Key Takeaways
- A randomized crossover trial involving 28 healthy adults found that eating 400 grams of prickly pear fruit pulp daily for two weeks reduced several inflammatory biomarkers compared with a diet containing other fresh fruits.
- Researchers reported reductions in C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β), interleukin-8 (IL-8), interferon-gamma (IFN-γ), and erythrocyte sedimentation rate (ESR), alongside an increase in the anti-inflammatory signaling protein IL-10.
- Skin carotenoid scores increased by approximately 30%, although this measurement does not directly establish protection against oxidative damage.
- The trial measured short-term biological changes in healthy adults, not improvements in inflammatory diseases or long-term health outcomes.
Introduction
Prickly pear fruit contains naturally occurring plant pigments and antioxidants. A randomized crossover trial involving 28 healthy adults found changes in several inflammatory biomarkers after two weeks of fruit consumption.
Eating prickly pear fruit may influence certain blood markers associated with inflammation, according to a randomized clinical trial involving 28 healthy adults.
In the study, published in Food & Nutrition Research, participants consumed 400 grams of fresh prickly pear pulp daily for two weeks. Researchers observed reductions in several inflammatory biomarkers compared with a diet containing other fresh fruits.
The results indicate that prickly pear fruit can affect measurable aspects of inflammatory activity. However, the study did not investigate whether eating the fruit prevents disease, relieves inflammatory symptoms, or produces lasting health benefits.
Understanding that distinction is essential when interpreting the findings.
What the Study Examined
The randomized crossover trial by Attanzio et al. (2018) enrolled 28 healthy adults, including 14 women and 14 men.
Participants had an average age of approximately 40 years and an average body mass index of 23.1. None had a history of major cardiovascular, metabolic, gastrointestinal, liver, or kidney disease.
The researchers, based at the University of Palermo in Italy, investigated whether consuming prickly pear fruit could influence inflammatory biomarkers and measurements associated with antioxidant status.
Participants Ate 400 Grams of Prickly Pear Fruit Daily
The study used a randomized crossover design, meaning every participant completed both dietary interventions.
During one two-week period, participants consumed 200 grams of peeled prickly pear pulp twice daily, totaling 400 grams per day.
During the comparison period, they followed a similar diet containing other fresh fruits, including apples, strawberries, oranges, pears, and grapefruit, instead of prickly pear.
The two dietary periods were separated by a three-week break.
Researchers used individualized meal plans to keep overall calorie and nutrient intake broadly comparable. This helped distinguish the effects of prickly pear from those of consuming fruit generally.
The study used fresh pulp from the yellow Sicilian Surfarina variety of Opuntia ficus-indica, rather than cactus pads, juice, or concentrated supplements.
Blood samples were collected before and after the interventions to measure inflammatory proteins, glucose, and blood lipids. The investigators also assessed skin carotenoids using a noninvasive optical scanner.
What Researchers Found
Several Inflammatory Markers Declined
Researchers reported significant reductions in several inflammatory measurements following the two-week prickly pear intervention compared with the control diet.
These included:
- C-reactive protein (CRP)
- Tumor necrosis factor-alpha (TNF-α)
- Interleukin-1β (IL-1β)
- Interleukin-8 (IL-8)
- Interferon-gamma (IFN-γ)
- Erythrocyte sedimentation rate (ESR)
The reported differences were statistically significant, although their magnitude and statistical strength varied among measurements.
CRP and ESR are commonly used in clinical practice to help assess inflammation. Both were already within normal reference ranges at the beginning of the study but declined after participants consumed prickly pear fruit.
Importantly, the participants were healthy and were not being treated for elevated inflammatory markers or diagnosed inflammatory disorders. The findings therefore demonstrate changes in laboratory measurements rather than improvements in an existing medical condition.
An Anti-Inflammatory Protein Increased
Researchers also measured interleukin-10 (IL-10), a signaling protein involved in regulating inflammatory responses.
Unlike the pro-inflammatory markers, IL-10 increased significantly following prickly pear consumption.
The investigators calculated ratios between several pro-inflammatory markers and IL-10. These ratios declined following the prickly pear intervention, consistent with a shift in the measured inflammatory profile.
