I know you are getting tired of reading about the dangers of eating ultra-processed food. I am really sorry about that, but the research just keeps piling up that these foods are really bad for your health. Just this week there was the early release of an article in Neurology (May 22, 2024) titled “Associations Between Ultra-Processed Food Consumption and Adverse Brain Health Outcomes.” This will appear in the June 11 issue of Neurology.
Here’s the bottom line from the authors themselves:
“…a 10% increase in relative intake of UPFs [ultra-processed foods] was associated with higher risk of cognitive impairment and intake of unprocessed or minimally processed foods with lower risk of cognitive impairment. Greater intake of UPFs and unprocessed or minimally processed foods were also associated with risk of stroke…The effect of UPFs on stroke risk was greater among Black than White participants. Associations between UPFs and both cognitive impairment and stroke were independent of adherence to the Mediterranean, DASH, and MIND diets.”
In plain English: even a little bit more consumption of ultra-processed foods ups the risk of both stroke and cognitive impairment. And that’s true even if you think you are following a so-called healthy Mediterranean diet. DASH stands for Dietary Approaches to Stop Hypertension. It has been shown to lower blood pressure and have many other health benefits. But UPFs can muck up even a healthy diet.
What are we talking about when we say UPFs or ultra-processed foods? If it comes in a bag or a box, chances are good that it belongs in the UPF category. Think breakfast cereals, crackers, chips, hot dogs and granola bars just for openers. A lot of frozen foods are considered UPFs.
Who Loves Ultra-Processed Food?
Although we often picture young people consuming a lot of these foods, older folks are not immune. According to a National Poll on Healthy Aging conducted by the University of Michigan, 13% of people over 50 can’t stop eating highly processed foods. The poll included 2,163 people between 50 and 80 years old and was nationally representative. Although 1 out of 8 confessed two or more symptoms of food addiction, the problem is actually much bigger. To wit, 44% of the respondents had at least one symptom such as intense cravings or an inability to cut back on salty snacks, sugary drinks or fatty foods.
What Are the Health Consequences of Eating Processed Snacks?
Two earlier studies in The BMJ showed some of the hazards of eating lots of ultra-processed foods. Read to the bottom for critical information on how fast food can affect liver health. The most recent study shows that people who eat lots of ultra-processed foods are more likely to die at a younger age.
Ultra-Processed Foods Are Linked to Higher Mortality:
A new analysis of decades of data from the Nurses Health Study and the Health Professionals Follow-Up Study shows that people who ate more ultra-processed foods were 4% more likely to die during the study time frame (BMJ. May 8, 2024). Nearly 75,000 female nurses and almost 50,000 male health professionals participated in these long-running cohort studies, with the data on ultra-processed food consumption dating back to the mid 1980s.
The death rate among people consuming the least ultra=processed foods was 1472 per 100,000 person-years. In comparison, that for people consuming the most was 1536 per 100,000 person-years. So, as you can see, the difference was not dramatic even though it was statistically significant.
Kids Are Not Immune to UPFs!
Scientists have found that people who consume ultra-processed food are more likely to die prematurely due to colorectal cancer or cardiovascular disease. Now a study shows the effects of such a diet on children (JAMA Network Open, May 17, 2024)
The Childhood Obesity Risk Assessment Longitudinal Study evaluated the dietary habits of 1400 children. Those who consumed more ultra-processed food were more likely to have an large waists, more fat, higher fasting blood sugar and lower HDL cholesterol.
Those who consumed unprocessed or minimally processed food instead had lower body mass index, fat mass index and fasting plasma glucose. In this study, the main ultraprocessed foods were baked goods, candy, cookies and sweet beverages. The researchers note:
“Ultraprocessed foods are typically rich in saturated fats, sugars, sodium, and other substances (eg, additives) and lower in essential nutrients, all of which are associated with cardiometabolic health.”
What Counts as Ultra-Processed Food?
The researchers used a standardized categorization to determine which foods fall into the ultra-processed category.
They list:
“ultra-processed breads and breakfast foods; fats, condiments, and sauces; packaged sweet snacks and desserts; sugar sweetened and artificially sweetened beverages; ready-to-eat/heat mixed dishes; meat/poultry/seafood based ready-to-eat products (for example, processed meat); packaged savory snacks; dairy based desserts; and other.”
