title: Effect of consuming a purple-fleshed sweet potato beverage on health-related biomarkers and safety parameters in Caucasian subjects with elevated levels of blood pressure and liver function biomarkers: a 4-week, open-label, non-comparative trial.
abstract: An open-label study with one treatment arm was conducted to investigate changes in health-related biomarkers (blood pressure and liver enzyme activity) and the safety of 4 weeks of consuming a purple-fleshed sweet potato beverage in Caucasian subjects. Twenty healthy adults, 18-70 years of age, with a body mass index >25 kg/m(2), elevated blood pressure and elevated levels of liver function biomarkers consumed two cartons of purple-fleshed sweet potato beverage (125 ml, including 117 mg anthocyanin per carton) daily for 4 weeks. Hematology, serum clinical profile, dipstick urinalysis and blood pressure were determined before consumption, at 2 and 4 weeks of consumption and after a 2-week washout period. A trend was found toward lowering systolic blood pressure during the treatment period (p=0.0590). No significant changes were found in diastolic blood pressure throughout the study period. Systolic blood pressure was significantly lower after 4 weeks of consumption compared with before consumption (p=0.0125) and was significantly higher after the 2-week washout period compared with after consumption (p=0.0496). The serum alanine aminotransferase level significantly increased over time, but aspartate aminotransferase and γ-glutamyltransferase levels stayed within the normal range of reference values. Safety parameters of the blood and urine showed no clinically relevant changes. The consumption of a purple-fleshed sweet potato beverage for 4 weeks resulted in no clinically relevant changes in safety parameters of the blood and urine and showed a trend toward lowering systolic blood pressure.
authors: Kyushu Okinawa Agricultural Research Center, National Agriculture and Food Research Organization, 2421 Suya, Koshi, Kumamoto 861-1192, Japan.
authors: Tomoyuki
authors: T
authors: Oki
authors: Yakult Central Institute, 5-11 Izumi, Kunitachi, Tokyo 186-8650, Japan.
authors: Mitsuyoshi
authors: M
authors: Kano
authors: Faculty of Research and Development, Yakult Honsha, Shimbashi, Tokyo 105-8660, Japan.
authors: Osamu
authors: O
authors: Watanabe
authors: Agri-Food Business Innovation Center, National Agriculture and Food Research Organization, 3-1-1 Kannondai, Tsukuba, Ibaraki 305-8517, Japan.
authors: Kazuhisa
authors: K
authors: Goto
authors: TNO, Utrechtseweg 48, NL-3704 HE, Zeist, The Netherlands.
authors: Esther
authors: E
authors: Boelsma
authors: Kyushu Okinawa Agricultural Research Center, National Agriculture and Food Research Organization, 2421 Suya, Koshi, Kumamoto 861-1192, Japan.
authors: Fumiyasu
authors: F
authors: Ishikawa
authors: Kyushu Okinawa Agricultural Research Center, National Agriculture and Food Research Organization, 2421 Suya, Koshi, Kumamoto 861-1192, Japan.
authors: Ikuo
authors: I
authors: Suda
keywords: Caucasians; anthocyanin; blood pressure; liver function biomarker; safety parameter; sweet potato