High-protein diets are all the rage these days, especially for those concerned with weight loss, but the more research that's been done on how these diets impact our health, the more controversial they seem to become. High-protein diets (combined with carbohydrate restrictions) have been linked to increased heart disease risk, bone loss issues and digestive system cancers, among other things.
Of course, not all high-protein diets are the same, and some variations may or may not carry the same health risks as others. But now there's a new study out of the South Australian Health & Medical Research Institute (SAHMRI) which appears to blow the lid off all high-protein diets with equal measure.
That's because the one thing that all high-protein diets share in common is, well, the protein. And protein, it turns out, might be the problem, reports MedicalXpress.
The study was originally conceived as an investigation into why individuals on high-protein diets tend to have shorter life spans. One might suspect that the shorter life spans of such dieters would be due to the negative health effects associated with these diets, but that's not what researchers found. Instead, they discovered that the more protein you eat, the faster protein synthesis occurs in your cells. And the faster that protein synthesis occurs, the more errors get produced. These errors are what lead to a shorter life span.
"Science has known for some time that eating too much, in particular protein, reduces life span; and now we know why," said Professor Christopher Proud, corresponding author on the paper. "Our team demonstrated that increased nutrient levels speed up protein synthesis within cells. The faster this process occurs the more errors are made. It's similar to everyday activities like driving – the faster you go, the more likely you are to make a mistake. The resulting build-up of faulty proteins within cells compromises health and shortens life span."
The research also found that low-protein, high carbohydrate diets have been unfairly demonized. Though they might not help with your calorie count, these diets are associated with longer life spans and improved brain health, provided that the primary sources of your carbs are whole foods like fruits, vegetables and unprocessed grains.
It should be noted that the study was performed exclusively on fruit flies and worms, so researchers will need long-term trials on humans before any of these results can be set in stone. That said, the link between high-protein consumption and increased rates of synthesis error is likely to translate to humans because these cellular processes are similar across the animal kingdom.
"We already knew that lower food intake extends life span," Professor Proud said. "But in our study this effect was lost when we removed the link by which nutrition affects the accuracy of protein synthesis, therefore revealing how overnutrition [in regards to protein] can shorten life span. Since this link also operates in humans, our findings show how lower protein consumption could promote longevity in people."