It turns out that the category most strongly associated with early death are meat/poultry/seafood items like hot dogs, bologna, fish fingers or chicken nuggets. Sweet beverages also contributed to the risk, with sugar-sweetened soft drinks somewhat worse than artifially sweetened ones. According to the investigators, overall dietary quality as measured by the Alternative Healthy Eating Index 2010 score was a better predictor of premature death than junk food consumption itself.
We were pleased to read that the scientists pointed out that nuts and dark chocolate, although included in the “packaged sweet snacks and desserts” category, do not appear to be dangerous for health. An editorial in the same issue urges countries to set food policies to discourage consumption of unhealthy foods whether or not they are heavily processed.
Men Eating Ultra-Processed Food Are More Prone to Colorectal Cancer:
One of the earlier analyses also utilized data from three long-running cohort studies of health care professionals (BMJ, Aug. 31, 2022). (You may recognize them as the Health Professionals Follow-Up Study, the Nurses’ Health Study and the Nurses’ Health Study 2. This last group was not included in the analysis described above.) More than 46,000 male health professionals and nearly 160,000 female nurses answered detailed dietary questionnaires every four years and provided health information.
The scientists followed these conscientious subjects for an average of about 25 years. Men who ate the most ultra-processed food had a 29 percent greater chance of developing colorectal cancer during that time. Highly processed meat, chicken or seafood products and sugar-sweetened beverages were particular culprits for these men. Perhaps beef jerky and chicken nuggets should be limited to very occasional snacks.
Oddly, the researchers did not detect a higher risk among women who ate the most ultra-processed food. However, they noticed a trend towards a higher cancer risk among women consuming more ready-to-heat or ready-to-eat foods. The scientists did need to make statistical adjustments for the fact that both men and women who ate more junk food were also likely to be smokers and less likely to exercise regularly.
Although the investigators are cautious about the conclusions they draw, they note:
“Such findings support the recommendation by the World Cancer Research Fund International/American Institute for Cancer Research to limit the intake of ‘fast foods’ for the primary prevention of cancer.”
Italians Fare Poorly on Junk Food, Too:
A second publication analyzed the diets of nearly 23,000 Italians over 14 years (BMJ, Aug. 31, 2022). (This was another large prospective study called Moli-sani.) People who ate the most ultra-processed food were 19 percent more likely to die during that time. Their risk of dying from a heart attack or other cardiovascular cause was actually 32 percent higher than that of the folks who ate the least processed foods.
The researchers analyzing these data observe
“A significant proportion of the higher mortality risk associated with an elevated intake of nutrient poor foods was explained by a high degree of food processing.”
Because these are both observational studies, they can’t establish cause and effect. However, an editorial in the same issue (BMJ, Aug. 31, 2022) argues that governments should make fresh, minimally processed foods accessible and affordable to promote the public health. Too often public policies designed to make food cheap does not take quality into account.
Fast Food and Fatty Livers:
In addition, fast food may be responsible for a troubling rise in fatty liver disease. To learn this, researchers analyzed data from people who participated in the National Health and Nutrition Examination Survey (NHANES) for 2017-2018 (Clinical Gastroenterology and Hepatology, Jan. 10, 2023). They measured liver fat in 4,000 adults using a technique called vibration-controlled transient elastography. Stiffness indicates the amount of fat stored in the liver (Biomolecules, May 2022).
The investigators also queried participants about their fast food consumption. More than half ate ultra-processed food at least occasionally. For 29%, fast food provided at least a fifth of their daily calories. These individuals tended to be younger and to drink more soda and less coffee. Most importantly, they were significantly more likely to have non-alcoholic fatty liver disease. This serious condition can lead to scarring, liver cancer or even liver failure.
The researchers conclude:
“Ultimately, public health efforts are needed to reduce consumption of nutrient-poor, highly caloric foods and improve access to healthier, nutritious food options in the U.S.”
Learn More:
Dr. Robert Lustig has been writing and speaking about the dangers of ultra-processed food for more than a decade. You may wish to listen to our interviews with him. Start with Show 947: Why Overdosing on Sugar Could Be Killing You. You may also wish to listen to Show 1145: Are Big Corporations Hacking the American Mind? He is equally clear in Show 1332: What Everyone Gets Wrong About Weight Loss.
