For long-term health, diet quality matters more than food processing level

 What makes a diet healthy—or not? According to a new study, nutritional quality matters more than processing level when it comes to long-term health.

The study of over 200,000 people found that the overall quality of a person’s diet was strongly associated with their risk of heart disease, type 2 diabetes, and death. However, these associations did not appear to substantially differ based on food processing levels.

“While many ultra-processed foods tend to be of poor nutritional quality and should generally be limited or avoided, processing itself is not inherently harmful,” said Xiaowen Wang, PhD, a postdoctoral research fellow in the Department of Nutrition at Harvard T. H. Chan School of Public Health. Based on the study results, she said individuals should “focus on what you’re eating overall, not just whether it’s processed. A healthy plant-based diet rich in whole grains, fruits, vegetables, nuts, legumes and healthy plant oils is beneficial, even if it includes some processed foods.”

Wang will present the findings at NUTRITION 2026, the flagship annual meeting of the American Society for Nutrition, held July 25–28 in National Harbor, Maryland, just outside Washington, D.C.

The nutritional quality of a person’s diet and the amount of ultra-processed foods they consume are often intertwined. Many ultra-processed foods are high in added sugars, sodium and refined carbohydrates, so eating a lot of these foods is associated with poor dietary quality. On the other hand, ultra-processed foods like fortified breakfast cereals, whole grain products, canned beans, or plant-based dairy can still provide important nutrients, fiber, antioxidants and other beneficial compounds, contributing to a healthy diet.

For the study, researchers sought to separate overall diet quality from the level of food processing. Using data from three studies that collectively followed over 200,000 U.S. adults from the 1980s through the 2020s, they used a framework known as the plant-based diet index to assess the degree to which each participant emphasized plant versus animal food products in their diet, the overall quality or healthfulness of their diet, and their consumption of plant-based foods across a wide spectrum of processing levels. The study was not limited to vegans or vegetarians; however, to enable consistent comparisons, the analysis focused on the plant-derived components of participants’ diets rather than animal-derived foods.

After assessing each participant’s overall diet and using the Nova classification system to categorize the processing level of the foods they consumed, researchers grouped participants according to their plant-based eating habits:

• Healthy/ultra-processed (for example, whole grain breakfast cereal with fortified plant-based milk, plant-based yogurt, whole-grain bread, and canned fruit);
• Healthy/minimally-processed (for example, oatmeal with fresh fruit and nuts, quinoa and vegetable salad with olive oil, and homemade lentil soup);
• Unhealthy/ultra-processed (for example, fast food meals, French fries, soda, packaged desserts, and refined snacks); and
• Unhealthy/minimally-processed (for example, white rice, fruit juice, potatoes, and homemade desserts made with refined flour and sugar).

About half of the study participants eventually died or developed heart disease or type 2 diabetes. According to the results, the risk of these outcomes varied significantly depending on overall diet quality: healthy diets were associated with lower risk, while unhealthy diets were associated with higher risk. Within each category, however, the risks were almost identical regardless of whether the diet was ultra-processed or minimally-processed.

The results call into question the use of processing level as a key indicator of healthy eating. Since the Nova classification does not take into account the nutritional value of foods, healthy foods can be classified as ultra-processed while minimally-processed foods can still be unhealthy. 

“Advising people to universally ‘avoid ultra-processed foods’ can lead to lower diet quality since healthy ultra-processed foods are beneficial and unhealthy minimally-processed foods are detrimental,” said Wang. “People should prioritize the quality of foods rather than focusing solely on the level of processing. Aim for more nutrient-dense, high-quality foods to help lower your risk of chronic diseases.”

Based on the findings, she suggested that dietary guidelines should continue to promote established high-quality diets, like the Mediterranean or healthy plant-based diets, rather than focusing on processing level. She noted that encouraging food manufacturers to improve the nutritional content of packaged foods could also help to make following a healthy plant-based diet more convenient and accessible.

The consumption of ultra-processed foods by fathers may influence their babies..

 

 birth weight and body measurements

A study conducted at the University of São Paulo reinforces the importance of including fathers in health and family planning guidance.

A father’s diet can affect his children’s health and body composition before they are even conceived. A study of 43 triads of fathers, mothers, and newborns treated in the public healthcare system of Ribeirão Preto in the state of São Paulo, Brazil, demonstrated this. The analysis revealed that the greater the consumption of ultra-processed foods by the fathers, the higher the birth weight and the greater the accumulation of fat in the baby’s thighs and suprailiac region (commonly known as “love handles”). High birth weight and elevated body fat early in life are risk factors for cardiometabolic diseases in adulthood.

