The Spinach is an annual plant, long cultivated for the sake of its succulent leaves, a native of Asia, probably of Persian origin, being introduced into Europe about the fifteenth century.
Spinach is relatively rich in nitrogenous substances, in hydrocarbons, and in iron sesqui-oxide, which last amounts to 3.3 per cent of the total ash. It is thus more nourishing than other green vegetables. It is a valuable part of the diet in anaemia, not only on account of its iron, but also for its chlorophyll.
Chlorophyll is known to have a chemical formula remarkably similar to that of hemoglobin, and it is stated that the ingestion of chlorophyll will raise the hemoglobin of the blood without increasing the formed elements.
The plant contains from 10 to 20 parts per 1,000 by weight of chlorophyll. During the war, wine fortified with Spinach juice 1 in 50 was given to French soldiers weakened by hemorrhage.
According to Chick and Roscoe (Biochem. Journal, 1926, XX, 137), fresh leaves of Spinach are a rich source of vitamin A, a small daily ration (0.1 gram and upward) encouraging growth and lessening or preventing xerophthalmia in young rats on diets devoid of fat-soluble vitamins.
Spinach also contains a powerful antioxidant called lutein.
Lutein is a complex compound which belongs to the carotenoid family that plants are able to synthesize, but the human body cannot.
Lutein has many uses in the body. For some time researchers have been looking at the role lutein and other antioxidants play in protecting the skin against the effects of the sun. The sun´s rays contain UVA radiation.
This radiation can cause the formation of free radicals in cells that have been shown to be a first step in the chain leading to cancer; they may also be responsible for the aging process that affects skin. It has been estimated that sun exposure is the largest factor contributing to skin aging caused by external factors.
Lutein is found in the skin and perhaps, not by chance, in highest concentrations in nasal skin - the part of the body that is often the most exposed to sunlight. The chemical structure of lutein gives it its antioxidant power and therefore it can protect against free radical damage caused by UVA radiation. This basically will act as an internal sunblock.
SRUCTURE OF LUTEIN
Zeaxanthin found abundantly in Spinach, is a yellow - colored lipid – soluble xanthophyll, which is also an oxidized dydroxy derivative of beta – carotene. This biochemical, is a strong antioxidant and one of two yellow carotenoids found in the retina.
It is widely believed that zeaxanthin acts to filter and shield harmful blue light from the eye and protect against age – related macular degeneration, leading cause of blindness in people over 65 years old.
Ounce for ounce, spinach contains more than twice as much zeaxanthin and more than 60 times more lutein as yellow corn. These carotenoids are now believed to protect against development of cataracts, and may have other health benefits as well.
Spinach grown in the open in winter, spring or autumn possesses no antirachitic properties that can be demonstrated by the methods employed. Spinach leaves when irradiated with ultraviolet rays from a Hg vapour quartz lamp become powerfully antirachitic.
Boas (Biochem. Journal, 1926, XX, 153) found that the fresh leaves of winter-grown Spinach added to an experimental diet caused an even greater improvement in the wellbeing of rats and in the rate of growth than was caused by the addition of cod-liver oil.
The weight of the skeleton was not, however, proportionally increased. The conclusion was drawn by Boas that winter Spinach contains an amount of vitamin D which is negligible compared with its content of vitamin A.