Jun 19th 2024

Ultra-processed foods: here’s how they may affect the way the immune system functions

by Samuel J. White and Philippe B. Wilson

 

Samuel J. White, Associate Professor & Head of Projects, York St John University

Philippe B. Wilson, Associate Pro Vice-Chancellor: Innovation and Knowledge Exchange, York St John University

 

In our fast-paced world, convenience can often come at the cost of nutrition. This shift has led to an increased reliance on ultra-processed foods.

But diets high in ultra-processed foods are increasingly being linked to numerous health issues – including obesity, metabolic syndrome and cardiovascular diseases. The poor nutritional profile of ultra-processed foods, which often lack essential nutrients and fibre, plays a significant role in these health risks.

There’s also growing evidence that ultra-processed foods may affect how our immune system works. This may explain why some studies have linked ultra-processed foods with inflammatory bowel disease and potentially autoimmune diseases.

Ultra-processed foods (such as packaged snacks, sugary drinks, instant noodles and ready-to-eat meals) often contain emulsifiers, microparticles (such as titanium dioxide), thickeners, stabilisers, flavours and colourants. While research on humans is limited, studies on mice have shown that these ingredients alter the gut microbiome (the community of microorganisms living in the intestines) in several ways. These many microbiome changes can in turn affect the way the immune system functions.

The microbiome and the immune system

Studies on mice have shown exposure to low concentrations of emulsifiers can weaken the gut’s mucus barrier. This can make it easier for microbes (including harmful ones) to cross in and out of the gut. Changes in the mucus barrier’s integrity also correlated with higher levels of inflammatory markers. These are signs the body’s immune system is activated.

The lack of fibre typical of diets high in ultra-processed foods may also affect the gut barrier’s integrity. The gut’s microbes need to digest fibre in order to produce short-chain fatty acids. These molecules help maintain the integrity of the intestinal barrier and regulate immune responses by dampening inflammation and helping produce T cells – a type of immune cell that attacks pathogens. Without these molecules, the integrity of the intestinal barrier may weaken and inflammation may increase.

Ultra-processed foods are also linked to changes in the gut microbiome’s composition. Diets high in saturated fats, sugars, salt and additives (such as emulsifiers) have all been shown to decrease the abundance of beneficial bacteria that help maintain the gut barrier in mice. There was also an increase in harmful bacteria that triggered inflammation.

 

Additionally, ultra-processed foods can turn on harmful genes in normally benign gut bacteria. This could potentially lead to chronic inflammation.

Real-world evidence

Observational studies in humans appear to support these findings.

Research has shown a link between diets high in ultra-processed foods and signs of systemic inflammation, changes in gut microbiome diversity, increased production of gut molecules that cause inflammation and decreased production of beneficial short-chain fatty acids.

For example, one trial showed that a diet high in ultra-processed foods led to higher calorie intake and weight gain compared to a diet without any ultra-processed foods that was matched for calories and sodium levels. Over time, highly ultra-processed diets may contribute to obesity and chronic inflammation. Both factors are closely linked to alterations in the gut microbiome – including decreased microbial diversity and increased gut permeability – which may subsequently affect immune function.

Other research has shown that consuming a lot of salt – common in ultra-processed foods – can increase the number of T cells the body generates, which may increase inflammation. A high-salt diet was also linked with lower levels of beneficial Lactobacillus bacteria in the gut. These bacteria help maintain good gut health by inhibiting harmful bacteria and supporting the gut barrier.

Another study found that when people avoided ultra-processed foods, they had significantly lower levels of systemic inflammation and a healthier gut microbiome compared to when they were following their usual diet. It’s not clear how many ultra-processed foods their normal diets included, however.

It’s important to note that these are observational studies, which can only show a correlation and cannot prove causation. There may very well be other factors (aside from diet) influencing these findings.

More research is needed to fully elucidate why ultra-processed foods are so harmful. But the current evidence linking ultra-processed foods to poor health, particularly concerning gut health and immune function, is compelling. As ultra-processed foods become a more significant part of global diets, understanding how they affect our health is crucial.

 

Samuel J. White, Associate Professor & Head of Projects, York St John University and Philippe B. Wilson, Associate Pro Vice-Chancellor: Innovation and Knowledge Exchange, York St John University

