Nutrition for Cognitive Health
As the rate of neuroscientific research continues to increase, the effects of diet and lifestyle on the brain are beginning to be understood in new and very interesting ways. It appears that a properly structured diet can not only reduce the risk of neurodegenerative conditions like Alzheimer’s , but also favorably impact brain plasticity processes like neurogenesis. Of course, while this is very exciting, it is probably best to understand the role of diet in cognitive performance as 1) the prevention of nutritional deficiencies and 2) the prevention of nutritional insults. Evidence for further cognitive improvements beyond these activities is limited, and your personal quest for telepathic omniscience may not be satisfied by diet alone.
At a high level, optimizing for cognitive health should start with optimizing for general health. That is, the brain is subject to metabolic and vascular processes as with the rest of the body, and wild metabolic deficiencies or risk factors are likely to also have deleterious impacts on the brain. To this end, controlling total calories (and potentially practicing sustained caloric deficits), while eating sufficient dietary protein and fiber is likely to lead to better cognitive outcomes.
While a number of vitamins, minerals and other compounds are implicated in maintaining or improving cognitive health, omega-3 fatty acids have perhaps the most diverse and impressive clinical track record. We look at each of these nutrients in turn, with the upfront caveat that more research is still necessary:
Omega 3 Fatty acids, and in particular the omega-3 fatty acids DHA and EPA – appear to play an important role in cognitive health. Critical in early neuronal development, there is also some evidence that omega-3 fatty acids can help reduce the risk of Alzheimer’s as well as cognitive decline . While the effect sizes in Alzheimer’s are likely to be marginal, the ameliorative effects on cognitive decline appear to be more robust , albeit not conclusive .
Omega-3 fatty acids appear to have beneficial effects on a number of cognitive processes in otherwise healthy individuals consuming diets relatively deficient in omega-3 fatty acids (DHA in particular) – including cerebral bloodflow , memory , attention processes , reduction of anxiety and some forms of depression . Omega-3 fatty acids may also favorably impact learning in children, particularly those with symptoms of ADHD (which might be close to, but not completely equivalent to all children ever) .
At a lower level, omega-3 fatty acids – and DHA in particular – have been shown to limit the production and accumulation of amyloid beta (a key peptide in Alzheimer’s), favorably modify BDNF and neurogenesis , potentially increase neuronal receptor expression and generally exert a variety of neuroprotective effects .
Vitamins C and E both appear to lower the risk of vascular dementia while prevention of vitamin C deficiency seems to offer some protection against cognitive decline and Alzheimer’s . As well, vitamin E may offer a marginal benefit against Parkinson’s .
Choline: is the precursor molecule for the neurotransmitter acetylcholine, and dietary choline appears to play some important role neuronal development in addition to a variety of general health processes . Choline may also potentially protect against depression and stress , and may have some favorable role to play in cognitive decline and memory - though the evidence is still very preliminary .
Magnesium: appears to have a role to play in synaptic plasticity: and might provide a marginal benefit in the treatment of Alzheimer’s as well as recovery from traumatic brain injury . It may also potentially play some role in reducing the risk of vascular dementia . To learn more about magnesium, click here.
Protect Against Insults:
Sugars: high sugar intake can produce more variability and spiking of energy throughout the day , potentially impairing cognitive performance. In hypoxia models, refined carbohydrate diets have also been shown to contribute to spatial learning deficits . Beyond this, the general health benefit to limiting sugar, especially for metabolic health, also make this a logical prescription for cognitive health .
Saturated Fat: While a deeper understanding of saturated fat indicates it may not be as problematic as previously believed, there are indications it would still be wise to limit saturated fat intake for cognitive health – particularly relative to consumption of polyunsaturated fats .