Study on Diet and Cognition after Cancer Treatment
The Perceived Relationship between Diet and Cognitive Function in Breast
and Colorectal Cancer Survivors: A Qualitative Study
- Summary of main findings –
Aim
The aim of this study was to identify what cancer survivors thought
about the relationship between their diet and cognitive function, and, how
their cancer-related cognitive changes have influenced their diet. Cognition
could refer to any aspect of thinking including someone’s ability to think,
their memory, to focus or concentrate on something, to respond or react to
things, or to make decisions. We also looked at what kind of changes survivors
made to their diet since being diagnosed with cancer, what survivors’ perceived
as contributing to those changes, and what prevented them making changes to
their diet.
Methods
Interviews were conducted with 15 cancer survivors. Thirteen participants were
breast cancer survivors and two participants were colorectal cancer survivors.
On average, survivors had been diagnosed with cancer 27 months before their
interview. ‘Thematic analysis’ was used to identify
the most common themes across all participants. Not all themes were applicable
to all participants, nor were the main themes able to capture all the unique
elements of survivors’ stories, however the most common themes are listed here.
There was an abundance of interesting and rich data that participants shared;
only the data relating to the main research questions are mentioned here.
Results
- There were four common themes relating to how
survivors perceived diet impacted their cognition:
i)
Directly (e.g. a healthy diet
improves cognition and thinking and a worse diet makes it harder)
ii)
Indirectly (e.g. diet affects things
like energy and tiredness, which in turn affect cognition and thinking)
iii)
No impact (e.g. diet doesn’t affect
cognition or thinking)
iv)
Potentially (e.g. survivors’ diet
quality was generally good, but if they had poorer diet quality they believed
their cognition would probably be worse)
- Three main themes emerged for how
cancer-related cognitive changes impacted survivors’ diets:
i)
Meal
planning was more difficult (e.g. it’s harder to think of what to cook, come up with menu plans and
do the shopping)
ii)
The process
of cooking became more challenging and more complex (e.g. it’s harder to
follow recipes; it’s a greater effort to cook foods/meals that used to be
easier)
iii)
It’s
harder to say no to less healthy food (e.g. cognitive fatigue makes it
harder to resist cravings; difficulties with meal planning leads to grabbing
more convenient foods).
- For survivors who had made changes to their
diet since being diagnosed with cancer (which had continued after active
treatment stopped), there were four changes that were most common:
i)
Changes to
meal timing
(e.g. eating when they are hungry and not by the clock or to an external
schedule)
ii)
Less
overall variety (e.g. using less variety of ingredients in recipes, or using fewer
types of recipes)
iii)
More
plant-based food (e.g. introducing more vegetables and legumes)
iv)
Using more
convenient food (e.g. using more frozen, jar, packet or ready-made meals).
- Survivors perceived four main causes of these
dietary changes (in addition to those that perceived their cognitive
changes also contributed to the changes):
i)
Persisting
side-effects from treatment (e.g. fatigue, changes to sense of taste, gastrointestinal discomfort)
ii)
Persisting
habits from treatment (e.g. avoiding foods that they weren’t able to eat when they were going
through primary treatment)
iii)
Changes to
work schedule (e.g. working less now meant greater flexibility with what and when
they could eat)
iv)
Preventative
health
(e.g. avoiding possible negative outcomes of treatment).
- There were three main barriers that survivors
experienced to making positive dietary changes
i)
Too much to
think about
(e.g. there’s a lot of other important things that need focussing on so diet
can’t always be a priority)
ii)
Tiredness (e.g. feeling more fatigue
means less energy to make dietary changes)
iii)
Other
people’s needs (e.g. they prepare meals for family members and are limited by what
foods can be enjoyed by the whole family).
One
paper has recently been published in the European Journal of Cancer Care,
an academic journal that disseminates research worldwide relating to cancer
patients and survivors, and cancer care (https://onlinelibrary.wiley.com/doi/10.1111/ecc.13303).
We
are currently preparing a second paper for publication, and are also recruiting
for a related study.
Conclusions
Many participants perceived that their diet and cognition can impact one
another in various ways. As this was a small study, more research is needed on
how diet and cognition might affect one another in cancer survivors, before any
specific recommendations can be made. However, initial findings from this study
suggest that dietary assistance with meal planning and preparing, especially in
ways that accommodate
cognitive changes such as difficulty focussing and
concentrating, memory challenges, and physical and mental tiredness, may be
beneficial for those experiencing cognitive changes.
While some of these findings may seem common-sense or expected, this is
one of the first studies that has begun to look at these important issues in
this way. More research can now build on these findings. This may include
trialling different dietary plans to see if diet can improve cancer-related
cognitive changes. It may also lead to the development of dietary resources
that support people who have survived cancer with meal planning and cooking.
We would like to thank all those involved in the project, especially the
participants for sharing their stories and experiences.
On behalf of the study team: Mr. Daniel Coro, Dr. Amanda Hutchinson,
Prof. Siobhan Banks, & Prof. Alison Coates
(Chief
Investigator and project supervisor: Dr. Amanda Hutchinson; e: Amanda.hutchinson@unisa.edu.au; p: +61 8 8302 4468)