“Maternal nutrition and health before, during, and after the baby’s birth have always received attention, but little is said about the role of the father’s diet. Our study shows that it also matters a great deal for the baby’s health," says Daniela Sartorelli, a professor at the Ribeirão Preto School of Medicine at the University of São Paulo (FMRP-USP) who coordinated the study published in the journal Nutrition Research. 

The study is the first to demonstrate an association between fathers’ consumption of ultra-processed foods and the body composition of newborns. So-called ultra-processed foods are industrial formulations mostly made of food-extracted substances and synthetic chemical additives; the presence of whole foods in the composition of items such as packaged snacks, filled cookies or soft drinks is either scarce or non-existing.

The researchers’ hypothesis is that consuming ultra-processed foods negatively impacts sperm formation, which occurs prior to conception. “Diets rich in ultra-processed foods can create a pro-inflammatory environment in the body, affecting sperm quality and altering the expression of genes that will be passed on to the baby. This process is known as epigenetics. Gene activity can be ‘activated’ or ‘deactivated’ depending on the father’s dietary habits,” explains Mariana Rinaldi Carvalho, a FAPESP doctoral scholarship recipient and co-author of the study.

One of the genes mentioned in the study is IGF-II, which is responsible for fetal growth and is inherited exclusively from the father. “Previous studies have shown that a father’s dietary habits can biochemically modify this gene in sperm through a process called methylation [the addition of a methyl group], thereby influencing fetal development,” says the researcher.

The study is part of a larger project supported by FAPESP that investigates how the diets of mothers and fathers influence the health of newborns.

According to the results, fathers’ consumption of ultra-processed foods was associated with higher birth weights, while the effect of mothers’ consumption was the opposite. Consuming these foods early in pregnancy (up to the 16th week) was associated with lower birth weight, shorter height, and smaller head circumference at birth.

“We believe that the impact of maternal consumption of ultra-processed foods on the baby’s birth weight and body measurements may be related to placental development, which depends on many nutrients. Ultra-processed foods are, in fact, nutrient-poor,” Carvalho assesses.

Health predictor

A baby’s birth weight is considered an important predictor of health in both childhood and adulthood. In addition to an increased risk of death, numerous studies have shown that babies born with low (or high) birth weights may develop noncommunicable diseases later in life, such as cardiovascular disease, type 2 diabetes, and certain types of cancer.

“Although the study didn’t find an increase in total body fat, only fat accumulation in certain regions of the baby’s body, the results suggest that the quality of the father’s diet may also influence fetal development. This is important because, on average, ultra-processed foods accounted for 30% of the total energy consumed by the fathers whose diets were analyzed in the study, particularly processed meats, sugary drinks, and cookies,” Sartorelli notes.

In a previous study, the same team of researchers observed that overweight fathers tended to have babies with lower birth weights. However, by specifically analyzing diet quality, they demonstrated that it isn’t only the father’s weight that matters but also what he eats (read more at agencia.fapesp.br/53400). 

“With these two studies, we’ve shown that it isn’t just a matter of whether the father is overweight. The quality of the father’s diet before conception has a significant impact on the baby’s health,” says Sartorelli. 

Although the sample size was small, with only 43 families, the study is a pioneering effort to investigate the impact of ultra-processed foods on paternal and neonatal health. “The results pave the way for larger studies and reinforce the need to include men, not just women, in family planning guidance,” says Sartorelli. 

Omega-3 fatty acids are highest in milk labeled as organic grass-fed

 — When you pick up a gallon of milk at the store, the nutrients it contains may depend on both what’s on the label and the time of year. A new study reports that omega-3 fatty acids are highest in milk labeled as organic grass-fed and lowest in conventionally-produced milk. Other fatty acids varied by dairy production method and season.

“These findings contribute to a greater understanding of the role that production systems may play in determining the nutritional composition and potential nutritional value of milk,” said Emily Youngmark, MS, a PhD student at the University of Vermont. “The observed differences in fatty acid composition may represent one factor consumers consider when choosing milk products.”

Youngmark will present the findings at NUTRITION 2026, the flagship annual meeting of the American Society for Nutrition, held July 25-28 in National Harbor, Maryland, just outside Washington, D.C. Youngmark conducted the study with Jana Kraft, PhD, associate professor at the University of Vermont.

