In the past three decades, total fat and saturated fat intake as a percentage of total calories has continuously decreased in Western diets, while the intake of omega-6 fatty acid increased and the omega-3 fatty acid decreased, resulting in a large increase in the omega-6/omega-3 ratio from 1:1 during evolution to 20:1 today or even higher. This change in the composition of fatty acids parallels a significant increase in the prevalence of overweight and obesity. Experimental studies have suggested that omega-6 and omega-3 fatty acids elicit divergent effects on body fat gain through mechanisms of adipogenesis, browning of adipose tissue, lipid homeostasis, brain-gut-adipose tissue axis, and most importantly systemic inflammation. Prospective studies clearly show an increase in the risk of obesity as the level of omega-6 fatty acids and the omega-6/omega-3 ratio increase in red blood cell (RBC) membrane phospholipids, whereas high omega-3 RBC membrane phospholipids decrease the risk of obesity. Recent studies in humans show that in addition to absolute amounts of omega-6 and omega-3 fatty acid intake, the omega-6/omega-3 ratio plays an important role in increasing the development of obesity via both AA eicosanoid metabolites and hyperactivity of the cannabinoid system, which can be reversed with increased intake of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). A balanced omega-6/omega-3 ratio is important for health and in the prevention and management of obesity. Full article

Western diets are characterized by both dietary omega-3 fatty acid deficiency and increased fructose intake. The latter found in high amounts in added sugars such as sucrose and high fructose corn syrup (HFCS). Both a low intake of omega-3 fatty acids or a high fructose intake contribute to metabolic syndrome, liver steatosis or non-alcoholic fatty liver disease (NAFLD), promote brain insulin resistance, and increase the vulnerability to cognitive dysfunction. Insulin resistance is the core perturbation of metabolic syndrome. Multiple cognitive domains are affected by metabolic syndrome in adults and in obese adolescents, with volume losses in the hippocampus and frontal lobe, affecting executive function. Fish oil supplementation maintains proper insulin signaling in the brain, ameliorates NAFLD and decreases the risk to metabolic syndrome suggesting that adequate levels of omega-3 fatty acids in the diet can cope with the metabolic challenges imposed by high fructose intake in Western diets which is of major public health importance. This review presents the current status of the mechanisms involved in the development of the metabolic syndrome, brain insulin resistance, and NAFLD a most promising area of research in Nutrition for the prevention of these conditions, chronic diseases, and improvement of Public Health. Full article

The Bellagio Report on Healthy Agriculture, Healthy Nutrition, Healthy People is the result of the meeting held at the Rockefeller Foundation Bellagio Center in Lake Como, Italy, 29 October–2 November 2012. The meeting was science-based but policy-oriented. The role and amount of healthy and unhealthy fats, with attention to the relative content of omega-3 and omega-6 fatty acids, sugar, and particularly fructose in foods that may underlie the epidemics of non-communicable diseases (NCD’s) worldwide were extensively discussed. The report concludes that sugar consumption, especially in the form of high energy fructose in soft drinks, poses a major and insidious health threat, especially in children, and most diets, although with regional differences, are deficient in omega-3 fatty acids and too high in omega-6 fatty acids. Gene-nutrient interactions in growth and development and in disease prevention are fundamental to health, therefore regional Centers on Genetics, Nutrition and Fitness for Health should be established worldwide. Heads of state and government must elevate, as a matter of urgency, Nutrition as a national priority, that access to a healthy diet should be considered a human right and that the lead responsibility for Nutrition should be placed in Ministries of Health rather than agriculture so that the health requirements drive agricultural priorities, not vice versa. Nutritional security should be given the same priority as food security. Full article