Frequently Asked Questions : - Food for the Brain

Cognitive Function Test & Dementia Risk Index

We have endeavoured to make these as comprehensive as possible and written in a way that provides clarification.

If you do not find answers to your own questions please email us at

I had a disappointing Cognitive Function test (CFT) result. Why?

Either the test has identified that you may have a slight degree of cognitive impairment in which case you might wish to follow the guidance on the results page. Alternatively there may have been another problem with the test. This could be one or more of the following:

A technical problem with the CFT.

Connection. As the CFT is online and involves timing, it requires that you have a reasonably fast and consistent connection. Therefore it is important that the network and your computer are all functioning properly. A broadband connection, if it is functioning correctly, should be adequate for the test, however if you have a dial up connection which is not working well, this could cause the pages of the test to load slowly which could have affected your test result. If your computer was running slowly for any reason such as running a scheduled scan, affected by a virus or suffering a problem with any software, this may have affected the speed with which it loaded the pages of the test.

Browser. The CFT should work on modern browsers, PC/Windows: Internet Explorer 9 onwards, Firefox, Safari, Chrome; Mac: Safari, Chrome, Firefox. However malware and virus may affect the performance of your browser.

Screen size. As specified at the introduction the test is designed for a computer with a minimum screen size of 1024 x 768 pixels (e.g. a 12 inch-wide screen), with normal settings. If you had to scroll down to during the test to see the whole page this could have affected your results. For this reason the CFT will not work correctly on iPhones or blackberries.


It is important to follow the instructions about not being disturbed, wearing glasses if necessary and ensuring your mouse is working well. If you were interrupted and had to restart the test this will have affected your result.

Completing the examples

Our pilot study showed that it is important that you do complete the examples. If you did skip the examples and then started a test unsure of exactly what to do, this could have affected your result.

I have taken the test and my result was ‘at risk’, should I be worried?

Your result means that you scored a little less well than the average person of your age, which could be for a number of reasons. For example, your concentration may not have been optimal while taking the test. It is important to remember that the Cognitive Function Test (CFT) is a useful tool to help to identify mild cognitive impairment, however it does not diagnose Alzheimer’s Disease nor impending Alzheimer’s Disease. It is advisable to follow up your CFT with a homocysteine test. If your homocysteine level is high you may be at some risk of memory decline. Also, please follow the guidelines given from completing your Dementia Risk Index questionnaire by joining COGNITION. Also, take the test again in 6 months time and see if your results improve or not. If they improve you should have no cause for concern.

I find a mouse difficult to use, will this affect my test result?

The Cognitive Function Test has been updated so that it can be conducted with, or without a mouse, ie. using a touch pad on a laptop or a tablet. However, it would still be wise to take the test with a mouse that you are familiar and can ‘select’ and ‘click’ with ease. The ability to control a mouse may be affected by issues such as tremor and arthritis, and therefore we have included a click speed test. The results of this are used to derive the test result appropriately using a complex algorithm, in this way we take computer skills into account. Please ensure that your mouse is working well before starting and is on a suitable mouse pad. If you are using an optical mouse it is a good idea to ensure that you are not using it on a reflective surface, similarly a mechanical mouse should have a very clean roller ball.

Why was I not told that I would need to remember the location of the items in the last test?

This test is designed to look at how you remember the locations of items even though you were not asked to learn their locations consciously. If you had been asked to remember the items it would have changed the kind of brain function that the test was designed to measure.

My test result was good, what does that mean?

This means that your score is similar to that of other people your age. It shows you had a quick response time on the computer, with good attentional skills and memory performance. This test does not give a comprehensive assessment of all cognitive abilities. Therefore, if you have concerns about your memory you might wish to try the test again in six month or one year’s time, or visit your GP or primary care provider. It is important to remember that the Cognitive Function Test (CFT) is a useful tool to help to identify mild cognitive impairment; however it does not diagnose nor preclude Alzheimer’s Disease. Please see Interpreting your Cognitive Function Test result

I am dyslexic. Will that affect my CFT test score?

We state on the results letter that some forms of dyslexia may affect your results, and we are researching this further. However, the pilot showed that different manifestations of dyslexia affect the test in different ways. For example those whose dyslexia coping strategy meant that they recognised the shapes of whole words did better than the norm in some parts of the test, whilst those who struggled with strings of letters did less well in other parts of the test.

Has the Cognitive Function Test been researched for accuracy?

