Consumption of processed foods and health risks

The researchers say further work is needed to better understand these effects, and a direct (causal) link remains to be established, but they call for policies that promote consumption of fresh or minimally processed foods over highly processed foods.

Ultra-processed foods include packaged baked goods and snacks, fizzy drinks, sugary cereals, ready meals containing food additives, dehydrated vegetable soups, and reconstituted meat and fish products - often containing high levels of added sugar, fat, and/or salt, but lacking in vitamins and fibre. They are thought to account for around 25-60% of daily energy intake in many countries.

Previous studies have linked ultra-processed foods to higher risks of obesity, high blood pressure, high cholesterol, and some cancers...^[3]

A pair of studies published Wednesday highlights the risk of frequently eating items such as hot dogs, cheese puffs, soda and french fries.

The first study, which looked at more than 24,000 adults in Italy, found that those who consumed ultra-processed foods in large quantities had a higher risk of death overall, and mortality from heart disease in particular, relative to people who ate less food in this category.

The second study followed more than 200,000 U.S. health care workers over a span of 24 to 28 years, and found that men who consumed lots of ultra-processed food — more than nine servings per day, on average — had a 29% higher risk of colorectal cancer than men who ate around three daily servings.

Fang Fang Zhang, the second study’s senior author and an associate professor at Tufts University, said the group with the highest consumption of ultra-processed foods probably got around 80% of their daily calories from those items. The U.S. average is around 57%.^[4]

If you are deciding whether or not to include a highly processed food in your diet, it may be useful to evaluate its nutritional content and long-term effect on health. An ultra-processed food that contains an unevenly high ratio of calories to nutrients may be considered unhealthy. For example, research supports an association between a high intake of sugar-sweetened beverages and an increased risk of obesity, diabetes, and heart disease.^[5]

In other words, losing weight or avoiding putting it on in the first place, may be as simple as avoiding consumption of processed foods. But wait, that’s not simple at all.

According to eatthis.com, while trading fake food for the real deal will most likely improve your health, mood and appearance, your body as well as your brain makes the transition tough.

“Processed foods are chemical-laden, addictive foods usually sold in jars, boxes and bags, and armies of well-paid food scientists make it their missions to come up with recipes that appeal to your taste buds, even if it means causing havoc to your health,” Eat This Not That! reported. And it's precisely these kinds of products that make up almost 60 percent of our daily calories and 90 percent of the added sugar we consume.

“These foods are so hard to say no to because they are loaded with added sugars and fats, which physically change how they feel inside the mouth,” Lauren Minchen MPH, RDN, CDN explained to eatthis.com. “The altered texture and taste actually make the body crave more of it.”

“When you put processed foods into your body, not only are you choosing to fuel your body with nasty chemicals, you’re depriving it of the nutrients it needs," Eat This! Not That!—an information source in the food and wellness spaces—reports. "Processed foods are often stripped or void of nutrients, so it’s not like you’re eating an apple slice that’s been dipped in gasoline; you’re not even getting the fiber from the apple anymore. From weight loss to migraine relief, you can reap some serious health benefits if you ditch processed foods.”

According to the editors at Eatthis.com, in “21 Things That Happen to Your Body When You Stop Eating Processed Food,” not only will you lose weight faster, age slower, get less headaches and have better hair, skin and brain function, among others, you will actually start to hate processed foods.^[7]

The category includes everything from cookies and sodas to jarred sauces, cereals, packaged breads and frozen meals, even ice creams. You might not realize you're eating one, but look close and you'll see many ingredients you wouldn't find in your kitchen – think bulking agents, hydrolyzed protein isolates, color stabilizers, humectants.

They dominate the food supply. And a large and growing body of evidence has consistently linked overconsumption of ultra-processed foods to poor health outcomes.

"Four of the top six killers are related to an inadequate diet, which in the U.S. is probably largely due to convenient, safe, inexpensive food that we eat too much of," says Christopher Gardner, the director of nutrition studies at Stanford University, who has spent decades studying the links between diet and chronic disease. "Too much of it leads to obesity and type two diabetes and heart disease and cancer."^[9]

Unfortunately, just like an expensive car, your brain can be damaged if you ingest anything other than premium fuel. If substances from "low-premium" fuel (such as what you get from processed or refined foods) get to the brain, it has little ability to get rid of them. Diets high in refined sugars, for example, are harmful to the brain. In addition to worsening your body's regulation of insulin, they also promote inflammation and oxidative stress. Multiple studies have found a correlation between a diet high in refined sugars and impaired brain function — and even a worsening of symptoms of mood disorders, such as depression.

