Joe A. Vinson, Thomas B. Howard III, Inhibition of protein glycation and advanced glycation end products by ascorbic acid and other vitamins and nutrients, The Journal of Nutritional Biochemistry, Volume 7, Issue 12, December 1996, Pages 659-663, ISSN 0955-2863, 10.1016/S0955-2863(96)00128-3. (http://www.sciencedi...955286396001283) Keywords: glycation; advanced glycation end products; vitamins; nutrients; ascorbic acid
The present Vitamin C supplementation study (in a bio-
flavonoid mixture) demonstrated an average decrease of
46.8% in protein glycation in normoglycemic subjects in
good agreement with Davie.30 He showed a 33% decrease
in glycated albumin after 3 months with 1 g/day of ascor-
bate and an 18% reduction in GHb. Stolba also found a
significant decrease in fructosamine in insulin-dependent
diabetics given 1.5 g of ascorbate/day.36 The glycation-
lowering effect in the supplement could be due to both the
ascorbate and flavonoids in the mixture. Odetti found that
the flavonoid rutin decreased collagen-linked AGE fluores-
cence in diabetic rats.37
Epidemiological studies have recently found a negative
correlation between vitamin C intake and GHb in normal
subjects.38 Ascorbate either alone or in the form of a citrus
extract has also been found to be an effective agent in low-
ering red blood cell sorbitol in human diabetic subjects at 2
g/day, 39 1 glday,40 and 100 mg/day.41 Vitamin C thus ben-
eficially influences the two mechanisms of diabetic compli-
cations; glycation and the sorbitol pathway.
Seems like 1g/day may be pretty effective. Taken away from exercise and maybe with food. The subjects were 7 college students and 11 middle-aged folks.
The referenced study (30) is this one:
Diabetes. 1992 Feb;41(2):167-73.Effect of vitamin C on glycosylation of proteins.Davie SJ, Gould BJ, Yudkin JS.
In the above study they used a product called Re-natured C which contains bioflavanoids, while I do not have access to the second study so unsure what product they used, however the results are fairly simliar. Both healthy groups too (as per the description, no detailed descriptive data).