Studies of the geographic variation of colon and rectal (colorectal) cancer mortality rates in the U.S. have long indicated that they are primariliy linked to solar ultraviolet-B (UVB) radiation: the more UVB in summer, the lower the mortality rate.
The hypothesis to explain this result is that UVB radiation produces vitamin D in the skin, and vitamin D acts to reduce the risk of colorectal and over a dozen other types of cancer. One major study found that intake of 150 IU/day of vitamin D was associated with a reduction by half in incidence of colon cancer, a result that was statistically significant. However, some studies that have investigated the link between dietary sources of vitamin D and colorectal cancer have found a smaller degree of risk reduction comparing the highest versus lowest levels of dietary vitamin D.
In a review of the literature published in the current issue of Nutrition and Cancer, Drs. William Grant and Cedric Garland report that the reason for the sometimes weak link between dietary sources of vitamin D and colorectal cancer incidence or mortality rates is that dietary sources often cannot supply enough vitamin D to be effective in quantities ordinarily consumed. In most such studies, the highest quartile or quintile of those studied consumed over 150-370 I.U./day from dietary sources. That was sufficient in some cases to provide a 10-50% reduction in colorectal cancer risk, but not always at a statistically significant level. However, studies that considered vitamin D intake from both diet and supplements for which the highest levels were over 500 I.U./day found 30-60% risk reduction for the highest versus lowest levels, and the results were uniformly tatistically significant.
Laser activated gold pyramids could deliver drugs, DNA into cells without harm
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24.03.2017 | University of California - San Diego
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
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