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The intake of preformed vitamin A from animal products is not sufficient in parts of the population in the U.S., Europe and Asia. The vitamin A precursor beta-carotene therefore has an important function in providing for an adequate supply of total vitamin A, international carotenoid experts state in a recently published consensus answer. An appropriate intake of beta-carotene from diet, fortified foods and/or dietary supplements could safely compensate for the lack of vitamin A. However, based on recent data from national nutrition surveys, the dietary intake of beta-carotene from food sources is insufficient in a substantial part of the population. Moreover, many people may suffer from a reduced ability to produce sufficient amounts of vitamin A from beta-carotene due to genetic variations. Consequently, experts are calling for guarantees that recommended intakes of beta-carotene are met or, if the current recommended dietary amounts for vitamin A are not met, that beta-carotene intake should be increased. This would ensure that at least 95% of the population consume an adequate amount of total vitamin A.
Leading experts in the fields of medical and nutritional science from the U.S., Europe and Asia met at a Consensus Conference to elucidate the current knowledge with respect to physiological function, supply situation, and intake recommendations of beta-carotene. The experts reached an agreement formulated in a consensus answer published recently in The Journal of Nutrition.
Vitamin A and beta-carotene intake often critically low
Vitamin A is essential for normal growth and development, immune system, vision and other functions in the human body. In situations such as pregnancy and lactation, vitamin A plays a particularly important role in the healthy development of the child, and an increase in vitamin A (retinol) intake has been recommended under these conditions. However, surveys undertaken in several countries suggest that vitamin A intake patterns vary considerably across Europe, the U.S. and Asia. National survey data show that the intake of preformed vitamin A (retinol) - as such only present in animal products (especially liver) - is often critically low and does not meet the recommendations. Groups especially at risk of inadequate vitamin A supply are pregnant and lactating women, newborns, children with frequent infections, young women, the elderly and people who avoid animal-derived foods.
National Consumption Surveys indicate that beta-carotene - as a vitamin A precursor - contributes significantly to balance inadequate vitamin A supply in large parts of the population. However, European, U.S. and Asian studies show that a substantial part of the population does not reach the recommendation for beta-carotene necessary to compensate the low vitamin A intake from sources containing preformed vitamin A in the regular diet.
Recent evidence has shown that suboptimal levels of vitamin A and beta-carotene, even well above those causing clinical deficiency syndromes, can be risk factors for chronic diseases.
Vitamin A deficiency through beta-carotene-dependent gene variants
The bioavailability of beta-carotene is influenced by numerous factors. In addition to food-related factors, such as food matrix, food processing, dosage, fat in the meal, and dietary fibers, the bioavailability of beta-carotene depends on consumer-related factors including vitamin A status, gut integrity and genetic variations.
Recent research on female subjects has shown that almost 50% of the population have a genetic variation which reduces their ability to produce sufficient amounts of vitamin A from beta-carotene. Studies indicate that younger women carrying the genetic variation are at particular risk as they tend to eat not enough vitamin A-rich foods relying heavily on the beta-carotene form of the nutrient.
Experts call for increase of beta-carotene intake recommendations
It is apparent from a variety of studies that beta-carotene is essential in striving for the recommended vitamin A intake. In cases of a poor vitamin A status due to low intake of preformed vitamin A, the current recommendations for beta-carotene in the range of 2-4 mg per day still might not sufficiently correct the individual vitamin A status.
In their consensus answer the experts conclude that ignoring inter-individual differences in the ability to convert beta-carotene to vitamin A and assuming that intakes of preformed retinol do not change, it should be ensured that the current recommended intakes of beta-carotene are attained. At the same time, people with an inadequate intake of preformed vitamin A should increase consumption to 7 mg per day, based on a realistic and now in the scientific community generally accepted conversion efficiency of 1:12 (12 milligrams of beta-carotene are necessary to form one milligram of vitamin A). This should ensure that at least 95% of the population meet the recommended intakes of total vitamin A.
Individuals with reduced conversion efficiencies due to a genetic variability in beta-carotene metabolism might need to increase their daily intakes even further. This is currently being investigated.
No functional difference between natural and synthetic beta-carotene
According to the experts, there is no difference in function between naturally occurring and chemically synthesized beta-carotene, whereas there is a difference in bioavailability from different food sources. In humans, the predominant molecular type is 'all-trans beta-carotene', used for most dietary supplements and fortified foods; it is absorbed preferentially compared to other forms.
As the general population is not obtaining sufficient beta-carotene from fruit and vegetables, foods fortified or colored with beta-carotene and dietary supplements can be important contributors to the daily supply of vitamin A.
