Search results
Results From The WOW.Com Content Network
A meta-analysis concluded that supplementation with β-carotene does not appear to decrease the risk of cancer overall, nor specific cancers including: pancreatic, colorectal, prostate, breast, melanoma, or skin cancer generally. [8] [40] High levels of β-carotene may increase the risk of lung cancer in current and former smokers.
These two publications are consistent with some previous meta-analyses that also suggested that vitamin E supplementation increased mortality, [145] and that antioxidant supplements increased the risk of colon cancer. [146] Beta-carotene may also increase lung cancer.
This is a list of antioxidants naturally occurring in food. Vitamin C and vitamin E – which are ubiquitous among raw plant foods – are confirmed as dietary antioxidants, whereas vitamin A becomes an antioxidant following metabolism of provitamin A beta-carotene and cryptoxanthin.
Long-term use of beta-carotene, vitamin A, and vitamin E supplements may shorten life, [2] and increase the risk of lung cancer in people who smoke (especially those smoking more than 20 cigarettes per day), former smokers, people exposed to asbestos, and those who use alcohol. [21]
The α-carotene molecule has a β-ring at one end; the other end is called an ε-ring. There is no such thing as an "α-ring". These and similar names for the ends of the carotenoid molecules form the basis of a systematic naming scheme, according to which: α-carotene is β,ε-carotene; β-carotene is β,β-carotene;
Also downregulated is the enzyme beta-carotene 15,15'-dioxygenase (formerly known as beta-carotene 15,15'-monooxygenase) coded for by the BCMO1 gene, responsible for symmetrically cleaving β-carotene into retinal. [8] Absorbed β-carotene is either incorporated as such into chylomicrons or first converted to retinal and then retinol, bound to ...
Overconsumption of beta-carotene can only cause carotenosis, a harmless and reversible cosmetic condition in which the skin turns orange. Preformed vitamin A absorption and storage in the liver occur very efficiently until a pathologic condition develops. [21] When ingested, 70–90% of preformed vitamin A is absorbed and used. [21]
Exposure to all commercially available forms of asbestos increases cancer risk, and cancer risk increases with time of exposure. [71] Asbestos and cigarette smoking increase risk synergistically – that is, the risk of someone who smokes and has asbestos exposure dying from lung cancer is much higher than would be expected from adding the two ...