The Benefits of DHA During Childhood
Docosahexaenoic acid, DHA, is an omega-3 fatty acid that is found throughout the body. It is an important structural fat in the brain and eyes and a key component of the heart. A growing body of research continues to support the important role of DHA for brain and eye development and function throughout life, including the critical role it plays in optimal visual and cognitive outcomes during the first few years of life. In addition, immune function and heart health benefits have also been found as a result of research conducted during the childhood years.
Prenatal, infancy and early childhood are recognized as particularly sensitive times to impact development through nutrition. As a result, children are particularly vulnerable to the effects of low DHA intake. Sources of preformed DHA are limited and uncommon in diets of toddlers and children, making it important to provide a continued intake of DHA beyond the early postnatal period. DHA-rich weaning and toddler foods promote healthy DHA levels and are associated with positive health outcomes in U.S. infants and toddlers.
Below are research highlights from studies examining the role of DHA in health and development in early life.
The Physiologic Need for DHA
DHA Supports the Development and Function of the Brain and Eye
- DHA is the predominant omega-3 fatty acid found in the brain. DHA represents about 97% of all omega-3 fatty acids in the brain and 93% of all the omega-3 fatty acids in the eye (retina).
- Uptake of preformed DHA by the brain is significant between ages 2 and 5 and supports the substantial accumulation of DHA by the brain during this critical growth period.
- Teenagers experience the equivalent of a second growth spurt around puberty, suggesting a continued need for DHA well beyond the early years.
- Many people believe that eating foods like flax and walnuts will provide all the omega-3 fatty acids they need; however, these foods are sources of alpha-linolenic acid, or ALA. Although ALA is an omega-3 fatty acid, the conversion to DHA is extremely limited.
- Including preformed DHA in the diet is the most reliable way to ensure that DHA is available to support optimal brain and eye development and function.
- DHA levels drop suddenly during early childhood when the transition to solid foods occurs, resulting in a dramatic shortfall between actual intake and guidance from the Institute of Medicine and other authoritative bodies (2005).
- Low dietary levels of DHA may have a negative impact on retinal and neurological development in childhood.
- Children ages 1–5 years have low DHA intakes, ranging from 30–50 mg/day. This is because the primary dietary sources of DHA are fatty fish and organ meats which are not popular food choices for young children.
- DHA supplementation is accepted and well tolerated by children.
Research evidence suggests a continued need for DHA during and beyond the first year of life to support optimal growth, cognitive and visual development. Modest intakes of DHA-rich weaning foods, toddler foods and supplements increase tissue DHA levels and are associated with improved visual and neurologic outcomes in infants, toddlers and children.
DHA Supports Heart Health
- One-year-old infants who received DHA-supplemented baby food since weaning showed improved vision, equivalent to 1.5 lines on the eye chart, compared to those who received baby food that did not contain DHA.
- Higher levels of red blood cell DHA are associated with higher test scores using the Hopkins Verbal Learning Test (HVLT) in schoolchildren 7–9 years of age. HVLT is a test of cognition designed to record memory and learning skills.
- Higher levels of DHA are associated with higher scores on a listening comprehension test and the Peabody Picture Vocabulary Test (PPVT) in preschool children. Higher scores on the PPVT in preschool children are associated with school readiness and a predictor of better school success.
- Total red blood cell (RBC) omega-3 fatty acids and a higher ratio of DHA to ARA measured at age 11 were associated with higher IQ scores at 64 years of age. Speed of information processing also correlated significantly with DHA RBC levels and the ratio of DHA to ARA in the RBC.
- DHA supplementation provides a consistent positive effect on vision, body coordination and fine motor skills in children with the metabolic disorder phenylketonuria.
- DHA-enriched supplements provide significant benefits in some children with behavior and learning disabilities. In these studies, improvements were noted in ADHD-type symptoms, with improvements in teacher-rated attention and parent-rated conduct, a reduction in the proportion of children showing oppositional defiant behavior and improvements in reading and spelling.
- Higher fish intakes are associated with improved cognition, as evidenced by higher scores on tests of intelligence. Similar observational studies conducted during early and late life have identified LCPUFAS including DHA as the beneficial nutrient.
- Higher levels of DHA intake are associated with increased levels of RBC DHA and alterations in the functional activity in cortical attention networks during sustained attention in healthy boys 8-10 years of age.
DHA Benefits in Immune Function
- DHA has been shown to have a cardio-protective role in adults. Signs of cardiovascular disease have beendetected early in life. Unfavorable blood lipids and high blood pressure are now increasingly being seen inyoung children. Supplementation of DHA in a younger population has been shown to improve blood lipid profiles and restore endothelial function in children with high cholesterol levels.
- DHA has been shown to reduce blood pressure in the early years of life. Blood pressure tracks from childhood into adult life. Thus, supplementation may reduce the risk of cardiovascular disease later in life.
- DHA has demonstrated benefits to immune function in children with as little as 14–21 mg DHA per day.
- Toddlers consuming a formula with 130 mg DHA per day had a lower incidence of respiratory illness compared to those receiving formula without DHA.
- Healthy schoolchildren supplemented with a DHA-enriched dairy product showed fewer episodes and shorter duration of mainly upper respiratory tract infection than the placebo group.