months. Note energy levels, digestion, and how clothes fit as informal markers of progress
This research shows associations between spermidine intake and health improvements but does not prove that spermidine directly causes these changes. Results apply specifically to older adults with metabolic syndrome and may not apply to other populations. Always consult with your healthcare provider before making significant dietary changes, especially if you have liver disease, take medications, or have other health conditions. This information is for educational purposes and should not replace professional medical advice. Do not use this information to self-diagnose or self-treat any medical condition.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.