Are all ultra-processed foods equally bad for health?

ISLAMABAD: An expanding collection of studies has indicated that the intake of ultra-processed foods (UPF) can have serious health repercussions. However, some researchers are now arguing that many studies examining UPFs and their negative impacts on health do not consider the variations in processing methods and ingredients among different subgroups.

Experts emphasize that it is more crucial to avoid specific UPFs, such as processed meats, hot dogs, sugary beverages, and salty snacks, rather than trying to steer clear of all processed foods. The evidence shows that consuming UPFs is linked to a range of severe health issues, including a higher overall mortality rate, an elevated risk of dementia, and the onset of type 2 diabetes, among other health problems.Healthcare in Crisis: Male Doctors Flee, Women Opt-Out, Warns PIMA

Nevertheless, a recent opinion piece published in the European Journal of Clinical Nutrition suggests that some of the concern surrounding UPFs may be overstated. The authors propose that many studies do not differentiate between the various processing techniques and ingredients used in different UPF categories, often leading to a one-size-fits-all conclusion.

“Different groups of UPFs evaluated in the same epidemiological study frequently exhibit significantly different correlations with health outcomes,” the authors noted. They pointed out that statistical analyses rely on numerous assumptions, such as accurate food intake measurements and known food compositions, which may not always hold true, potentially questioning the validity of the results.

Do cooking methods impact the healthiness of food? Melanie Murphy Richter, MS, RDN, a registered dietitian nutritionist and communication director at the nutrition company Prolon, who did not contribute to the paper, explained to Medical News Today that nearly all foods undergo some form of processing, but consumers should recognize the distinctions that matter.

Whether through cooking, freezing, or nutrient fortification, the term “processed” can be misleading in health discussions. It’s not the processing itself that is harmful; rather, it’s what occurs during the process. For instance, yogurt undergoes processing but is not necessarily unhealthy. This paper highlights that not all ultra-processed foods are equal, and classifying them all as harmful is overly simplistic.

Some UPFs may have neutral or even positive health effects, while others are associated with an increased risk of chronic diseases. “This indicates that UPFs are often unjustly categorized together, skewing our understanding of their health effects,” Richter remarked.

The issue lies not in the fact that foods are “processed,” but in how they are processed, the types of ingredients used, and their overall role in a person’s diet. “This distinction is crucial to recognize before making broad dietary recommendations or public health policies,” she added.

MNT also consulted Mir Ali, MD, a board-certified bariatric surgeon and medical director at MemorialCare Surgical Weight Loss Center in California, who did not participate in the paper. He concurred that UPFs encompass a broad spectrum and that assessing their direct health impacts can be challenging. Ali noted that minimally processed foods often get grouped with those containing many additives.

In general, the more additives a food contains for flavor or preservation, the more processed it is. For example, sweetened breakfast cereals are worse than plain bran cereal, which is superior to plain oats. Conversely, the fewer additives, the better. “Drip coffee is preferable to store-bought cold brew, which is better than a frozen blended coffee drink,” he explained.

What are the most problematic ultra-processed foods? The NOVA classification system categorizes foods based on the level and type of processing involved. It defines ultra-processed foods as industrial products largely made from substances like oils, fats, sugars, and proteins derived from natural foods, along with modified starch and hydrogenated fats, as well as added colors and flavor enhancers.

These include inexpensive ready-to-eat meat, poultry, and seafood products, sugary sodas, dairy desserts, and processed breakfast cereals. Richter pointed out that the worst offenders are sugary drinks like sodas and energy drinks, overly salty snacks like chips and instant noodles, and other UPFs containing trans fats and hydrogenated oils, all of which should ideally be avoided. Ultimately, it’s wise to read ingredient labels before purchasing food items.

Sugary drinks can cause insulin spikes and elevate blood sugar, which may lead to type 2 diabetes. They also contribute to overeating and weight gain, which can lead to fat accumulation in the liver and non-alcoholic fatty liver disease. Snacks with hydrogenated oils and trans fats are known for raising “bad” LDL cholesterol while lowering “good” HDL cholesterol, Richter added. This imbalance can result in arterial plaque buildup, promoting atherosclerosis and increasing the risk of heart attacks and strokes. Trans fats also contribute to inflammation and have been linked to insulin resistance and other metabolic disorders.

Processed meats carry their own health risks. Richter noted their classification as Group 1 carcinogens by the World Health Organization (WHO). “Hot dogs, sausages, and deli meats are preserved with nitrates and nitrites, which can form cancer-causing compounds during cooking or metabolism. Additionally, these meats typically contain high sodium and saturated fat levels, which can lead to hypertension and heart disease. The inflammatory properties of these foods can further heighten health risks,” she explained.

Are there ultra-processed foods that present fewer health risks? The authors of the paper emphasize that not all UPFs are alike, considering the various ingredients involved in different categories.

The evidence linking different UPFs to health outcomes and studies investigating specific food additives challenge the notion that ultraprocessing itself is the primary issue. “Other unconsidered factors may play significant roles. Thus, the recommendation to limit or avoid foods labeled as ‘ultra-processed’ based on the NOVA classification lacks robust scientific support and requires further experimental validation,” they suggested.

One attractive aspect of UPFs for consumers is their affordability compared to many natural or organic products. However, as Richter points out, there are nuances within the UPF label, with subgroups such as whole-grain bread, canned or frozen fruits and vegetables, and various dairy products offering health benefits.

For example, fortified cereals have significantly reduced the incidence of neural tube defects in infants due to the added folic acid pregnant women receive. Whole grain breads and cereals retain much of their fiber and nutrients, making them a convenient source of complex carbohydrates, vitamins, and minerals.

Yogurt is technically an ultra-processed food but can provide health benefits if low in added sugars. Yogurt enriched with probiotics promotes gut health, while calcium and vitamin D support bone health. Choosing unsweetened or minimally sweetened options allows consumers to enjoy these benefits without the drawbacks of excessive added sugars.

Ali mentioned that there is a balance that can be achieved between minimally processed foods and essential grocery items like fresh fruits and vegetables. Given the economic choices many families face, maintaining a routine that includes home-cooked meals should be a priority.