Alpha-Carotene in a nutshell:
Alpha-Carotene can be used to make vitamin A, though not very efficiently. It’s main role is more likely to be as a cofactor for other substances. Alpha-carotene has been implicated in helping prevent cervical cancer.
Best source of alpha-carotene for Juicers
Alpha-Carotene can be found in carrots, bell peppers , grape leaves, plantains & dandelion greens
What Is Alpha-Carotene?
Nutrition “experts” often recommend supplementation with beta-carotene to prevent cancer. But sometimes it's alpha-carotene that actually works.
Alternative Names: Alpha-carotene.
Alpha-carotene is a substance some plants make from lycopene that they can further transform into lutein. Plants use this intermediary chemical to manage their ability to deal with sun and shade. It enables the plant to use different wavelengths of light in shade to continue to make carbohydrates and oxygen through photosynthesis.
Because the role of alpha-carotene in plants is helping it deal with sun and shade, plants tend to concentrate this substance in their fruit, leaves, and stems. Alpha-carotene is usually bound to proteins that are themselves bound in fiber. It is not soluble in water and but it is soluble in fat.
What Does Alpha-Carotene Do in the Human Body?
For alpha-carotene to get into the human body from food, the food has to be thoroughly chewed. Proteins in the fibers that carry the tiny crystals of alpha-carotene have to be digested by stomach acid, and then there has to be the right mix of foods in the small intestine for alpha-carotene to be absorbed through the lining of the small intestine and into general circulation.
The body seems to be able to buffer the absorption of alpha-carotene by holding it in the villi, or microscopic pockets, in the lining of the small intestine. Alpha-carotene slowly “seeps” into the bloodstream for as long as five days after food is eaten. However, lots of things can go wrong.
If the food is insufficiently chewed, alpha-carotene will not be absorbed. If there is not enough stomach acid to digest the food in the stomach, alpha-carotene will not be absorbed. If the meal does not include at least 3 to 5 grams (about 1/2 to 1 teaspoon) of some kind of fat, the alpha-carotene will not “stick” to the lining of the small intestine long enough to be absorbed. And if there is too much fiber in the meal or the lining of the small intestine is coated with a film of bacteria, the alpha-carotene in the food will not find its way into the bloodstream.
What do scientists know for sure about alpha-carotene?
The human body can use alpha-carotene to make vitamin A; however, it takes 24 molecules of alpha-carotene to make one molecule of the retinal form form of vitamin A whereas one molecule of beta-carotene becomes not just one but two molecules of vitamin A.
What do scientists surmise about alpha-carotene?
While the body can convert alpha-carotene into vitamin A, the more important role of alpha-carotene in the body seems to be as a cofactor for other plant antioxidants. Researchers first noticed the importance of alpha-carotene when they were looking at nutritional methods for controlling the progression of cervical dysplasia to cervical cancer in women.
These scientists observed that women who have cervical cancer have lower levels of beta-carotene in the bloodstreams. It seemed only sensible to try giving women who have cervical dysplasia (which sometimes progresses into cervical cancer) beta-carotene supplements to try to prevent the disease. Australian researchers tried putting women who had cervical dysplasia on 30 milligrams (about 50,000 IU) of a daily beta-carotene supplement to see if it would slow down the disease.
Beta-carotene supplementation didn't work. It actually accelerated the progression from cervical dysplasia to cervical cancer. More women taking beta-carotene than women taking the placebo came down with cancer.
It was time to look for another explanation of the relationship between plant foods and cervical cancer. Japanese researchers discovered that women who had cervical cancer also had lower levels of alpha-carotene in the bloodstreams. Women who consumed the most alpha-carotene had an 83% lower rate of cervical cancer. The scientists in Japan did not try to hand out alpha-carotene supplements. Instead, they asked women to eat foods that provided alpha-carotene, beta-carotene, lycopene, lutein and zeaxanthin.
This intervention worked. And when it was repeated in the USA, it was found to be especially helpful for preventing cervical cancer in African-American women.
Taking beta-carotene alone seems to interfere with the ability of the body to absorb other plant nutrients, making the condition worse.
Since these studies, researchers have found 10 more kinds of cancer in both men and women that respond better to alpha-carotene than they respond to beta-carotene. But since the idea is to get all the different related plant compounds together instead of just one, it's not advisable to take synthetic alpha-carotene. Either take natural alpha-carotene (along with five other naturally occurring carotenoids) in the form of “mixed carotenoids,” usually made from a kind of colorful algae known as Dunaliella.
How to Get Enough Alpha-Carotene in Your Diet
Nutritionists have never determined a recommended daily intake for alpha-carotene. They have measured alpha-carotene in a number of common foods.
- A 3-1/2 oz (100 gram) serving of dried red bell peppers contains 6930 micrograms of alpha-carotene
- A 3-1/2 oz (100 gram) serving of canned pumpkin contains 4796 micrograms of alpha-carotene.
- A 3-1/2 oz (100 gram) serving of carrot juice contains 4344 micrograms of alpha-carotene.
- A 3-1/2 oz (100 gram) serving of boiled carrots contains 3767 micrograms of alpha-carotene.
- A 3-1/2 oz (100 gram) serving of raw carrots contains 3676 micrograms of alpha-carotene.
- A 3-1/2 oz (100 gram) serving of canned mixed vegetables (corn, lima beans, peas, carrots) contains 2636 micrograms of alpha-carotene.
- A 3-1/2 oz (100 gram) serving of canned peas and carrots contains 1353 micrograms of alpha-carotene.
- A 3-1/2 oz (100 gram) serving baked acorn (winter) squash contains 1130 micrograms of alpha-carotene.
The same size servings of grape leaves, plantains, or dandelion greens contain about 300 micrograms of alpha-carotene. But how much is enough?
Eating an average of one serving of any one of these foods every day is probably enough to have a protective effect. Eating 5 to 9 servings of vegetables and fruits per day gives you all the plant nutrients you need in the right proportions—eating more than 9 servings of plant foods per day may actually fill your small intestine with so much fiber that the nutrients are not absorbed. If you don't eat any vegetables, then take supplemental mixed carotenoids.