The significant increase in average life expectancy is one of society’s great achievements which has been associated with a shift in the leading causes of illnesses from infectious to noncommunicable diseases. It is well known that the percentage of populations categorized as elderly (e.g. 65 years and older) will increase dramatically in almost every country in the next few decades.
By 2060, the elderly population will be expected to grow from 17.4% to nearly 30% worldwide (European Comission and Eurostat, 2012). At the same time, there is a wealth of data related to how nutrients, non-nutrient, food components, and whole diets may impact on cognitive health and ageing. Numerous studies indicate that long-term intake of a Mediterranean diet (emphasizing amongst others fruits, vegetables, and olive oil) correlates with better cognition in aged populations
Anti-inflammatory compounds in plants stimulate protect and neurons. However, studies could not be replicated in humans, and treatments with ibuprofen, or foods, such as turmeric, rarely are definitive. Due to the lack of highly sensitive cognitive test batteries and control for individual differences, diets and nutrients are not proven to robustly alleviate cognitive decline over short periods.
In the past 10 years, high-calorie/low-dietary fibre diets and risk and incidence of diet-related diseases (i.e. Type 2 Diabetes Mellitus (T2DM) or cardiovascular disease (CVD)) have been associated with age-related cognitive decline. Data on beneficial effects of several ingredients or nutrients suggest that their consumption may have the potential to help prevent cognitive decline.
Placebo-controlled trials (RCTs) are the gold standard to confirm the effect of a nutritional intervention on cognitive decline, maintenance or improvement. However, subtle effects are predicted to add up over decades and may be significantly influenced by individual differences in the rate of cognitive decline.
Although the present review is mostly focused on the role of nutrients in cognitive decline, it also offers some insights about different aspects related to the process of ageing. Thus, it highlights important considerations about normal and pathological ageing and its measurement through the use of biomarkers of cognitive status, as well as metabolic conditions that are considered as risk factors for cognitive decline.
Therefore, the main goal of the present review is to provide the most recent evidence from human observational and intervention trials along with key mechanistic studies in cell and animal models, on the current state of knowledge on nutrition and healthy brain ageing