**6.5 Vegetable oils**

The beneficial effects of the MedDiet on cognitive functions have been attributed to its high MUFA content. Medium-chain triglycerides (MCTs) or medium-chain fatty acids in coconut oil improve cognition in Alzheimer's patients, also helps to improve insulin resistance, which is an excellent treatment for dementia patients and diabetics. Caprylic acid is the MCT derived from coconut or palm oil helps to improve cognitive function in Alzheimer's patients. Olive oil is a source of fatty acids and antioxidant-rich food. The best quality form of olive oil is extra-virgin olive oil (EVOO). Regular intake of EVOO is linked with lower mitochondrial oxidative stress, which counteracts age-related cognitive decline. The secoiridoid oleuropein, resp. oleuropein aglycone in olive oil is responsible for its neuroprotective effect. The results of in vitro and in vivo studies specify that the regular intake of EVOO is associated with enhanced cognitive functions, which proves that olive oil has a neuroprotective effect and positively prevents the development of dementia and Alzheimer's disease [27].
