Nutritional Strategies to Preserve Memory and CognitionFebruary 2007
By Laurie Barclay, MD
Ashwagandha: Brain Support Through Stress Relief
The herb ashwagandha (Withania somnifera) has long been used to boost energy and blood supply, reduce inflammation, and increase longevity. Modern science is now uncovering ashwagandha’s benefits for cognitive health.60,61
Ashwagandha has been shown to alleviate stress, which not only influences hormonal status and various bodily systems, but also directly affects brain function. In one study, rats were subjected to stress and evaluated for changes in brain cells, particularly in the hippocampus. Control animals kept under stress-free conditions exhibited no changes; however, in the stressed animals, 85% of brain cells examined showed signs of degeneration. When ashwagandha was administered to stressed subjects, the number of degraded brain cells was reduced by 80%.62
Ashwagandha has shown promise in treating Parkinson’s and Alzheimer’s diseases. For example, a recent study in laboratory animals showed that administering ashwagandha extract significantly and dose-dependently reversed all studied parameters of Parkinson’s-type neurodegeneration.63 In treating Alzheimer’s, physicians often rely on acetylcholinesterase-inhibitor drugs like Aricept®, which block the degradation of the neurotransmitter acetylcholine in order to slow the symptoms and progression of the disease. Ashwagandha extract likewise acts as an acetylcholinesterase inhibitor, and may thus help to preserve cognitive function and memory by protecting acetylcholine from breakdown.64
In any situation of cognitive decline, regeneration of the neuronal network may present a promising therapeutic option. Japanese researchers found that ashwagandha helped promote the regeneration and outgrowth of neurites that facilitate communication between nerve cells. Additionally, ashwagandha produced improvements in memory in a mouse model of Alzheimer’s disease.65
Blueberries: Antioxidant Protection for Brain Health
Neuroscientists are continually searching for natural agents that can protect brain cells from the devastating effects of oxidative stress and inflammation. Blueberries are rich in the powerful antioxidant phytochemicals known as polyphenols, which include proanthocyanidins that are particularly beneficial for brain health.66-69
A recent report found that blueberry extracts exert the same anti-inflammatory and antioxidant activities as the whole fruit.70 Anthocyanidin molecules from such extracts have been shown to cross the blood-brain barrier, making them accessible to neurons.71
When free radicals attack delicate brain cells, they disrupt optimal cellular function and often cause age-related cognitive decline.72 In an experimental rat model, a diet supplemented with plant-derived antioxidants reversed age-related decline in memory and cognition.73 Other studies have shown that increasing dietary intake of antioxidant-rich fruits and vegetables can maintain optimal neuronal function and cognition well into old age.74-76
In one study, scientists discovered that supplementation with blueberries prevented memory loss in aged rats. Researchers fed one group of rats a diet supplemented with blueberries and fed another group a control diet. The animals were then tested for object-recognition memory. The blueberry-fed rats performed significantly better than the control group, suggesting that supplementation with blueberries restored youthful levels of function in the aging brain.75
Intriguingly, the researchers also tested for levels of nuclear factor-kappa beta (NFkB) in the rats after supplementation with blueberries. A naturally occurring compound in cells, NFkB increases production of inflammatory mediators that often initiate degenerative diseases. The scientists found that NFkB levels were significantly lower in rats fed blueberries compared to controls, and that when NFkB levels were lower, the rats scored higher on memory tests.75
Animal studies also indicate that blueberries help maintain high levels of new cell generation in the hippocampus, the brain area that suffers extensive damage in Alzheimer’s disease.77
Oxidative stress is a major factor in the development of Alzheimer’s, along with overproduction of the beta-amyloid protein, which appears to cause cell destruction. The result is damaged cells that are then unable to manufacture or respond normally to the neurotransmitter acetylcholine.
A group of scientists sought to determine whether blueberries have a protective effect on rats bred to have Alzheimer’s disease.78 Astonishingly, they determined that a blueberry-supplemented diet caused Alzheimer’s-bred rats to perform normally on tests of memory and motor behavior. A surprising finding was that levels of destructive beta-amyloid protein in the test animals’ brains did not differ from those of normal rats. The researchers concluded that a diet incorporating blueberries may help overcome genetic predispositions to Alzheimer’s disease.
Other studies of blueberries and cognitive health have found that blueberries provide important protection against destructive inflammation in the brain.79 Brain memory regions of young and old rats fed either a blueberry diet or control diet were subjected to an inflammatory challenge and then examined for production of a protein that would indicate a normal protective response to stress. The protein level in the blueberry-fed aged rats was completely restored within four hours of the inflammatory stimulus. This kind of rapid effect suggests that blueberry supplementation could improve neuroprotective responses to diseases with a mixed oxidative and inflammatory cause, such as Alzheimer’s.
Grape Seed Extract: Guarding Against Senile Plaque Formation
The brain’s extraordinarily complex circuitry generates massive amounts of oxygen free radicals that may play an important role in the impairment of healthy brain activity that commonly accompanies aging.
Rich in polyphenols, grape seed extract is considered one of nature’s most potent antioxidants. Researchers believe that grape seed’s antioxidant properties confer broad-spectrum protection against premature aging, disease, and decay; in fact, grape seed extract packs 20 times more antioxidant power than vitamin E and 50 times more antioxidant power than vitamin C.80 These attributes have led many scientists to suggest that grape seed extract is an essential nutrient for maintaining optimal brain health and function.
Grape seed extract not only improves blood circulation by strengthening capillaries, arteries, and veins, but also prevents the formation of senile plaques that can severely damage the brains of those with dementia.81 For example, South Korean scientists treated the brain cells of rats with grape seed extract before exposing them to the toxic beta-amyloid protein. Beta amyloid promotes the development of plaques that accumulate in the brains of patients with Alzheimer’s disease. Treatment with grape seed extract conferred significant protection on the rat brain cells. While the untreated rat brain cells sustained acute free-radical damage and subsequently died, cells treated with grape seed extract suffered little damage.81
In research published in 2006, Indian scientists sought to evaluate grape seed extract’s effects on the accumulation of oxidative DNA damage seen in normal aging. They administered grape seed extract to young and aged albino rats for 30 days. In rats that received the extract, grape seed extract inhibited the accumulation of age-related oxidative DNA damage in the spinal cord and in various brain regions such as the cerebral cortex, striatum, and hippocampus—the very sites involved in thinking, processing, and memory that are most degraded in neurodegenerative disorders such as Alzheimer’s and Parkinson’s disease.82
Conclusion: Prevention Is the Best Brain Medicine
An abundance of scientific evidence indicates that any program to protect the brain from dementia and other ravages of aging should incorporate compounds that have been shown to stimulate brain energy metabolism, boost acetylcholine levels, and protect against inflammation, thrombosis, and oxidative stress. By taking advantage of recent advances in our understanding of nerve cell function, cognition and memory, and how these processes are disrupted during normal aging, health-conscious adults can devise an individualized anti-aging program utilizing the most potent brain-protective nutrients available today.
Supplements such as uridine, GPC, phosphatidylserine, DHA, vinpocetine, ashwagandha, blueberries, and grape seed extract work via numerous mechanisms to provide natural, broad-spectrum support for optimal brain health and function. Because it is so much easier to protect the health of your brain cells than it is to restore their function once damage has manifested, it makes sense to begin a preventive program as soon as possible. When it comes to protecting and preserving brain health, “an ounce of prevention is worth a pound of cure” is truly a no-brainer.
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