The claim
The claim has to do with ketones. Ketones are what our bodies produce when they convert fat into energy. The primary source of energy for the brain is glucose. In Alzheimer’s disease, it’s believed that brain cells have difficulty metabolizing glucose. But the theory is that ketones that are produced in our bodies when digesting coconut oil may provide an alternative fuel source to keep the brain nourished.

The evidence
Currently, there is no research to support or refute the theory that coconut oil can prevent or treat dementia. However, the interest in coconut oil highlights some important questions to consider when evaluating research evidence:

• Where was the study published?
  Research results are reported in many places, including the media. But for health-care providers, researchers, policymakers and others who rely on research findings, they will typically consult peer-reviewed journals. Peer review is a system whereby an article is evaluated by experts, providing credibility to the research, including assurance that the study’s methods and conclusions are appropriate.
• How was the study carried out?
  There are many ways researchers could study the effects of something like coconut oil. For example, they could identify a group of people and measure how much coconut oil each one consumes then follow them over time and compare the risk of developing dementia. This type of study is called “observational.” Researchers study peoples’ behaviours and link these behaviours to health outcomes. Observational studies can be very powerful. However, observational studies must also be interpreted in context with their susceptibility to bias. In this example, people who consume coconut oil may differ from those who do not in various ways. These differences could explain why dementia is (or is not) more common in one group. For this reason, to obtain stronger evidence of “cause and effect” researchers conduct randomized controlled trials (RCTs). With RCTs, study participants are randomly assigned to receive an intervention such as a drug, diet or lifestyle program, or not. This random assignment is meant to make the groups as similar as possible, except for having received the intervention being studied. The study participants are followed over time and their health outcomes are compared.

The bottom line
The effect of coconut oil on Alzheimer’s disease is unclear and more research is required before drawing any firm conclusions. But the interest in coconut oil reinforces the value we place on research. It’s our best hope of finding effective treatments for Alzheimer’s disease and other dementias and improving the quality of life and care for those affected.