Most Recent Research Findings about the Chemicals that Keep the Brain Sharp

The brain, the nervous and vascular systems, and to a lesser extent, all cells in the body use a special kind of fat in their construction, known as essential fat (Richardson, 2006). The brain alone is comprised of three quarters of this fat, which has a different chemical composition to the visible fat the body uses as a way of storing energy. At a molecular level, fat is comprised of a string of carbons, saturated with hydrogen and with an acid group at one end. The carbon atoms are normally joined by single bonds (Walter et al 2003). With some fats, some of the hydrogens can be moved to form double bonds between adjacent carbons. Essential fatty acids have more than one double bond and are called polyunsaturated.

There are two different types of essential fatty acids:

• Linoleic acid and its derivatives, including arachidonic acid (AA), are known as the Omega-6 series of fatty acids;
• Alpha-linolenic acid and its derivatives are the Omega-3 series of essential fatty acids, which include EPA and DHA.
  

These essential fatty acids cannot be made in the body and must be eaten in the diet. Animals and fish eat the plants containing the shorter chain fatty acids, and their digestive systems change the fat, extending the length of the carbon chain. When people eat meat or fish they build on these building blocks again. It is the long chain fatty acid derivatives that are used in human brain construction, in particular in the construction of cell membranes. These different chemical structures give the fats different properties: saturated fats are hard and inflexible, while polyunsaturated fats are liquid. Essential fats are unstable, so they are stripped from foods by industrial processing where shelf life and stability are considered more important.