Ginkgo is not a smart pill

ABSTRACT

BACKGROUND: Extracts of ginkgo have shown some promise in enhancing memory in demented elderly individuals.¹ These authors set out to test the veracity of one manufacturer’s claim that ginkgo biloba “enhances mental focus and improves memory and concentration” in nondemented older adults.

POPULATION STUDIED: The authors solicited community-dwelling, functionally independent individuals older than 60 years who volunteered to participate in a study to improve memory. They excluded individuals with recent strokes, head injuries, or other “life-threatening illnesses,” mental illness or retardation, and persons who lacked someone to provide an evaluation of their memory and concentration. Participants were excluded if they scored less than 27 out of a possible 30 points on the Mini-Mental Status Examination at baseline. Highly educated or intelligent participants with mild dementia may have been included.

STUDY DESIGN AND VALIDITY: In this randomized controlled trial, participants received 40 mg of ginkgo biloba 3 times daily (the dose recommended by the manufacturer) or identical-appearing placebo for 6 weeks. This duration is 2 weeks longer than the manufacturer’s indicated onset of action. The number of subjects (230) was sufficient to detect a large effect. The researchers involved in dispensing study drugs and evaluating outcomes were effectively blinded, as were patients. Allocation to the control treatment groups may not have been concealed from the enrolling investigators. All persons screened for participation were accounted for, and the few dropouts were evenly balanced between the treatment and placebo groups. Analysis was by intention to treat.

OUTCOMES MEASURED: The authors measured performance on a wide variety of age-normed tests of memory, intelligence, and word-finding, such as the Wechsler Adult Intelligence Scale, well chosen to allow measurements to increase dramatically from baseline (ie, avoiding the ceiling effect that would be present if only tests for dementia were used). No quality of life measures were included. Companions were asked whether the subjects’ memory improved.

RESULTS: No statistically significant differences were noted between placebo and control groups on any of the scales measured. No significant changes from baseline to posttreatment and no adverse effects were found in either of the groups.

ABSTRACT

BACKGROUND: Extracts of ginkgo have shown some promise in enhancing memory in demented elderly individuals.¹ These authors set out to test the veracity of one manufacturer’s claim that ginkgo biloba “enhances mental focus and improves memory and concentration” in nondemented older adults.

POPULATION STUDIED: The authors solicited community-dwelling, functionally independent individuals older than 60 years who volunteered to participate in a study to improve memory. They excluded individuals with recent strokes, head injuries, or other “life-threatening illnesses,” mental illness or retardation, and persons who lacked someone to provide an evaluation of their memory and concentration. Participants were excluded if they scored less than 27 out of a possible 30 points on the Mini-Mental Status Examination at baseline. Highly educated or intelligent participants with mild dementia may have been included.

STUDY DESIGN AND VALIDITY: In this randomized controlled trial, participants received 40 mg of ginkgo biloba 3 times daily (the dose recommended by the manufacturer) or identical-appearing placebo for 6 weeks. This duration is 2 weeks longer than the manufacturer’s indicated onset of action. The number of subjects (230) was sufficient to detect a large effect. The researchers involved in dispensing study drugs and evaluating outcomes were effectively blinded, as were patients. Allocation to the control treatment groups may not have been concealed from the enrolling investigators. All persons screened for participation were accounted for, and the few dropouts were evenly balanced between the treatment and placebo groups. Analysis was by intention to treat.

OUTCOMES MEASURED: The authors measured performance on a wide variety of age-normed tests of memory, intelligence, and word-finding, such as the Wechsler Adult Intelligence Scale, well chosen to allow measurements to increase dramatically from baseline (ie, avoiding the ceiling effect that would be present if only tests for dementia were used). No quality of life measures were included. Companions were asked whether the subjects’ memory improved.

RESULTS: No statistically significant differences were noted between placebo and control groups on any of the scales measured. No significant changes from baseline to posttreatment and no adverse effects were found in either of the groups.

ABSTRACT

BACKGROUND: Extracts of ginkgo have shown some promise in enhancing memory in demented elderly individuals.¹ These authors set out to test the veracity of one manufacturer’s claim that ginkgo biloba “enhances mental focus and improves memory and concentration” in nondemented older adults.

POPULATION STUDIED: The authors solicited community-dwelling, functionally independent individuals older than 60 years who volunteered to participate in a study to improve memory. They excluded individuals with recent strokes, head injuries, or other “life-threatening illnesses,” mental illness or retardation, and persons who lacked someone to provide an evaluation of their memory and concentration. Participants were excluded if they scored less than 27 out of a possible 30 points on the Mini-Mental Status Examination at baseline. Highly educated or intelligent participants with mild dementia may have been included.

STUDY DESIGN AND VALIDITY: In this randomized controlled trial, participants received 40 mg of ginkgo biloba 3 times daily (the dose recommended by the manufacturer) or identical-appearing placebo for 6 weeks. This duration is 2 weeks longer than the manufacturer’s indicated onset of action. The number of subjects (230) was sufficient to detect a large effect. The researchers involved in dispensing study drugs and evaluating outcomes were effectively blinded, as were patients. Allocation to the control treatment groups may not have been concealed from the enrolling investigators. All persons screened for participation were accounted for, and the few dropouts were evenly balanced between the treatment and placebo groups. Analysis was by intention to treat.

OUTCOMES MEASURED: The authors measured performance on a wide variety of age-normed tests of memory, intelligence, and word-finding, such as the Wechsler Adult Intelligence Scale, well chosen to allow measurements to increase dramatically from baseline (ie, avoiding the ceiling effect that would be present if only tests for dementia were used). No quality of life measures were included. Companions were asked whether the subjects’ memory improved.

RESULTS: No statistically significant differences were noted between placebo and control groups on any of the scales measured. No significant changes from baseline to posttreatment and no adverse effects were found in either of the groups.