Study
Effects of Spermidine Supplementation on Cognition and Biomarkers in Older Adults With Subjective Cognitive Decline (SmartAge): A Randomized Clinical Trial
SmartAge: 12-month spermidine 0.9 mg/day did not improve memory in 100 older adults with subjective cognitive decline.
Summary Does spermidine improve memory in older adults worried about decline? Show / hide ↓
Researchers randomly gave 100 older adults with self-noticed memory problems either 0.9 milligrams of spermidine from wheat germ or an inactive placebo pill each day for 12 months. Neither the participants nor the researchers knew who received which pill until the study ended. The main memory test measured how well people could tell similar memories apart. Memory scores, other thinking tests, and hippocampal size, a brain area important for memory, were similar in both groups.
What this means for you: This well-controlled study found no meaningful memory benefit from spermidine over one year. It does not support buying spermidine for memory, although longer studies or different doses could produce different results.
moderate evidenceSmartAge tested wheat-germ spermidine 0.9 mg/day versus microcrystalline cellulose in 100 adults (mean age 69) with subjective cognitive decline over 12 months. The primary endpoint was mnemonic discrimination on the Mnemonic Similarity Task. Between-group difference −0.03, 95% CI −0.11 to 0.05, P = 0.47. Secondary cognitive outcomes and hippocampal volume did not differ. The trial was well-powered, blinded, and industry-independent. This is the longest and largest randomized trial of spermidine for cognition in older adults, and its result was null. A smaller 30-person pilot (Wirth 2018, Cortex) reported a numerical improvement (contrast 0.17, 95% CI −0.01 to 0.35) but the confidence interval crossed zero.
Spermidine supplementation for 12 months did not modify mnemonic discrimination performance in older adults with subjective cognitive decline compared with placebo.
The 2018 Wirth pilot is often cited as positive evidence but had 30 participants and a confidence interval crossing zero. SmartAge is the definitive trial to date and it was null on its primary endpoint. Any grade above C for spermidine cognition needs justification.
Cited by
1 encyclopedia entries reference this study.