Absolutely, the big ones are health discoveries where a study has found such and such is good/bad for you. It hits the headlines and suddenly everyone is eating more/less of X or taking supplement Y. The follow up studies that discover procedural/statistical problems or just over reaching claims get far less press and the meme continues.
It is like the myth that you should drink 8 glasses of water a day. In this case the advice (from the WHO I think) was people needed 2 litres of water a day, which can be sourced from your normal food and beverage intake. This was altered to drinking 8 glasses of water a day and promoted by the bottled water industry. I get into discussions with people about it over and over but because it is all pervading I rarely make headway.
Another one is wheat grass . . though I find a more receptive audience for that one usually, except from the committed hippy types.
The protein myth (that vegetarians don't get enough protein) was introduced in 1971. In 1991 the author of the book that created the myth retracted her statement but the idea will not die: http://www.diseaseproof.com/archives/diet-myths-complementar...
> A dangerous myth
To wrongly suggest people need to eat animal protein for nutrients will encourage them to add foods that are known to contribute to the incidence of heart disease, diabetes, obesity, and many forms of cancer, to name just a few common problems.
The World Cancer Research Fund and American Institute for Cancer Research published a report linking diet to cancer. http://www.dietandcancerreport.org/pr/?d=overview Unfortunately, I can't find the details easily accessible online, but there is a nice summary in the book Becoming Vegan. The basic findings were that increasing your intake of fruits and vegetables tended to prevent cancer and eating more meat tended to increase certain kinds of cancer. More specifically, they were able to link meat-eating to increased risk of breast, colon, prostate and pancreas cancer.
I'm also under the impression that the typical American's diet is out of balance--eating too much meat and not enough fresh fruits and vegetables. The protein myth could encourage people to add more meat to their diet when they may need to cut back.
It is like the myth that you should drink 8 glasses of water a day. In this case the advice (from the WHO I think) was people needed 2 litres of water a day, which can be sourced from your normal food and beverage intake. This was altered to drinking 8 glasses of water a day and promoted by the bottled water industry. I get into discussions with people about it over and over but because it is all pervading I rarely make headway.
Another one is wheat grass . . though I find a more receptive audience for that one usually, except from the committed hippy types.