Effects of Spermidine-Rich Rice Germ Extract Supplement on Biomarkers of Healthy Aging and Autophagy-Proof-of-Concept Pilot Study.

Background: Although epidemiological and preclinical research suggests that the polyamine spermidine improves the efficiency of autophagy, human clinical research demonstrating a specific dose of any source of spermidine capable of increasing biomarkers of autophagy is lacking.

Primary study objective: The study aimed to examine the effects of spermidine from Miricell™ rice germ extract (Nutraland USA) on biomarkers/indices of autophagy, neuroprotection, and cardiometabolic health, as well as safety and adverse events.

Methods/design: This 56-day study was conducted as a single-blinded, interventional, parallel-group, pilot trial. Vitals, diet records, and protocol compliance were recorded at weeks 0 and 8. Blood draws for cardiometabolic markers and adverse event monitoring took place at screening and weeks 0 and 8.

Setting: Conducted at a clinical research laboratory in Ohio.

Participants: Twelve (N=12) healthy men and women (age: 54.5 ± 7.9 years).

Intervention: Random assignment to 1.5 mg or 3.3 mg of spermidine daily from Miricell™ rice germ extract (Nutraland USA).

Primary outcome measures: Biomarkers of autophagy [Beclin-1 and Unc-51-like kinase 1(ULK1)], and biomarkers/indices of neuroprotection, including brain-derived neurotrophic factor (BDNF), homocysteine, and cardiometabolic health (high sensitivity C-reactive protein (hs-CRP), lipid panel).

Results: Compared to baseline, only the 3.3 mg dose of spermidine from Miricell® increased Beclin-1 by 7.3%, ULK-1 by 13.4%, and BDNF by 12.1%. Compared to baseline, the same dose resulted in a 20.8% decrease in hs-CRP, a 20.1% decrease in VLDL, and a 26.9% decrease in triglycerides. Secondary outcomes, including clinical chemistry panel, CBC, vital signs, and adverse events, reflect a good safety profile for the use of 3.3 mg/day of spermidine from Miricell®.

Conclusion: This pilot study found that 3.3 mg/day of spermidine from Miricell® rice germ extract tends to improve biomarkers of autophagy, neuroprotection, and cardiometabolic health. Appropriate follow-up studies are warranted to confirm these findings.

Keywords: spermidine, autophagy, beclin-1, ULK1, rice germ extract, neuroprotection, BDNF, homocysteine, cardiometabolic, CRP, C-reactive protein, VLDL, triglycerides, aging.