Have you ever tried to bring back fond memories by eating or drinking something unique to that time and place?

It could be a Pina Colada that recalls an island holiday? Or a steaming bowl of pho just like the one you had in Vietnam? Perhaps eating a favourite dish reminds you of a lost loved one – like the sticky date pudding Nanna used to make?

If you have, you have tapped into food-evoked nostalgia.

As researchers, we are exploring how eating and drinking certain things from your past may be important for your mood and mental health.

Bittersweet longing

First named in 1688 by Swiss medical student, Johannes Hoffer, nostalgia is that bittersweet, sentimental longing for the past. It is experienced universally across different cultures and lifespans from childhood into older age.

But nostalgia does not just involve positive or happy memories – we can also experience nostalgia for sad and unhappy moments in our lives.

In the short and long term, nostalgia can positively impact our health by improving mood and wellbeing, fostering social connection and increasing quality of life. It can also trigger feelings of loneliness or meaninglessness.

We can use nostalgia to turn around a negative mood or enhance our sense of self, meaning and positivity.

Research suggests nostalgia alters activity in the brain regions associated with reward processing – the same areas involved when we seek and receive things we like. This could explain the positive feelings it can bring.

Nostalgia can also increase feelings of loneliness and sadness, particularly if the memories highlight dissatisfaction, grieving, loss, or wistful feelings for the past. This is likely due to activation of brain areas such as the amygdala, responsible for processing emotions and the prefrontal cortex that helps us integrate feelings and memories and regulate emotion.

How to get back there

There are several ways we can trigger or tap into nostalgia.

Conversations with family and friends who have shared experiences, unique objects like photos, and smells can transport us back to old times or places. So can a favourite song or old TV show, reunions with former classmates, even social media posts and anniversaries.

What we eat and drink can trigger food-evoked nostalgia. For instance, when we think of something as “comfort food”, there are likely elements of nostalgia at play.

Foods you found comforting as a child can evoke memories of being cared for and nurtured by loved ones. The form of these foods and the stories we tell about them may have been handed down through generations.

Food-evoked nostalgia can be very powerful because it engages multiple senses: taste, smell, texture, sight and sound. The sense of smell is closely linked to the limbic system in the brain responsible for emotion and memory making food-related memories particularly vivid and emotionally charged.

But, food-evoked nostalgia can also give rise to negative memories, such as of being forced to eat a certain vegetable you disliked as a child, or a food eaten during a sad moment like a loved ones funeral. Understanding why these foods evoke negative memories could help us process and overcome some of our adult food aversions. Encountering these foods in a positive light may help us reframe the memory associated with them.

What people told us about food and nostalgia

Recently we interviewed eight Australians and asked them about their experiences with food-evoked nostalgia and the influence on their mood. We wanted to find out whether they experienced food-evoked nostalgia and if so, what foods triggered pleasant and unpleasant memories and feelings for them.

They reported they could use foods that were linked to times in their past to manipulate and influence their mood. Common foods they described as particularly nostalgia triggering were homemade meals, foods from school camp, cultural and ethnic foods, childhood favourites, comfort foods, special treats and snacks they were allowed as children, and holiday or celebration foods. One participant commented:

I guess part of this nostalgia is maybe […] The healing qualities that food has in mental wellbeing. I think food heals for us.

Another explained

I feel really happy, and I guess fortunate to have these kinds of foods that I can turn to, and they have these memories, and I love the feeling of nostalgia and reminiscing and things that remind me of good times.

Understanding food-evoked nostalgia is valuable because it provides us with an insight into how our sensory experiences and emotions intertwine with our memories and identity. While we know a lot about how food triggers nostalgic memories, there is still much to learn about the specific brain areas involved and the differences in food-evoked nostalgia in different cultures.

In the future we may be able to use the science behind food-evoked nostalgia to help people experiencing dementia to tap into lost memories or in psychological therapy to help people reframe negative experiences.

So, if you are ever feeling a little down and want to improve your mood, consider turning to one of your favourite comfort foods that remind you of home, your loved ones or a holiday long ago. Transporting yourself back to those times could help turn things around.

