Western diets fatty acid content

Within the last decade, the health benefits of ALA have been documented in numerous studies and may be related to an improved n-6 to n-3 fatty acid intake. Nettleton (2003) summarized the recommendations of leading health organizations regarding the proper ratio of n-6 to n-3 fatty acid intake. Most organizations agree that a 5 1 to 10 1 n-6 to n-3 fatty acid ratio is preferred (Institute of Medicine, 2002 WHO/FAO, 2003). However, a typical western diet has an n-6 to n-3 fatty add ratio well beyond 10 1 thus, flaxseed can be a valuable lipid source to improve the n-6 to n-3 fatty acid ratio due to the high n-3 content of flaxseed oil. 

A typical Western diet contains approximately 100-300 mg and 20-50 mg of plant sterol and plant stanol, respectively. The relationship between total dietary phytosterol content and the fatty acid composition of the diet decreases with increasing saturated fatty acids, whereas the total dietary phytosterol content increases with increasing PUFA (89). Fortification of lipid foods, such as margarine, with plant sterols will dramatically increase the daily intake of phytosterols and significantly lower serum cholesterol (90). The dietary consumption of large amounts of plant sterols will interfere with cholesterol absorption, thereby leading to an increased daily neutral steroid excretion. 

The typical Western diet supplies about 100 mg of carnitine per day. Meat and milk are good sources beef contains about 500 mg/kg, and cow milk contains 5 to 40 mg/kg of fluid. Hen eggs and plant food contain little or no carnitine. The trimethyllysine present in food proteins contributes, to a very small extent, to the carnitine made in the body. There is, however, some concern about a transient deficiency of carnitine in newborn infants fed camitine-free diets. Soy-based infant formula may lack carrutine, and the neonate seems to have a lesser capacity to synthesize the cofactor than adults. Breast milk contains high levels of carnitine after about a month of lactation, the content declines to about half of its mitial value. There is little evidence that the lowered levels of plasma carnitine found in infants fed soy formulas are associated with an impairment of the oxidation of long-chain fatty acids. 

The Working Group recognizes that in countries hke Japan, the breast milk content of LA is 6-10% of fatty acids and the DHA is higher, about 0.6%. The formula/diet composition described here is patterned on infant formula studies in Western countries. 

The metabolism of n-3 and n-6 PUFAs is interlinked, as they compete for enzymes and metabolic substrates at all levels. Therefore, relative as well as absolute dietary intake is relevant in the determination of tissue n-3 and n-6 fatty acid levels. The Western diet typically contains high levels of n-6 fatty acids, as these are components of most animal and vegetable fats. Dietary sources of n-3 PUFA are varied. The most plentiful sources are fish, shellfish, and marine products, which contain large amounts of EPA and DHA. Certain plant oils, such as rapeseed (canola), soybean, and perilla contain large amounts of LNA (Crawford Sinclair, 1972 Sinclair, 1975). Although beef and lamb do contain n-3 PUFAs, both the absolute content and the n-3 n-6 ratio of PUFAs within these meats is low. 

Seaweeds are known as low-energy food. Despite low lipid content, (B-3 and (B-6 polyunsaturated fatty acids (PUFAs) introduce a significant part of seaweed lipids. PUFAs are the important components of all cell membranes and precursors of eicosanoids that are essential bioregulators of many cellular processes. PUFAs effectively reduce the risk of cardiovascular diseases, cancer, ostheo-porosis, and diabetes. Because of the frequent usage of seaweeds in Asia and their increasing utilization as food also in other parts of the world, seaweeds could contribute to the improvement of a low level of (B-3 PUFAs, especially in the Western diet The major... 

Phillips et al. (1999) analysed the plant sterol content of 9 experimental US diets and showed that dietary intakes of plant sterols increased with increasing intakes of polyunsaturated fatty acids and decreasing intakes of saturated fatty acids. In that study, average US diets were found to contain 223-273 mg cholesterol and 138-171 mg total plant sterols, whereas American Heart Association (AHA) National Cholesterol Education Program Step 1 and Step 2 diets contain 264 mg and 274 mg cholesterol, and 189 mg and 208 mg total phytosterols, respectively. Average Western intakes vary from study to study, and are summarized in Table 3. 

Recently, novel dietary oils with modified fatty acid profiles have been manufactured to improve fatty acid intakes and reduce CVD risk. Our objective was to evaluate the efficacy of novel high-oleic rapeseed (canola) oil (HOCO), alone or blended with flaxseed oil (FXCO), on circulating lipids and inflammatory biomarkers v. a typical Western diet (WD). Using a randomized, controlled, crossover trial, thirty-six hypercholesterolaemic subjects consumed three isoenergetic diets for 28 d each containing approximately 36% energy from fat, of which 70% was provided by HOCO, FXCO or WD. Dietary fat content of SFA, MUFA, PUFA n-6 and n-3 was 6, 23, 5,... 

---