Decreased cholesterol, tau protein levels

Animals in the rat model were placed on either a continuous or intermittent keto diet or a control diet at six months old.

Researchers found that by 12 months old, rats on both types of keto diet did not show any improved spatial learning memory or motor coordination compared to those in the control group.

However, rats on both an intermittent and continuous ketogenic diet experienced decreased cholesterol levels. Additionally, scientists found the keto diet significantly decreased blood levels of tau protein in female rats.

“Our study did show that a ketogenic diet dramatically decreased blood lipid levels and significantly decreased blood tau levels in female mice, suggesting that in individuals with genetic susceptibility for late-onset Alzheimer’s disease, changes in diet may be beneficial in slowing or mitigating some aspects of disease onset/progression. Further, the ketogenic diet produced changes that may improve some aspects of health in these animals.”

– Jennifer Rutkowsky, PhD

“The next step is to determine if the ketogenic diet significantly alters markers of pathology and cellular processes that contribute to disease progression,” Rutkowsky continued.

“Translation of the present study to humans would involve consumption of a ketogenic diet, or possibly a ketone supplement, prior to the development of major disease symptoms. This would require motivated people who would commit to a diet change for a significant portion of their lives. Therefore, it is important to determine if the diet produces sufficient changes to warrant long-term diet studies in humans,” she cautioned.

The keto diet is not for everyone

MNT also spoke with Monique Richard, MS, RDN, LDN, a registered dietitian nutritionist and owner of Nutrition-In-Sight, about this study.

Richard stressed that the keto diet, while an effective, well-researched therapeutic diet for epilepsy and other specific medical health conditions when being closely monitored by a registered dietitian nutritionist and respective healthcare team, is not for everyone.

“For most individuals, a ketogenic diet is difficult to follow, is not sustainable long-term, and could have negative consequences,” she explained.

“In clinical practice, I have observed individuals’ goals such as a decrease in weight or blood glucose levels be positively affected almost immediately following a ketogenic diet — they either self-prescribed or followed social media to implement a keto diet,” said Richard.

“However, after a ‘honeymoon phase’ of 8-12 weeks, many individuals’ lipid profiles and liver enzymes dramatically increased while their digestive health — bowel movements, gastrointestinal issues — cognition, and satisfaction or pleasure with eating were adversely affected,” she warned. “In addition, both their macro- and micronutrient needs are commonly not consistently being met which may cause other symptoms or exacerbate other issues.”

Richard said it is also important to remember that brain health is not only supported by proper nutrition and a standard lipid profile does not tell the whole story of internal health.

“It would be interesting to see if there was any correlation between those following a ketogenic diet or modified ketogenic diet for five to 10 years or more and increased risk for colon cancer or digestive impairment including integrity of the gallbladder, liver, and gut lining,” she added.