Eat to Beat the Common Cold? Part One: Review of Vitamin C

Untitled design-24

We all know how it goes. It starts will a small, unassuming tickle in your throat, a funny feeling that something isn’t quite right… and before you know it, your head is sore and pounding, your nose is stuffy and runny and your throat appears to have reformed into a new structure, made up entirely of tiny pieces of glass. On top of all this, you quickly discover you are suddenly outcast by society. People hurry past you, hands over their mouths, throwing you worried glances, and even those people who are supposed to love you the most won’t consider giving you a much needed hug or simply let you join them for dinner (aww your sick….wouldn’t you much prefer to have your food in your room, Helen?). So you’re stuck with your miserable self and your germy friend, the common cold, until your immune system gathers the troops and sends him (obviously a him) on his merry way.

Okay, okay. I realise I’m probably being a little melodramatic here,  *snuffle* but as a recent victim, things are still a  little raw ;)

There are actually over 200 strains of virus that can cause a cold.  I don’t know if you have noticed, but when you are struck down by the dreaded bug, it’s not uncommon to receive a million little gems of wisdom on how to get better, usually from all those well meaning folk who care about your well being (from a distance). The world is full of these weird and wonderful forms of dietary trickery, each one promising that they will be sure to rid you of a colds vice like grip on your nostrils, throat and head, and these little pieces of advice must come from somewhere, right?  But what do we really know about them? Can you really ‘cure’ your cold just by eating the right foods?

So I decided to do a little run down of the most frequently cited nutrition based cold ‘fixes’ & the truth behind the claims…..

First up, the classic advice:


“Take some Vitamin C”

Vitamin C has been touted as a treatment for respiratory infection since the early 1930’s, but it only became REALLY popular in the 70’s  after the world famous chemist (and nobel prize winner) Linus Pauling carried out  a review of scientific literature and concluded that high dose vitamin C could cure the common cold.  Despite little sound evidence for his claims and widespread criticism of his review, vitamin C is remains a popular product, sold in bucket loads as preventative therapy and cure for the common cold.

Untitled design-25

What does the science say?

Although there has been widespread public interest in vitamin C as a go to remedy for the cold,  results from extensive research that has been carried out in this area have been a little underwhelming, to say the least. The most recent review, carried out by Cochrane (THE Gold standard in reviews of scientific literature due to their stringent methodology) looked at over 11,000 people supplementing their diets with a minimum of 200mg of vitamin C a day (the RDI or recommended daily intake for adults is 40mg).  Unfortunately they found that vitamin C supplementation did not prevent the occurrence of colds.  

There were some positive results though.

Firstly, there did seem to be a reduction in the severity and duration of colds in people who routinely used vitamin C supplements (although the effect was minimal and only equated to about 1 day over a whole year).

Secondly, for athletes or those people with very high exercise loads, e.g. marathon runners, vitamin C supplementation reduced the incidence of colds by about 50% – interesting!

So simply put:
  • Taking vitamin C supplements wont stop you getting a cold.
  • Taking vitamin C supplements after the onset of a cold will have no effect on how bad your symptoms are or how long you have it for
  • If you routinely supplement with vitamin C, you might experience a small reduction in the severity & duration of your cold
  • If you’re an athlete, taking a vitamin C supplement along side your regular diet may prevent you getting a cold


My Thoughts…

Most of us should be able to meet our daily vitamin C requirements (and more!) from our diet.  200mg per day isn’t that much vitamin C, and supplementing regularly can be expensive. To me, meeting your requirements as part of a well balanced diet makes more sense and is a little more enjoyable too! If you’re an athlete, elderly or someone with poor fruit and vegetable intake you might benefit from taking a supplement in addition to your regular diet.

Side Note: Some people recommend ‘mega dosing’ vitamin C in doses of >2000mg per day.  This practice has very little scientific backing and it is worth noting that high doses of vitamin C have been linked to stomach cramps, diarrhoea and in some cases, kidney stones. 

Next up!! Echinacea!

Have you any cold cures you would like to me review?  Please, share them in the comment or drop me a line!



Cochrane Review (2013) Vitamin C for Preventing & Treating the Common Cold

Tweet about this on TwitterShare on FacebookPin on Pinterest

7 Responses

  1. Tina Muir
    March 26, 2014 at 11:29 am

    Great post Helen, I will be passing this on to my athletes as they are constantly getting sick! I am glad you went over the fact that it does not affect the cold once you have it. I tell them this over and over! Hope you are feeling better :)

    • helen
      March 27, 2014 at 11:14 am

      Thanks Tina! Hopefully it will aid your quest to stop repeating yourself!! :) I’m on the mend (thank goodness!) xx

  2. Jo
    March 27, 2014 at 8:42 am

    This is a really interesting topic and great to hear some facts among the fiction. Thanks for putting it together!

    I’m intrigued that vitamin C supplements have such a big effect on athletes when they’re obviously already very healthy and their immune system is presumably working well. Could it be that 50% of ‘not many colds’ is ‘not many colds at all’ so the figures just look big?

    I’d love to know if reducing dairy during a cold makes a difference. I’m sure it does for me, but that could be purely psychological!

    • helen
      March 27, 2014 at 11:09 am

      Hey Jo,

      Interesting point, I hadn’t thought of it like that! I’m really not sure what the mechanism of action would be in athletes (if anyone has any suggestions, feel free to post!) The Cochrane Review found the decrease in incidence in people undertaking bouts of heavy exercise and I know that high exercise loads have been linked with immunosuppression in the period immediately after exercise, which increases infection risk…so it could have influence in that period? (I’m guessing, can you tell?!). I would say though, that not all athletes have a ‘healthy’ diet. Travel, body composition goals and high energy requirements are just a few things that can make it difficult for them to meet their requirements and mean their intake is sub-par. Amateur athletes undertaking endurance exercise perhaps as a newbie or one off who have less knowledge would probably be especially at risk (maybe this is where it has its influence).

      I’m not sure about dairy & colds….happy to have a look & share if I find anything though! :)

  3. Juliet McBean
    March 27, 2014 at 8:46 am

    Thanks Helen. Random factoid: my great aunt (Dr Blake) was a junior researcher in the 1930s who did some of the data collection on vitamin C supplementation. Interesting as 1) not many female scientist back then and 2) as a family if I ever complained of beginning to feel under the weather, I would be told to take an effervescent vitamin c tablet from the medicine cabinet-straight away to prevent the cold!! I stopped following this advice years ago, but my mum still tells me (and Malcolm!!!!) to take it.This always makes me smile, which at least provides a bit of comfort- so perhaps its the action of trying to do something nice which is the real ‘cure’ for when you feel yucky and snotty.

    • helen
      March 27, 2014 at 11:12 am

      Awww Juliet thats super interesting, & lovely! What a woman :) I’m all for anything which gives you a warm fuzzy feeling of home, especially when you are sick!

Leave a Reply