It makes sense. If your brain is deprived of good-quality nutrition, or if free radicals or damaging inflammatory cells are circulating within the brain's enclosed space, further contributing to brain tissue injury, consequences are to be expected. What's interesting is that for many years, the medical field did not fully acknowledge the connection between mood and food.^[10]

UPFs, which are food products that consist of highly processed food components such as oils, fats, sugars, starch, and protein isolates, offer little to no health benefit for the consumer. In addition to these ingredients, UPFs also often consist of artificial flavorings, colorings, emulsifiers, and other cosmetic additives. Some examples of common UPFs include breakfast cereals, sweet and savory snacks, ice cream, ready-to-eat frozen meals, processed meats, and sugar-sweetened beverages.

Over the past 40 years, the production of UPFs by the global food industry has increased substantially. In fact, recent estimates indicate that UPFs comprise 58% of the calories consumed by U.S. citizens, 57% of those consumed by British citizens, 48% of those consumed by Canadian citizens, and 30% of calories consumed by Brazilian citizens.

Previous studies indicate widespread consumption of UPFs is directly related to an increased risk of cardiovascular diseases, metabolic syndrome, and obesity. However, due to the lack of data correlating the risk of UPF consumption and dementia, the current study aimed to better understand this potential association.^[11]

In a study published today in the journal JAMA Neurology, researchers looked at more than 10,000 individuals over a median period of 8 years.

They concluded that people whose daily calorie intake is at least 20% from ultra-processed foods had a 25% faster decline in executive functions and a 28% faster rate of overall cognitive impairment.

The researchers noted that if a person’s overall diet quality was high, the effect of ultra-processed foods was less.

“While this is a study of association, not designed to prove cause and effect, there are a number of elements to fortify the proposition that some acceleration in cognitive decay may be attributed to ultra-processed foods,” Dr. David Katz, a specialist in preventive and lifestyle medicine and nutrition, told CNN.

“The sample size is substantial and the follow-up extensive. While short of proof, this is robust enough that we should conclude ultra-processed foods are probably bad for our brains,” he added.^[13]

While high intake of ultra-processed foods have been associated with cardiovascular disease and cancer and believed to induce systemic inflammation and oxidative stress, little was known about its effect on cognition until now.

The study, which was presented Monday at the 2022 Alzheimer’s Association International Conference in San Diego by Natalia Gonçalves, PhD from the University of São Paulo, followed roughly 10,000 Brazilians for up to 10 years and defined ultra-processed foods as “those that go through significant industrial processes and contain large quantities of fats, sugar, salt, artificial flavors/colors, stabilizers and/or preservatives.”

More than half of the participants were white and women and the average age was 51. Cognitive performance was evaluated using an array of tests: immediate recall, late recall, recognition, semantic and phonemic verbal fluency and trail-making tests. The most common foods participants reported eating were hot dogs, burgers, pizza, fast food, instant noodles, packaged bread, according to Gonçalves.

While the suggested daily caloric intake depends on a variety of factors, including age, weight and height, as well as level of physical activity, the U.S. Department of Agriculture suggests 2,200–2,800 calories for men between 41-50 years old and 1,800–2,200 calories for women between 41-50 years old, so 20% of a 2,200-calorie diet would be 440 calories. Meanwhile, a snack-sized bag of chips is about 150 calories and there are roughly 285 calories in a slice of pizza.^[14]

Research from the past ten or so years has shown that the more ultraprocessed foods a person eats, the higher the chances that they feel depressed and anxious. A few studies have suggested a link between eating UPFs and increased risk of cognitive decline...

Recent research has demonstrated a link between highly processed foods and low mood. In one 2022 study of over 10,000 adults in the United States, the more UPFs participants ate, the more likely they were to report mild depression or feelings of anxiety. “There was a significant increase in mentally unhealthy days for those eating 60 percent or more of their calories from UPFs,” Dr. Hecht, the study’s author, said. “This is not proof of causation, but we can say that there seems to be an association...

“Many high-quality, randomized studies have shown the beneficial effect of a nutrient-dense diet on depression, but we still do not fully understand the role of food processing on mental health,” said Melissa Lane, a researcher at the Food & Mood Centre at Deakin University in Australia. However, there are some clues.

Much of the research has focused on how poor gut health might affect the brain. Diets that are high in ultraprocessed foods are typically low in fiber, which is mostly found in plant-based foods like whole grains, fruits, vegetables, nuts and seeds. Fiber helps feed the good bacteria in the gut. Fiber is also necessary for the production of short-chain fatty acids, the substances produced when it breaks down in the digestive system, and which play an important role in brain function, said Wolfgang Marx, the president of the International Society for Nutritional Psychiatry Research and a senior research fellow at Deakin University. “We know that people with depression and other mental disorders have a less diverse composition of gut bacteria and fewer short-chain fatty acids.” ^[16]