Key points
Data indicates increasing imbalance in the n-6/n-3 ratio in the food supply over time with some reviews indicating ratios above 20:1. Smaller studies using intake from 24-h diet recalls or records, and even the National Health and Nutrition Examination Survey (NHANES) data, often find ratios closer to 10:1. The increase in n-6 coupled with the decrease in n-3 in the food supply has produced speculation that most people consume well above recommended amounts of n-6 and well below recommended amounts of n-3. In the present study, the fatty acid intake among children 7 to 12 years old and older adults 65 to 79 years old, were assessed.
There are no current guidelines for the n-6/n-3 ratio, but the current recommendations for n-6 and n-3 intake can be used to calculate what dietary n-6/n-3 ratio a person would have if they followed recommendations. For instance, current recommendations for children between 4 and 8 years old are to consume 10 g of linoleic acid (LA, n-6) and 0.9 g of alpha-linolenic acid (ALA, n-3) combined with either 0.1 g or 0.2 g of docosahexaenoic acid (DHA, n-3) and eicospentaenoic acid (EPA, n-3), producing an n-6/n-3 ratio of 9.1–10.1. Recommendations for males and females between 9 and 13 years old range from ratios of 7.1 (9 to 13 year old males) to 10.9 (9 to 13 year old females). Even if ratios of 1:1 are not the goal at every age, researchers have generally found ratios below 10 to be more optimal.
Results from these analyses indicated that children and older adults generally consumed more ALA than recommended and approximately the recommended amount of LA, whereas only a small percentage consumed the recommended amounts of the longer-chain fatty acids, EPA and DHA. 71.8% of 7- to 12-year-olds and 58.4% of 65- to 79-year-olds consumed at least the recommended amount of ALA for their age and gender. Regardless of the recommendation used, children 7 to 12 years of age rarely consumed recommended amounts of DHA and EPA (up to 14.1% reached recommendations). Adults were more likely to reach recommended DHA and EPA intake (at least 24.1% reached recommendations), but the differing recommendations produced more variability with almost 60% of adults reaching IOM recommendations. The n-6/n-3 ratios were slightly lower (9.2 in children and 7.8 in older adults) than would be produced by consuming recommended quantities of LA and LNA. The n-6/n-3 ratios were as low as 2 (children) or 3 (adults) and as high as 17 (children) or 20 (adults). No n-6/n-3 ratios above 20 were found in children or older adults.
In conclusion, individuals in the Southeastern United States are able to consume recommended amounts of the shorter chain, but not the longer chain n-6 and n-3 fatty acids. Recommendations for DHA and EPA can be improved with studies that better reflect current dietary patterns, by including genetic and epigenetic mechanisms that affect fatty acid metabolism, and most importantly, by considering both n-6 and n-3 intake and their balance. Despite changes in n-3 availability in the food supply that have caused many researchers to be concerned about the effect of n-3 consumption and the overall balance of n-6 and n-3 in a typical diet, most children and older adults in the present analyses were able to consume recommended amounts of LNA and not significantly exceed recommendations for LA. Participants were less likely to consume recommended amounts of DHA and EPA, but that issue did not result in significantly elevated ratios.
ABSTRACT
BACKGROUND: Omega-6 and omega-3 fatty acids (FAs) and their ratio have been shown to affect cognitive function in children and older adults. With these analyses, we aimed to describe omega-6 and omega-3 FA intake among children and older adults in light of FA intake recommendations and with consideration of overall diet. METHODS: Data were merged from two cross-sectional studies with 219 children 7 to 12 years old and one longitudinal study with 133 adults 65 to 79 years old. Demographic data, anthropometric data, and Healthy Eating Index scores were used to study relations among the omega-6 to omega-3 FA ratio and age, education, body mass index, and diet quality. FA intake, demographic, and anthropometric data were examined using partial correlations, t-tests, and analysis of variance. RESULTS: Most children and adults consumed at least the recommended amount of alpha-linolenic acid (LNA; omega-3) for their age and gender without consuming high amounts of linoleic acid (LA; omega-6) but did not consume sufficient eicosapentaenoic acid (EPA; omega-3) and docosahexaenoic acid (DHA; omega-3). The average omega-6 to omega-3 ratios in both groups were lower than previously reported. Eating lower ratios was associated with healthier diets and consuming adequate amounts of several other nutrients. No demographic or anthropometric variables were related to FA intake in children. Adults with a college degree had significantly lower ratios than those without a college degree. CONCLUSIONS: American children and older adults are able to consume more balanced omega-6 to omega-3 ratios than has been indicated by commodity data. However, very few American children met even the lowest recommendations for EPA and DHA intake. Research is needed to clarify recommendations for the optimal ratio across development, which may aid in increasing EPA and DHA intake and improving health outcomes in the United States.
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