Megan Lee, Senior Teaching Fellow, Psychology, Bond University; Doug Angus, Assistant Professor of Psychology, Bond University, and Kate Simpson, Sessional academic, Bond University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Social media is full of claims that everyday habits can harm your skin. It’s also full of recommendations or advertisements for products that can protect you.

Now social media has blue light from our devices in its sights.

So can scrolling on our phones really damage your skin? And will applying creams or lotions help?

Here’s what the evidence says and what we should really be focusing on.

Remind me, what actually is blue light?

Blue light is part of the visible light spectrum. Sunlight is the strongest source. But our electronic devices – such as our phones, laptops and TVs – also emit it, albeit at levels 100-1,000 times lower.

Seeing as we spend so much time using these devices, there has been some concern about the impact of blue light on our health, including on our eyes and sleep.

Now, we’re learning more about the impact of blue light on our skin.

How does blue light affect the skin?

The evidence for blue light’s impact on skin is still emerging. But there are some interesting findings.

1. Blue light can increase pigmentation

Studies suggest exposure to blue light can stimulate production of melanin, the natural skin pigment that gives skin its colour.

So too much blue light can potentially worsen hyperpigmentation – overproduction of melanin leading to dark spots on the skin – especially in people with darker skin.

2. Blue light can give you wrinkles

Some research suggests blue light might damage collagen, a protein essential for skin structure, potentially accelerating the formation of wrinkles.

A laboratory study suggests this can happen if you hold your device one centimetre from your skin for as little as an hour.

However, for most people, if you hold your device more than 10cm away from your skin, that would reduce your exposure 100-fold. So this is much less likely to be significant.

3. Blue light can disrupt your sleep, affecting your skin

If the skin around your eyes looks dull or puffy, it’s easy to blame this directly on blue light. But as we know blue light affects sleep, what you’re probably seeing are some of the visible signs of sleep deprivation.

We know blue light is particularly good at suppressing production of melatonin. This natural hormone normally signals to our bodies when it’s time for sleep and helps regulate our sleep-wake cycle.

By suppressing melatonin, blue light exposure before bed disrupts this natural process, making it harder to fall asleep and potentially reducing the quality of your sleep.

The stimulating nature of screen content further disrupts sleep. Social media feeds, news articles, video games, or even work emails can keep our brains active and alert, hindering the transition into a sleep state.

Long-term sleep problems can also worsen existing skin conditions, such as acne, eczema and rosacea.

Sleep deprivation can elevate cortisol levels, a stress hormone that breaks down collagen, the protein responsible for skin’s firmness. Lack of sleep can also weaken the skin’s natural barrier, making it more susceptible to environmental damage and dryness.

Can skincare protect me?

The beauty industry has capitalised on concerns about blue light and offers a range of protective products such as mists, serums and lip glosses.

From a practical perspective, probably only those with the more troublesome hyperpigmentation known as melasma need to be concerned about blue light from devices.

This condition requires the skin to be well protected from all visible light at all times. The only products that are totally effective are those that block all light, namely mineral-based suncreens or some cosmetics. If you can’t see the skin through them they are going to be effective.

But there is a lack of rigorous testing for non-opaque products outside laboratories. This makes it difficult to assess if they work and if it’s worth adding them to your skincare routine.

What can I do to minimise blue light then?

Here are some simple steps you can take to minimise your exposure to blue light, especially at night when it can disrupt your sleep:

• use the “night mode” setting on your device or use a blue-light filter app to reduce your exposure to blue light in the evening
• minimise screen time before bed and create a relaxing bedtime routine to avoid the types of sleep disturbances that can affect the health of your skin
• hold your phone or device away from your skin to minimise exposure to blue light
• use sunscreen. Mineral and physical sunscreens containing titanium dioxide and iron oxides offer broad protection, including from blue light.

In a nutshell

Blue light exposure has been linked with some skin concerns, particularly pigmentation for people with darker skin. However, research is ongoing.

While skincare to protect against blue light shows promise, more testing is needed to determine if it works.

For now, prioritise good sun protection with a broad-spectrum sunscreen, which not only protects against UV, but also light.

Michael Freeman, Associate Professor of Dermatology, Bond University

This article is republished from The Conversation under a Creative Commons license. Read the original article.