Info

Source: Modified from Simopoulos and Salem, 1986.

Source: Modified from Simopoulos and Salem, 1986.

3.2. Agribusiness and Modern Agriculture

Agribusiness contributed further to the decrease in omega-3 fatty acids in animal carcasses. Wild animals and birds who feed on wild plants are very lean, with a carcass fat content of only 3.9% (Ledger, 1968) and contain about five times more PUFA per gram than is found in domestic livestock (Crawford, 1968; Eaton et al. 1998). Most importantly, 4% of the fat of wild animals contains eicosapentaenoic acid (EPA). Domestic beef contains very small or undetectable amounts of LNA because cattle are fed grains rich in omega-6 fatty acids and poor in omega-3 fatty acids (Crawford et al., 1969) whereas deer that forage on ferns and mosses contain more omega-3 fatty acids (LNA) in their meat. Modern agriculture with its emphasis on production has decreased the omega-3 fatty acid content in many foods. In addition to animal meats mentioned earlier (Crawford, 1968; Crawford et al., 1969; Eaton et al., 1998; Ledger, 1968), green leafy vegetables (Simopoulos and Salem, 1986; Simopoulos et al., 1992; Simopoulos et al., 1995), eggs (Simopoulos and Salem, 1989; Simopoulos and Salem, 1992), and even fish (van Vliet and Katan, 1990) contain less omega-3 fatty acids than those in the wild. Foods from edible wild plants contain a good balance of omega-6 and omega-3 fatty acids. Table 4 shows purslane, a wild plant, and compares it to spinach, red leaf lettuce, buttercrunch lettuce, and mustard greens. Purslane has eight times more LNA than the cultivated plants. Modern aquaculture produces fish that contain less omega-3 fatty acids than do fish grown naturally in the ocean, rivers, and lakes (Table 5). As can be seen from Table 6 comparing the fatty acid composition of egg yolk from free-ranging chickens in the Ampelistra farm in Greece and the standard US Department of Agriculture (USDA) egg, the former has an omega-6 : omega-3 ratio of 1.3, whereas the USDA egg has a ratio of 19.9 (Simopoulos and Salem, 1989; Simopoulos and Salem, 1992). By enriching the chicken feed with fishmeal or flax, the ratio of omega-6 : omega-3 decreased to 6.6 and 1.6, respectively (Simopoulos and Salem, 1992). Similarly, milk and cheese from animals that graze contain arachidonic acid (AA), EPA, and docosahexaenoic acid (DHA), whereas milk and cheese from grain-fed animals do not (Table 7) (Simopoulos, 1998b).

Table 5

Fat Content and Fatty Acid Composition of Wild and Cultured Salmon (Salmo Salar)

Table 5

Fat Content and Fatty Acid Composition of Wild and Cultured Salmon (Salmo Salar)

0 0

Post a comment