Seeing red in dementia care: does the colour red stimulate appetite, or not?

If you’ve ever tapped this into Google, you’re likely to have been left more confused than when you started. Lots of web pages claim that the colour red can stimulate appetite (“look at all those fast food joints who use red in their branding – that must be for a reason!”). However, some news articles also suggest red plates could be a silver bullet for those looking to lose weight, as the colour might cause you to subconsciously eat less.

So which is it? Do red plates make you likely to eat more, or less?

It’s an important question. Up to 40% of Alzheimer’s patients experience significant weight loss (Dunne et al, 2003), so if there’s an easy, low-tech solution – we want to know about it. But is that solution red plates?

We’ve reviewed three independent studies, two of which were conducted with healthy adult participants, and one which was conducted with participants living with Alzheimer’s. And we think the answer is “sort of, it depends”.

Don’t worry, we’re about to explain…

The first study (Bruno et al., 2013) explored whether food consumption in healthy adults varied based on plate colour: red, blue and white. The participants were asked to taste snacks and report sensory experiences via a supplied questionnaire. However, the questionnaire was bogus – what the researchers were really looking for was how much of each snack the individual participants consumed, and whether plate colour affected it.

And the results showed that it did. Participants who were provided popcorn and chocolate chips on red plates ate significantly less than participants who were provided popcorn and chocolate chips on blue or white plates.
So, surely this flies in the face of all claims that red plates can boost food consumption in dementia sufferers? Well, perhaps not.

The second study also explored the effect of colour on food intake, but this time the participants were living dementia. And, although the study sample was small, the results showed an impressive 24.6% increase in food consumption when red plates were used as opposed to white.

However, there’s a caveat. The researchers used both a high-contrast red and a low-contrast red. The high-contrast red produced the impressive 24.6% increase, whereas the low-contrast red prompted no significant increase in food consumption.

This suggests that it is the contrast, rather than the colour, that causes increased food intake. The second half of the study, which was conducted a year later, used the same methodology. Except, instead of using high-contrast and low-contrast red, the researchers used high-contrast and low-contrast blue. Again, the low-contrast blue yielded no significant result and the high-contrast blue was shown to have significantly increased food intake (in fact, even a little more than high-contrast red, at 25.1%).

It should also be mentioned that high contrast-colour caused an increase in liquid consumption, too. Highly-contrasting red cups caused a massive 83.7% increase in liquid intake. Highly-contrasting blue also saw higher levels of liquid intake, but at a more modest increase of 29.8%.

So, perhaps increased appetite is more to do with the colour contrast of the dinnerware in relation to the food within it and the table its served on, rather than the hue itself?

This would make sense, as many studies that show individuals living with dementia are less sensitive to contrast, and therefore the contrast has to be greater for them to notice it (Bassi et al., 1993, Cronin-Golomb et al., 1991; Crow et al., 2003).

For example, if you served plain chicken and mashed potatoes on a white plate, it might be difficult for the person you’re serving it to distinguish the food from the plate. And if that plate was on a white table, they may well struggle to distinguish the plate from the table top.

Interestingly, the third study we reviewed suggests that colour contrast could also affect food consumption, but this time the participants were healthy adults (Van Ittersum and Wansink, 2012) .

The authors also found that the perception of a consistent portion size was significantly affected by the size of the bowl. Both servers and the people being served perceived there to be more food in the smaller bowls and less food in the larger bowls. This false perception was exaggerated further when there was a high colour contrast between both: a) the tablecloth and dinnerware and, b) the dinnerware and food (e.g creamy pasta in a red bowl).

This distorted perception of portion size could potentially be useful for people with reduced appetite. If a carer is serving the food, it may be beneficial to serve the food in a large bowl that is of high colour-contrast with the food within it, as this will make it seem like there is less food being served than there actually is. This could potentially help avoid any feelings of being overwhelmed with the amount of food.

On the other hand, if a person with Alzheimer’s is living independently, they may be more likely to serve themselves larger portions if using larger bowls.

Either way, it seems that ensuring there is a high colour contrast is key.

So why, particularly, is the colour red so dominant in dementia care equipment? We ourselves sell a lot of red tableware and cutlery. Well, red seems to be the easiest colour to contrast, standing out equally well against light and dark backgrounds. It was also shown to be one of the easiest colours to identify for Alzheimer’s patients (Wijk et al., 1999), along with blue, yellow, green and black. Mixed colours and colours with more elaborate names are more difficult for them to identify.

So in conclusion, we would advise some experimentation. Our Ornamin food preparation tools and dinnerware are available in red, blue, green and yellow. Why not try a little research of your own? After all, out of the 850,000 people in the UK living with dementia, no two will experience it the same way. Give it a go and let us know how it went.

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References

Bassi, C., Solomon, K. and Young, D. (1993). Vision in Aging and Dementia. Optometry and Vision Science, 70(10), pp.809-813.

Cronin-Golomb, A., Corkin, S., Rizzo, J., Cohen, J., Growdon, J. and Banks, K. (1991). Visual dysfunction in Alzheimer’s disease: Relation to normal aging. Annals of Neurology, 29(1), pp.41-52.

Crow, R., Levin, L., LaBree, L., Rubin, R. and Feldon, S. (2003). Sweep Visual Evoked Potential Evaluation of Contrast Sensitivity in Alzheimer’s Dementia. Investigative Opthalmology & Visual Science, 44(2), p.875.

Dunne, T., Neargarder, S., Cipolloni, P. and Cronin-Golomb, A. (2004). Visual contrast enhances food and liquid intake in advanced Alzheimer’s disease. Clinical Nutrition, 23(4), pp.533-538.

Van Ittersum, K. and Wansink, B. (2012). Plate Size and Color Suggestibility: The Delboeuf Illusion’s Bias on Serving and Eating Behavior. Journal of Consumer Research, 39(2), pp.215-228.

Wijk, H., Berg, S., Sivik, L. and Steen, B. (1999). Colour discrimination, colour naming and colour preferences among individuals with Alzheimer’s disease. International Journal of Geriatric Psychiatry, 14(12), pp.1000-1005.

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