Once a week.
Subscribe to our weekly newsletter.
Can't quit smoking? It might be to do with how sad you are
Smoking is not just habit-based but is deeply entwined with emotions.
Emotions have a powerful part to play in both our behavioural choices and our health.
Experiencing a range of positive emotions has been associated with lower levels of inflammation, for example, and emotional control has even been linked to higher performance in sportspeople. Negative emotions, too, can have a serious impact on behaviour: research has investigated the emotional triggers of self-harm, for instance.
Now new research from Charles Dorison and colleagues at Harvard University, published in PNAS, has looked at the role of negative emotions in addiction. Though some theories say negative mood in general is associated with problematic substance use, the study suggests that, for tobacco at least, it's sadness per se that is related to addiction.
For their first study, the team looked at data from a national survey that tracked 10,685 people over 20 years. It found that sadness significantly predicted smoking status — something that no other emotion, positive or negative, did. There seemed to be a long-term effect, too: sadness reported at the first phase of the data predicted smoking ten and twenty years later.
In the second study, which looked at cravings for cigarettes, 425 smokers were placed into three conditions: sadness, disgust and neutral. Those in the sadness condition were shown a clip from the notoriously tear-jerking Pixar film Up, and were then asked to write about a time they themselves had experienced significant loss, like the elderly man in the film.
Participants in the disgust condition were shown another iconic film clip: the scene from Trainspotting in which Ewan McGregor roots around in a decidedly unclean toilet. They were then asked to write about an unsanitary experience in their own life. And in the neutral condition, participants viewed a video about furniture making and were asked to write about their work.
Before and after watching the clips, participants were asked three questions about how much they were craving cigarettes — and, once again, sadness was related to tobacco use. Sadness increased craving compared to both the neutral and disgusted states, the latter of which appeared to decrease cravings (perhaps rather unsurprisingly, although the effect wasn't statistically significant).
A third study again looked at cravings, asking 760 participants to watch either neutral or sad videos, and then indicate whether they'd prefer to have a few puffs of a cigarette immediately, or wait to have more puffs after a small delay. Those in the sadness condition were far more impatient, craving fewer puffs sooner than those in the neutral condition.
And in a final study, 158 smokers were asked to abstain from smoking for at least eight hours, with their breath verified through a carbon monoxide test. Participants were again asked to watch either a sad or neutral video. They then smoked a cigarette through a device that measures volume, speed and duration of puffs. Mirroring previous results, smokers in the sadness condition were both more impatient and smoked more per puff.
Though the findings certainly do present a strong argument for an emotion-specific model for smoking cessation, there were things left unaddressed. Only one of the experimental studies looked at other negative emotions (i.e. disgust, induced by watching the Trainspotting clip). Concluding that sadness is more potent than other negative emotional states may be too strong a statement — we have no idea how anxiety, fear or anger, for example, could trigger tobacco use.
It may also be worth conducting further research on the link between negative emotions and other addictive substances: the relationship between sadness and heroin use, for example, may be entirely different.
But encouraging people to give up smoking is not an insignificant health intervention: in both the US and the UK, tobacco use is the leading cause of preventable death, and one billion more premature deaths worldwide are expected to occur because of smoking by the end of the century. Understanding that, for many, smoking is not just habit-based but is deeply entwined with emotions may be a good way to develop anti-smoking programmes that work for everyone.
- The Big Five Personality Traits and What They Mean to Psychologists ›
- Lonely people may lose the reflex to mimic other people's smiles ... ›
A new study finds that dogs fed fresh human-grade food don't need to eat—or do their business—as much.
- Most dogs eat a diet that's primarily kibble.
- When fed a fresh-food diet, however, they don't need to consume as much.
- Dogs on fresh-food diets have healthier gut biomes.