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

Browse articles by author

More Essays

Nov 28th 2024
EXTRACT: "Researchers analysed data from two major prostate cancer prevention trials, linking them with Medicare health records to track outcomes for over 29,000 participants. Among these, nearly 4,000 men were diagnosed with prostate cancer. Of this group, 655 underwent surgery to remove the prostate (prostatectomy), 1,056 received radiotherapy, and 2,235 did not receive treatment."
Nov 17th 2024
EXTRACT: "The weight-loss jab Wegovy made its debut on June 4 2021. It was the first new weight-loss drug to be approved by the US Food and Drug Administration since 2014. There has been a lot of excitement since the launch. Not only is the drug extremely effective (people lose about 15% of their body weight in a year), it also appears to have many benefits beyond just weight loss. It’s worth noting that the drug (generic name: semaglutide) was first used to treat diabetes, and indeed is still a blockbuster diabetes drug. So that’s two benefits already. Let’s look at some of the other potential benefits. Here are eight (and the list isn’t exhaustive)."
Oct 11th 2024
EXTRACTS: "Between 1939 and 1945, around 10% of concentration camp guards were women, yet these Aufseherinnen (overseers) as they were known, barely feature in Holocaust history or literature." ------ "One little Aufseherin, twenty years old, who had so little knowledge that she said 'excuse me' when walking in front of a prisoner, and who was visibly frightened by the first round of brutality she saw, needed exactly four days to adjust her tone and procedures, although it was totally new to her." ----- " 'The most frightening news brought about by the Holocaust and by what we learned of its perpetrators was not the likelihood that ‘this’ could be done to us, but the idea that we could do it.' ---- The true horror of genocide is found in the similarity between us and the perpetrators, not in the difference."
Oct 9th 2024
EXTRACT: "In 1928, Walt Disney's fledgling animation studio lost most of its staff to a rival company, his two latest cartoons had not found a buyer, and he had had to sell his car to meet payroll.  Disney's innovative response changed his industry, and American popular culture."
Sep 26th 2024
EXTRACT: "When it comes to economic policy, Carter is sometimes blamed for excessive regulation, government spending, and runaway inflation. His successor, Ronald Reagan, is often credited with ending the era of “big government.” But the conventional narrative fails to acknowledge that it was Carter who launched the deregulatory push that bore fruit during the Reagan years."
Sep 26th 2024
EXTRACT: "Buffett's status as the Oracle of Omaha stemmed from his ability to develop the wisdom and judgment that transformed him from a good conceptual investor into an exceptional experimental one."
Sep 26th 2024
EXTRACT: "Last year, a social-media trend featured women asking men how often they thought about the Roman Empire. The answer, it seemed, was “very”: many men claimed that the ancient empire crossed their minds weekly or even daily. That did not surprise Mike Duncan, the host of the popular 'History of Rome' podcast, and probably not Tom Holland, who has written multiple bestselling books on the topic. Mary Beard certainly understands the popular fascination, too. Her study of ancient Rome – together with her unpretentious style and brash charisma – has made her what one observer called 'a national treasure, and easily the world’s most famous classicist.' ” ----- "Beard challenges this mythology of whiteness, arguing in her 2016 book SPQR: A History of Ancient Rome that the story of the Roman Empire, which was necessarily ethnically diverse, is 'the history of people of color'. In fact, the book concludes with Emperor Caracalla’s grant of citizenship to all the empire’s subjects. The old Roman aristocracy lost its privileges, because it had not shared them."
Sep 22nd 2024
EXTRACTS: "Since the golden age of Athenian democracy, freedom of speech has been viewed as a defining feature of open societies, even as it remains under constant attack. The Athenians believed that the proper functioning of government depended on free and honest exchange of ideas, no matter how controversial or unpopular. In ancient Rome, by contrast, only senators enjoyed anything resembling free speech – and even then, as the statesman Marcus Tullius Cicero learned the hard way, speaking out could have deadly consequences." ----- "In our hyper-connected world, where mobile phones outnumber people and most of the global population has internet access, the decline of traditional news outlets has deepened our dependence on social media. As opaque algorithms shape the news we consume and our perception of reality, the corporations and oligarchs controlling these platforms pose a growing threat to free speech. Although they claim to be its ultimate defenders, their business model, by amplifying disinformation and identity-based grievances for profit, renounces the responsibility that sustains it."
Jul 27th 2024
EXTRACT: "Some conservative intellectuals think the west has already adopted Christianity-lite. Many point to the book Dominion: The Making of the Western Mind (2019), by historian Tom Holland. Holland argues that despite declining religious belief, Christian ideas remain central to western civilisation. He views liberalism – our dominant political philosophy – as secularised Christianity. For him, core western ideas, like universal human rights, equality and dignity, stem from Christianity."
Jul 26th 2024
EXTRACTS: "We often hear about the importance of the human microbiome – the vast collection of bacteria and fungi that live on and inside us – when it comes to our health. But there’s another, equally important part of this microbial community that remains far less known: the virome." ----- "Viruses are the most abundant biological entities on Earth, with an estimated 10³¹ viral particles globally and about 10¹³ in each human being." ----- "Understanding the virome could revolutionise medicine and public health."
Jul 16th 2024
