The City I work for generally provides flu shots to any City Worker who would like them. This year, for obvious reasons, that won’t be happening. Instead we got an email stating that the shots would not be available and giving us, instead, a short list of 6 things that we could all do to help us stay healthy this winter, like washing our hands and not touching our faces.
One of the things on the list was eating a cup of yogurt a day. “A study” had determined that this could cut the incidence of colds 25%. I tried to google the information up, but it seems that the City had cribbed its little list from the internet. There are a slew of “12 ways to stay well” lists on the web at many, many sites and they are all the same list.
The City cut the following from the Ur-list: eat foods containing phytochemicals (that’s vegetables for those who don’t do trend-speak), do aerobic exercize regularly, don’t smoke, cut alchohol consumption, relax, and take a sauna twice a week (cuts colds in half).
Does anyone know anything about a real study involving colds and yogurt? Or colds and saunas? (What’s up with that - saunas were touted as twice as effective as yogurt and the City didn’t say a peep about them. What, were they aftaid we’d ask for one? We could sit in it and eat yogurt and relax - - hey, they ditched relaxing, too. Hmmm.)
I’m our group’s safety officer, so I though I’d try to get the straight dope.
Doubtful that yogurt prevents colds. With much googling, I found the following:
[quote]
According to one Finnish study, children attending day care who ate milk containing the strain lactobacilli GG could reduce respiratory infections in these children by 10% to 20%. More research is warranted. (The strain used was not the kind found in most commercial yogurt products.) http://www.morehead.org/wellconnected/000094.htm (look under the bolded heading “dietary factors”)
I’ve been unable to locate the actual article. So I don’t know if the rate of infections was reduced by 10-20% or if it was the severity, the duration, or the frequency that was reduced. Or something else.
My doctor’s office had a poster up containing this dubious yogurt claim. (Also nothing about the saunas, which I had read about somewhere earlier.) I asked my doctor and he had no idea what it was about.
I don’t eat yogurt. I do have a sauna and use it. I haven’t had a cold in three years. Go figure.
I did some Medline searches, and I have a feeling that the ‘study’ might be Am J Clin Nutr. 2003 Feb;77(2):517-20. (Abstract) The study was the only hit with the search term ‘yogurt and upper respiratory’. The conclusion is that there was a 19% reduction in certain bacteria in the noses of people who consumed a probiotic fermented milk drink containing various beneficial bacteria each day for 3 weeks. The study also tested with yogurt and found no significant reduction in the nasal bacteria. The bacteria involved include Staphylococcus aureus, Streptococcus pneumoniae and Hemophilus influenzae but do not, of course, include the viruses that cause colds.
There are a fair number of articles about yogurt and a few that suggest it might have some effect on the immune system. Note that this effect would only occur if the right bacteria were in the yogurt, and presumably they would have to be alive when the yogurt was eaten. Most commercial yogurt would be essentially just milk, with no beneficial bacterial cultures.
I think this is the most likely article from a peer-reviewed scientific publication indexed in Medline because it makes a vaguely similar claim to ‘eating a cup of yogurt a day will reduce the incidence of colds by 25%’. The actual claim is that ‘consuming a fermented milk drink decreases the amount of potentially pathogenic bacteria in the nasal cavity by 19% and yogurt has no effect’, but I can see someone writing an article or webpage about the study that misinterprets it into the claim that was made. Note that I wouldn’t have found any ‘studies’ presented in an alternative medicine magazine or on a website. The article is from 2003, which is another reason I think it might be the one described.
The literature reference about saunas seems to be Ann Med. 1990;22(4):225-7. 25 people were ‘submitted to sauna bathing’ and 25 avoided saunas. After 6 months, the number of colds among those who had taken saunas was ‘significantly’ lower. In the last three months, the incidence of colds among sauna bathers was roughly half that of the non-sauna-takers. The duration and severity of colds did not differ between the groups. As with many articles, the abstract (the only part I could get) ends with ‘further studies are needed to prove this’.
Qadgop: The reference is BMJ. 2001 Jun 2;322(7298):1327. The paper is available for free here. It’s a readable paper with a clear abstract and a ‘what is already known/what this study adds’ box for busy doctors who just want the bottom line. There is a potential conflict of interest declared in the footnotes.
Lactobacillus GG has been available as a nutritional supplement in Finland since 1990 and is very popular. There have been a few cases of illness due to infection by Lactobacillus GG, but it’s relatively rare.
Just a non-scientific personal observation: my wife and I have been taking C for 3 years now (500 Mg./day). WE never get severe colds any more! Before this, I would usually get 4-6 severe colds every winter…this would start as sniffles, and progress to sre throat, congetsed sinuses, etc. They would last about 2-3 weeks. Now, I might have a sneeze or tewo, but its over in a day or so.
Just my 2 cents…vitamine C works for us!
Stonyfield Farm yogurts do contain Lactobacillus Reuteri, if anyone cares. I find theirs the only commercial yogurt that gets rid of vaginal yeast infections and thrush. Can’t really say anything about colds, though.
