Cognitive impairment (CI) is a syndrome characterized by progressive degeneration of memory, learning, execution, attention, calculation, understanding, or judgment. Among the aging population, the incidence of CI is increasing worldwide. Approximately 10–15% of the population over the age of 65 develop CI, and more than half of them further progress to dementia within 5 years. A study showed that about 46.8 million people had dementia in 2015, a number expected to increase to 131.5 million by 2050, which could seriously impact people’s elderly quality of life and longevity .
Dementia is a broad term that describes a decline in cognitive function and memory loss that interferes with daily activities. Alzheimer's disease is the most common form of dementia, accounting for 60-80% of all cases. Dementia is a progressive condition that affects millions of people worldwide, and there is currently no cure for it.
CI has become a major cause of the increased risk of mortality among the elderly and put a heavy economic burden on the healthcare system. There are several etiologies of CI, including neurodegenerative diseases (e.g., Alzheimer’s disease (AD)), neurovascular diseases (e.g., strokes), psychiatric causes (e.g., depression), and non-central nerve system (CNS) diseases (e.g., diabetes). At present, drugs approved by the Food and Drug Administration for AD dementia can only provide symptomatic relief. However, the risk of the adverse effects of these drugs has gradually appeared. The rate of gastrointestinal effects was reported to be up to 50% in a randomized trial. Thus, there is always an urgent need for the investigation of safe and effective therapeutic candidates for CI. Recently, traditional herbal medicine has attracted widespread attention as a safe therapy candidate for CI.
One of the potential benefits of American ginseng for dementia is its ability to improve cognitive function. A study published in the Journal of Psychopharmacology in 2010 found that American ginseng improved working memory and attention in healthy young adults. Another study published in the Journal of Ginseng Research in 2013 found that American ginseng improved cognitive function in older adults with mild CI.
Mild CI is a condition that often precedes dementia and is characterized by a decline in cognitive function that is greater than expected for age but does not interfere significantly with daily activities. The study involved 32 older adults with mild cognitive impairment who were randomly assigned to receive either American ginseng or a placebo for 12 weeks. Those who received American ginseng had a significant improvement in cognitive function compared to those who received the placebo.
In addition to improving cognitive function, American ginseng has also been shown to have neuroprotective properties. A study published in the Journal of Ethnopharmacology in 2012 found that American ginseng protected against amyloid-beta-induced neurotoxicity in cultured neurons. Amyloid-beta is a protein that accumulates in the brains of people with Alzheimer's disease and is believed to play a role in the development of the disease.
Another study published in the Journal of Alzheimer's Disease in 2018 found that American ginseng improved mitochondrial function in the brains of mice with Alzheimer's disease. Mitochondria are the energy-producing organelles within cells, and dysfunction of mitochondria has been implicated in the development of Alzheimer's disease.
For more reading, see Ginsenoside and Its Therapeutic Potential for Cognitive Impairment
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