A recent observational study showed an association between a healthy diet that corresponds to current guidelines for healthy eating, and a reduction in cognitive decline, in a population group that included those at high risk of cardiovascular disease (CVD).
The World Health Organization (WHO) estimates that 35.6 million people worldwide suffer from cognitive decline. Projections indicate that number will double every 20 years, to 115 million by 2050.1 Furthermore, cognitive decline can be financially and emotional burdensome to individuals and their families.1,2 Finding preventative measures or ways to slow this decline is imperative. A study by Andrew Smyth, et al., published in the Neurology in 2015 focused on the relationship between diet and cognitive decline in a high-risk cardiovascular population.
The largest of its kind, this study examined over 27,000 middle aged and elderly participants for 5.5 years. Participants were enrolled in one of two larger international studies that encompassed over 40 different countries (ONTARGET: Ongoing Telmisartan Alone and in Combination with Ramipril Global Endpoint Trial and TRANSCEND: Telmisartan Randomised Assessment Study in ACE Intolerant Subjects with Cardiovascular Disease).2 These large double-blind trials enrolled participants who had a history of renal insufficiency, acute coronary syndrome (ACS) or stroke, or congestive heart failure (CHF).
Health, diet (Alternative Healthy Eating Index) and cognition data were obtained at baseline, 2 years into the study and at the 5.5-year follow-up. The Alternative Healthy Eating Index used in this study examined seven domains of diet including vegetable servings, fruit, whole grains, red meat and fried foods. Results from this observational study showed that there was an inverse relationship between cognitive decline and a healthy diet (hazard ratio =0.76). These results indicate those following a healthy diet are less likely to have mental decline.
While this association is important, the mechanisms by which a diet slows cognitive decline needs further research.
Why is this Clinically Relevant?
- A healthy diet in CVD risk population showed an inverse relationship with cognitive decline
- Due to the rise in cognitive decline finding preventative measures or ways to slow decline is imperative
- Omega-3 fatty acids, folate, and vitamins may play a role in this process by reducing inflammation and oxidative stress.2
1 Prevalences of dementia and cognitive impairment among older people in sub-Saharan Africa: a systematic review. WHO. http://www.who.int/bulletin/volumes/91/10/13-118422/en/. Accessed July 5, 2017.
2Smyth A, Dehghan M, Odonnell M, et al. Healthy eating and reduced risk of cognitive decline: A cohort from 40 countries. Neurology. 2015