Conversion of linoleic acid and alpha‐linolenic acid to long‐chain polyunsaturated fatty acids (LCPUFAs), with a focus on pregnancy, lactation and the first 2 years of life

Abstract

Over the past two decades, there has been a marked shift in the fatty acid composition of the diets of industrialized nations towards increased intake of the n-6 fatty acid linoleic acid (LA, 18:2n-6), largely as a result of the replacement of saturated fats with plant-based polyunsaturated fatty acid (PUFA). While health agencies internationally continue to advocate for high n-6 PUFA intake combined with increased intakes of preformed n-3 long-chain PUFAs (LCPUFA) docosahexaenoic acid (DHA, 22:6n-3) and eicosapentaenoic acid (EPA, 20:5n-3) to reduce the incidence of cardiovascular disease (CVD), there are questions as to whether this is the best approach. LA competes with alpha-linolenic acid (18:3n-3) for endogenous conversion to the LC derivatives EPA and DHA, and LA also inhibits incorporation of DHA and EPA into tissues. Thus, high-LA levels in the diet generally result in low n-3 LCPUFA status. Pregnancy and infancy are developmental periods during which the fatty acid supply is particularly critical. The importance of an adequate supply of n-3 LCPUFA for ensuring optimal development of infant brain and visual systems is well established, and there is now evidence that the supply of n-3 LCPUFA also influences a range of growth, metabolic and immune outcomes in childhood. This review will re-evaluate the health benefits of modern Western diets and pose the question of whether the introduction of similar diets to nations with emerging economies is the most prudent public health strategy for improving health in these populations.

A multidisciplinary reconstruction of Palaeolithic nutrition that holds promise for the prevention and treatment of diseases of civilisation

“…The (from an evolutionary point of view) abnormally high LA intake is, despite a lack of evidence (415) , advocated for cardiovascular health (416) . The resulting high LA status is likely to interfere with both the incorporation of AA and DHA into phospholipids and also inhibits their synthesis from their parent essential fatty acid (417) . Major differences are noted in the comparison of the human milk fatty acid compositions of Western mothers compared with some traditional African women (409,418) , with unknown consequences for infant health or the occurrence of disease at adult age (i.e.…”

Reliability and Validity of a Culturally Appropriate Food Frequency Questionnaire to Measure Omega-3 Fatty Acid Intakes in Midwestern African American Women of Childbearing Age

“…The closer the coefficient alpha is to 1.00 indicates the ability of the FFQ to distinguish intakes between participants. The current FFQ is considered reliable with high between-person variation, which is to be expected because subjects differ from each other in their usual daily food intake 33 The coefficient alphas in the current study, may suggest that the current FFQ was able to distinguish between subject's omega-3 fatty acid intakes and participants were able to provide the same information between all three administrations of the FFQ, though there is a risk that participants remember responses with shorter intervals between questionnaire administrations. 16 The current study provided a week between each administration of the FFQ.…”

“…31,32 According to Gibson, the number of days for food records depends on the objective of the study. One day is adequate to 33 describe intake in a group, as long as all days of the week are equally represented. 29 Other researchers suggest that if multiple days are recorded, then typically no more than seven days are included, and anything more than four days may lead to an increase in respondent fatigue .…”

“…29 FFQs should be culturally and population specific and can be created or adapted to fit the population or purpose needed for the specific study by adding foods commonly eaten by the study population. [30][31][32] This dietary assessment method has been developed and/or validated to measure omega-3 fatty acids in several diverse pregnant populations, including Mexican, 33 Finnish, 34 Dutch, 35 and Canadians. 36 FFQs that measure n-3 fatty acids have been validated in African American pregnant populations, 36,37 but to date there has not been an omega-3 fatty acid FFQ specifically created to measure African American female intakes.…”

Diets Rich in Polyunsaturated Fatty Acids With Different Omega-6/Omega-3 Ratio Decrease Liver Content of Saturated Fatty Acids Across Generations of Wistar Rats

“…The diets from Western society have excessive amounts of omega-6, with an estimated n-6/n-3 ratio of 15-20/1, so a lower ratio should be desirable in reducing the risk of the chronic diseases, varying from the ideal 1:1 to 5:1(Simopoulos 2002). Considering the health benefits of PUFAs consumption, some studies demonstrate the nutrition effect during pregnancy, where the maternal nutrition has been one of the most important factors at the programming of division and redirection of nutrients to fetal growth and development (Gibson et al 2011). It is already proved that maternal nutrition balance during pregnancy affect fetal body adiposity and its relation with offspring's risk of future disease (Blumfield et al 2012).…”