Resveratrol is a chemical known as trans-3,5,4’-trihydroxystilbene. Produced by grapes, berries, peanuts, and certain other plants in response to stressful conditions, resveratrol and related biochemicals known as phytoalexins function as natural antibiotics, protecting plants against attack by pathogens.
Senile dementia is increasing worldwide substantially, paralleling the “graying” of the world’s population. In particular, recent statistics suggest that mild cognitive impairment affects 5.5 to 7.7% of subjects aged more than 60 years old and 22% of those over 70 years old, more frequently in those with neuropsychiatric symptoms.
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Resveratrol …
33% improvement in overall cognitive performance
In a 14-week pilot study, a study showed that supplementation with low-dose resveratrol improved cerebrovascular and cognitive functions in postmenopausal women. Compared to placebo, resveratrol supplementation resulted a significant 33% improvement in overall cognitive performance. (1)
This appeared to be due to improvements in processing speed and cognitive flexibility, which are critical to supporting executive function in the aging population. “This observed improvement in overall cognitive performance could pottentially reverse cognitive aging by up to 10 years” said Dr. Rachel Wong, a dementia research fellow with the National Health and Medical Research Council and the Australian Research Council.
The conclusions were that regular supplementation with low-dose resveratrol can enhance cognition, cerebrovascular function and insulin sensitivity in postmenopausal women. This may translate into a slowing of the accelerated cognitive decline due to aging and menopause, especially in late-life women.
Resveratrol mimics caloric restriction to prevent diseases of aging
A 2015 study shows that resveratrol may have the ability to help destroy abnormal cells, prevent vascular disease, and help prevent brain disorders like dementia. (2)
The amyloid hypothesis suggests that the progressive accumulation and deposition of central nervous system amyloid with aging is the proximate cause of Alzheimer’s disease (AD). Thus, targeting molecular mechanisms of aging may represent a viable treatment approach. Caloric restriction prevents diseases of aging, including AD, in animal models, perhaps by activation of sirtuins. The sirtuins (such as mammalian SIRT1) are deacetylases that link energy balance (NAD+/NADH) to regulation of gene transcription. Resveratrol is a potent activator of SIRT1, and thus may mimic caloric restriction to prevent diseases of aging.
It was found, during one study, that CSF Aβ40 and plasma Aβ40 levels declined significantly during the 52-week study in the placebo group, as expected with disease progression. In contrast, CSF Aβ40 and plasma Aβ40 levels were stabilized in the resveratrol-treated group, resulting in a significant difference at week 52.
In summary, resveratrol robustly stabilizes the progressive decline in plasma Aβ40 and CSF Aβ40 level as dementia advances and is associated with brain pseudoatrophy. Additionally, despite the study being underpowered to detect clinical benefit, resveratrol attenuates decline in a functional measure. (3)
A potent antioxidant activity
Resveratrol displays potent antioxidant activity by scavenging free radicals and metals, protecting against NO toxicity, reducing QR2 activity and upregulating endogenous enzymes such as glutathione peroxidase, AMPK and LKB1. Resveratrol also inhibits pro-inflammatory enzyme (i.e., COX-1 and -2) expression, reduces NF-κB activation as well as PGE2, NO, and TNF-α production, and cytokine release. It may promote Aβ clearance. Treatment with resveratrol can affect multiple signaling pathway effectors involved in cell survival (AMPK, PI3-k and AkT), programmed cell death (caspase-3/12, Bax, and cytochrome c) and synaptic plasticity (ERK1/2). Direct and/or indirect activation of the deacetylase sirtuins by resveratrol has also been suggested.
In conclusion, long-term treatment with adequate dosages of resveratrol with improved bioavailability could exert clinically significant protective effects against cognitive decline in humans. (4)
Proper oxygen and nutrient supply to the brain
Resveratrol also promotes vasodilation, which increases blood flow in the brain during cognitively demanding tasks, indicating another unique mechanism for this phytonutrient’s nootropic benefits. Sufficient cerebral blood flow means proper oxygen and nutrient supply to the brain and effective elimination of metabolic waste. (5)
Sources:
(2) – A randomized, double-blind, placebo-controlled trial of resveratrol for Alzheimer disease.
(3) – Resveratrol for Alzheimer’s disease.
(4) – Resveratrol and cognitive decline: a clinician perspective
