‘베타카로틴(β-carotene)’이 노화를 억제? Carotenoids: From (vitamin) A to zeaxanthin

Carotenoids: From (vitamin) A to zeaxanthin

The properties of many carotenoids are being studied, such as their pro-vitamin A and antioxidant activities; immune, endocrine and metabolic activities; and their role in cell cycle regulation, apoptosis and cell differentiation.

Robin Koon | Oct 31, 2018

naturalproductsinsider.com

‘베타카로틴’이 노화를 억제? 당근은 베타카로틴이 많이 들어있는 식품 중 하나 우선 눈에 좋다 항산화 작용, 노화 방지, 세포 재생 촉진,  암 예방, 심장병, 면역력, 불임, 여드름 잇몸병 등등 만병통치약?    ‘건강식품 삐딱보기’ 코너를 시작하면서 첫 번째로 눈에 들어온 논문이 있었습니다. 바로 ‘베타카로틴’이 어떤 능력이 있는지 임상 실험한 내용이었습니다. 야맹증과 피부 재생에 좋은 베타카로틴 베타카로틴은 식물에 들어있는 색소 중 하나입니다. 노랗고 붉은 색을 내는 카로티노이드 색소 중 하나지요. 당근이나 고추, 시금치, 쑥, 쑥갓 같은 채소나 클로렐라, 스피룰리나 같은 조류에 많이 들어 있습니다. 검색 창에 ‘베타카로틴 효능’이라고 검색하면 가장 먼저 눈에 좋다는 내용이 나옵니다. 베타카로틴은 일부가 소장에서 레티놀로 변하기 때문이지요. 레티놀은 비타민 A로 더 잘 알려져 있습니다. 비타민A가 부족하면 야맹증이 생깁니다. 이 외에도 사람들이 전하는 베타카로틴의 효능은 다양합니다. 항산화 작용, 노화 방지, 세포 재생 촉진, 암 예방, 심장병, 면역력, 불임, 여드름 잇몸병…. 그대로 보기만 하면 무슨 만병통치약처럼 보입니다. ‘베타카로틴’ 영양제가 ‘건강기능식품’으로 인정을 받기 위해서는 어떤 효능을 인정받아야 하는지 식품안전정보포털에서 찾아봤습니다. ① 어두운 곳에서 시각 적응을 위해 필요 : 비타민A가 부족할 때 생기는 야맹증과 관련된 기능이겠지요? ② 피부와 점막을 형성하고 기능을 유지하는데 필요 : 피부와 점막은 신체에서 외부 물질과 가장 먼저 닿는 부분입니다. 베타카로틴을 섭취하면 피부세포가 형성되고 기능이 유지될테니, 베타카로틴이 부족했더라면 영양제를 먹음으로써 피부가 좋아질 수도 있겠습니다. ③ 상피세포의 성장과 발달에 필요 : 우리 몸의 모든 기관을 덮고 있는 세포가 바로 상피세포입니다. ②의 효능과 유사하다고 보면 되겠네요. 네, 여기까지입니다. 베타카로틴 영양제 섭취에 있어 그 외의 기능은 우리나라에서는 실제로 기능한다고 인정하지 않고 있습니다. 베타카로틴 섭취 효능에 대해 임상으로 실험한다면 베나카로틴은 피부 세포에 대해 효능을 인정받았는데, ‘상피 세포의 성장과 발달’이라는 말을 살짝 바꾸면 세포의 성장과 발달입니다. 관대하게 쓴다면 ‘세포 재생’으로 쓸 수 있을 것도 같습니다. 세포 재생이라는 말에 자동적으로 따라 붙는 말은 노화 방지입니다. 무엇의 노화를 방지할 수 있을지는 모르겠습니다만, 역시 또 그럴싸 해보입니다. 저처럼 의심이 많은 사람들은 ‘노화 방지’ ‘세포 재생’ ‘항산화 작용’ 이라는 단어를 들으면 진짜인지 의문을 갖습니다. 호주 웨스턴대 연구진도 저와 비슷한 생각이었나봅니다. 베타카로틴의 여러 효능을 정확하게 판단하고자 사람을 대상으로 실험을 진행했습니다. 평균 21세의 남성 43명을 실험 참가자로 모아 이들의 피부색, 면역력, 산화 스트레스, 정액 상태 등을 측정했습니다. 그 뒤 두 그룹으로 나눠 한 그룹은 베타카로틴을, 다른 그룹에게는 베타카로틴이라고 알려줬지만 사실은 아무 효능이 없는 위약을 12주 동안 복용하게 했습니다. 12주 뒤 이들에게 무슨 변화가 일어났을까요? 실제 베타카로틴을 꾸준히 복용한 그룹이나 위약을 복용한 그룹이나 면역력, 산화 스트레스, 정액 상태는 아무런 변화가 없었습니다. 베타카로틴이 면역력을 증진시키거나 항산화 작용을 하지는 않았다는 거지요. 반면 한 가지는 뚜렷하게 변했습니다. 피부색입니다. 베타카로틴을 섭취한 그룹은 피부색이 좋아져 더 건강하게 보이게 됐습니다.  베타카로틴을 복용한 그룹의 피부색 변화(윗줄)와 위약을 복용한 그룹의 피부색 변화(아랫줄). 베타카로틴을 꾸준히 복용한 그룹이 더 건강한 느낌을 주는 방향으로 피부색이 변했다.  - 용지후 호주 웨스턴대 석사후연구원 제공   베타카로틴을 복용한 그룹의 피부색 변화(윗줄)와 위약을 복용한 그룹의 피부색 변화(아랫줄). 베타카로틴을 꾸준히 복용한 그룹이 더 건강한 느낌을 주는 방향으로 피부색이 변했다. 연구팀은 이 사실을 바탕으로 어느 쪽이 더 매력적으로 보이는지 테스트도 추가로 진행했는데, 설문에 응답한 여성들은 베타카로틴을 꾸준히 복용해 피부색이 바뀐 사진이 가장 매력적으로 보인다고 답했다 - 용지후 호주 웨스턴대 석사후연구원 제공 지금쯤 다시 처음으로 돌아가 봅시다. 식품안전포털 공지에 따르면, 베타카로틴은 야맹증을 돕는 비타민A로서의 효능과 피부 세포를 만들고 기능을 유지하도록 돕는 효능을 갖고 있습니다. 그 이상도, 이하도 아닌 것이지요. ※ 편집자 주 이 글을 포함해 수많은 건강보조식품을 안내하는 칼럼들에서 이야기하듯 보조식품은 ‘보조’할 뿐입니다. [건강식품 삐딱보기]에서는 건강보조식품에서 단골로 등장하는 성분이나 제품들이 실제로 어떤 효능을 가갖고 있는지 최신 논문을 통해 소개할 예정입니다. 많은 사랑과 관심 부탁드립니다. 오가희 기자 solea@donga.com동아사이언스

