What Does the Keto Diet Have to Do with Memory Loss?
Simply put, a keto diet involves drastically reducing carbohydrate intake and replacing it with fat. This reduction in carbohydrates puts your body into a metabolic state called ketosis. As a result, your body begins burning fats for fuel instead of carbohydrates. As you probably already know, carbohydrates are metabolized into glucose or blood sugar. In turn, this leads to a host of troublesome health issues, including everything from diabetes to dementia. On the flipside, fats are an alternate way of providing your body with an energy source, without spiking blood sugar. Why is this beneficial? When your body is in ketosis it becomes incredibly efficient at burning fat for energy. Importantly, it also turns fat into ketones in the liver, which can supply energy for the brain.3 Recently, scientists discovered yet another benefit of the keto diet that impacts brain health.Preventing Dementia Might Begin in the Gut
As we’ve reported in this newsletter before, recent research has revealed a strong link between overall brain health and overall gut health. In particular, studies suggest a link between certain bacterial communities living in the gut and neurological disorders, including MCI, dementia and Alzheimer’s disease. So, it’s not a surprise that scientists at the Wake Forest School of Medicine explored how modifying one’s diet may influence the microbial communities as a whole in the gut. These microbial communities include bacteria, fungi and other microbes that live in the human intestinal tract. Researchers studied a group of 17 older adults whose average age was 65. Eleven of the participants had MCI and six had no cognitive issues at the beginning of the study. Interestingly, the gut bacteria of those with MCI had a distinctive “signature,” featuring certain types of fungi, not found in their cognitively normal-functioning peers. This discovery was a scientific “first” since MCI has only been associated with a high-risk profile of Alzheimer’s biomarkers in cerebrospinal fluid. But things were about to get even more interesting.Brain Benefits of Specific Diets
Researchers turned to a diet they called a Mediterranean-style keto diet (MMKD) which provided high levels of healthy, low-saturated fats featuring lean meats, fish and olive oil. This diet was also low carbohydrate with carbohydrates making up less than ten percent of total caloric intake. That’s very low! For six weeks, the researchers assigned the adults to eat either an MMKD that’s high in healthy fats, or the American Heart Association diet, which is low in fat and high in carbohydrates. Despite participants with MCI initially having less fungal diversity in their guts, after eating an MMKD their healthy gut diversity was restored. “Although we do not fully understand how these fungi contribute to Alzheimer’s disease, this is the first study of its kind to reveal their role in our mental health, which we hope will ignite thinking in the scientific community to develop better understanding of them in relation to Alzheimer’s disease,” says principal investigator HariomYadav, Ph.D. “It also indicates that dietary habits such as eating a ketogenic diet can reduce harmful fungi in the gut, which might help in reducing Alzheimer’s disease processes in the brain,” he explains.Fights Inflammation
Some types of bacteria produce substances known to suppress the growth of certain fungi. The authors say that this may explain why eating an MMKD curb the growth of fungi called Candida in the guts of participants with MCI. It’s important to note that Candida has been linked to a range of inflammatory diseases of the gut, not to mention Alzheimer’s disease. Studies show that inflammation plays an important role in Alzheimer’s disease.4And researchers believe that because a keto diet thwarts Candida and reduces inflammation, it may help reduce the risk of Alzheimer’s. Prof. Yadav and his team published their findings in the journal EbioMedicine.5My Takeaway
Prof. Yadav’s investigation was a small pilot study with limitations that the authors acknowledge. In particular, the small sample size that made it impossible to account for other variables that can increase one’s Alzheimer’s risk. It’s also important to clarify that the MMKD is not a standard keto diet. The folks in this study ate a keto diet low in saturated fat and high in healthy oils. They didn’t gorge themselves on burgers and steaks like many people who follow the keto diet choose to do. In my opinion, these healthy, lean fats and oils are what made all the difference in the positive results in gut and brain health. Regardless, I’m eager to see more research on the keto diet and brain connection. I’m a firm believer that any diet that can balance the gut microbiome and fight inflammation at the same time will be a game changer for anyone who is at risk for MCI or Alzheimer’s disease, not to mention a host of other health problems like cancer. For more information on the cognitive benefits of a keto diet, read https://www.awakeningfromalzheimers.com/reap-the-cognitive-benefits-of-ketones-without-the-full-ketogenic-diet/- https://www.alz.org/alzheimers-dementia/what-is-dementia/related_conditions/mild- cognitive-impairment
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2843530/
- https://pubmed.ncbi.nlm.nih.gov/14525681/
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6214864/
- https://www.thelancet.com/journals/ebiom/article/PIIS2352-3964(20)30326-1/fulltext
