by John & Barbara Connor, M.Ac., L.Ac.
John and I would like to share with you today some of the research we have come across on different foods that are beneficial for the brain. Age-related cognitive decline is rising as one of the world’s most detrimental health problems. We feel that one of the many ways in slowing down this cognitive decline is to eat foods that are good for the brain. We hope that what we present here is helpful in your quest for optimal cognitive function.
Every year, more than 10 million people suffer from neurodegenerative diseases worldwide, and this figure is expected to grow by 20% over the next decade. Neurodegenerative diseases are a group of progressive neurological disorders that damage or destroy the function of neurons. (Kannappan et al 2011)
One leading theory of aging is based on the concept that damage, either due to the toxic products of metabolism or inefficient repair/defensive systems, accumulates throughout our entire life span and gradually leads to cell and organ dysfunction. There is substantial support for the role of reactive oxygen species (ROS) in the aging process. The free radical theory of aging proposes that ROS are responsible for macromolecular damage and for age-related tissue degeneration. (Pierno et al 2014)
Oxidative stress has been implicated in normal aging and many neurodegenerative diseases. The term “oxidative stress” refers to an imbalance between the production of reactive oxygen species (ROS) and their neutralization by antioxidant defenses. (Choi et al 2015)
At high levels, ROS can react with different cell molecules, causing damage to DNA, lipids, and proteins and modulate intracellular signaling pathways, leading to cellular degeneration and apoptosis. ROS can also initiate proinflammatory pathways, further exacerbating the deleterious oxidized environment. The brain is particularly vulnerable to oxidative stress because of its high oxygen consumption, high content of oxidizable polyunsatured fatty acids, and low antioxidant defense capacities especially in aging brains. (Tarozzi et al 2013)
There is increasing evidence to suggest that diet, one of the most important modifiable lifestyle factors, may play a role in preventing or delaying cognitive decline and Alzheimer’s disease (AD), a major public health problem. (Berti et al 2015)
The following is a list of foods that John and I think may be beneficial for your brain health followed by the various studies describing their benefits:
Concord grape juice
Orange juice – Chronic daily consumption of flavanone-rich 100% orange juice over 8 weeks is beneficial for cognitive function in healthy older adults. The potential for flavanone-rich foods and drinks to attenuate cognitive decline in aging and the mechanisms that underlie these effects should be investigated. (Kean et al 2015)
DHA (the n-3 fatty acid found in fish) – Overall, where individual omega-3 PUFAs have been investigated in trials of healthy aging, mild cognitive impairment and Alzheimer’s disease the focus has been on DHA, which is consistent with the pre-clinical evidence. DHA treatment appears to show the greatest promise compared to EPA and DPA, and the benefits of DHA treatment currently appear to be to improve memory and learning in participants with MMSE scores above 26–27, particularly non-ApoE-ε4 carriers, although support from clinical trials is currently extremely limited. (Dyall SC 2015)
Coconut oil comprises medium-chain fatty acids (MCFA). MCFA are unique in that they are easily absorbed and metabolised by the liver, and can be converted to ketones. Ketone bodies are an important alternative energy source in the brain, and may be beneficial to people developing or already with memory impairment, as in Alzheimer’s disease (AD). (Fernando et al 2015)
Fruits, vegetables, and juices – The data suggest that chronic consumption of fruits, vegetables, and juices is beneficial for cognition in healthy older adults. The limited data from acute interventions indicate that consumption of fruit juices can have immediate benefits for memory function in adults with mild cognitive impairment; however, as of yet, acute benefits have not been observed in healthy adults. Conclusions regarding an optimum dietary intake for fruits, vegetables, and juices are difficult to quantify because of substantial heterogeneity in the categorization of consumption of these foods. (Lamport et al 2014)
Blueberry and grape seed extracts rescued rotenone-induced defects in mitochondrial respiration in a dopaminergic cell line, and a purple basal extract attenuated nitrite release from microglial cells stimulated by lipopolysaccharide. These findings suggest that anthocyanin- and proanthocyanidin-rich botanical extracts may alleviate neurodegeneration in Parkinson’s disease (PD) via enhancement of mitochondrial function. (Strathearn et al 2014)
Fruits and Vegetables – For a long time, the increased consumption of fruits and vegetables was considered critical in protecting humans against a number of diseases, such as cancer, diabetes, neurodegenerative diseases, and heart and brain vascular diseases. Presently, it is thought that the protective properties of these foods result from the presence of low-molecular antioxidants that protect the cells and their structures against oxidative damage. A number of studies have shown, however, that consuming less common fruits and vegetables contribute much more to the reduction of free-radical processes, most likely because they contain a large amount of non-vitamin antioxidants, such as polyphenols and anthocyanins. (Harasym & Oledzki 2014)