Source:
CommuniPoweR Wolfgang Zoell
A Case Western Reserve University School of Medicine study in the November 22 issue of Journal of Biological Chemistry, explains how vitamin A is generated from beta carotene, its dietary precursors. The discovery sheds new light into how beta carotene’s enzymes are utilized differently contributing to the vitamin’s production. This insight will help guide solutions for vitamin A deficiency, a global public health problem affecting more than half of all countries, according to the World Health Organization.
The study, named a Paper of the Week, led by Johannes von Lintig, PhD, associate professor of pharmacology, demonstrates that beta-carotene is converted to Vitamin A and not other metabolites, which some theorized were toxic compounds.
Vitamin A deficiency is especially prevalent in developing countries of Asia, due to largely rice-based diets which lack beta-carotene, a member of the micronutrient carotenoid family. The deficiency mainly affects pregnant women and children and leads to blindness and increases morbidity.
Understanding how vitamin A is produced in the body is essential to effective public health interventions. Efforts are underway by humanitarian groups to supplement young children and fortify foods, for example in the form of “golden rice,” rice genetically modified to contain beta-carotene. The von Lintig Laboratory’s discovery validates the benefits of fortifying foods to combat the worldwide deficiency problem. Some reports indicate the problem exists in areas of the U.S. where access to fresh fruits and vegetables is scarce.
The research team provided evidence that BCO1 directly converts beta-carotene to vitamin A. However, they discovered the second enzyme, BCO2, is also significant. It helps prepare carotenoids, other than beta-carotene, for vitamin A production. Specifically, BCO2 removes the part of the carotenoid that cannot be utilized for vitamin A production. The remaining portion of the carotenoid is then further processed by BCO1 to generate vitamin A.
“Our study shows that beta-carotene’s second enzyme does not produce a toxic compound, as had been proposed by some researchers. Rather, the enzyme aids in the metabolizing of carotenoids, aside from beta-carotene, to become vitamin A,” said von Lintig and concluded “that beta-carotene is an important and safe precursor for vitamin A in our diet. Our findings also suggest that golden rice plants are likely very safe for consumption.”
Despite past safety concerns, the antioxidant supplement beta-carotene, is safe to use during radiation therapy treatments for prostate cancer and does not increase the risk of prostate cancer death or metastases, according to a study in the May issue of the International Journal of Radiation Oncology•Biology•Physics, the official scientific journal of the American Society for Radiation Oncology (ASTRO).
The use of vitamin supplements and antioxidants is common, but the safety of using antioxidant supplements during radiation treatments for prostate cancer is controversial. Radiation therapy relies on the pro-oxidant effects of DNA, which involves damaging tumor cells while leaving normal cells unharmed. However, some scientists have suggested that supplemental antioxidants may weaken the oxidizing effects of radiation and potentially lead to cancer recurrence.
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In the largest study to date of its kind, researchers followed 383 prostate cancer patients who were randomized to receive beta-carotene or placebo to determine if antioxidants could potentially counteract the pro-oxidant effects of radiation therapy and increase a patient's risk of death or metastases. The primary endpoint was prostate cancer death or bone metastases.
Researchers found no significant differences in lethal outcomes among the patients who took the antioxidant beta-carotene versus those who did not.
"This study shows that antioxidant supplementation with beta-carotene during radiation therapy does not appear to detract from the benefit of radiation therapy." Danielle Margalit, MD, MPH, lead author of the study and a radiation oncologist at the Dana-Farber Cancer Institute in Boston, said. "It also suggests that patients may continue to eat a well-balanced diet that contains foods with natural sources of antioxidants at the recommended daily amount.
As reported by Mehr News Agency, the achievement of the biologists of California University in San Diego in using seaweed for generating a medicine for treatment of cancer, has been published in the Journal of “Articles of National Academy of Sciences” and has opened doors for generating this protein and other proteins in more and cheaper quantities.
Stephan Mifield, Professor of Biology of California University in San Diego and Head of Center of San Diego Seaweed Biotechnology Center, as a research Institute, working on generating of biological fuel from seaweed, stated: “Since we generate the said medicine using the said seaweed, it is possible to decease its protraction cost accordingly”.
This method may be used for more advanced and modern plans of medicine so that the said medicines will be used for treatment of cancer and other forms of human diseases in new forms.
He further added: “The said medicines can’t be generated from bacterium because bacteria lack bending proteins: in three-dimensional complicated forms. Moreover, said proteins can’t be generated from cells of mammals because poison will damage the same.
This achievement has been obtained pursuant to seven years of working at laboratory in order to find that “Chlamydomonas Reinhardt” is a kind of green seaweed, which is mainly used in biological laboratories is a genetic model of organism, which may generate a wide range of medical proteins used for humans, at remarkable quantities and even at low cost compared to bacteria and cells of mammals.
