Tuesday, April 24, 2007


...by scurvy or DNA damage. Hopefully, none.

An interesting study has appeared in the British Journal of Nutrition (2007, 97, p.639), which seems to say what many of us may have suspected; that nature knows best. The study investigates the effect of Vitamin C as an antioxidant when taken alone in the form of pills, or as a component of oranges or orange juice. It concludes that Vitamin C in the form of oranges or orange juice may be much better than Vitamin C in the form of a pill or supplement.

The study made volunteers drink Vit C water, orange juice, and sugar water as a control. After the Vit C levels in all the volunteers' blood were equalised, samples were taken and were exposed to hydrogen peroxide, a known DNA damage agent. Surprisingly, the levels of DNA damage were much lower in the orange juice-fed volunteers than the Vit C water volunteers.

I have not had access to the full paper, but the authors conjecture that it may be the other substances in oranges which protect against DNA damage. As I see it, these other substances may be acting as "sacrificial" molecules, themselves getting oxidised and thereby protecting both DNA and Vit C.

Actually, these results should not be surprising. Nature has evolved intricate packages of chemicals that play roles in organisms. Oranges are not just containers for holding Vit C and other compounds, but intricate systems in which there is an essential synergistic interplay of all these substances as well as their container. Taking one out of context creates the same problems as when politicians take words out of contexts. As in many aspects of of nature, the whole is much more than the sum of the parts. In light of this, I sometimes wonder how we have so many effective drugs which are isolated from natural sources and used separately. But then, it's not perfect, is it? Think of how many side effects they have, and this may well be because you are not providing a holistic environment for them to act. Sometimes the leaf is really better than the pill. Validation for old Ayurveda and herbal medicine?

Next time, maybe we can think twice before we substitute a Vitamin tablet for its natural source.

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Anonymous Anonymous said...

Hi Ashutosh,
FYI: Whenever I visit your blog, it tries to download 'Office provider' or some such other crap. Ya know anything about it?

7:40 PM  
Blogger Nikhil K said...

Does this study imply that Vitamin C in its pure form is harmful?

And why should evolution have led to a form of Vitamin C fit for human consumption? Is it just an accidental byproduct of evolution that an Orange offers itself as the best container for Ascorbic acid?

7:37 PM  
Blogger Hirak said...

That puts a dampener on the idea that there will be a 'pill for everything', one that combines all the nutrients you would need.

My cousin who is doctor advises that oranges are better than orange juice. The less processed the better.

11:49 AM  
Anonymous anya said...

I would say that the vit C from the pills is not as easily absorbed by the body as from natural sources. The study does say that they let the vitamin levels in the blood of the subjects balance out. Is that the same as absorption for usage?

Hirak - Oranges are definitely better than orange juice - as they have fiber too.

2:38 AM  
Blogger Ashutosh said...

Anon: Thanks for letting me know, will look into it, had no idea this was happening.

Nikhil: You ask a question which goes much deeper. Why did evolution in any of the beneficial natural sources that we consume lead to species that were good for humans? Why did evolution care about human beings?
I think it is an accident, as you said, that Vit C in oranges is good for human beings, because there's also an important function for Vit C in oranges themselves. Oranges evolved their particular repository of Vit C to increase their own fitness, naturally not caring for human beings. That this form was also good for human beings is an accident, but humans also evolved to digest this form better. If fruits were the only easy sources of Vit C around, then mutations leading to changes that could exploit the Vit C in them efficiently surely could have been propagated into future generations.

Hirak and Anya: Orange juice also has plain sugar in it, which I guess is not as good as the complex carbohydrates in fruits. As far as sugar metabolism is concerned, I don't know if drinking a full glass of orange juice is any better than drinking a can of coke. But the other benefits in orange juice like fiber of course outweigh the lack thereof in coke. Let the less processed thrive and galore!

10:35 AM  

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