FOOD AND MENTAL HEALTH

How Food and Food Production are Implicated

Most of the brain is derived directly from food. The last fifty years have witnessed remarkable alterations to what we eat, how we process and refine it, food additives, use of pesticides and the alteration of animal fats through intensive farming.  Changes to our diet in recent years mean that what we consume daily is very different in its nutritional content from that of even our closest ancestors.

It has been estimated that the average person in the Uk and other industrialised countries will eat more than 4 kilogrammes of additives every year. The impact of this situation is still controversial as governments have appeared reluctant to fund, conduct or publish rigorously controlled studies examining the effects of additives.

Changing methods of farming have also introduced higher levels and different types of fat into our diet. For example, chickens now reach their slaughter weight twice as fast as they did thirty years ago, which has changed the nutritional profile of the meat. Whereas a chicken carcass used to be 2% fat, it is now 22%. Also, the diet fed to chickens has changed dramatically, which has reduced omega-3 fatty acids and increased omega-6 fatty acids in chicken meat. Similarly, the diet fed to farmed fish is changing the ratio of fatty acids in the fish we eat.

How EFA's, Omega-6 and omega-3 Fatty Acids, work in our Brains

Because the ‘dry weight’ of the brain is composed of about 60% fat, the fats we eat directly affect the structure and substance of the brain cell membranes. saturated fats – those that are hard at room temperature, like lard – make the cell membranes in our brain and body tissue less flexible.

Twenty per cent  of the fat in our brain is made from the essential fatty acids omega-3 and omega-6. They are termed ’essential’ as they cannot be made within the body, so must be derived directly from the diet. Each fatty acid performs vital functions in the structuring of brain cells (or neurons), ensuring that smooth communication is possible within the brain. Both are found in equal amounts in the brain, and it is believed they should be eaten in equal amounts. 

Unequal intakes of omega-3 and omega-6 fats are implicated in a number of mental health problems, including depression, and concentration and memory problems. Experts suggest that most people consuming western
diets eat far too much omega-6 and not enough omega-3.

The recent and widespread appearance of trans-fats in the diet raises great concern, primarily  because these fats assume the same position as essential fatty acids (eFAs) in the brain, meaning vital nutrients are not able to assume their rightful position  for the brain to function effectively. Trans-fats are prevalent and pervasive, found in processed foods like commercially-made cakes, crisps and ready meals.

Neurotransmitters are messengers passed back and forth within the brain. They allow neurons to communicate information amongst themselves. neurotransmitters are made from amino acids, which often must be derived directly from the diet. For example, the neurotransmitter serotonin, which is associated with feelings of contentment, is made from the amino acid tryptophan. Adrenaline and dopamine, the ‘motivating’
neurotransmitters, are made from phenylalanine.

Diet, Essential Fatty Acids (EFA's) and the Brain