For example, the average CRP-to-IL-10 ratio decreased from 0.46 at baseline to 0.17 after the prickly pear diet, while the corresponding value after the control diet was 0.49.
Not every marker responded. Interleukin-6 (IL-6), another important inflammatory signaling protein, did not change significantly.
However, the IL-6-to-IL-10 ratio declined because IL-10 increased.
The response was therefore selective rather than a uniform reduction in every inflammatory measurement.
Skin Carotenoid Scores Increased
Researchers also observed an approximately 30% increase in skin carotenoid scores after participants consumed prickly pear fruit.
Carotenoids are naturally occurring pigments found in many fruits and vegetables. Their concentration in the skin can provide information about carotenoid status and dietary exposure, although it does not directly measure the body’s overall antioxidant defenses.
The researchers used Raman spectroscopy, a noninvasive optical technique that detects these pigments in the skin.
In the trial, higher skin carotenoid scores were associated with lower levels of CRP and IL-8 and higher levels of IL-10.
These correlations were statistically significant, but they do not establish that increased carotenoids caused the changes in inflammatory markers.
The findings provide additional biological context rather than proof that prickly pear protects cells from oxidative damage or reduces the risk of chronic disease.
Blood Glucose and Cholesterol Did Not Change Significantly
The researchers also measured glucose, total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides.
None of these conventional metabolic measurements changed significantly relative to baseline during the study.
Consequently, the trial does not establish that two weeks of prickly pear fruit consumption meaningfully lowers cholesterol or blood glucose in healthy adults.
Its principal contribution concerns inflammatory biomarkers and skin carotenoid measurements.
Why Might Prickly Pear Fruit Affect Inflammation?
Prickly pear fruit contains vitamin C and several naturally occurring plant compounds, including betalain pigments.
Betalains contribute to the distinctive yellow, red, and purple coloration found in different prickly pear varieties.
The 2018 trial used the yellow Sicilian Surfarina cultivar, which contains the betalain pigment indicaxanthin.
These compounds have attracted scientific interest because oxidative stress and inflammation are closely connected biological processes.
Oxidative stress occurs when reactive molecules and the body’s protective systems become imbalanced, potentially contributing to cellular damage. Inflammatory signaling can influence this process, while oxidative changes can also affect inflammation.
The researchers proposed that components of the whole fruit might influence pathways involved in maintaining this balance.
However, the trial did not establish which specific compounds caused the observed changes.
It also did not determine whether different prickly pear varieties, smaller portions, or processed fruit products would produce comparable results.
How the Findings Compare With Earlier Research
The 2018 trial builds on earlier human research investigating the antioxidant effects of prickly pear fruit.
In a randomized crossover study published in The American Journal of Clinical Nutrition, 18 healthy volunteers consumed either 500 grams of fresh prickly pear pulp daily or 150 milligrams of vitamin C daily for two weeks.
The researchers measured several indicators of oxidative stress, including markers of lipid damage.
Prickly pear consumption was associated with reductions in several oxidative-stress measurements, while vitamin C alone did not produce the same pattern of results (Tesoriere et al., 2004).
These findings are consistent with the possibility that prickly pear fruit contains biologically active substances beyond vitamin C.
Nevertheless, the earlier study also involved a small number of healthy participants and lasted only two weeks.
Taken together, the two trials provide preliminary human evidence that prickly pear fruit can influence biomarkers related to oxidative stress and inflammation.
They do not establish that these changes translate into fewer cardiovascular events, reduced arthritis symptoms, improved immune function, or protection against chronic disease.
What the Results May Mean for Human Health
Inflammation is a normal part of the body’s immune response, helping protect against infections and repair damaged tissue. However, persistently elevated inflammatory activity is associated with several chronic health conditions.
The significance of the prickly pear findings depends on an important detail: the study participants were healthy, and their inflammatory measurements were generally within normal reference ranges before the intervention.
A reduction in these markers therefore does not necessarily indicate that participants became healthier or experienced a clinically meaningful benefit.
The trial also did not measure symptoms, disease progression, or long-term health outcomes.
