Brazil nuts improve brain health

Posted on Sun, 14 Feb 16

Just one Brazil nut a day eliminated selenium deficiency, improved anti-oxidant defences and enhanced cognitive function in older age adults with mild cognitive impairment. 

Mild cognitive impairment (MCI) is cognitive decline beyond what is healthy for your age, but not severe enough to be classified as dementia. MCI is very common in older age and can progress to dementia, therefore preventative strategies are important. 

Like many age related illnesses MCI has multiple causes, but one factor thought to contribute is increased levels of oxidative stress. Deficiency in selenium, a mineral unusually abundant in Brazil nuts, is also common in older age and improving selenium intake could reduce oxidative stress and improve brain health. 

To test the potential of Brazil nuts as a selenium-rich “brain food,” a study examined the effects of one Brazil nut daily (estimated to provide selenium 288.75 µg/day) for 6-months in older adults with MCI. 

They found that the daily nut eliminated selenium deficiency (only one person was not deficient at the beginning of the study), improved antioxidant defences (erythrocyte glutathione peroxidase), and improved some cognitive functions (namely semantic verbal fluency and constructional praxis).

“Older individuals are more vulnerable to selenium deficiency because of increased requirements, metabolic changes, lower bioavailability, and changes in diet,” commented the study investigators. “As a result, they may be more susceptible to damage resulting from oxidative stress in the central nervous system.”

This simple food-as-medicine intervention may help safely treat selenium deficiency, reduce oxidative stress and benefit brain health.  

Reference:  

Rita Cardoso B, Apolinário D, da Silva Bandeira V, et al. Effects of Brazil nut consumption on selenium status and cognitive performance in older adults with mild cognitive impairment: a randomized controlled pilot trial. Eur J Nutr. 2016 Feb;55(1):107-16.