In fact, taking the asparagus root extract (ARE) alone could lead to the unintended effect of increased lipid levels instead, according to findings of a 12-week clinical trial conducted in Thailand, with findings published in the International Journal of Molecular Sciences.
A total of 72 young adults who were either obese or overweight, with a body mass index (BMI) of 23.10–44.90 kg/m2, took part in the clinical trial.
They were randomized into four groups: 1) HIIT and ARE supplementation (COM group), 2) only HIIT, 3) only ARE supplementation, or 4) neither HIIT nor ARE supplementation, which was also the control group.
The ARE supplement consisted of the hard stems of Asparagus officinalis L. roots. Its bioactive compound is 20-hydroxyecdysone (20E), a polyhydroxylated steroid hormone that exhibits potent antioxidant and anti-inflammatory activities.
Those randomized to take ARE were given 20E at a dose of 1.71 ± 0.24 mg/kg/day.
To assess the effects of each assigned regimen, researchers measured the metabolic profile, including blood glucose and lipid levels, oxidative stress biomarkers, inflammatory cytokines and white blood cells of the participants.
Effects on blood glucose and lipids
Findings showed that taking ARE alone did not lead to a significant reduction in blood glucose and lipid levels. Significant reductions were seen only when paired with HIIT – aka the COM group.
Out of the four groups, the group doing HIIT alone had the best results when it comes to lowering blood glucose and lipid levels.
In the HIIT group, blood glucose levels fell by 4.39 mg/dL, while that of the COM group dropped by 2.78 mg/dL after 12 weeks of intervention.
The COM group also showed a significantly greater decrease in blood glucose levels as compared with the ARE group, which the researchers said showed a synergistic interaction between HIIT and ARE supplementation.
“Asparagus phytochemicals such as quercetin, rutin, and saponins possess antioxidant, anti-inflammatory, and insulin-sensitizing properties that may potentiate HIIT-induced AMPK activation and GLUT4 upregulation, resulting in additive improvements in glucose regulation,” the researchers wrote.
A similar trend was seen in the lipid profiles, where significant improvements were seen in both the HIIT and COM groups, but not in the ARE group.
For example, total cholesterol in the HIIT group dropped by 13.89 mg/dL and 7.83 mg/dL in the COM group, while TC/HDLC ratio was down 0.63 in the former and 0.43 in the latter.
HDL-cholesterol increased by 4.56mg/dL in the HIIT group and 1.95 mg/dL in the COM group.
In fact, taking ARE alone had significantly increased lipid levels.
For instance, the “bad cholesterol” LDL-cholesterol levels went up 14.06 mg/dL, and LDLC/HDLC ratio was also increased by 0.33.
Possible reasons
A possible reason for the unintended increase in lipid levels in the ARE group could be due to a lack of concurrent metabolic activation.
The researchers explained that certain constituents within the ARE may “behave differently under low metabolic demand”.
“Although asparagus-derived bioactives have been reported to inhibit HMG-CoA reductase and facilitate bile acid excretion, such effects may depend on longer intervention periods, higher compound bioavailability, or the presence of concurrent metabolic stress,” the researchers wrote.
Another reason could be that the administered dose may have induced an adaptive oxidative response that did not resolve within the 12-week research period.
“Therefore, the effects of ARE alone should be interpreted with caution. Future studies should examine dose–response relationships and determine whether exercise-induced metabolic stress is required to unlock the beneficial actions of ARE," the researchers wrote.
Effects on inflammatory markers
Analysis on the inflammatory markers IL-6 and TNF-α showed that the COM group had significantly lower IL-6 levels as compared to the control group, but none of the four groups saw a significant reduction in TNF-α levels.
“Regular exercise promotes the release of myokines such as IL-10 and IL-1Ra, contributing to an anti-inflammatory milieu through suppression of NF-κB signaling. Likewise, plant extracts from the genus Asparagus have been shown in vitro to inhibit NF-κB activation and nitric oxide release, supporting a mechanistic basis for their anti-inflammatory activity," the researchers wrote.
HIIT still the primary driver
The researchers concluded that HIIT served as the primary driver of improvements in glucose regulation and lipid metabolism.
They also acknowledged that although the combination of HIIT and ARE had produced favorable metabolic, oxidative, and inflammatory outcomes, those effects were not substantially greater than those achieved through HIIT alone.
As for ARE supplementation alone, the researchers raised the need for caution when considering ARE as a standalone supplement.
They also highlighted the importance of evaluating factors such as dose, bioactive composition, and the potential synergistic interaction between supplementation and exercise.
“Collectively, the findings support HIIT as an effective strategy for improving glycemic and lipid profiles and demonstrate that combining HIIT with ARE amplifies metabolic, redox, and inflammatory benefits without adverse hepatic effects,” they wrote.
Source: International Journal of Molecular Sciences, 2025 Dec 15;26(24):12054. DOI: 10.3390/ijms262412054. “Synergistic Effects of High-Intensity Interval Training andAsparagus officinalisL. Root Extract Supplementation on Metabolic Regulation, Oxidative Stress, and Inflammation in Overweight and Obese Adults." Authors: Prasertsri P et al.
