Whenever we talk about diets, we recommend avoiding ones with overly strict rules or ones that are particularly restrictive. Generally speaking, we recommend avoiding diets and eating a healthy mix of beneficial foods. We recommend enjoying foods that are higher in carbs sparingly and paying attention to your portion sizes so you can meet your goals.
There are so many faddish, crash diets in the world that we recommend avoiding the trends unless a doctor recommends it to you. But we know that some people find the structure of a diet helpful. That’s why we review diets so frequently.
When we review the science behind diets and studies in general, we often address the fact that animal studies don’t directly translate to humans. Even though trials in mice can give researchers some crucial insights, the results aren’t always replicable in humans, as our bodies are different and more complex.
Three new mouse studies were published within days of each other, saying vastly different things about the keto diet. Depending on the study, you would think you should avoid it like the plague or embrace it as the best thing to ever happen to womankind. But, again, it wasn’t human trials.
One study found that female mice at high risk for Alzheimer’s disease, because they had the APOE4 gene, had a significantly lower risk when following the keto diet. The diet seemed to even stop cognitive decline and preserve brain health.
“When we eat carbs, our brains convert the glucose into fuel for our brains, but those with the APOE4 gene — particularly females — struggle to convert the glucose into brain energy, and this can lead to cognitive decline down the road,” said Univ. of Missouri doctoral student Kira Ivanich. “By switching to a keto diet, ketones are produced and used as an alternative fuel source. This may decrease the chance of developing Alzheimer’s by preserving the health of brain cells.”
The next study found that being on a long-term keto diet caused mice to develop fatty liver disease, stressed out pancreatic cells and impaired blood sugar regulation. The results were particularly bad in male mice. But female mice also had liver fat buildup. Some metabolic problems improved after the mice were taken off the diet, suggesting the damage wasn’t permanent.
The third study found that the keto diet sped up the growth of tumors in mice with breast cancer. The researchers found that triple-negative breast cancer is driven by lipid cells. When the researchers lowered the amount of lipids in the mice, the cancer growth slowed.
“Eating a high-fat diet like Keto could make things worse,” Dr. Greg Ducker, of the Univ. of Utah, a co-author of the study, added. “It could even provide more fuel for the tumor to grow.”
Every one of these studies noted that mice are different than humans. They have different metabolisms, different genetics and react to stress differently. But it is interesting to see massively different results.
Obviously, three animal studies are not the final word on keto. But this is a reminder that all diets deserve to be closely studied.
Dr. Molly Gallop of Earlham College, who worked on the second study, put it best: “I would urge anyone to talk to a health care provider if they’re thinking about going on a ketogenic diet.”
