again, not from a journal
Up until the 1990s, no research had ever been conducted to determine the impact of fluoride on the pineal gland - a small gland located between the two hemispheres of the brain that regulates the production of the hormone melatonin. Melatonin is a hormone that helps regulate the onset of puberty and helps protect the body from cell damage caused by free radicals.
It is now known - thanks to the meticulous research of Dr. Jennifer Luke from the University of Surrey in England - that the pineal gland is the primary target of fluoride accumulation within the body.
The soft tissue of the adult pineal gland contains more fluoride than any other soft tissue in the body - a level of fluoride (~300 ppm) capable of inhibiting enzymes.
The pineal gland also contains hard tissue (hyroxyapatite crystals), and this hard tissue accumulates more fluoride (up to 21,000 ppm) than any other hard tissue in the body (e.g. teeth and bone).
After finding that the pineal gland is a major target for fluoride accumulation in humans, Dr. Luke conducted animal experiments to determine if the accumulated fluoride could impact the functioning of the gland - particulalry the gland's regulation of melatonin.
Luke found that animals treated with fluoride had lower levels of circulating melatonin, as reflected by reduced levels of melatonin metabolites in the animals' urine. This reduced level of circulating melatonin was accompanied - as might be expected - by an earlier onset of puberty in the fluoride-treated female animals.
Luke summarized her human and animal findings as follows:
"In conclusion, the human pineal gland contains the highest concentration of fluoride in the body. Fluoride is associated with depressed pineal melatonin synthesis by prepubertal gerbils and an accelerated onset of sexual maturation in the female gerbil. The results strengthen the hypothesis that the pineal has a role in the timing of the onset of puberty. Whether or not fluoride interferes with pineal function in humans requires further investigation."
here's something journalesque about fluoride...http://star.tau.ac.il/~eshel/Bio_complexity/8.Human%20Brain/Autism-Mitochondria-mercury.pdf
et voila, i like it when i can find nutrition involvement, even if it's just birds:
Comp Biochem Physiol A Mol Integr Physiol. 1998 Feb;119(2):593-8. Related Articles, Links
Vitamin A deficiency reduces the responsiveness of pineal gland to light in Japanese quail (Coturnix japonica).
Fu Z, Kato H, Sugahara K, Kubo T.
Faculty of Agriculture, Utsunomiya University, Japan.
Synthesis of melatonin in pineal gland is under the control of light environment. The recent finding of the presence of rhodopsin-like photopigment (pinopsin) and retinal in the avian pinealocytes has led to a hypothesis that vitamin A is involved in photoresponses of the pineal gland. We have thus analyzed the effect of vitamin A deficiency on the regulatory system of melatonin synthesis in the pineal gland of Japanese quail. Depletion of vitamin A from Japanese quails was attained by feeding them with a vitamin A-free diet supplemented with retinoic acid. In the vitamin A-deficient birds, diurnal rhythm in melatonin production persisted such that the phase of the wave was similar to that seen in the control birds. However, the amplitude of the nighttime surge of pineal melatonin was damped by vitamin A deficiency. When the control birds were briefly exposed to light at night, pineal melatonin dropped to the daytime level. In contrast, only slight decrease was observed in the vitamin A-deficient quails. The light responsiveness was restored after feeding the vitamin A-deficient quails with the control diet for 1 week. These results indicate that vitamin A plays essential roles in maintaining sufficient responsiveness of the avian pineal gland to photic input.
jus rollin thru the alphabet now...
Vol. 95, Issue 11, 6097-6102, May 26, 1998
Vitamin B2-based blue-light photoreceptors in the retinohypothalamic tract as the photoactive pigments for setting the circadian clock in mammals
(cryptochromes / retina / suprachiasmatic nucleus)
Yasuhide Miyamoto and Aziz Sancar*
Department of Biochemistry and Biophysics, University of North Carolina School of Medicine, Chapel Hill, NC 27599
Communicated by Johann Deisenhofer, University of Texas Southwestern Medical Center, Dallas, TX, April 1, 1998 (received for review March 9, 1998)
In mammals the retina contains photoactive molecules responsible for both vision and circadian photoresponse systems. Opsins, which are located in rods and cones, are the pigments for vision but it is not known whether they play a role in circadian regulation. A subset of retinal ganglion cells with direct projections to the suprachiasmatic nucleus (SCN) are at the origin of the retinohypothalamic tract that transmits the light signal to the master circadian clock in the SCN. However, the ganglion cells are not known to contain rhodopsin or other opsins that may function as photoreceptors. We have found that the two blue-light photoreceptors, cryptochromes 1 and 2 (CRY1 and CRY2), recently discovered in mammals are specifically expressed in the ganglion cell and inner nuclear layers of the mouse retina. In addition, CRY1 is expressed at high level in the SCN and oscillates in this tissue in a circadian manner. These data, in conjunction with the established role of CRY2 in photoperiodism in plants, lead us to propose that mammals have a vitamin A-based photopigment (opsin) for vision and a vitamin B2-based pigment (cryptochrome) for entrainment of the circadian clock.
Vitamin D3 enhances mood in healthy subjects during winter
Allen T. G. Lansdowne1, S. C. Provost1
Mood changes synchronised to the seasons exist on a continuum between individuals, with anxiety and depression increasing during the winter months. An extreme form of seasonality is manifested as the clinical syndrome of seasonal affective disorder (SAD) with carbohydrate craving, hypersomnia, lethargy, and changes in circadian rhythms also evident. It has been suggested that seasonality and the symptoms of SAD may be due to changing levels of vitamin D3, the hormone of sunlight, leading to changes in brain serotonin. Forty-four healthy subjects were given 400rIU, 800rIU, or no vitamin D3 for 5 days during late winter in a random double-blind study. Results on a self-report measure showed that vitamin D3 significantly enhanced positive affect and there was some evidence of a reduction in negative affect. Results are discussed in terms of their implications for seasonality, SAD, serotonin, food preference, sleep, and circadian rhythms.
k i've had enough of this for now, need lunch