Agriculture Reference
In-Depth Information
A key function of α-linolenic acid (ALA) is as a substrate for the synthesis of
longer-chain ω-3 fatty acids found in fish, eicosapentaenoic acid (EPA; C20:5n-3) and
docosahexaenoic acid (DHA; C22:6n-3) which play an important role in the regulation
of inflammatory immune reactions and blood pressure, brain development in utero,
and, in early postnatal life, the development of cognitive function. Stearidonic acid
(SDA; C18:4n-3), EPA, and DHA also possess anti-cancer properties (Christensen et al.
1999; Reiffel and McDonald 2006; Smuts 2003). Research indicates that the ratio of n-3
to n-6 fatty acids may be as important to health and nutrition as the absolute amounts
present in the diet or in body tissues. Current Western diets tend to be relatively high
in n-6 fatty acids and relatively low in n-3 fatty acids. Production of a readily available
source of long-chain-PUFA, specifically ω-3 fatty acids, delivered in widely consumed
prepared foods could deliver much needed ω-3-fatty acids to large sectors of the popu-
lation with skewed n-6:n-3 ratios. In plants, the microsomal ω-6 desaturase-catalyzed
pathway is the primary route of production of polyunsaturated lipids. Ursin et al. (2000,
2003) has introduced the Δ-6 desaturase gene from a fungus
(Mortierella
) succeeding in
producing ω-3 in canola. In subsequent work the same gene was added to soybean, and
transgenic soybean oil was obtained containing greater than 23% SDA. It had an overall
n-6:n-3 ratio of 0.5, which the body converts to heart-healthy EPA, one of three omega-3
fatty acids used by the body. This product is now being developed for commercialization
by Monsanto (SDA 2011).
However, not all omega-6 fatty acids are created equal. Gamma linolenic acid (GLA,
C18:3n-6) is an omega-6 fatty acid with health benefits similar and complementary
to the benefits of omega-3 fatty acids including anti-inflammatory effects, improved
skin health, and weight loss maintenance (Schirmer et al. 2007). Arcadia has engi-
neered GLA safflower oil with up to 40% GLA, essentially quadrupling the levels
obtained in source plants such as evening primrose and borage (Arcadia Biosciences,
2008). Structural lipids also have positive health benefits. For example, in addition to
their effect in lowering cholesterol, membrane lipid phytosterols have been found to
inhibit the proliferation of cancer cells by inducing apoptosis and G1/S cell cycle arrest
through the HMG-CoAR as noted already (Awad 2000). In addition, specialty oils
may also be developed with further pharmaceutical and chemical feedstock applica-
tions in mind.
Micronutrients: Vitamins and Minerals
Even mild levels of micronutrient malnutrition may damage cognitive develop-
ment and lower disease resistance in children and increase incidences of childbirth
mortality (UN SCN, 2004). The costs of these deficiencies, in terms of diminished
quality of life and lives lost, are large (Pfeiffera and McClafferty 2007). Such defi-
ciencies prevent children from reaching their full potential as adults; malnutrition,
especially during the one thousand days between conception and age two, can lead
to irreversible physical stunting and cognitive impairment. But children who are well
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