Table 3.

Effects of l-Theanine on Biomarkers

Group	N	–1 Week (baseline)	12 Weeks	Amount of change from baseline
Plasma Aβ (1–40) (pg/mL)
Placebo	22	219 ± 56	210 ± 65	–9.21 ± 35
Theanine	26	243 ± 175	205 ± 94	–38.6 ± 105
Plasma Aβ (1–42) (pg/mL)
Placebo	3	11.6 ± 5.8	22.7 ± 10.5	11.2 ± 9.4
Theanine	9	21.6 ± 21	46.0 ± 59	24.3 ± 52
Aβ(1–42)/Aβ(1–40)
Placebo	10	0.04 ± 0.03	0.09 ± 0.04	0.05 ± 0.02
Theanine	12	0.08 ± 0.06	0.24 ± 0.31	0.16 ± 0.27
Plasma sAPPα (ng/mL)
Placebo	25	8.07 ± 4.1	9.82 ± 3.1	1.75 ± 2.4
Theanine	22	8.38 ± 3.3	10.2 ± 4.7	1.80 ± 4.7
Plasma APP770 (ng/mL)
Placebo	23	29.2 ± 13	28.9 ± 9.1	–0.32 ± 8.5
Theanine	26	30.6 ± 12	28.6 ± 10	–1.95 ± 11
Serum BDNF (ng/mL)
Placebo	24	18.2 ± 14	24.3 ± 11	6.07 ± 18
Theanine	26	21.8 ± 12	20.5 ± 12	–1.30 ± 18

Values are presented as mean ± SD.

Aβ, amyloid-β; APP770, Aβ precursor protein 770; BDNF, brain-derived neurotrophic factor; sAPPα, secreted form of Aβ precursor protein α; SD, standard deviation.