Mayfield et al have achieved the first progress five years ago. At that time, they could generate Amyloid protein serum from seaweed. One year later, said researchers could obtain a human antibody protein from seaweed and in 2010, they showed that a more complicated protein, which is used as a human medicine for treatment of patients, suffering from pulmonary Emphysema, may be obtained from seaweed accordingly.
As their latest achievement, the said scientist could generate a three dimensional and complicated protein with domain benefiting from seaweed genetic engineering. One of the said domains contains one antibody, which is joined to carcinoma cells and another domain contains a poison, which limits cancer cells.
Presently, this protein fusion, which has been done from seaweed by scientists at laboratory is a complicated process, which is being generated by pharmaceutical companies, spending over 100,000.- Dollars for this purpose. However, since the said protein has been generated from seaweed in laboratory, it may be possible to decrease respective costs accordingly.
Journal of Biological Chemistry “Paper of the Week” Provides Insight into Vitamin Production
A Case Western Reserve University School of Medicine study in the November 22 issue of Journal of Biological Chemistry, explains how vitamin A is generated from beta carotene, its dietary precursors. The discovery sheds new light into how beta carotene’s enzymes are utilized differently contributing to the vitamin’s production. This insight will help guide solutions for vitamin A deficiency, a global public health problem affecting more than half of all countries, according to the World Health Organization.
The study, named a Paper of the Week, led by Johannes von Lintig, PhD, associate professor of pharmacology, demonstrates that beta-carotene is converted to Vitamin A and not other metabolites, which some theorized were toxic compounds.
Vitamin A deficiency is especially prevalent in developing countries of Asia, due to largely rice-based diets which lack beta-carotene, a member of the micronutrient carotenoid family. The deficiency mainly affects pregnant women and children and leads to blindness and increases morbidity.
Understanding how vitamin A is produced in the body is essential to effective public health interventions. Efforts are underway by humanitarian groups to supplement young children and fortify foods, for example in the form of “golden rice,” rice genetically modified to contain beta-carotene. The von Lintig Laboratory’s discovery validates the benefits of fortifying foods to combat the worldwide deficiency problem. Some reports indicate the problem exists in areas of the U.S. where access to fresh fruits and vegetables is scarce.
While the benefit of beta-carotene and fellow carotenoids are widely known, how the body metabolizes beta-carotene has remained a matter of debate. The reason for this controversy is the existence of the micronutrient’s two different metabolizing enzymes, BCO1 and BCO2. Some studies have suggested BCO2 metabolizes beta-carotene differently, thereby inhibiting the beneficial effects of Vitamin A.
The research team provided evidence that BCO1 directly converts beta-carotene to vitamin A. However, they discovered the second enzyme, BCO2, is also significant. It helps prepare carotenoids, other than beta-carotene, for vitamin A production. Specifically, BCO2 removes the part of the carotenoid that cannot be utilized for vitamin A production. The remaining portion of the carotenoid is then further processed by BCO1 to generate vitamin A.
“Our study shows that beta-carotene’s second enzyme does not produce a toxic compound, as had been proposed by some researchers. Rather, the enzyme aids in the metabolizing of carotenoids, aside from beta-carotene, to become vitamin A,” said von Lintig and concluded “that beta-carotene is an important and safe precursor for vitamin A in our diet. Our findings also suggest that golden rice plants are likely very safe for consumption.”
Source:
http://casemed.case.edu/
Scientists have produced a kind of headband. One may put this specific kind of headband on his/her forehead for 30 days every day in order to prevent migraine headaches.
This tool, which is called Cefaly, transmits electrical pulses to the nerve above eye bowel, controlling the sense inside and surrounding the eye.
As reported by Mehr, according to a study, of which results have been published in Neurology Journal, researchers have found that disabling headaches of the individuals who use this specific kind of headband have been decreased by about 1/3rd .
Using the said headband, number of individuals, whose migraine headaches have been reduced by 1/2nd , has been tripled.
Professor Jean Shonen, from Belgium University, stated: “This specific kind of headband is devised across the forehead and the patient must use the said headband for 20 minutes every day”. As stated by the above-named, this treatment causes side-effects.
The above-named researcher further added: “The results obtained from this fresh treatment method are too much similar to the medicines, prescribed for prevention of occurrence of migraine headaches. However, the said medicines usually cause many side-effects and eventually, the patients have to stop using the said medicines.
In this study, 67 persons, with four migraine seizures on average per month have been studied for four months, receiving no treatment.
The candidates were divided into two groups. One group was stimulated by electrical pulses for three months, 20 minutes every day. The second group was treated for the similar period, using a device (a device with electrical pulses of low or no effect).
Researchers have found that these underwent real irritation, number of days during which they suffer from migraine headaches has been decreased by 1/3 per month. It means that number of such days has been reached from seven to five days while no changes have been observed in another group using device.