Benefits
Smaller blood sugar rise after carbohydrate meals (nopal pads)
In 14 adults with type 2 diabetes, adding 300 g of steamed nopal to a high-carbohydrate breakfast gave a smaller glucose and insulin rise than the same breakfast alone. A cladode and fruit-skin extract trimmed the glucose curve in 6 healthy men. These were single-meal tests; a 16-week extract trial found no glucose difference from placebo.
Dietary fat binding and body weight support (cactus pad fiber)
A cactus pad fiber blend, also containing acacia fiber, raised the share of dietary fat passed in stool in 20 healthy adults, and with a reduced calorie diet gave more weight loss than placebo over 12 weeks. These trials were funded by the maker. A pooled analysis of five Opuntia trials found no significant overall effect on body weight.
Total cholesterol and blood lipids
A pooled analysis of five randomized Opuntia trials reported a significant fall in total cholesterol, though the trials varied widely in design and reporting quality. Single trials of a dried pad product and of pasta made with an Opuntia extract reported lipid changes, but the first found effects only in a subgroup and the second had no control group.
Lower markers of oxidative stress with the fruit
In 18 healthy adults, eating 250 g of fresh cactus pear fruit pulp twice a day for 2 weeks lowered blood markers of lipid oxidation and shifted the glutathione balance in red blood cells. A comparable dose of vitamin C alone did not significantly change these markers. The study was small and short, and it tested whole fruit, not an extract.
Lower inflammation markers with the fruit
In a 2-week crossover feeding study of 28 healthy adults, adding 200 g of cactus pear fruit pulp twice a day lowered blood inflammation markers, including CRP and TNF-alpha, compared with a diet using other fresh fruit. Those are lab markers in healthy people, not a measured change in how anyone felt.
Fewer hangover symptoms after heavy drinking
In a crossover trial of young adults, an Opuntia ficus-indica extract taken 5 hours before drinking reduced nausea, dry mouth and loss of appetite the next morning and halved the odds of a severe hangover. The overall symptom score was not significantly lower, and the paper's summary does not say which plant part was used.
Bowel symptom relief with nopal fiber powder
In a one-week trial of 60 adults with irritable bowel syndrome, 20 g or 30 g a day of extracted nopal fiber gave adequate symptom relief to more people than placebo. The 30 g dose caused more loose stools. The trial was short and small, and its authors call for a longer, fully powered study.
Mechanism of action
Viscous fiber slows the meal
Nopal pads are rich in mucilage and other soluble and insoluble fiber. Viscous fiber is thought to slow how quickly carbohydrate is digested and absorbed, a likely explanation for the smaller blood sugar peaks seen when nopal is eaten with a meal. In one meal study nopal also lowered the post-meal peak of the gut hormone GIP.
Fiber that binds dietary fat
A cactus pad fiber concentrate binds some dietary fat in the gut so that it leaves in stool instead of being absorbed. This was measured directly in a human feeding study. It applies to that fiber preparation at gram doses, not to small doses of fruit extract.
Betalain pigments in the fruit
The fruit's red and yellow color comes from betalains such as betanin and indicaxanthin, which act as antioxidants in laboratory tests. Because whole fruit lowered oxidative stress markers when a similar amount of vitamin C alone did not, the researchers concluded that fruit components other than antioxidant vitamins may play a role; the betalains are one candidate.
Clinical trials
Two-part meal study. Seven healthy adults ate dehydrated nopal to measure its glycemic index; then 14 adults with type 2 diabetes ate a high-carbohydrate or high-soy-protein breakfast with or without 300 g steamed nopal (López-Romero et al. 2014, J Acad Nutr Diet)
7 healthy adults and 14 Mexican adults with type 2 diabetes.
Adding nopal to the high-carbohydrate breakfast lowered the glucose area under the curve (287 versus 443) and the insulin response. With the soy-protein breakfast, nopal lowered early GIP peaks and raised a blood antioxidant measure at 2 hours. Dehydrated nopal had a glycemic index of about 32. Single-meal results in a small group.