Fruit, vegetables, fish, (whole) grains and legumes/pulses and potatoes – According to both a posteriori and a priori dietary patterns, some key ‘ingredients’ can be identified that are associated consistently with longevity and better cardiometabolic and cognitive health. These include high intake of fruit, vegetables, fish, (whole) grains and legumes/pulses and potatoes, whereas dietary patterns rich in red meat and sugar-rich foods have been associated with an increased risk of mortality and cardiometabolic outcomes. (Kiefte-de Jong et al 2014)
Red wine – Several epidemiological studies have shown that moderate wine consumption can be effective in slowing down age-related cognitive decline. Resveratrol, a natural polyphenol, is mainly present in red wine and has been suspected to be the major driving force behind the French paradox. Resveratrol is a multi target compound and may represent an effective therapeutic tool in aging-related neurodegenerative processes. Consistently, several clinical trials are ongoing to test its effectiveness as dietary supplement to slow dementia progression. In agreement, pterostilbene, a resveratrol derivative, has shown promise in preclinical models of neurodegeneration, resulting more efficient than resveratrol itself in modifying Alzheimer’s disease and aging-related cognitive decline. (Granzotto & Zatta 2014)
Nuts – We found a modest relationship between long-term total nut intake and cognitive function. In multivariable-adjusted linear regression models, higher long-term total nut intake was associated with better average cognitive status for all cognitive outcomes. Nut intake could potentially represent a fairly simple dietary modification if future research confirms our findings. Additional investigations- particularly with a focus on those who consume nuts frequently – is warranted. (O’Brien et al 2014)
Tea, Cocoa and Blueberry -Phytochemical–rich foods, particularly those rich in flavonoids, have been shown to be effective in reversing age-related deficits in memory and learning. In particular, studies using Camellia sinensis (tea), Gingko Biloba, Theobroma cacao (cocoa) and Vaccinium spp (blueberry) have demonstrated beneficial effects on memory and learning in both humans and animal models. Our data support the claim that flavonoids are likely causal agents in mediating the cognitive effects of flavonoid-rich foods. (Rendeiro et al 2013) Flavonoids are capable of crossing the blood-brain barrier (BBB) and reaching the central nervous system. (Faria et al 2014)
Pomegranate juice – This preliminary randomized placebo-controlled, double-blind trial of pomegranate juice in older adults with mild memory complaints suggests that 8 ounces of pomegranate juice taken daily over one month improve a sensitive measure of verbal memory and alter neural activity during a visual source memory task. The presence of polyphenol metabolites validated compliance with the experimental regimen and efficacy of pomegranate juice in releasing polyphenols. fMRI results suggest that the mechanisms of change may involve increases in task-related cerebral blood flow, particularly during associative encoding tasks. While preliminary, these results suggest a role for pomegranate juice in augmenting memory function through task-related increases in functional brain activity. (Bookheimer et al 2013)
Mediterranean diet – We assessed 522 participants at high vascular risk (44.6% men, age 74.6 ± 5.7 years at cognitive evaluation) enrolled in a multicentre, randomised, primary prevention trial (PREDIMED), after a nutritional intervention comparing two Mediterranean diets (supplemented with either extra-virgin olive oil (EVOO) or mixed nuts) versus a low-fat control diet. An intervention with Mediterranean diets enhanced with either EVOO or nuts appears to improve cognition compared with a low-fat diet. (Martinez-Lapiscina et al 2013)
Concord grape juice – Polyphenol compounds found in berry fruits, in particular flavonoids, have been associated with health benefits including improvement in cognition and neuronal function with aging. Concord grape juice contains polyphenols, including anthocyanins and flavanols, and previous research has shown improvement in a number of human health conditions with grape juice supplementation. These findings provide further evidence that Concord grape juice can enhance neurocognitive function in older adults with mild memory decline. (Kirkorian et al 2012)
n-3 fatty acid, DHA, found in fish – The objective of this review is to provide an overview of nutritional factors involved in cognitive aging and dementia with a focus on nutrients that are also important in neurocognitive development. Several dietary components were targeted, including antioxidant nutrients, dietary fats and B-vitamins. A critical review of the literature on each nutrient group is presented, beginning with laboratory and animal studies of the underlying biological mechanisms, followed by prospective epidemiological studies and randomised clinical trials. The evidence to date is fairly strong for protective associations of vitamin E from food sources, the n-3 fatty acid, DHA, found in fish, a high ratio of polyunsaturated to saturated fats, and vitamin B12 and folate. (Morris MC 2011)