EXTRACTS: "Trump joins tens of thousands of Americans treated for non-fatal gunshot wounds each year. Such experiences can shatter people’s assumptions that they are living in a safe, understandable and controllable world, leaving them feeling unworthy, unsafe and unsure. As a result, survivors of non-fatal gun violence face increased risks of depression, anxiety, substance use and post-traumatic stress disorder (PTSD). PTSD can feel overwhelming." ---- ".... some trauma survivors experience post-traumatic growth. They may develop greater empathy, stronger relationships, deeper spirituality and find new meaning in life. After being shot in 1981, the then president Ronald Reagan’s trauma seemed to deepen his sense of empathy and humility. He felt God had spared him for a reason, spurring him to reduce nuclear tensions with the Soviet Union."
Jul 15th 2024
EXTRACTS: "Artificial sweeteners such as sucralose are not metabolised by the human body so they are excreted – this is what makes them low-calorie sugar alternatives. And that’s where the environmental problem begins. Current wastewater treatment plants are unable to remove these sugar mimics, meaning they end up in our environment – in our water, rivers and soil." --- "Forever chemicals are increasingly present in our streams, rivers and oceans – most notably per- and polyfluoroalkyl substances (PFAS) that don’t degrade. PFAS are synthetic chemicals found in many consumer products, including skincare products, cosmetics and waterproof clothing. PFAS can remain in the human body for many years, and some present significant risks to our health – potentially causing liver damage, thyroid disease, obesity, infertility and cancer."
Jul 3rd 2024
EXTRACTS: "Psychologist, James Hillman had concerns about what I like to call the 'loneliness-as-pathology' "---- "....Hillman went on to argue...: 'If loneliness is an archetypal sense built into us all from the very beginning, then, to be alive is also to be lonely. Loneliness, therefore, will come and go as it chooses in the course of a lifetime, quite apart from our efforts to deny or avoid this reality.' "
Jul 3rd 2024
EXTRACT: "How can we be at least 15 times richer than our pre-industrial Agrarian Age predecessors, and yet so unhappy? One explanation is that we are not wired for it: nothing in our heritage or evolutionary past prepared us to deal with a society of more than 150 people. To operate our increasingly complex technologies and advance our prosperity, we somehow must coordinate among more than eight billion people."
Jun 25th 2024
EXTRACTS: "What’s interesting about the entire Russia-North Korea showy display of camaraderie is China’s response: silence. China has misgivings about how things are unfolding, which reports suggest prompted Chinese president Xi Jinping’s call to Putin to call off the latter’s visit to Pyongyang. Obviously, Putin didn’t heed Xi’s request." ----- "The Sino-Korean animosity dates back centuries and took shape when Korea was a vassal state of imperial China. Unfortunately, this animosity extended to modern times when Mao Zedong decided to station Chinese troops in North Korea even after the conclusion of the Korean war, and when Beijing did not aid Pyongyang in its nuclear ambitions. It didn’t help either that the founding leader of North Korea, Kim Il-sung, was suspected of espionage and was nearly executed by the Chinese Communist party in the 1930s."
Jun 19th 2024
EXTRACT: "Ultra-processed foods (such as packaged snacks, sugary drinks, instant noodles and ready-to-eat meals) often contain emulsifiers, microparticles (such as titanium dioxide), thickeners, stabilisers, flavours and colourants. While research on humans is limited, studies on mice have shown that these ingredients alter the gut microbiome (the community of microorganisms living in the intestines) in several ways. These many microbiome changes can in turn affect the way the immune system functions."
Jun 9th 2024
EXTRACT: "Alzheimer’s disease can be split in two subgroups, familial and sporadic. Only 5% of patients with Alzheimer’s are familial, inherited, and 95% of Alzheimer’s patients are sporadic, due to environmental, lifestyle and genetic risk factors. Consequently, the most effective tactic for tackling Alzheimer’s is preventative and living a healthy lifestyle. This has led researchers to study risk factors associated with Alzheimer’s."
Mar 8th 2024
EXTRACT: "This study suggests that around 10% of people diagnosed with dementia may instead have underlying silent liver disease with HE causing or contributing to the symptoms – an important diagnosis to make as HE is treatable."
Jan 28th 2024
EXTRACT: "Health disparity is a powerful weapon in the savage class warfare otherwise known as neoliberalism. (In 2020, the RAND Corporation did a study of the transfer of wealth over the last several decades from the working-class and the middle-class to the top one percent. Their estimate is a staggering $47 trillion – that is how much the “upward redistribution of income” cost American workers between 1975 and 2018.) Neoliberalism is a brutal form of labor suppression, which uses health as a means of maintaining and reproducing a condition in which wealth is constantly being redistributed upwards, and the middle-class is kept in a constant state of fear of sinking into the ranks of the poor. Medical expenses are the leading cause of bankruptcies in America – and that’s according to the American Bankruptcy Institute. The ballooning costs of healthcare serve to maintain a system marked by morally unacceptable health inequity and injustice."
Jan 28th 2024
EXTRACT. "But living longer has also come at a price. We’re now seeing higher rates of chronic and degenerative diseases – with heart disease consistently topping the list. So while we’re fascinated by what may help us live longer, maybe we should be more interested in being healthier for longer. Improving our “healthy life expectancy” remains a global challenge. Interestingly, certain locations around the world have been discovered where there are a high proportion of centenarians who display remarkable physical and mental health. The AKEA study of Sardinia, Italy, as example, identified a “blue zone” (named because it was marked with blue pen),....."