The March, 2006 issue of The American Journal of Clinical Nutrition published the findings of
UK researchers of an association between dietary and plasma levels of vitamin C and reduced markers of
inflammation and endothelial dysfunction in older men.
S. Goya Wannamethee and colleagues studied 3,258 men between the ages of 60 and 79 who had not been
diagnosed with heart attack, stroke, or diabetes. Responses to food frequency questionnaires provided
information concerning vitamin C intake. Blood samples were analyzed for plasma vitamin C, the
inflammatory marker C-reactive protein, tissue plasminogen activator (t-PA) antigen, which is a
marker of endothelial dysfunction (abnormal function of the lining of the blood vessels); and other
factors.
It was found that higher plasma vitamin C levels, greater fruit intake, and greater vitamin C
intake were all correlated with lower levels of C-reactive protein and t-PA. High vegetable intake was
associated with a reduction in t-PA but not C-reactive protein. Men whose plasma vitamin C was in the
highest one-fourth of participants had a 44 percent less risk of having elevated C-reactive protein
and a 21 percent lower risk of an elevated t-PA than those whose levels were in the lowest fourth. For
those whose fruit intake was in the top quarter the risk of having either factor elevated was 24 percent
lower than that of men whose fruit intake was in the bottom fourth. Additionally, higher plasma vitamin
C levels were associated with reduced blood viscosity and fibrinogen concentrations.
?Several studies have reported that vitamin C can improve endothelial dysfunction in smokers,
hypertension patients, and patients with coronary artery disease,? the authors write. ?Our finding is
consistent with a protective effect of vitamin C on endothelial function, which could be mediated by the
effects of vitamin C on low-grade inflammation, effects that may result from its antioxidant
properties.
Commentary by Jerry Hickey, R.Ph.
Studies show it is not the caffeine which helps decrease
the risk of developing diabetes but probably the polyphenols.
New Study Linking Tocotrienol to Inhibition of Cancer Cell Proliferation - Anti-Angiogenic Activity
Edison, New Jersey, March 13th 2006 - According to researchers in Japan, "Tocotrienols, vitamin E
compounds that have an unsaturated side chain with three double bonds, selectively inhibited the
activity of mammalian DNA polymerase lambda (pol lambda) in vitro. Polymerases are involved in
cellular DNA synthesis during cell replication."The researchers also showed that tocotrienols
inhibited the proliferation of and formation of tubes by bovine aortic endothelial cells, with
delta-tocotrienol having the greatest effect. "The isomer's structure might be an important factor
in the inhibition of pol lambda," suggested Y. Mizushina and colleagues at the Kobe Gakuin
University. The study published in the recent issue of Biochemical and Biophysical Research
Communication, 2006 (339), 949-955 suggests that tocotrienols may act as potent anti-cancer agents
by inhibiting pol lambda and angiogenesis. What is interesting is that the regular tocopherols
(alpha, beta, gamma and delta-tocopherol) do not influence the activities of mammalian polymerase
and angiogenesis at all, suggesting that the three double bonds in the unsaturated side chain of
tocotrienols play an important factor in the inhibition of polymerase lambda. The fact that
tocotrienols, which are a natural form of vitamin E in plants, are inhibitor or a polymerase
species, pol lambda, is of great interest in the science of how natural compounds inhibit cancer
cells. It is therefore possible that the greater anti-angiogenic effect of tocotrienols may be due,
in part, to the highly effective inhibition of polymerase lambda.
