New American Heart Association Science Advisory Reviews Ultra-Processed Foods

DALLAS — Ultra-processed foods (UPFs) have drawn heightened scrutiny lately due to their widespread consumption and impact on potential health risks. A new Science Advisory from the American Heart Association (AHA), “Ultra-processed Foods and Their Association with Cardiometabolic Health: Evidence, Gaps and Opportunities,” summarizes current knowledge about UPFs and their impact on cardiometabolic health, and outlines opportunities for research, policy and regulatory reform to improve dietary intake and overall health.

The manuscript published in Circulation, the flagship journal of the American Heart Association.  

Most UPFs, particularly those in U.S. dietary patterns, are high in saturated fat, added sugars and sodium (HFSS) and contribute to excess calories, said AHA. These include sugar-sweetened drinks, ultra-processed meats, refined grains, candy and commercial baked goods, among others. Other ultra-processed foods, such as certain commercial whole grains, low-fat-low-sugar dairy and some plant-based items, have positive nutritional value and, therefore, can be part of an overall healthy dietary pattern, the association said. This overlap can be confusing for health care professionals and the public.

“The relationship between UPFs and health is complex and multifaceted,” said Maya K. Vadiveloo, Ph.D., R.D., FAHA, volunteer chair of the writing group for this Science Advisory. “We know that eating foods with too much saturated fat, added sugars and salt is unhealthy. What we don’t know is if certain ingredients or processing techniques make a food unhealthy above and beyond their poor nutritional composition. And if certain additives and processing steps used to make healthier food like commercial whole grain breads have any health impact.”

The rapid rise in UPF consumption since the 1990s disrupted traditional dietary patterns, potentially contributing to adverse health effects, said AHA. About 70% of grocery store products in the U.S. contain at least one ultra-processed ingredient. As detailed in a recent CDC report, 55% of calories consumed by people ages 1 and older in the U.S. were UPFs. Among youth ages 1-18 years of age, total UPF calories jumped to nearly 62%, and among adults ages 19 and older, total UPF calories was 53%. Families with lower mean income had a higher percentage of UPFs consumed per day: 54.7% for the lowest income group vs. 50.4% for highest income group.

UPFs are relatively inexpensive, convenient for use and aggressively marketed, particularly toward youth and under-resourced communities, often displacing healthier alternatives, said AHA. This shift resulted in lowering the overall nutritional quality of typical eating patterns in the U.S. and is misaligned with the American Heart Association’s dietary guidance, the association said.

The new Science Advisory reinforces current dietary guidelines from the American Heart Association to:

• Reduce the intake of most UPFs, especially those high in saturated fat, added sugars and sodium, and those that contribute to excessive calories; and
• Replace UPF consumption with healthier options like vegetables, fruits, whole grains, beans, nuts, seeds and lean proteins.

How are ultra-processed foods classified?

UPFs are multi-ingredient foods containing additives (likely intended to enhance shelf life, appearance, flavor or texture) widely used in industrial food production and not commonly used in home cooking. Human diets are increasingly including more industrially processed foods, leading to various systems for classifying foods based on processing criteria. Multiple food classification systems exist currently; this Science Advisory focuses on the Nova framework for food classification. The Nova system, the most widely used, is based on the nature, extent and purpose of the food’s industrial processing. However, this categorization does not consider the nutritional quality of foods, said AHA. Certain types of industrial food processing are beneficial for preservation and safety and/or lowering cost, such as techniques that extend shelf life, control microbial growth, mitigate chemical toxicants, preserve functional, nutritional and sensory (taste) qualities and reduce food loss and waste.

Efforts to understand UPFs are hindered by differing definitions, limitations in dietary assessment tools and food composition databases, which often lack detailed information on additives and processing methods, said AHA. Currently, U.S. manufacturers are not required to disclose processing techniques or cosmetic additive quantities, which contributes to the variability in risk estimates and confusion for consumers.

The AHA writing group cautioned that an overreliance on the degree of processing as a proxy for healthfulness of foods could sway the food industry to reduce or remove the markers of ultra-processing from foods that are high in saturated fats, added sugars and sodium and promote them as “better-for-you alternatives.”

Health Impact of UPFs

A meta-analysis of prospective studies cited in the advisory found a dose-response relationship between UPF consumption and cardiovascular events, such as heart attack, transient ischemic attack and stroke, Type 2 diabetes, obesity and all-cause mortality. High versus low UPF intake was linked to a 25%-58% higher risk of cardiometabolic outcomes and a 21%-66% higher risk of mortality. More research is needed to understand the appropriate thresholds for daily consumption of UPFs — what a safe amount is and the incremental risks of eating more UPFs, said AHA.

Research has also found that there may be underlying mechanisms that affect eating behaviors and obesity for some people, and that UPFs may promote obesity. UPFs frequently contain combinations of ingredients and additives that are uncommon in whole foods to enhance palatability and reduce cost, and these may influence reward-related brain activity. For example, ingredients like artificial flavors may mimic sweetness without sugar, and this disruption in flavor-nutrient relationships often leads to irregular eating habits and results in weight gain.