Healthy intakes of n-3 and n-6 fatty acids: estimations considering worldwide diversity.

BACKGROUND: The worldwide diversity of dietary intakes of n-6 and n-3 fatty acids influences tissue compositions of n-3 long-chain fatty acids (LCFAs: eicosapentaenoic, docosapentaenoic, and docosahexaenoic acids) and risks of cardiovascular and mental illnesses. OBJECTIVE: We aimed to estimate healthy dietary allowances for n-3 LCFAs that would meet the nutrient requirements of 97-98% of the population. DESIGN: Deficiency in n-3 LCFAs was defined as attributable risk from 13 morbidity and mortality outcomes, including all causes, coronary heart disease, stroke, cardiovascular disease, homicide, bipolar disorder, and major and postpartum depressions. Dietary availability of n-3 LCFAs from commodities for 38 countries and tissue composition data were correlated by best fit to each illness in deficiency risk models. RESULTS: The potential attributable burden of disease ranged from 20.8% (all-cause mortality in men) to 99.9% (bipolar disorder). n-3 LCFA intake for Japan (0.37% of energy, or 750 mg/d) met criteria for uniformly protecting >98% of the populations worldwide. n-3 LCFA intakes needed to meet a tissue target representative of Japan (60% n-3 in LCFA) ranged from 278 mg/d (Philippines, with intakes of 0.8% of energy as linoleate, 0.08% of energy as alpha-linolenate, and 0.06% of energy as arachidonic acid) to 3667 mg/d (United States, with 8.91% of energy as linoleate, 1.06% of energy as alpha-linolenate, and 0.08% of energy as arachidonic acid). CONCLUSIONS: With caveats inherent for ecologic, nutrient disappearance analyses, a healthy dietary allowance for n-3 LCFAs for current US diets was estimated at 3.5 g/d for a 2000-kcal diet. This allowance for n-3 LCFAs can likely be reduced to one-tenth of that amount by consuming fewer n-6 fats.

Dietary fat and health: the evidence and the politics of prevention: careful use of dietary fats can improve life and prevent disease.

Every year, more young people start the slow progressive injury that eventually becomes cardiovascular disease and death. It could be prevented with nutrition education, but medical efforts focus more on treatments for older people than on preventing primary causes of disease in young people. Two avoidable risks are prevented by simple dietary interventions: (1) Eat more omega-3 and less omega-6 fats, so tissues have less intense n-6 eicosanoid action, and (2) eat less food per meal to lower vascular postprandial oxidant stress. An empirical diet-tissue relationship was developed and put into an interactive personalized software program to aid informed food choices.

Diets could prevent many diseases.

The 2002 ISSFAL Meeting arranged a special evening discussion with professional dietitians about diet-tissue-disease relationships involving essential fatty acids and eicosanoids. The balance of eicosanoid precursors in human tissues differs widely, reflecting voluntary dietary choices among different groups worldwide. An empirical quantitative diet-tissue relationship fits these diverse values as well as other research reports on essential fatty acid metabolism. Information for dietitians and nutritionists about essential fatty acids and eicosanoids is also given in two distance learning web sites, http://ods.od.nih.gov/eicosanoids/ and http:// efaeducation.nih.gov/, which facilitate dietitian education and diet counseling. These sites also have an innovative, interactive diet planning software program with the empirical equation embedded in it to help evaluate personal food choices in the context of the diet-tissue-disease relationship and other widely recommended dietary advice.

Increasing homicide rates and linoleic acid consumption among five Western countries, 1961-2000.

Clinical intervention trials and animal studies indicate that increasing dietary intakes of long chain n-3 FA or reducing linoleic acid intake may reduce aggressive and violent behaviors. Here we examine if economic measures of greater n-6 consumption across time and countries correlate with greater risk of homicide. Linoleic acid available for human consumption was calculated from World Health Organization disappearance data for 12 major seed oils in the food supply for the years 1961 to 2000 in Argentina, Australia, Canada, the United Kingdom, and the United States (US). Homicide mortality rates, adjusted for age, were obtained from the central judicial authority of each country. Apparent linoleic acid intake from seed oil sources ranged from 0.29 en% (percentage of daily food energy) (Australia 1962) to 8.3 en% (US 1990s). Greater apparent consumption of linoleic acid correlated with higher rates of homicide mortality over a 20-fold range (0.51-10.2/100,000) across countries and time in an exponential growth regression model (r = 0.94, F = 567, P < 0.00001). Within each country, correlations between greater linoleic acid disappearance and homicide mortality over time were significant in linear regression models. Randomized controlled trials are needed to determine if reducing high intakes of linoleic acid by seed oils with alternative compositions can reduce the risk of violent behaviors. These dietary interventions merit exploration as relatively cost-effective measures for reducing the pandemic of violence in Western societies, just as dietary interventions are reducing cardiovascular mortality. Low linoleate diets may prevent behavioral maladies that correctional institutions, social service programs, and mental health providers intend to treat.

Automated high-throughput fatty acid analysis of umbilical cord serum and application to an epidemiological study.

Large population studies show that polyunsaturated fatty acids are important for human health, but determining relationships between the health benefits and the fatty acid content has been hampered by the unavailability of labor-effective high-throughput technologies. An automated high throughput fatty acid analysis was developed from a previous procedure based on direct transesterification including the automation of chemical procedures, data acquisition and automatic data processing. The method was validated and applied to umbilical cord serum samples in an epidemiological study. The method was linear in the range of 1-600 µg/mL serum with r² ≥ 0.99. The within-run CV was <5.4% for 23 fatty acids and a range of recoveries over three concentrations were 76-119% in a low-lipid matrix with the exception of 14:0. The fatty acid concentration as measured by the robotic method for human plasma was in good agreement with the Lepage & Roy method. The fatty acid profile in umbilical cord serum from American subjects (n = 287) showed an average of 38.0, 24.9, 32.0 and 4.6% of total fatty acids for saturates, monounsaturates, n-6 and n-3 polyunsaturates, respectively. This is the first report of a complete, validated, cost-effective, automated, high throughput fatty acid measurement method along with application to a population-based study. Automated fatty acid analysis coupled with automated data processing greatly facilitates the high throughput, 72 samples transesterified in 6 h, required for large population-based studies.