Patrick Holford is tremendously keen on the life and health-enhancing benefits of Vitamin C. Holford’s current recommendations are below his previous claim that he takes 5 grammes of Vitamin C per day:
Dr. Michael Colgan takes 5 grams daily. Dr. Linus Pauling takes 10 to 18 grams daily. I take 5 grams daily on top of a diet rich in food sources of vitamin C. The choice is yours.
Nonetheless, as Jon will detail in future posts about Holford and Vitamin C, there is a marked emphasis on supplementation because it is not practical to obtain large amounts of Vitamin C from dietary sources.
There are many studies on Vitamin C but suprisingly few address the obvious issue of whether Vitamin C supplementation is comparable to obtaining it as part of the anti-oxidant complex available from eating fruit and vegetables.
Here at Holford Watch, we are not particularly keen on in vitro rather than in vivo studies but they are sometimes interesting in default of other relevant evidence. One of these interesting in vitro studies is Orange juice vs vitamin C: effect on hydrogen peroxide-induced DNA damage in mononuclear blood cells.
The researchers investigated the protective effects of orange juice or Vitamin C on blood samples that were treated with hydrogen peroxide (H2O2, an oxidiser) which would ordinarily cause oxidative DNA damage to mononuclear blood cells (MNBC). There were 3 different drinks: a single portion of blood orange juice (BOJ, 300 ml, providing 150 mg Vitamin C); a drink with 150 mg Vitamin C (C-drink); a drink with the sugars (S-drink). The 7 participants were randomised to receive each drink on different occasions at 2 week intervals.
After a baseline blood sample, the participant consumed a drink; the researchers took blood samples every hour for 8 hours and then at 24 hours. The plasma Vitamin C levels were measured in each sample. H2O2-induced MNBC DNA damage was evaluated with the 0, 3 and 24 h samples by treating the sample with H202 and then measuring the damage.
In line with expectations, plasma Vitamin C concentration increased similarly following BOJ or C-drink intake and was not affected by the S-drink. However, according to the researchers’ report, the BOJ lessened the oxidative DNA damage to the MNBC but neither the C-drink nor S-drink had any discernible impact. The authors conclude:
the intake of a single portion of BOJ provided an early protection of MNBC against oxidative DNA damage; however, the protective effect of BOJ was not explained by vitamin C alone, thus other phytochemicals could be involved.
This simple investigation indicates that, for this experiment, blood orange juice had a greater impact than Vitamin C and it would be futile to expect the same anti-oxidant protection from a Vitamin C supplement as can be obtained from the juice. There is a lot of emphasis from dietitians and similarly-qualified people on the benefits of a diet that contains a broad range of foods, with a particular emphasis on the mediterranean diet.
It does look like as if the benefits of obtaining our nutrients from food, rather than supplements, are striking. So, you might want to reject Holford’s forced choice of how much Vitamin C you wish to obtain from supplements and concentrate on obtaining Vitamin C from the whole fruit and nothing but the fruit (or vegetable). You might even enjoy it.
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