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Phytochemicals: the nutritional values of beets


Phytochemical bouquet


The word phytochemical means simply plant (phyto from the Greek phuton, meaning plant) chemical. 

Phytochemicals are pigments, chemical compounds other than essential chemicals, that are found in richly cloloured fruit and vegetables. It is agreed to some extent that phytochemicals affect health or may affect health. There is, however, no broadly accepted evidence that any specific phytochemical provides any specific health benefit. 

Amongst the phytochemicals found in foods are the Flavinoids (polyphenols) which are red, blue, and purple pigments. There are a variety of identified flavinoids. Those that have been commonly associated with beets are Anthocyanins (flavinals) and Anthocyanidins with names such as pelargonidin, peonidin, cyanidin, delphinidin, malvidin, and petunidin. They are found in red wine, and red, purple or blue fruits and vegetables, i.e. red apple, red pear, bilberry, blackberry, blueberry, cherry, cranberry, peach, plum, hawthorn, loganberry, cocoa, and eggplant. 

It has been stated in a large variety of sources, and frequently repeated, that:
(1) Anthocyanins and Anthocyanidins are phytochemicals found in beets
(2) Anthocyanins are anti-carcinogenic
(3)thus, the eating of beets provides defences against cancer. 

This claim is not only incorrect, it is unfounded. It is not supported by research results. 

The US Food and Drug Association (FDA) allows only limited health claims for the efficacy of foods containing phytochemicals, and these are related to the benefits of fermentable dietary fibers, not to the pigments. The jury is still out on whether any perceived or suggested health benefits are attributable to essential nutrients, or to phytochemicals.

Neither is it true that Anthocyanins are found in beets. That Anthocyanins are pigments found in most red, purple and blue foods is true. This, however, is not true of beet roots, beet greens, and chard. In these roots and leaves, Betalains replace Anthocyanins found elsewhere. 

Often, it has been asserted that Betalains are related to Anthocyanins. This, too, is untrue. Betalains contain nitrogen whilst Anthocyanins do not. Anthocyanins are flavinoids whilst Betalains are not even related to the flavinoids. They are glycosides, i.e. a sugar is bonded to a pigment. Betalains have never been found to occur in plants containing Anthocyandins.


Betalains

This pigment derives its name from the Latin name for beets, i.e., beta vulgaris. It is the pigment that gives beets, many cacti, and Caryophyllales (bougainvillea, amaranth, and carnivorous plants) their red or yellow colour. Red-blue-purple shades of Betalain pigments are distinctive and quite unlike reds, purples and blues generated by Anthocyanin pigments. Betalains are found in plant roots, stems, leaves, fruits and flowers.
There are two Betalains: Betacyanins and Betaxanthins 

Betacyanins - These red to purple pigments, that are found in beets and chard of the rhubarb Swiss chard varieties, are betanin, isobetanin, probetanin and neobetanin. Others are amaranthine and isoamaranthine, found in the Amaranthus plant.

Betaxanthins (non glycosidic versions) - These are yellow to orange pigments found in some some Swiss chard stems and beet roots, eg., the Golden Detroit beet (Betterave Golden Detroit) which has an orange root and golden flesh.The pigments named are indicaxanthin (found in beets and Sicillian prickly pear), miraxanthin, portulaxanthin, and vulgazanthin (found in beets).

While the function of betalains in plants is uncertain, there is preliminary evidence that they act as an anti-fungal agents for the plants. 

There is some indication that they act as natural antioxidants in animals, which has piqued the interest of the health food industry.  

Amaranthus growing in a monastery
north-east of Iasi, Romania

The Betacyanin named betanin is used as a natural dye in the food industry, and amaranthine, which is found in Amaranthus, is used to produce the dyestuff called "Hopi Red." It is the same as was used by Hopi aboriginals to produce a deep red dyestuff.

Betanin is the pigment that causes one's urine and faeces to turn red, a condition called beeturia. This condition, which is said to occur in approximately 15 per cent of people, results from the digestive system's inability to break the betanin down into its component parts.  Betanin is harmlessly excreted from the body.

Betaxanthins from the prickly pear have shown evidence of acting as free radical scavengers and antioxidants; thus, betaxanthins' potential as tumor-fighting agents is being investigated. The best that can be stated at this point is the Scottish judgement: "not proven."

When cooking beets, to preserve the Betalains and gain whatever benefit they confer, it is best to cook beet roots whole, that is, in their skins. The more they bleed the less nutrition is maintained in the vegetable, so slip the skins off after the roots have been cooked. 

There is no evidence found that anyone (except me) eats the velvety skins of beets as a rule. Since potato skins and fruit skins are eaten without harmful effect, it would seem that eating the skin may enable the consumption of the entire nutrient package of the beet. Possibly, the skins harbour beneficial chemicals. Who knows? 

When beets are young and the plants are being thinned, often the entire tender plant is eaten, root and all. This is considered to be nutrient rich food. One may also reap the greatest possible benefit by consuming beets raw as juice, smoothie, or salad.

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