Benefits
Verbal memory preservation in older adults
In 39 healthy adults aged 60 to 78, about 1 gram a day of an anserine plus carnosine blend for 3 months preserved delayed-recall verbal memory compared with placebo. A 60-person trial and a 12-month trial from the same group reported similar memory preservation. All of these trials are small, come from one Japanese research group, and tested the blend rather than anserine alone.
Brain blood flow in older adults, clearest in APOE4 carriers
In a further analysis of a 12-month trial in 68 people aged 65 and over, the anserine plus carnosine blend preserved verbal memory and blood flow in frontal brain areas compared with placebo. Split by genotype, prefrontal blood flow and white matter were preserved in APOE4 carriers but not in non-carriers. The genotype result is a subgroup look within one small trial, and a food company, NH Foods, supplied the product free of charge.
Global clinical rating score in a 12-week trial
In 54 people already diagnosed with mild cognitive impairment, 12 weeks of the blend improved the global Clinical Dementia Rating more than placebo, but the MMSE, the Wechsler Memory Scale and the ADAS showed no benefit. In APOE4 carriers analyzed separately, the global rating and the MMSE improved. It is one small trial and does not show that the blend treats or slows any disease.
Lower CCL24 inflammatory marker in older adults
In 60 healthy older adults, 3 months of the blend lowered expression of CCL24, an inflammatory signalling protein, in white blood cells and preserved verbal memory. Memory gains tracked lower CCL24 only in the 18 participants in their 70s, an after-the-fact subgroup look that cannot show cause and effect. CCL24 is a lab marker, not a health outcome.
Short sprint power after one pre-exercise dose with carnosine
In small Belgian studies, one dose of anserine plus carnosine (20 to 30 mg per kg body weight of each) taken before cycling raised power in the first seconds of all-out sprints by about 3 to 6% versus placebo. A follow-up group of 15 men saw no gain on average, and people with lower carnosinase activity responded best. These were single-dose lab tests, not training studies.
Mechanism of action
Acid Buffering at Body pH
In laboratory chemistry, anserine buffers acid somewhat better than carnosine at neutral pH, and pH buffering is a core property of this family of dipeptides. No human trial cited here measured buffering in muscle or brain, so this is a proposed mechanism rather than a measured effect in people.
Slower Breakdown by Carnosinase
Carnosine is broken down quickly in human blood by the enzyme serum carnosinase (CN1). In tests with human plasma, anserine was broken down more slowly, and adding carnosine slowed its breakdown further. In five volunteers, blood anserine was about 2.5 times higher when taken with carnosine than alone, which is one reason the two are usually combined.
Antioxidant and Anti-Glycation Activity
Carnosine and its relatives, including anserine, bind metal ions, neutralize reactive oxygen species and limit the formation of advanced glycation end products (AGEs) in laboratory studies. This has not been shown to produce a health effect in people, and it does not mean anserine treats or prevents diabetes or any other disease.
Neurovascular Unit Protection
In aged Alzheimer's-model mice, 8 weeks of anserine restored memory, improved pericyte coverage of small brain blood vessels and reduced chronic inflammation in glial cells. The authors propose protection of the neurovascular unit (vessel cells, pericytes and glial cells). This is mouse data and only one possible explanation for the blood flow findings in people.
Clinical trials
Double-blind, randomized, placebo-controlled trial: 1.0 g a day of an anserine/carnosine (3:1) blend or placebo for 3 months, with memory tests, blood markers and MRI brain blood flow. (Hisatsune et al. 2016, J Alzheimers Dis)
39 healthy adults aged 60 to 78 who completed follow-up.
Delayed-recall verbal memory (Wechsler Memory Scale-Logical Memory) was better preserved with the blend than with placebo (p = 0.0128). The blend group also had lower blood CCL-2 and IL-8 and a smaller age-related drop in blood flow in the posterior cingulate area (p = 0.0248). The paper reports a second small trial with a similar memory result (p = 0.0202). Small trials from one research group.
Sub-analysis of a double-blind, randomized, placebo-controlled trial: 750 mg anserine plus 250 mg carnosine a day or placebo for 12 months, with memory tests and MRI scans of blood flow (ASL) and white matter (DTI). NH Foods supplied the supplements free of charge. (Ding et al. 2018, Aging Dis)
68 participants aged 65 and over, analyzed by APOE genotype.
Across the whole group, the blend preserved verbal memory (p = 0.0445) and blood flow in frontal brain areas compared with placebo. Split by genotype, APOE4 carriers on the blend kept prefrontal blood flow (p = 0.002) and white matter structure (p = 0.003), while non-carriers showed no difference from placebo. The genotype split is a subgroup analysis that the authors say needs confirming, and it does not show prevention or slowing of any disease.
Randomized, double-blind, placebo-controlled 12-week trial: 750 mg anserine plus 250 mg carnosine a day or placebo. Outcomes: global Clinical Dementia Rating (gloCDR), MMSE, Wechsler Memory Scale and ADAS. (Masuoka et al. 2019, Nutrients)
54 people with mild cognitive impairment.
The gloCDR score improved more with the blend than with placebo (p = 0.023). The MMSE, Wechsler Memory Scale and ADAS showed no benefit. In APOE4 carriers analyzed separately, the MMSE (p = 0.025) and gloCDR (p = 0.026) improved. One positive measure out of four in the whole group, and the APOE4 result is a subgroup analysis.
Double-blind, randomized, placebo-controlled trial: 1.0 g a day of an anserine/carnosine (3:1) blend or placebo for 3 months, with gene-expression analysis of white blood cells and verbal memory testing. (Katakura et al. 2017, Nutrients)
60 healthy older adults (30 per group).
CCL24 expression in white blood cells fell with the blend (p < 0.05), and verbal memory was preserved, including in age subgroups in their 60s (p = 0.048) and 70s (p = 0.017). Only in the 18 people in their 70s did memory preservation correlate with lower CCL24 (r = 0.46). These are subgroup analyses that cannot show cause and effect, and CCL24 is a lab marker.
Plasma breakdown tests, a blood-level test in 5 volunteers, and two double-blind, placebo-controlled crossover studies of 20 mg per kg body weight each of anserine and carnosine taken before all-out cycling sprints (Wingate tests). (Blancquaert et al. 2021, J Appl Physiol)
Healthy volunteers in small crossover studies.
Anserine broke down more slowly than carnosine in human plasma. Power in the first 5 seconds of a sprint after hard cycling was 6% higher than with placebo (P = 0.04), and peak power was about 3% higher across three repeated sprints. Single-dose lab tests in small groups.
Three studies: a randomized dose-response study (placebo or 10, 20 or 30 mg per kg body weight of both dipeptides) with sprint and maximal contraction tests, a test of 30 mg per kg with nerve stimulation, and a muscle blood flow study. (de Jager et al. 2022, J Int Soc Sports Nutr)
Men: 11, 15 and 8 in the three studies.
In the 11-man study, 30 mg per kg taken 60 minutes before exercise gave about 3% higher peak sprint power and 4.5% higher peak torque than placebo. The 15-man study found no gain on average, though people with lower carnosinase activity improved more. No effect on nerve-muscle function or muscle blood flow was found, so how it might work is unclear.