The Effects of dietary n−3/n−6 ratio on brain development in the mouse: a dose response study with long‐chain n−3 fatty acids

Abstract

This study examines the effects of the ratio of n-3/n-6 fatty acids (FA) on brain development in mice when long-chain n-3 FA are supplied in the diet. From conception until 12 days after birth, B6D2F1 mice were fed liquid diets, each providing 10% of energy from olive oil, and a further 10% from different combinations of free FA concentrates derived from safflower oil (18:2n-6), and fish oil (20:5n-3 and 22:6n-3). The range of dietary n-3/n-6 ratios was 0, 0.25, 0.5, 1.0, 2.0 and 4.0, with an n-6 content of greater than 1.5% of energy in all diets, and similar levels of total polyunsaturated fatty acids (PUFA). In an additional group of ratio 0.5, 18:2n-6 was partially replaced by its delta 6 desaturation product, 18:3n-6. Biochemical analyses were conducted on 12-day-old pup brains, as well as on samples of maternal milk. No obvious effects on overall pup growth and development were observed, apart from a smaller litter size at ratio 1. Co-variance analysis indicated that increasing the n-3/n-6 ratio was associated with slightly smaller brains, relative to body weight. We found that 18:2n-6 and 20:5n-3 were the predominant n-6 and n-3 FA in the milk; in the brain these were 20:4n-6 and 22:6n-3, respectively. Increasing dietary n-3/n-6 ratios generally resulted in an increase in n-3 FA, with a corresponding decrease in n-6 FA.(ABSTRACT TRUNCATED AT 250 WORDS)

Modulation of learning, pain thresholds, and thermoregulation in the rat by preparations of free purified alpha-linolenic and linoleic acids: determination of the optimal omega 3-to-omega 6 ratio.

“…Although alteration of the fatty acid composition of brain lipids by varying levels of ingested EFAs was demonstrated almost three decades ago (41), only recently has research focused on determination ofthe optimal 3-to-w6 ratio in adult diet and in infant or parenteral formulas. Whereas Neuringer et al (18) considered a ratio in the range 1:4-1:10 to be prudent, several recent reports (42)(43)(44)(45) support our observation that a 1:4 ratio may be optimal. A recent North Atlantic Treaty Organization conference on essential fatty acids recommended a ratio of 1:4 (42).…”

RETRACTED: Why Fish Oil Fails to Prevent or Improve CVD: A 21st Century Analysis

“…A pharmacologic overdose can't all be oxidized away for energy or otherwise. Consequently, much of "the overdose" is forced into tissue composition, causing an improper structureoften in maintaining a linear relationship as does plasma, liver, and RBCs [7][8][9]. Cellular bilipid membrane structure and its LDL-C structure warrant intense investigation.…”

“…Importantly, fish oil potentially damages the brains of both infants and adults because critical omega-6 series metabolites are displaced [7]. The medical journal's authors specifically warned against feeding fish oil to human infants.…”

Spatial and visual discrimination reversals in adult and geriatric rats exposed during gestation to methylmercury and n−3 polyunsaturated fatty acids

“…Marine fish also contain docosahexaenoic acid (DHA), an essential omega-3 polyunsaturated fatty acid (n-3 PUFA) that supports brain development and visual and motor function (Egeland and Middaugh, 1997;. Dietary deficiencies in n-3 PUFAs reduce brain weight (Wainwright et al, 1992), impair vision (Okaniwa et al, 1996;Yamamoto et al, 1987;Yamamoto et al, 1988), and produce motor deficits (Greiner et al, 1999). There is mixed evidence about whether n-3 PUFAs affect such cognitive functions as learning, behavior change, or memory (Becker and Kyle, 2001;Wainwright, 1997;Wainwright et al, 1999).…”