Omega-3 and omega-6 fatty acids are absolutely essential for human life and health, but they must be provided by our diet. They play particularly key roles in brain development and function.
Various physical signs are associated with deficiencies in these essential fatty acids. These include excessive thirst, frequent urination, rough, dry or scaly skin, dry, dull or ‘lifeless’ hair, dandruff, and soft or brittle nails. Raised bumps on the skin are particularly characteristic. (This is called ‘follicular keratosis’ as it results from a build-up of hard, dry skin around the hair follicles).
Research has shown that these fatty acid deficiency signs are unusually common in people with ADHD, dyslexia and autistic spectrum disorders.(1-7) They have also been linked with behaviour, learning and health problems in boys with and without an ADHD diagnosis,(4) with the severity of reading, spelling and related difficulties in dyslexic children(5) and with visual, auditory and other features of dyslexia in adults.(6)
This and other evidence has led to treatment trials to find out if supplementing the diet with fatty acids may help in these conditions.
A simple checklist rating scale has been used in many of these studies to assess fatty acid deficiency signs. Across groups, scores have been shown to correlate with blood levels of fatty acids. However, results from this scale should never be interpreted in isolation, as any reliable diagnosis of fatty acid deficiency would require other information such as blood fatty acid analyses, and ideally a full dietary assessment.
Many other features or clinical signs can sometimes reflect deficiencies or imbalances of omega-3 or omega-6 fatty acids, although research to confirm these links is ongoing. These include:
IMPORTANT: Any of these signs can have other causes, so it should never be assumed that fatty acid deficiencies are responsible. Always seek medical attention for any such symptoms, and before taking food supplements or making any other major dietary changes.