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13 August 2025

3 minute read

Pigs on sow farms often die from various causes, including contagious diseases. An association between using rendering for dead animal disposal and higher risk or porcine reproductive and respiratory syndrome virus (PRRSV) outbreaks has been reported in the literature. However, a detailed characterization of disposal practices and facilities used in the US is needed to understand and mitigate associated risks.

A study by I.A.D. Paploski and colleagues at the University of Minnesota, USA, aimed to characterize the facilities, structures and procedures for dead animal disposal on sow farms, as well as test if environmental samples collected in and around dead animal disposal structures contain detectable quantities of PRRSV and porcine epidemic diarrhea virus (PEDV). The results of the study were presented at the 2024 North American PRRS Symposium.

Ten standard operating procedures (SOPs) from different systems were obtained. Data from SOPs were categorized into sections: biosecurity, dead animal gathering space in the barn, removal from the barn, transport out of the barn, and final destination and used to create a questionnaire for on-site visits. Five farms with 2,000 to 5,000 sows on each from three systems were visited to apply the questionnaire and collect environmental samples for PRRSV and PEDV testing.

The SOPs varied significantly in detail, with the most comprehensive being 12 pages and the shortest having only 1 page containing 11 lines. Biosecurity measures were generally outlined but inconsistent, particularly regarding personnel roles. Dead animal gathering spaces were mentioned in most SOPs, often cleaned and disinfected, but methods varied.

Dead sow removal methods were usually detailed, while dead piglet removal and afterbirth were less consistently addressed. Transport methods of carcasses between the barn and the compost pile or rendering truck pick up site were done primarily using tractors or pickups and were cited in most SOPs, but cleaning protocols were often not mentioned.

Final disposal destinations were inconsistently mentioned. Farm visits revealed that dead animal removal was typically the last task of the day, regardless of PRRS status. Environmental conditions, especially wind direction, can be important if removal happens daily. Wildlife exposure to disposal areas was commonly reported.

Three finisher sites (all PRRSV positive, one PEDV positive) were visited and a total of 25 environmental samples were collected from roads, machines and structures involved in moving dead animals. All samples from one farm tested negative for PRRSV and PEDV by RT-PCR. From the remaining two farms, a total of 12 and 5 samples tested RT-PCR positive for PRRSV-2 and PEDV, respectively. Positive samples were found on dead animals, rendering boxes, skid loader buckets and nearby ground. One PRRSV isolate was obtained from a sample collected on the ground, while no viable PEDV was isolated.

Creating SOPs for dead animal removal on farms is challenging due to the need for specific yet adaptable instructions. SOPs should include detailed biosecurity protocols, procedures for removing dead animals and cleaning and disinfection guidelines.

This study shows that samples collected from or near rendering boxes can test positive for farm-specific viruses and may contain viable viruses. Positive samples on roads suggest potential PRRSV transmission pathways between farms. Further studies on different disposal methods, such as composting or incineration, are warranted to ensure effective biocontainment of viruses on farms.

Struggling to go No. 2? You’re not alone. In fact, the National Institute for Diabetes and Digestive and Kidney Diseases estimates that around 16% of the adult population struggles with constipation daily. The good news is there are proactive things you can do to ease your constipation woes without spending a fortune. 

Enter—simple food swaps! No, we’re not suggesting swapping cauliflower pizza crust for the real deal (though don’t knock that one until you try it). Rather, we’re encouraging you to explore the better-for-you alternatives for common snacks that pack a bit more nutritional bang per bite. Dietitians say the easiest high-fiber swap to help you poop is choosing air-popped popcorn in place of potato chips. 

Why Air-Popped Popcorn Is the #1 Swap

It’s High In Fiber 

Fiber is a key component of a diet that promotes regular bowel movements, and unfortunately, most Americans are falling short on eating enough of this nutrient. High sources of dietary fiber positively impact metabolic health and the microbiome. You see, popcorn contains resistant starch and serves as a prebiotic, providing food for the good gut bugs in your gut that keep your digestive system running smooth., Gut-health nutrition expert Jessie Wong, MAcc, RDN, LD, is also a popcorn advocate, sharing, “Popcorn is a whole-grain snack packed with insoluble fiber, which adds bulk to stool and helps food move more efficiently through the digestive tract. This promotes regularity and supports overall bowel health.” 

