In addition to adding flavor to foods, we also get taste sensations, such as richness and mouth-feel, from fat. Another player in the sense of taste is the trigeminal system, or 'free nerve endings' in the mouth and nose that connect with the brain. Smell occurs when nerve receptors in your nose send messages to your brain. The sense of smell plays an important role in perception of foods. The interaction of the oral and nasal senses blend together to give us the impression of a certain food, or increase the sensory perceptions we receive.
Smells can also create emotional responses to food.
This is because emotions and smell sensations overlap in your brain. Smells can create both positive and negative emotional responses to food. A positive response can improve the desire to eat, while a negative response may decrease the desire to eat. Declining taste and smell is a normal part of the aging process for many people. Age-related impairment of the senses can be caused by many factors including environmental pollutants.