The brain is the most complex and important organ that control all the body functions. Quantity and quality of fat consumed play an important role in maintaining brain health, thus affect brain functions.

The aim of this study was to assess the harmful effect of high intake of unhealthy source of fat as well as to detect the role of healthy oils on brain functions from chemical and histological point of view.

This study was conducted on (56) adult male rats divided into two major groups : the first was normal diet group ND ( fed normal diet )that include 4 subgroups(7 rats in each group) the first served as control with corn oil as fat source while in the other (3) groups corn oil was substituted by sesame, flaxseed and chia oils. The second major group was high fat diet group divided into 4 subgroups fed high fat diet HFD (13% oil + 7% vegetable shortening).

In high fat control group oil used was corn oil while in the remaining (3) groups corn oil was substituted by sesame, flaxseed and chia oils.

After 6 weeks brain was separated for biochemical analysis of neurotransmitters and oxidative stress. Samples were also prepared for histological examination .In addition, Chemical analysis and sensory evaluation were conducted for the .experimental oils .

Our results revealed that diet rich in corn oil and vegetable shortening (rich in high saturated fatty acid) caused disturbances in both neurotransmitters and oxidative stress. Damage was also detected in histological sections from brain cortex.

It is worthy to mention that using sesame, flaxseed and chia oils instead of corn oil had a protective effect on brain. In addition, those oils were highly acceptable in our products. It could be concluded that adding those healthy oils to daily meals could have a protective effect on brain injury.