The best part—swapping 1-ounce of popcorn in place of 1-ounce of chips provides 3 additional grams of dietary fiber, inching you closer to the recommended 25 to 38 grams of fiber per day.,

It’s a Whole Grain 

The 2020-2025 Dietary Guidelines for Americans recommend consuming at least 50% of your grains from whole grains sources. Whole grains contain the entire bran layer of the grain kernel, meaning they pack more fiber and other nutrients that other refined grains lack. In fact, dietitian Roxana Ehsani, MS, RD, CSSD, shares, “One serving of popcorn provides one-third of your daily whole grain needs, and 4 grams of dietary fiber.” Wong points out eating more whole grains routinely helps nourish your microbiome, “contributing to more predictable bowel movements.” 

It’s Filled with Polyphenols 

Popcorn contains compounds known as polyphenols, which have antioxidant properties. Antioxidants help protect cells from damage caused by free radicals–the “bad guys” that may cause harm to our health in the long run. Research has explored the health benefits of popcorn throughout the decades, concluding it has a positive influence on gut health thanks to its polyphenol activity specifically. Ehsani shares, “Popcorn’s polyphenols can help reduce inflammation in the gut and support the growth of healthy gut bacteria. A healthy gut microbiome results in better digestion and more regular bowel movements.”

It’s Low in Saturated Fat & Sugar 

The high fiber content of air-popped popcorn helps fill you up while delivering important vitamins and minerals with no saturated fat or added sugar. Research shows that people who struggle with constipation may have poor diet quality, such as high intakes of saturated fat and added sugar. Replacing foods high in these with better-for-you options, like popcorn or other high fiber foods, provides support for your microbiome and can ease constipation while promoting better digestion. Wong shares, “Air-popped popcorn is low in calories, but high in volume, providing a satisfying crunch and fullness without the heavy fats or additives often found in chips, making it a gut-friendly choice for snacking.”

Strategies for Better Digestion

Better gut health is possible, but it involves taking a close look at both diet and lifestyle.  Wong shares, “Bowel health isn’t just about eating more fiber — it’s about the whole picture. Managing stress, getting enough sleep, and listening to your body’s natural cues are just as important as what’s on your plate.” Consider these dietitian-recommended tips for better digestion too.

• Move Your Body: Regular exercise is essential for better bowel health. Wong and Ehsani recommend consistent daily movement in whatever form feels enjoyable. Pick your favorite–a short walk, resistance exercise, or a swim all count. 
• Stay Hydrated: Drinking water throughout your day helps prevent dehydration, a common culprit in struggling to go number 2. Carry a large reusable water and make a goal to refill it with every mealtime, ensuring you’re constantly drinking throughout your day. 
• Eat probiotic rich foods: Probiotics help nourish a healthy gut and aid digestion, helping to keep your bowel movements regular. Consider adding more probiotic rich foods into your diet, like kefir, yogurt, sauerkraut, kimchi, or kombucha.
• Slow down. Being mindful as you eat is important, notes Braddock, as quickly consuming large volumes of food can disrupt your digestion. Consider taking some deep breaths before eating to help calm your nervous system and prepare to properly digest. 
• And yes, eat more fiber. Braddock recommends eating more high-fiber fruits and veggies routinely to find relief. She writes, “Raspberries are one of the highest fiber fruits per serving. Plus, eating two kiwis a day can help improve constipation and abdominal discomfort.”

Our Expert Take 

Smart foods swaps can help improve your gut health—in turn offering relief from constipation that may be weighing you down. While fruits and vegetables are natural choices to swap in for other less nutritious choices, they don’t always satisfy you the same way. That’s why nutrition experts recommend starting small with easy swaps that may be more satisfying, like trying air-popped popcorn in lieu of potato chips to get that same crunch with more fiber and antioxidants. Fiber is a key component to helping you poop, and every gram counts! Consider making a bowl of our EatingWell reader favorite, Cinnamon Popcorn, to nosh on when hunger strikes.

From kimchi to leafy greens, scientists uncover how mineral-rich diets, especially potassium, may help protect mental health across cultures.

Study: Mineral Intake and Depression: A Cross-Sectional Comparative Study Based on National Health and Nutrition Examination Surveys in Korea and the United States. Image Credit: Yulia Furman / Shutterstock

In a recent article published in the journal Nutrients, researchers investigated the relationship between the intake of minerals such as calcium, zinc, and iron, and the incidence of depression among adults in the United States and Korea.