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“I smell carrots a-cooking, and where there's carrots, there's rabbits.”

—Yosemite Sam 

Carotenoids belong to the category of lipid-soluble terpenes (as a tetraterpenoid) non-polar compounds. Of the more than 600 carotenoids found in nature, about 40 are present in a typical human diet. Of these carotenoids, only 14 and some of their metabolites have been identified in blood and tissues.1 More than 1,100 known carotenoid compounds2 are split into two chemical classes: carotenes (which are unoxygenated), such as alpha-carotene, beta-carotene and lycopene; and xanthophylls (which contain oxygen), such as astaxanthin, canthaxanthin, beta-cryptoxanthin, lutein and zeaxanthin. Both classes have at least nine conjugated double bonds, which absorb specific wavelengths of visible light during a plant’s photosynthesis process; and thus, provide carotenoids their characteristic colors.  Xanthophylls are more yellow, while carotenes are reddish-orange.3 

Carotenoids are found in high concentrations in plants, algae and microorganisms. Humans cannot synthesize them and therefore are required to ingest them in their diet. The carotenoids that have been .studied the most for human health are: astaxanthin, beta-carotene, lycopene, lutein and zeaxanthin.4

Carotenoids are found in plants, algae and photosynthetic bacteria, where they play a critical role in the photosynthetic process. They synthesize photosynthetic pigments (lipochromes), which are important for photosynthesis process, since they absorb ultraviolet (UV) light wavelengths. Carotenes typically appear blue, violet, orange, red and, in low concentrations, yellow. Xanthophylls appear yellow, orange and red. Carotenoids contribute to photosynthesis by transmitting the light energy they absorb to chlorophyll. They also protect plant tissues by acting as antioxidants, helping to absorb the energy from singlet oxygen.

The term carotene (from the Latin carota, "carrot," daucus carota L.) is used for many related unsaturated hydrocarbon compounds (with no oxygen atoms). Because they are hydrocarbons containing no oxygen, carotenes are lipophilic, meaning they are insoluble in water. Carotenes are terpenoid hydrocarbons found in plants with several isomers forms. The isomers are designated by characters from the Greek alphabet. The two primary isomers are alpha-carotene and beta-carotene, which are precursors of vitamin A. Gamma-carotene, delta-carotene, epsilon-carotene and zeta-carotene isomeric forms also exist.

Carotenes can be found in many dark green and yellow leafy vegetables, and appear as fat-soluble pigments, while beta-carotene can be found in yellow, orange and red colored fruits and vegetables. Beta-carotene is sold separately commercially and has several sources: plant (palm oil), algae (dunaliella salina), fungal (blakeslea trispora and mucor circinelloides), and synthetic.

Xanthophylls (originally called phylloxanthins) are yellow pigments that occur widely in nature. In 1837, the Swedish chemist Jöns Jacob Berzelius described the yellow pigments extracted from autumn leaves, which he named xanthophylls (from the Greek words “xanthos” [yellow] and “phyllon” [leaf]), due to their formation of the yellow, orange, red leaf pigments. They are also considered accessory pigments, along with anthocyanins, carotenes and sometimes phycobiliproteins.