Double-blind, placebo-controlled crossover study: 1,000 mg Opuntia ficus-indica cladode and fruit-skin extract or placebo, taken 30 minutes before and right after a resting 75 g glucose tolerance test, with a second glucose test after 30 minutes of cycling (Van Proeyen et al. 2012, Int J Sport Nutr Exerc Metab)
6 healthy, physically active young men.
At rest the extract cut the glucose area under the curve by 26 percent and raised insulin early on. After exercise the glucose area was 37 percent lower, without an insulin difference. A very small acute study.
Double-blind, placebo-controlled trial of the proprietary extract OpunDia (200 mg) or placebo for 16 weeks, with an acute glucose test after a 400 mg dose (Godard et al. 2010, J Ethnopharmacol)
29 obese adults aged 20 to 50 with prediabetes (15 extract, 14 placebo).
Blood glucose at 60, 90 and 120 minutes of a glucose test was lower after a 400 mg dose than in the earlier test without it. Over 16 weeks there were no differences from placebo in glucose curves, insulin, HbA1c, inflammation markers, body composition or safety blood tests.
Double-blind, randomized, placebo-controlled trial of Litramine IQP G-002AS, an Opuntia ficus-indica pad fiber enriched with acacia fiber, 3 g a day, alongside a reduced calorie diet and activity advice; funded by the maker, InQpharm (Grube et al. 2013, Obesity)
125 overweight and obese adults; 123 completed (mean BMI 29.6).
Weight fell 3.8 kg on the fiber and 1.4 kg on placebo, and more people on the fiber lost at least 5 percent of body weight. BMI, body fat and waist also fell more. No adverse reactions were reported. Funded by the maker and not independently repeated.
Double-blind, randomized, placebo-controlled crossover study of the same cactus pad fiber, two 500 mg tablets with each main meal, on a standardized diet with 35 percent of energy from fat; funded by the maker, with two employee authors (Uebelhack et al. 2014, Curr Ther Res Clin Exp)
20 healthy adults.
Fat passed in stool was 15.8 percent of intake on the fiber against 4.6 percent on placebo. No adverse events were reported. A direct measure of fat binding, not of weight.
Double-blind, placebo-controlled crossover trial: an Opuntia ficus-indica extract (reported as 1600 IU) or placebo taken 5 hours before drinking up to 1.75 g of alcohol per kg of body weight, repeated two weeks later with treatments swapped (Wiese et al. 2004, Arch Intern Med)
64 healthy young adults randomized; 55 completed both arms.
Three of nine hangover symptoms (nausea, dry mouth and loss of appetite) were significantly reduced. The overall symptom index fell 2.7 points, which was not statistically significant, while the odds of a severe hangover were roughly halved. Morning CRP was 40 percent higher after placebo than after the extract.
Randomized crossover study: 250 g fresh fruit pulp or 75 mg vitamin C twice a day for 2 weeks each, separated by a 6-week washout (Tesoriere et al. 2004, Am J Clin Nutr)
18 healthy adults.
After the fruit, plasma 8-epi-prostaglandin F2-alpha fell about 30 percent and malondialdehyde about 75 percent, LDL lipid hydroperoxides fell by almost half, and red-cell glutathione balance improved. Vitamin C raised blood vitamin levels similarly but did not significantly change any oxidative stress marker.
Four-arm, double-blind, parallel randomized trial of extracted nopal fiber at 10, 20 or 30 g a day, or 30 g dextrose placebo, for one week on a usual diet (Remes-Troche et al. 2021, Neurogastroenterol Motil)
60 adults meeting Rome IV criteria for irritable bowel syndrome.
Adequate relief was reported by 87 percent on 20 g and 80 percent on 30 g, against 33 percent on placebo, and more people on 20 g had a large drop in symptom score. The 30 g dose caused more loose stools. Breath hydrogen and stool short-chain fatty acids did not differ. Short and small.