Instead, its contribution is to show that replacing other fresh fruits with substantial amounts of prickly pear pulp can influence certain laboratory measurements over a short period.
Whether these biological changes have lasting consequences for human health remains an open research question.
Should You Eat Prickly Pear Fruit to Reduce Inflammation?
Prickly pear can be included as part of a varied diet, but current evidence is insufficient to recommend it specifically for treating or preventing inflammatory conditions.
The participants in the 2018 trial consumed 400 grams of peeled fruit pulp every day, divided into two servings. Researchers did not test whether smaller quantities produce similar changes in inflammatory markers.
The study also used fresh pulp from a particular yellow prickly pear variety. Its findings cannot automatically be applied to juices, extracts, powders, or supplements.
If you enjoy prickly pear, eating it as part of a balanced diet is reasonable. However, there is no established daily serving that has been shown to reduce the risk of inflammatory disease.
People with chronic inflammatory conditions should continue following their prescribed treatment plans rather than relying on prickly pear or other individual foods to control their condition.
Limitations
Several factors limit how broadly the results can be applied.
Small sample size. Only 28 participants completed the trial. Although the crossover design allowed each participant to serve as their own comparison, the study remained small.
Short intervention. Each dietary period lasted two weeks. The research did not establish whether the biomarker changes persist with longer consumption or produce meaningful long-term health benefits.
Healthy, relatively homogeneous participants. Volunteers were recruited from a limited geographic and professional population, and their average body mass index was within the healthy range. The findings may not apply to older adults or people with diabetes, obesity, autoimmune diseases, or chronic inflammatory conditions.
High fruit intake. Participants consumed 400 grams of prickly pear pulp daily. The trial does not establish whether smaller, more typical servings have similar effects.
Surrogate outcomes. The study measured inflammatory proteins and skin carotenoids, not clinical outcomes such as pain, disease progression, hospitalizations, or cardiovascular events.
Multiple biomarker comparisons. The researchers examined numerous inflammatory measurements and correlations in a relatively small group of participants. This increases the importance of interpreting individual statistically significant findings cautiously, particularly when considering whether they represent reproducible biological effects.
Limited generalizability across products. The intervention involved fresh pulp from a specific yellow prickly pear cultivar. Its results should not automatically be extended to juices, supplements, extracts, or cactus pads.
The study also did not establish a biological mechanism that definitively explains the changes.
Larger, longer-term studies involving people with clinically elevated inflammation would be needed to determine whether these biomarker effects have therapeutic significance.
Final Thoughts
A small randomized crossover trial involving 28 healthy adults found that consuming 400 grams of prickly pear fruit pulp daily for two weeks reduced several measured inflammatory biomarkers and increased skin carotenoid scores compared with a control diet containing other fruits.
The findings contribute to preliminary human evidence that prickly pear contains compounds with potentially interesting biological effects.
However, the research was short-term and did not examine whether these changes lead to fewer symptoms, improved disease outcomes, or long-term health benefits.
Prickly pear can be enjoyed as part of a varied diet, but more research is needed before it can be recommended specifically for reducing harmful inflammation.
Funding and Disclosures
The 2018 study was conducted by researchers affiliated with the University of Palermo in Italy.
The published paper reports that the authors declared no conflicts of interest. No specific funding source was identified in the funding and disclosure information previously reviewed.
The earlier 2004 study was also conducted by researchers based in Italy.
References
Attanzio, A., Tesoriere, L., Vasto, S., Pintaudi, A. M., Livrea, M. A., & Allegra, M. (2018). Short-term cactus pear [Opuntia ficus-indica (L.) Mill] fruit supplementation ameliorates the inflammatory profile and is associated with improved antioxidant status among healthy humans. Food & Nutrition Research, 62, Article 1262. https://doi.org/10.29219/fnr.v62.1262
Tesoriere, L., Butera, D., Pintaudi, A. M., Allegra, M., & Livrea, M. A. (2004). Supplementation with cactus pear (Opuntia ficus-indica) fruit decreases oxidative stress in healthy humans: A comparative study with vitamin C. The American Journal of Clinical Nutrition, 80(2), 391–395. https://doi.org/10.1093/ajcn/80.2.391
