Researchers wanted to know if a special type of chicory vegetable could improve how well blood vessels work and improve cholesterol health. Thirty-two healthy men who were overweight drank smoothies containing either chicory leaves, chicory roots, or a control drink for one week at a time. While the chicory didn’t improve blood vessel flexibility, it did help improve how the body’s “good cholesterol” (HDL) worked after meals. The chicory appeared to help the good cholesterol remove harmful substances from blood vessel walls more effectively, which could be beneficial for heart health over time.
The Quick Take
- What they studied: Whether eating chicory vegetables could improve blood vessel function and the quality of good cholesterol (HDL) in the body
- Who participated: 32 healthy men who were overweight, averaging about 37 years old. Each man tested three different smoothies over three weeks with breaks in between
- Key finding: Chicory improved how well good cholesterol worked after meals by helping it clean harmful substances from blood vessel walls more effectively, even though it didn’t improve overall blood vessel flexibility
- What it means for you: Eating chicory vegetables may help your good cholesterol work better, which could support heart health. However, this was a small study in men only, so more research is needed before making strong recommendations
The Research Details
This was a carefully controlled experiment where 32 men participated in three separate one-week eating periods. In each period, they drank a smoothie with either chicory leaves (containing lots of plant compounds), chicory roots (containing fewer plant compounds), or a plain control drink. The men didn’t know which smoothie they were drinking (called “single-blind”). Between each week, they took a one-week break to let their bodies return to normal. Before and after each week, researchers measured how well their blood vessels worked and tested their cholesterol levels.
The researchers chose this design because it allowed each person to be their own comparison. This is stronger than comparing different groups of people because it removes differences between individuals. The one-week washout period between tests helped ensure that one smoothie’s effects didn’t carry over to the next test.
This study design is important because it can show real cause-and-effect relationships. By having each person try all three options, researchers could see exactly what the chicory did compared to a control. The careful measurements of blood vessel function and cholesterol types gave detailed information about how chicory might help the heart.
Strengths: The study was randomized (random order of smoothies), controlled (included a comparison group), and each person served as their own control. Researchers measured specific markers of heart health. Limitations: The study only included 32 men who were overweight and healthy, so results may not apply to women, older people, or people with existing health conditions. The study period was short (one week per condition), so we don’t know about long-term effects. The amount of chicory used (100g of leaves or 26.7g of roots) may be more than people typically eat.
What the Results Show
The chicory smoothies did not improve how well blood vessels expanded when blood flow increased (called flow-mediated dilation), which was the original main goal. However, the researchers discovered something important: both the chicory leaves and roots improved how well the good cholesterol (HDL) worked after meals.
Specifically, the chicory helped good cholesterol become better at removing a harmful substance called 7-ketocholesterol from the inside of blood vessels. This is important because this harmful substance can contribute to clogged arteries. The chicory also changed the types of good cholesterol in the blood—it increased the medium-sized HDL particles (HDL3) and decreased the smallest type (pre-β1-HDL).
Interestingly, these improvements only happened after meals, not during fasting. The researchers found that the amount of good cholesterol in the blood didn’t change, but how well it worked definitely improved. Both the chicory leaves (which had more plant compounds) and chicory roots (which had fewer plant compounds) produced similar improvements, suggesting that other parts of the chicory besides just the phenolic acids might be responsible.
The study revealed that the improvement in how well good cholesterol worked was directly connected to its ability to remove the harmful 7-ketocholesterol. When this cleaning function improved, the types of good cholesterol particles changed in beneficial ways. The researchers also noted that the effects were specific to the time after eating—fasting measurements showed no changes in blood vessel function or cholesterol markers.
Previous research in mice had shown that chicory’s plant compounds could improve blood vessel function by increasing a substance called nitric oxide. This study in humans confirmed that chicory does increase nitric oxide activity in good cholesterol, but surprisingly, this didn’t translate to improved blood vessel flexibility in the short term. This suggests that the benefits of chicory on heart health may work through improving cholesterol function rather than directly improving blood vessel flexibility. The findings add to growing evidence that plant-rich foods can improve cholesterol quality, not just cholesterol quantity.
This study has several important limitations: Only 32 men participated, and they were all healthy and overweight, so results may not apply to women, older adults, or people with heart disease or diabetes. The study lasted only one week per condition, so we don’t know if benefits continue or increase with longer-term eating. The amount of chicory used (100g of leaves daily) is quite large and may be more than most people would typically eat. The study measured effects only in the hours after eating, not over a full day. Finally, because this is one study, the findings need to be confirmed by other research before making strong recommendations.
The Bottom Line
Based on this research, eating chicory vegetables appears to be safe and may help improve how your good cholesterol works, particularly after meals. However, confidence in this recommendation is moderate because the study was small and short-term. If you enjoy chicory, including it in your diet as part of a healthy eating pattern is reasonable. This should not replace other proven heart-healthy habits like regular exercise, not smoking, managing stress, and eating a variety of vegetables.
This research may be most relevant to healthy adults who are overweight and interested in supporting heart health through diet. People with existing heart disease, diabetes, or those taking blood-thinning medications should talk to their doctor before making significant dietary changes. The study was done in men, so benefits in women are unknown. Older adults and children were not studied.
The improvements in good cholesterol function appeared within one week of eating chicory, which is encouraging. However, we don’t know if these benefits continue with longer-term eating or if they eventually lead to better heart health outcomes. It typically takes months to years of healthy habits to see measurable improvements in heart disease risk, so patience is important.
Want to Apply This Research?
- Track daily chicory consumption (in grams) and note any digestive changes or energy levels. Also track other heart-healthy behaviors like exercise minutes and overall vegetable servings to see patterns in how diet affects your wellbeing
- Add chicory to your diet gradually—try adding chicory leaves to salads, blending chicory root into smoothies, or including it in cooked dishes. Start with small amounts (10-25g) and increase over a week to reach 50-100g daily while monitoring how your body responds
- Keep a weekly log of chicory intake and any changes you notice in energy, digestion, or how you feel after meals. If possible, work with a healthcare provider to monitor cholesterol levels every 3-6 months to see if dietary changes are having measurable effects
This research describes findings from a single study in a limited population of healthy overweight men. These results should not be considered medical advice. Before making significant dietary changes, especially if you have heart disease, diabetes, high cholesterol, or take medications, please consult with your doctor or a registered dietitian. This study does not prove that chicory prevents or treats any disease. Individual results may vary, and more research is needed to confirm these findings in diverse populations and over longer time periods.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.