Decades of research have revealed that brain glucose absorption is impaired in individuals with Alzheimer’s disease (AD), even before symptoms of cognitive decline appear. Glucose, derived from ingested carbohydrates, is the primary fuel used by the brain. However, individuals with AD have a decreased ability to use the glucose that is available.
KETONES – DERIVED FROM FATTY ACIDS IN THE DIET AND BODY FAT – ARE AN ALTERNATIVE FUEL SOURCE FOR THE BRAIN, AND ONE THAT SEEMS TO WORK BETTER IN AN ALZHEIMER’S BRAIN THAN GLUCOSE.
When the body uses ketones for energy, it is in a metabolic state referred to as ketosis (pronounced key-toe-sis). Ketosis can be induced in a few ways:
1. By consuming a ketogenic diet (one that is extremely high in fat, extremely low in carbo hydrates, with moderate amounts of protein, thereby minimizing the dietary sources of glucose);
2. By adding MCT or ketone supplements to a regular diet; and
3. During prolonged fasting.
Ketogenic diets have been used since the 1920s to successfully treat symptoms of epilepsy, so it is not surprising that ketosis is now being explored as a potential treatment for other neurological disorders, including AD. Research conducted to date suggests that ketosis may indeed have beneficial effects in individuals with mild cognitive impairment (MCI) or AD.
KETONE AND DEMENTIA RESEARCH HIGHLIGHTS
A single dose of MCT improves memory in individuals with mild-to-moderate Alzheimer’s disease. A 2004 study by Reger et al., published in Neurobiology of Aging, involved 20 individuals with AD or mild cognitive impairment who consumed a drink containing emulsified medium chain triglycerides (MCTs) or a placebo. Ninety minutes later, those who drank the MCT beverage experienced significant increases in ketones, as well as greater improvement in paragraph recall (a measure of memory), compared to the control group.
A ketogenic supplement taken over a 90-day period boosts cognitive scores in mild-to-moderate AD patients. In a study conducted by Henderson et al., published in the August 2009 issue of Nutrition & Metabolism, 152 individuals who had been diagnosed with mild-to-moderate AD were given either an oral keto- genic compound (AC-1202, which is a MCT supplement) or a placebo while eating as they normally would. AC-1202 was found to quickly elevate the participants’ ketone levels and induce a mild level of ketosis. By the end of the 90-day trial, those who took the MCT supplement experienced significant improvements in their cogni- tive scores, compared to the placebo group.
Low-carb diet improves memory among small group of older adults with MCI. A more recent study conducted by Krikorian et al., published in the February 2012 issue of Neurobiology of Aging, involved 23 older adults with mild cognitive impairment who ate either a high carbo- hydrate or very low carbohydrate diet over a six-week period.
The very low carbohydrate diet was designed to induce ketone metabolism. The results showed that ketone levels were “posi- tively correlated with memory performance.” In other words, very low carbohydrate consumption, and the accompanying increase in ketone levels, was found to improve memory function in a short period of time.
Ketone ester proves effective in a single case study of a man with Alzheimer’s disease. A 2014 case study conducted by Newport et al., published in Alzheimer’s & Dementia, shared the results of administering a ketone ester (a synthetically-made supplement to induce ketosis) to one individual with younger-onset AD. The study participant maintained his usual diet and continued with the MCT/coconut oil supplementation he had been taking since 2008. During the 20-month study period, improvements were noted in his behaviour, as well as cognitive and daily-activity performance, leading the researchers to conclude that the ketone ester treatment was “robust, convenient and safe.”
THE LIMITED RESEARCH TO DATE SUGGESTS THAT MANY DIFFERENT KINDS OF KETOGENIC INTERVENTION OFFER NEUROLOGICAL AND COGNITIVE BENEFITS.
Improvements seem to occur regardless of whether ketosis is achieved through prolonged fasting or a very high-fat ketogenic diet (both of which are difficult to adhere to, especially for individ- uals with cognitive impairment), or whether ketosis is induced by taking MCT or ketone supplements while maintaining a regular diet.
It is important to note, though, that the mechanisms through which ketosis boosts cognitive function are not fully understood at this early stage in the research. Ketosis has not been rigorously studied in large-scale or controlled clinical trials, so there is a lot that remains unknown. For example, the positive effects of ketosis may not apply to everyone, and it is uncertain whether there are any long-term side effects to the various ketogenic treatments. Nevertheless, the research to date is certainly promising, and suggests that further investigations would be valuable to determine whether ketosis could be the cure or effective treatment that we have been hoping for.
DEFINITIONS:
WHAT IS MCT? Medium chain triglycerides (MCT) are fatty acids of a particular length (i.e. medium). These fats are unique because they are processed in the liver, rather than being metabolized through the digestive system like most other foods. MCT oil occurs naturally in certain foods, including coconut and palm oil, but can also be consumed as a concentrated MCT oil (which is typically extracted from coconut or palm oil).
WHAT IS A PLACEBO? A placebo is a harmless substance that has no ther- apeutic effect. Placebos are used as a control when testing new drugs to assess whether there is a psycho- logical impact of simply being treated (i.e. in the absence of any real physiological effect).
Read the original article in Volume 4, Page 51 of Mind Over Matter magazine.
