Low calorie diets have had a very mixed press; some women love them, but there are health risks associated with such strict regimes. Now it seems that there might also be an advantage in terms of cancer risk. Researchers who studied a group of vegetarians who’d maintained a diet relatively low in protein and calories found that they had lower blood levels of several hormones and other substances that have been tied to certain cancers.
The study was published in the American Journal of Clinical Nutrition and also studied a comparison group of distance runners and a control group who had higher levels of protein and calories such as are found in the average Western diet which is relatively high in protein from meat and dairy foods.
Dr. Luigi Fontana, an assistant professor of medicine at Washington University in St. Louis, was the author of the study and he reported that the low-protein group had a potential advantage over the sedentary group as they had lower levels of insulin-like growth factor 1 (IGF-1). This is a body protein that helps cells grow and multiply and high IGF-1 levels in the blood have been linked to breast, prostate and colon cancers.
On average, the vegetarians ate just below the recommended daily amount of protein – 0.8 grams per kilogram of body weight- and both the runners and the sedentary group ate significantly more than the recommended amount. When the low calorie group’s results were compared with their sedentary counterparts on a standard Western diet, the runners and vegetarians had lower levels of several hormones and inflammatory proteins linked to cancer risk.
When it came to IGF-1, specifically, the low-protein group had lower levels than runners did, even though they were equally lean – suggesting an effect of diet and not just body weight, according to the researchers. In addition, IGF-1 levels in the sedentary control group generally rose along with their protein intake.
This is not a definitive study, but as most people in the West eat more protein than their body actually needs, it does indicate that lower protein diets could mean a lower risk of developing cancer and more research is certainly needed into this.