They found that Korean adults with higher intakes of potassium and sodium were less likely to experience depression, with phosphorus showing a borderline association, a finding similar to that of American adults with higher intakes of potassium and zinc, with iron showing borderline significance.

Background

Depression is a widespread mood disorder marked by persistent sadness and hopelessness, and is expected to become a major global health burden. In South Korea, about 5% of adults report depressive disorders, while in the U.S., over 17 million adults experience at least one major depressive episode each year.

Many affected individuals remain untreated, often due to stigma and reluctance to seek help, while high recurrence rates make management challenging. Nutrition has been increasingly linked to mental health, with deficiencies in minerals such as magnesium, zinc, and selenium associated with cognitive decline and psychiatric conditions.

However, the roles of sodium and potassium in depression have received little attention, despite their abundance in everyday diets. Sodium is mainly consumed as table salt, while potassium is found in a variety of foods.

Given the limited research and the potential for dietary guidance to improve mental health outcomes, this study aimed to comprehensively assess the association between seven dietary minerals and depression in Korean and American adults.

The comparison between these two culturally and nutritionally distinct populations could help identify shared and unique patterns, offering a foundation for future research and public health strategies in mental health nutrition.

About the Study

In this cross-sectional analysis, researchers utilized data from nationally representative health and nutrition surveys in both countries, employing multistage, stratified sampling. Korean adults aged 19 and above and American adults aged 18 and above who completed depression screening were included, excluding those who were pregnant, under depression treatment, or with missing key data.

The final sample included 12,996 Koreans and 9,547 Americans. People with a depression score of 10 or over were considered to be depressed. Dietary mineral intake (calcium, zinc, iron, magnesium, phosphorus, sodium, and potassium) was estimated from 24-hour dietary recalls, using national food composition databases.

Covariates included demographics, socioeconomic factors, body mass index (BMI), lifestyle habits, comorbidities, and total energy intake. Associations between mineral intake and depression were assessed using multivariable logistic regression, adjusting for potential confounders. Survey-specific sampling weights ensured national representativeness.

Key Findings

In the Korean sample, 4.1% of 12,996 participants had depression, while in the American sample, 6.2% of 9,547 participants were affected.

In both countries, individuals with depression were more often female, had lower income and education levels, were more likely to live alone, and showed higher depression screening scores, smoking rates, diabetes prevalence, and comorbidity scores.

Regular exercise was less common in the U.S. depression group. Mineral intake was generally lower among those with depression, except for calcium, which did not follow this pattern.

Multivariable-adjusted analyses showed that in Korea, higher sodium and potassium intakes were significantly associated with lower odds of depression, with phosphorus showing borderline significance.

In the U.S., potassium and zinc were significantly associated, and iron showed borderline significance. Restricted cubic spline analysis indicated that intakes below certain thresholds were linked to higher depression risk.

Subgroup analysis revealed population- and group-specific patterns: for example, sodium was protective among Korean men, potassium among older Americans, and zinc among non-obese Americans. Additional subgroup findings included significant associations for phosphorus among Korean females, potassium, iron, and zinc among U.S. males, and sodium among Koreans aged ≤65 years.

Some minerals were associated with depression in one sex or BMI category but not the other. Potassium was the only mineral consistently linked to lower depression risk in both countries, highlighting its potential universal relevance for mental health. Notably, magnesium and calcium showed no significant associations with depression in either population.

Conclusions

This study found inverse associations between certain minerals and depression, with patterns differing between Korea and the U.S. Potassium consistently showed protective effects in both populations, while sodium was significant in Korea, phosphorus showed borderline significance in Korea, and iron showed borderline significance, and zinc was substantial in the U.S.

These differences may reflect variations in average intake, dietary sources, and nutrient bioavailability, such as substantially higher sodium intake in Korea from fermented vegetables, soups, and stews, or greater bioavailable heme iron and zinc from red meat in the U.S.. In contrast, Korean diets feature more plant-based and seafood sources with lower nutrient bioavailability.

Strengths include large, nationally representative datasets from two culturally distinct countries, the examination of seven minerals, and subgroup analyses revealing demographic and lifestyle influences.

Limitations involve the cross-sectional design, preventing causal inference, possible reverse causation, reliance on 24-hour recall, which may be particularly inaccurate, especially due to depression-related memory impairment, and the use of self-reported depression measures that can be subject to bias.

Overall, the findings suggest that dietary mineral intake could be integrated into mental health strategies. Longitudinal studies are needed to confirm causality and clarify mechanisms linking minerals to depression risk.