Yes – A study published in the International Journal of Geriatric Psychiatry in January 2014, confirms that Food for the Brain’s free online Cognitive Function Test accurately measures the most sensitive memory functions that are the first indicators of increasing risk of Alzheimer’s Disease. Brain changes that affect memory often start 30 years before diagnosis, in people in their 50s.
In the study, the CFT, which measures the three aspects of memory and cognition that decline in Alzheimer’s (episodic memory, executive function and processing speed) was compared to the best paper and pencil tests currently used to diagnose mild cognitive impairment, the forerunner of dementia/Alzheimer’s. There was almost perfect correlation showing the CFT test to be highly sensitive.

The upgraded CFT, launched in 2021, has been validated via a pilot study involving 50 volunteers carried out in the summer of 2021 prior to the upgrade being implemented. There was a very high correlation between test scores (p <.001) from the original and the upgraded CFT.

Who owns or designed the test?

The owner of the Cognitive Function Test is the Food for the Brain (FfB) Foundation. The CFT composes three elements:

Episodic memory, using cued recall and paired associate learning test constructs, developed by Catharine Trustram Eve for FfB, with the advice of Dr Celeste de Jager.

Executive Function, using a Symbol Matching test, similar in design to the Symbol Digits Modalities Test (Smith, 1995) developed as an integral part of the CFT. Reference: Smith A. Symbol Digits Modalities Test. 1995 (Eds) WPS, LA.

Processing Speed, using the Pattern and Letter Comparison Speed test, developed by Professor Salthouse, with permission to use as an integral part of the CFT, on a non-exclusive basis. Professor Salthouse retains the rights to this part of the test for use elsewhere.

Does the CFT diagnose dementia, Alzheimer’s disease or Mild Cognitive Impairment?

No. The CFT is not a diagnostic test, but a test designed to inform/educate the user about their cognitive function. If the result is below a threshold we suggest that they visit their primary healthcare provider who can perform whatever diagnostic tests are required at their discretion.

Did the charity seek IRB/ethical approval for either the pilot studies or the collection of data?

IRB approval is not required for such testing and data collection provided the information obtained is stored anonymously, with no identifier to the subject’s identification.

Is confidential information, which might in any way compromise the individual who has taken the test stored, or shared with any third parties?

In relation to the data, firstly, we only ask for a first name. We have an email address only if a person chooses to give it for the purposes of receiving reminders for retesting, and we have their age. The programme calculates their CFT score. The participant is then assigned a number, and their score and other details such as age, is only stored against this number. This dataset is available to us for research, and may be made available to other research groups on request as guiding by our Scientific Advisory Board and the charity. So, the subject cannot be identified, directly or through identifiers linked to the subjects. The participant is required to give consent for their data to be used, anonymously, for such research purposes.

Are you concerned that the test may either create undue fear or alarm in those receiving a poor score, or undue ease in those scoring well?

If an individual has cognitive impairment it is unlikely that it is possible to score well on this test. We do, however, still recommend homocysteine testing, because raised homocysteine is an independent risk factor for cognitive impairment. On the basis of current evidence a person scoring well on a cognitive function test measuring all three factors included in the CFT, and having a homocysteine below 9.5 micromol/l is currently unlikely to be ‘at risk’, although of course we do not assess other known risk factors. We also encourage repeating the test annually to ensure that this status does not change.

If a person scores poorly there are three possibilities. The first is that the result has arisen by chance; the second is that there might be genuine cognitive impairment, which can be caused or contributed to by a number of factors, and we encourage them to see their GP since early identification of cognitive impairment is essential, given that there is no evidence that Alzheimer’s disease, the most prevalent cause of dementia, is reversible. In our opinion, the ‘results report’ that the individual receives makes this clear (see below).

The third possibility is that they scored poorly due to other factors, including interruptions or technical problems during the test. We make this clear in the report and further explain the results, and possible confounding factors in linked web pages. No doubt, as we learn more we can make improvements and refinements to the test. In the ‘worst case’ scenario, where someone becomes unduly concerned due to, for example, an operator error, one imagines it will motivate them to see their GP, test their homocysteine, and/or improve diet and lifestyle factors that predispose to increased risk. None of these actions can be deemed to be harmful and may prove to be beneficial. We do our best to eliminate and adjust for these confounding factors (for example, the mouse speed test adjusts time allocated for each test; we put up copious notes about having a good internet connection, suitable screen size, no interruptions etc)

With 790 people diagnosed with dementia every day in the UK alone, most of which is Alzheimer’s, the need for early screening of decline in cognitive function is of paramount importance to the prevention of dementia and Alzheimer’s disease. We hope to conduct further research regarding this association, and also to research the impact of diet and lifestyle changes inspired by the test. You help support this research by becoming a Friend of Food for the Brain.

