Sunday, March 27, 2011

The nutritional value of beets - Part 13: Carotene-B

Beets are a nutrient-rich source of antioxidants; Carotene-B is one of them. You can enhance your health and vitality by eating beets.

Carotene-B is commonly known as beta-carotene. As the name indicates, it is a carotenoid; it is one of the more than 600 Carotenoids that scientists have revealed are in our highly coloured foods. 

A beet, a good source of Carotene-B

Beta-carotene is an antioxidant. One of its functions in our bodies is to provide protection against the development of heart disease and cancers, especially lung cancer. Both raw and cooked beets -- the roots, the stalks and the leaves -- are good sources of Carotene-B.

Why is this important for you? 
It is important because your body, your liver, converts beta-carotene into retinol: Vitamin A. 

And why is this great news? 
It is great news because Vitamin A supports your vitality, inside and out (see Part 6, where one aspect of the nutritional value of raw beet greens is discussed). Vitamin A enables you to grow healthy, glowing skin.

Antioxidants, such as beta-carotene, provide you with defences against the ravages of the natural processes of oxidation which result in the production of free radicals. From freckles to 'age spots' and 'liver spots', the unsightly brown patches often seen on sun-exposed parts of white skin -- hands, faces, arms, necks, feet, ankles -- are the result of internal skin cell damage caused by free radicals. Of course, the sun's energy penetrates fabrics, so it isn't only exposed skin that exhibits free radical damage.

Antioxidants neutralize free radicals. Although there are some external applications, such as sun screens, that provide some topical protection, many sunscreens do not provide both UV-A and UV-B protection. Both are essential. The primary -- and the best -- protection is gained by eating a diet rich in antioxidants. Carotene-B is one of those antioxidants.

Your immune system and normal cell replication is enhanced when your body transforms Carotene-B into Vitamin A. In addition, the integrity of your sight, internal membranes, and skin is maintained. Deficiency results in scaly skin, visual deficiencies such as night blindness, compromised immunity, and decreased resistance to infection.

In Part 1 of this series of discussions about the nutritional value of beets, we saw that 100g of raw beet root (approximately ½ cup) provides 20 micrograms (mcg) of Carotene-B.

In comparison, in Part 12, the table of nutrients shows that 100g of cooked beet root (approximately ¾ cup) provides 21 mcg of Carotene-B.

Concerning beet greens, the USDA National Nutrient database informs us that:

  • 100 g. (approximately 2½ cups) of raw, fresh beet greens provides 3794 mcg of Carotene-B. Thus, 1 cup (38g) provides1442 mcg of same.

  • 100 g (approximately cup) of cooked beet greens provides 4590 mcg of beta-carotene.

According to the Journal of Nutrition*, the current recommended beta-carotene intake is 2 - 4 milligrams (mg) daily. Some professors have concluded that the recommended daily intake should be raised to 7 mg. Since this opinion was expressed at a conference co-sponsored by DSM Nutritional Products Ltd., where the professors also stated that there is no difference between natural beta-carotene and the synthesized version, I am deeply sceptical of the veracity of the opinions expressed. 

It is well known that phytonutrients do not function in isolation, so I will not be adding beta-carotene supplements to my dietary intake. In addition, during the era when the Recommended Daily Allowance (RDA) was considered valid, the USDA National Nutrient database never specified an RDA for Carotene-B (as far as I am aware) although it did specify an RDA for Vitamin A.

* The Journal of Nutrition
Published ahead of print, doi: 10.3945/jn.109.119024
“b-Carotene Is an Important Vitamin A Source for Humans”
Authors: T. Grune, G. Lietz, A. Palou, A.C. Ross, W. Stahl, G. Tang, D. Thurnham, S. Yin, H.K. Biesalski

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