Alzheimer’s: Fusing these two diets would be ideal for preventing disease
In France, nearly one million people are estimated to have Alzheimer’s disease. ‘In addition, it is estimated that 225,000 new cases are diagnosed each year in France,’ writes the Defeat Alzheimer Foundation. By 2050, there could be 152 million people affected by the disease, according to the World Health Organization (WHO). Factors that contribute to its development include age, sedentary lifestyles, but also cardiovascular risks and diabetes.
But according to an American study, following “a Mediterranean-based ketogenic diet” could reduce the risk of Alzheimer’s disease. Their findings are published in the journal Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association.
Alzheimer’s: a ‘modified Mediterranean ketogenic diet’ could reduce the risks
To arrive at these results, the researchers relied on a panel of 20 adult volunteers. Nine of them had mild cognitive impairment (MCI) and 11 had normal cognition. For 6 weeks, half of the participants followed what the researchers call a ‘modified Mediterranean ketogenic diet’, i.e. it is composed of healthy fats and proteins and is low carbohydrates (sugars). At the same time, the other half followed a low-fat, high-carbohydrate diet. Then, over the next 6 weeks, both groups switched diets.
As a reminder, the ketogenic diet is a diet that reduces carbohydrate (sugar) intake and increases fat (fat) intake. The goal is to achieve a state of “ketosis”, that is, the body gets its energy from fat.
The Mediterranean diet is a diet “rich in vitamins, antioxidants but also in fiber” as the National Nutrition Health Program (PNNS) writes. It is rich in omega-3 and aims to reduce ultra-processed foods.
Throughout the 18-week experiment, the researchers collected stool samples to analyze the gut microbiome, the bacteria that live in the digestive tract. They were particularly interested in the impact on gamma-aminobutyric acid, also known as GABA, one of the main inhibitory neurotransmitters in the central nervous system. ‘Its dysfunction is associated with neuropsychiatric disorders, including Alzheimer’s disease,’ the researchers write.
Diet: Microbiome could affect brain health
The authors noted that people with mild cognitive impairment on a ‘modified Mediterranean ketogenic diet’ ‘had lower levels of gamma-aminobutyric acid (GABA) and GABA-producing microbes’. In addition, they had a greater amount of bacteria that regulate this neurotransmitter.
In addition, people with mild cognitive impairment who used curcumin (a molecule found in turmeric) had fewer BSH-containing bacteria. These bacteria are involved in the regulation of bile acids (helping to digest fat) produced by the liver and gut. A decrease in the number of these bacteria results in an increase in the time it takes for food to pass through the intestine. ‘Abnormal bile acid profiles have been observed in adults with Alzheimer’s disease,’ the researchers write.
‘These findings provide crucial information on how diet can affect the microbiome and improve brain health,’ Suzanne Craft, professor of gerontology and geriatric medicine at the Wake Forest University School of Medicine, said in a statement. The latter stresses that further studies are needed “to assess the role of dietary interventions in patients with cognitive impairment.”