Four diets were tested<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTU5ODI1MS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY1NjY0NjIxMn0._w0k-qFOC86AqmtPHJBK_i-9F5oVyVYsYtUrdvfUxWQ/img.jpg?width=980" id="1b1e4" class="rm-shortcode" data-rm-shortcode-id="87937436a81c700a8ab3b1d763354843" data-rm-shortcode-name="rebelmouse-image" data-width="1440" data-height="960" />
Credit: AntonioDiaz/Adobe Stock<p>The researchers tested refrigerated and fresh human-grade foods against kibble, the food most dogs live on. The <a href="https://frontierpets.com.au/blogs/news/how-kibble-or-dry-dog-food-is-made" target="_blank">ingredients</a> of kibble are mashed into a dough and then extruded, forced through a die of some kind into the desired shape — think a <a href="https://en.wikipedia.org/wiki/Food_extrusion" target="_blank">pasta maker</a>. The resulting pellets are sprayed with additional flavor and color.</p><p>For four weeks, researchers fed 12 beagles one of four diets:</p><ol><li>a extruded diet — Blue Buffalo Chicken and Brown Rice Recipe</li><li>a fresh refrigerated diet — Freshpet Roasted Meals Tender Chicken Recipe</li><li>a fresh diet — JustFoodforDogs Beef & Russet Potato Recipe</li><li>another fresh diet — JustFoodforDogs Chicken & White Rice Recipe.</li></ol><p>The two fresh diets contained minimally processed beef, chicken, broccoli, rice, carrots, and various food chunks in a canine casserole of sorts. </p><p>(One can't help but think how hard it would be to get finicky cats to test new diets. As if.)</p><p>Senior author <a href="https://ansc.illinois.edu/directory/ksswanso" target="_blank" rel="noopener noreferrer">Kelly S. Swanson</a> of U of I's Department of Animal Sciences and the Division of Nutritional Sciences, was a bit surprised at how much better dogs did on people food than even refrigerated dog chow. "Based on past research we've conducted I'm not surprised with the results when feeding human-grade compared to an extruded dry diet," he <a href="https://aces.illinois.edu/news/feed-fido-fresh-human-grade-dog-food-scoop-less-poop" target="_blank">says</a>, adding, "However, I did not expect to see how well the human-grade fresh food performed, even compared to a fresh commercial processed brand."</p>
Tracking the effect of each diet<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTU5ODI1OC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY3NjY1NTgyOX0.AdyMb8OEcjCD6iWYnXjToDmcnjfTSn-0-dfG96SIpUA/img.jpg?width=980" id="da892" class="rm-shortcode" data-rm-shortcode-id="880d952420679aeccd1eaf32b5339810" data-rm-shortcode-name="rebelmouse-image" data-width="1440" data-height="960" />
Credit: Patryk Kosmider/Adobe Stock<p>The researchers tracked the dogs' weights and analyzed the microbiota in their fecal matter.</p><p>It turned out that the dogs on kibble had to eat more to maintain their body weight. This resulted in their producing 1.5 to 2.9 times the amount of poop produced by dogs on the fresh diets.</p><p>Says Swanson, "This is consistent with a 2019 National Institute of Health study in humans that found people eating a fresh whole food diet consumed on average 500 less calories per day, and reported being more satisfied, than people eating a more processed diet."</p><p>Maybe even more interesting was the effect of fresh food on the gut biome. Though there remains much we don't yet know about microbiota, it was nonetheless the case that the microbial communities found in fresh-food poo was different.</p><p>"Because a healthy gut means a healthy mutt," says Swanson, "fecal microbial and metabolite profiles are important readouts of diet assessment. As we have shown in <a href="https://academic.oup.com/jas/article/92/9/3781/4702209#110855647" target="_blank">previous studies</a>, the fecal microbial communities of healthy dogs fed fresh diets were different than those fed kibble. These unique microbial profiles were likely due to differences in diet processing, ingredient source, and the concentration and type of dietary fibers, proteins, and fats that are known to influence what is digested by the dog and what reaches the colon for fermentation."</p>
How did kibble take over canine diets?<p>Historically, dogs ate scraps left over by humans. It has only been <a href="https://www.thefarmersdog.com/digest/the-history-of-commercial-pet-food-a-great-american-marketing-story/" target="_blank">since 1870</a>, with the arrival of the luxe Spratt's Meat Fibrine Dog Cakes—made from "the dried unsalted gelatinous parts of Prairie Beef", mmm—that commercial dog food began to take hold. Dog bone-shaped biscuits first appeared in 1907. Ken-L Ration dates from 1922. Kibble was first extruded in 1956. Pet food had become a great way to turn <a href="https://www.dogfoodadvisor.com/choosing-dog-food/animal-by-products/" target="_blank">human-food waste</a> into profit.</p><p>Commercial dog food became the norm for most household canines only after a massive marketing campaign led by a group of dog-food industry lobbyists called the Pet Food Institute in 1964. Over time, for most households, dog food was what dogs ate — what else? Human food? These days more than half of U.S. dogs are <a href="https://www.nytimes.com/2014/08/03/magazine/who-made-that-dog-biscuit.html" target="_blank">overweight or obese</a>, and certainly their diet is a factor.<span></span></p><p>We're not so special among animals after all. If something's healthy for us to eat—we're <em>not</em> looking at you, chocolate—maybe we should remember to share with our canine compatriots. Not from the table, though.</p>
What makes some people more likely to shiver than others?
Some people just aren't bothered by the cold, no matter how low the temperature dips. And the reason for this may be in a person's genes.
Eating veggies is good for you. Now we can stop debating how much we should eat.
- A massive new study confirms that five servings of fruit and veggies a day can lower the risk of death.
- The maximum benefit is found at two servings of fruit and three of veggies—anything more offers no extra benefit according to the researchers.
- Not all fruits and veggies are equal. Leafy greens are better for you than starchy corn and potatoes.