mineral waters and bone

The consumption of mineral waters is increasing in industrialised countries. High intakes of Ca and other alkalising cations as. well as a low acid intake are beneficial to bone. Wynn and colleagues looked to see which components of mineral waters are influencing their Ca content and alkalinising power, in order to define the optimal profile. European mineral waters were randomly selected on the Internet: 100 waters with less than 200 mg Cal (9·98 mEqll) and fifty with more than 200 mgl, all with complete data for S04, P, Cl, Na, K, Mg and Ca, and most also for RC03. For comparison, forty North American mineral waters were randomly chosen. The potential renal acid load (pRAL) was calculated for each mineral water. North American waters did not reveal significant results because of their low mineralisation.
They undertook correlations between all eight components in order to explore the properties of the mineral waters. A high Ca content is associated with either a high S04 or a high RC03 content. S04 theoretically increases Ca excretion, while RC03 and low PRAL values are associated with positive effects on bone. Therefore, the best waters for bone health are rich in both RC03 and Ca, and by consequence low in S04'

Wynn et al (2009) The composition of mineral waters sourced from Europe and North America in respect to bone health: composition of mineral water optimal for bone British Journal of Nutrition (2009), 101, 1195-1199
Acid-base balance: Potential renal acid load: Mineral water: Calcium metabolism: Bone health

sulfur amino acids

This is an outstanding review of sulfur amino acids by Tesseraud et al .
Sulfur amino acids have a very significant place amongst amino acids due to their numerous roles Protein synthesis is affected when an insufficient level of sulfur amino acids is available. This defect may originate from dietary amino acid deficiency and/or excessive amino acid utilisation for other purposes such as the synthesis of glutathione and acute-phase proteins during catabolic stress. Sulfur amino acids are recognised to exert other significant functions since they are precursors of essential molecules, They are precursors of major components such as glutatione, taurine, H2S and sulfates and act on oxidative status and signalling pathways. Methionine has a central role in epigenetic regulation with its effect on DNA methylatio.
Many questions still remain unanswered due to the complexity of the mechanisms involved. Moreover, surprising effects of dietary sulfur amino acids have been reported, with the development of disorders in cases of both deficiency and excess. These findings indicate the importance of defining adequate levels of intake and providing a rationale for nutritional advice.

Tesseraud et al 2009 Role of sulfur amino acids in controlling nutrient metabolism and cell functions: implications for nutrition British Journal of Nutrition,, vol 101, pp 1132-1139

niacin and flushing

Niacin lowers blood triglycerides and raises high density lipoproteins. It also however provokes a burning flush sensation which is not comfortable. that the mechanism is meaited through the G-protein coupled pathway GPR109A.
When niacin comes into contact with the G-protein coupled pathway GPR109A, a protein Β-arrestin 1 comes to the recptor which results in the expression of arachidonate which causes the flushing.
Walters et al ( 2009) beta-Arrestin1 mediates nicotinic acid-induced flushing, but not its antilipolytic effect, in mice. J Clin Invest.vol 119(5):pp 1312-21.