n-3 PUFA, DHA and EPA – The aim of the present study was to investigate the benefits of supplementing a diet with n-3 PUFA, DHA and EPA, for depressive symptoms, quality of life (QOL) and cognition in elderly people with MCI. We conducted a 6-month double-blind, randomised controlled trial. Compared with the LA (n-6 PUFA linoleic acid) group, GDS scores improved in the EPA and DHA groups and verbal fluency in the DHA group. Improved GDS scores were correlated with increased DHA plus EPA. Improved self-reported physical health was associated with increased DHA. There were no treatment effects on other cognitive or QOL parameters. Increased intakes of DHA and EPA benefited mental health in older people with MCI. Increasing n-3 PUFA intakes may reduce depressive symptoms and the risk of progressing to dementia. (Sinn et al 2011)
Mediterranean diet – A high adherence to the Mediterranean diet has been associated with slower cognitive decline, with reduced risk of mild cognitive impairment conversion to Alzheimer’s disease and with reduced risk of Alzheimer’s disease. This dietary pattern is characterized by abundant plant foods consumption in the form of fruits, vegetables, breads, other forms of cereals, potatoes, beans, nuts and seeds; fresh fruit as the typical dessert; olive oil as the main source of monounsaturated fat; dairy products as principally cheese and yogurt; a low to moderate consumption of fish depending of the proximity of the sea; a low to moderate consumption of poultry; fewer than four eggs consumed per week; low amount of red meat and wine consumed in low to moderate amounts, normally during meals. (Feart et al 2010)
Flavonoids – Recent evidence has indicated that a group of plant-derived compounds known as flavonoids may exert particularly powerful actions on mammalian cognition and may reverse age-related declines in memory and learning. In particular, evidence suggests that foods rich in three specific flavonoid sub-groups, the flavanols, anthocyanins and/or flavanones, possess the greatest potential to act on the cognitive processes. (Spencer JP 2010)
Cocoa, wine, grape seed, berries, tea, tomatoes, soy and pomegranate – Several epidemiological studies suggest that the regular consumption of foods and beverages rich in flavonoids is associated with a reduction in the risk of several pathological conditions ranging from hypertension to coronary heart disease, stroke and dementia. The impairment of endothelial function is directly related to ageing and an association between decreased cerebral perfusion and dementia has been shown to exist. Cerebral blood flow (CBF) must be maintained to ensure a constant delivery of oxygen and glucose as well as the removal of waste products. Increasing blood flow is one potential way for improving brain function and the prospect for increasing CBF with dietary polyphenols is extremely promising. The major polyphenols shown to have some of these effects in humans are primarily from cocoa, wine, grape seed, berries, tea, tomatoes (polyphenolics and nonpolyphenolics), soy and pomegranate. (Ghosh & Scheepens 2009)
Berries and cocoa – The consumption of flavonoid-rich foods, such as berries and cocoa, throughout life holds a potential to limit neurodegeneration and prevent or reverse age-dependent deteriorations cognitive performance. However, at present, the precise temporal nature of the effects of flavonoids on these events is unclear. For example, it is presently unclear as to when one needs to begin consuming flavonoids in order to obtain maximum benefits. It is also unclear which flavonoids are most effective in inducing these changes. (Spencer JP 2009)
Fruits, nuts, vegetables, and spices – Recent studies suggest that consumption of diets rich in antioxidants and anti-inflammatory components such as those found in fruits, nuts, vegetables, and spices, or even reduced caloric intake, may lower age-related cognitive declines and the risk of developing neurodegenerative disease. (Joseph et al 2009)
Spinach, kale, asparagus, broccoli, avocado and parsley– A reduction in key antioxidants such as glutathione has been noted in brain tissue undergoing oxidative stress in aging and neurodegeneration. Protection against oxidative stress is directly afforded through the oxidation of glutathione in mitochondria, and decreased concentrations of glutathione were reported in the aging rat brain. (Choi et al 2015) Glutathione containing foods include spinach, kale, asparagus, broccoli, avocado and parsley. They are rich in constituents which form glutathione precursors.
Avoid sugar substitutes – After long-term treatment with fructose, erythritol (sugar alcohols), acesulfame K (artificial sweeteners), or rebaudioside A (rare sugars), the cerebral ischemic injury (both infarct volumes and neurobehavioral outcomes) was significantly aggravated, angiogenesis in ischemic brain was reduced, and endothelial progenitor cell function was impaired in mice compared with control. Long-term consumption of sugar substitutes aggravated cerebral ischemic injury in mice, which might be partly attributed to the impairment of endothelial progenitor cells and the reduction of angiogenesis in ischemic brain. (Dong et al 2015)
Compassionate Acupuncture and Healing Arts, providing craniosacral acupuncture, herbal and nutritional medicine in Durham, North Carolina. Phone number 919-309-7753.