We have received literally hundreds of thank you letters, and remarkably few expressing undue concern.

The test was vaildated in a trial of people aged 50 to 70. If you are younger or older than this when you take the test the results may be slightly less accurate but still relevant. It is likely that for older people the risk is slightly less for a lower score as one expects test performance to decline with age.

However, everybody is welcome to take the test and we would encourage everyone to monitor their cognitive function from a relatively young age and then retake the test annually throughout their lifetime. The more people across a wider range of ages the more information we have to establish optimal scores across all ages.

Can I compare my annual retest score with my previous CFT score?

If you previously did the Cognitive Function Test before February 2022, before the latest substantial update, your results are not lost but have not yet been integrated into the new database. We hope to complete this merger in early 2023 so you’ll be able to track your CFT changes over time, dpending on funding. You support this project by becoming a Friend of Food for the Brain.

If your annual test results differ considerably please consider the factors that may have influenced your test, in particular basic elements such as internet speed and screen size. If you are concerned please contact your GP and, as ever, follow the six simple steps for Alzheimer’s prevention, or complete the DRI questionnaire for even more detailed recommendations.

Why does the Dementia Risk Index (DRI) have eight areas for action?

The Dementia Risk Index is substantially more comprehensive and has subdivided the previous ‘active lifestyle’ domain in into ‘active mind’ and ‘active body’ domains. A new domain of ‘healthy gut’ has been added as there is a new gut-brain frontier with a growing body of research in relation to dementia. The CFT remains valid and the six simple steps are certainly just as beneficial as ever, but the DRI follow up steps go even further, so it is really worth completing.

How does the DRI scoring work?

Based on an analysis of meta-analyses (studies of studies) a percentage of total dementia risk has been allocated to each domain. One’s Homocysteine/ Vitamin B status accounts for approximately 16% of total risk, while ‘active mind’ attributes 6.5% of risk. Each question within each domain is weighted in relation to their predictive importance. The maximum (worst) score within each domain adds up to the maximum risk. The scientific advisory board (SAB) reviewed several systematic reviews and meta-analyses assigning ‘population attributable risk’ (PAR) to specific risks factors for dementia. They excluded risk factors such as genetic or head injuries, which cannot be changed, thus focussing only on those factors a person can change and thus reduce their future risk for dementia. From these, listed below, the SAB derived the following allocation of risk, out of 100%:

Low GL 10.8

Brain Fats 13.4

Antioxidants 15.9

B Vitamins/ Homocysteine 15.9

Active Body 5.8

Sleep/Calm 18.8

Active Mind 6.5

Healthy Gut 13

To read more about the scientific basis of the Dementia Risk Index read

What is the relationship between my CFT score and my DRI score?

Your CFT result is a validated measure that reflects your actual cognitive function right now, whereas your DRI score is predictive. The assumption, based on the totality of research in the field of dementia prevention, is that lowering your DRI score by making positive diet and lifestyle changes, will have a positive impact on your CFT score, either by improving it, keeping it in the optimal zone, or slowing down any decline with age. This assumption will be proven or disproven over time. The purpose of our behavioural change and healthy habits lifestyle program, COGNITION (launching in November) is to take you through a personalised, interactive journey from gradual changes to your diet and lifestyle habits over a six month period, feeding back to you how each domain score in the DRI improves, thus lowering your DRI overall, then reassessing your CFT after six months. As more people do this we will be able to research which changes make the most difference and therefore improve the predictive power of the DRI questionnaire and score, and hone our recommendations to help people further. By taking the test and completing the DRI questionnaire you are directly (and anonymously) helping with this research.

How does the ‘active body’ section of the DRI relate to people with physical disabilities?

We acknowledge that some of the questions within this section and the recommended changes are less pertinent to, or even impossible to action for, some people with some kinds of physical disabilities. Since there are a wide range of physical disabilities and no known research of specific actions for specific disabilities that impact dementia risk is currently available, we would recommend that those with disabilities interpret the questions in the context of the range of what is possible for them in their individual circumstances.

Reminder, if you do not find all the answers you need in our “frequently asked questions” please email us at