The molecular structure of xanthophylls is like that of carotenes, but xanthophylls contain oxygen atoms (the oxidized form of carotenes). Xanthophylls contain their oxygen either as hydroxyl groups and/or as pairs of hydrogen atoms that are substituted by oxygen atoms (an epoxide). For this reason, they are more polar than the carotenes.

 

β-carotene/Sci-Toys.com

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Commercial xanthophylls include: astaxanthin (algae), beta-cryptoxanthin (plant), canthxanthin (plant), fucoxanthin (algae), lutein (plant). and zeaxanthin (algae, plant). Other examples of xanthophylls are: capsanthin, neoxanthin, violaxanthin. and flavoxanthin.

Carotenoid’s health benefits

Carotenoids are fat-soluble micronutrients that play an important role in human health. Studies have shown several carotenoids can provide a multitude of health benefits, including provitamin A activities, a role as antioxidants, preventing age-related macular degeneration (AMD), reducing risk for cardiovascular disease and reducing the risk of some cancers.5

Astaxanthin—antioxidant, anti-inflammatory, anti-diabetic, cardiovascular benefits, cancer reduction, Immuno-modulation, etc.6

Beta-carotene—Vitamin A precursor,7 supports eye health, antioxidant,8 cardiovascular benefits,9 etc.

Lycopene—antioxidant, reduces benign prostatic hyperplasia (BPH), reduced risks of prostate, ovarian, gastric, and pancreatic cancers, prevents UV-induced sunburn, etc.10

Lutein/Zeaxanthin—reduces age-related macular degeneration (AMD), eye health/development, cognitive development, antioxidant, etc.11

Vitamin A precursor

Vitamin A consists of both retinol from animal sources, and provitamin A carotenoids from plant sources. In Western societies, the provitamin A carotenoids derived from plants provide less than 30 percent of daily vitamin A intake, whereas retinol vitamin A derived from animal products provides more than 70 percent daily vitamin A intake, according to the National Health and Nutrition Examination Survey.

Four provitamin A carotenoids can be claimed as vitamin A on product labels: alpha-carotene, beta-carotene, gamma-caroten. and beta-cryptoxanthin. Other carotenoids such as astaxanthin, lutein, lycopene, and zeaxanthin are not provitamin A carotenoids.

Currently, international units (IU) describe vitamin A activity. This is changing, starting in January 2020, to RAE (retinol activity equivalents), which will be used to compare the vitamin A activity of the different forms of vitamin A.  

Beta-Carotene Color/foodcolor.com

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Carotenoid conversion to vitamin A

The BCMO1 gene codes the BCMO1 protein, which cleaves provitamin A carotene into two molecules of retinal (a form of vitamin A that can be converted to and from retinol, which is the storage and transport form of vitamin A). This conversion happens mainly in the intestinal mucosa (gut barrier), but also occurs in the liver and other organs. Every person has two copies of the BCMO1 gene. But, about 45 percent of the population carries at least one gene variation that reduces BCMO1 enzyme activity, resulting in significantly impaired ability to convert beta-carotene into retinal. Depending on which combination of variants someone inherits, beta-carotene conversion can be nearly 70 percent lower than its normal efficiency, according to the National Institutes of Health (NIH).

Absorption

Carotenoids are absorbed into the body as lipids and transported via the lymphatic system into the liver. With the exception of carotenoid epoxides, all of the carotenoids described earlier are absorbed by humans into the blood and tissues intact, including: pro-vitamin A carotenoids (such as alpha-carotene, beta-carotene, beta-cryptoxanthin and gamma-carotene) and non-vitamin A carotenoids.12 For the carotenoid fraction remaining in the body, little information is available on their further metabolism, but most likely many are degraded into smaller, more polar fragments via the formation of epoxides and carotenals (apocarotenoids).13

Historically, the ingesting of carotenoids has been known to have beneficial properties for human health. Scientists continue to study their biological role in the prevention and treatment of some human chronic diseases. The properties of many carotenoids are being studied, such as their provitamin A and antioxidant activities; immune, endocrine and metabolic activities; and their role in cell cycle regulation, apoptosis and cell differentiation.

Robin C. Koon, executive vice-president at Best Formulations, has more than 35 years of pharmaceutical experience in clinical pharmacy practice, in retail drug chain operations, in managed care, and in nutraceutical/pharmaceutical manufacturing.

Carotenoids are among many supplements that can support the needs of aging consumers. For tools, tips and tricks on how to effectively market to healthy aging consumers, join us for the "Healthy Aging: Lifelong Wellness" workshop on Wednesday, Nov. 7, at SupplySide West 2018. This workshop is underwritten by Lonza.

https://www.naturalproductsinsider.com/ingredients/carotenoids-vitamin-zeaxanthin

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