U.S. consumers can often find a large array of options in the dairy aisle, but the differences among them are not always clear. Since products marketed as organic, grass-fed or pasture-based are often sold at premium prices and promoted as having nutritional advantages, the researchers sought to find out whether production systems actually influence milk composition.

Over the course of a year, the team collected over 300 samples of milk sold by retailers across Vermont and New York. Using information from dairy producers and product labels, they categorized each sample as conventional (63 samples), organic (111), organic grass-fed (91) or non-organic, pasture-based (40).

On average across all seasons, organic grass-fed milk contained significantly more omega-3 fatty acids than all other milks, providing 88 milligrams per serving compared with 25 mg/serving in conventionally-produced milk. By contrast, omega-6 fatty acids were highest in conventionally-produced milk, which contained 166 mg/serving versus 92 mg/serving in organic grass-fed milk. While both types of fatty acids are part of a healthy diet, experts recommend focusing on increasing omega-3 intake, which is linked with a reduced risk of heart disease, type 2 diabetes and inflammation.

The fatty acid composition of non-organic, pasture-based milk was generally comparable to organic milk, with some seasonal variation. In general, it appears that cows with more access to pasture and fresh forage produce milk with more beneficial fatty acids. Variation in nutritional composition throughout the year likely results from seasonal differences in forage quality.

Although the results revealed significant differences in fatty acid composition among milk samples, researchers noted that the health implications of these differences remain uncertain. Further studies would be needed to determine whether regularly consuming certain types of milk leads to measurable improvements in health outcomes.

“It is important to put these findings in perspective. While the differences we observed may be nutritionally relevant, they are unlikely to produce major health effects on their own. Rather, the fatty acid composition of organic grass-fed milk may contribute as one component of an overall healthy dietary pattern and lifestyle,” said Youngmark.

Conventional milk has no formal definition but generally refers to milk produced from intensively managed dairy systems. Certified organic milk is produced under federally regulated standards that prohibit the use of pesticides, genetically modified feeds and most synthetic additives and require pasture access for at least 120 days per year. Organic grass-fed certification imposes additional requirements, including pasture access for at least 160 days per year and the exclusion of grain products from feed. The term “pasture-based” can appear on both organic and non-organic milk; non-organic, pasture-based milk production systems emphasize pasture access but are not certified organic. 

A daily multivitamin may help older adults maintain functional health

 

The ability to perform everyday activities free of debilitating symptoms profoundly affects quality of life as we age. In a new study, older adults who took a daily multivitamin had significantly better measures of functional health after 3 years compared with those who took a placebo.

According to researchers, the findings suggest a daily multivitamin can help older people maintain day-to-day functioning by helping to preserve cognitive abilities, and it may also benefit blood circulation and physical stamina.

“What makes this work unique is our focus on functional health, how people actually feel and function in their daily lives—rather than just the prevention of major diseases,” said Bayu B. Bekele, PhD, a postdoctoral fellow at the Georgia Prevention Institute of the Medical College of Georgia at Augusta University. “For older adults, these findings suggest that a daily multivitamin could be a helpful, low-risk addition to a healthy lifestyle to support physical well-being as they age, although it is not a substitute for a good diet or exercise.”

The researchers analyzed data from over 16,000 people aged 60 years and older who participated in the COcoa Supplement Multivitamins Outcomes Study (COSMOS). COSMOS participants were randomly assigned to take a daily multivitamin, a cocoa extract supplement, both or neither, with placebos used for the control group and for those taking only one supplement.

After 3 years, participants taking a multivitamin had significantly better functional health than those taking a placebo based on their responses to the Kansas City Cardiomyopathy Questionnaire. The greatest differences were seen in symptom burden and clinical summary score, which reflects an average of symptom burden and physical ability scores. 

“Multivitamin use supporting heart health and overall physical function may help maintain the ability to perform everyday activities such as dressing, bathing, walking, climbing stairs, jogging or hurrying, and completing household chores. These benefits may be particularly relevant for individuals experiencing fatigue, shortness of breath or swelling in the feet, which can limit daily functioning,” said Bekele.

Cocoa extract did not significantly change functional health scores in the overall population, although it provided a significant benefit in the patients with congestive heart failure.

It is important to check with a doctor before taking any new supplements.

Is your diet driving up your cholesterol? That may depend on your gene

 

Study suggests genetic factors explain why some people see their LDL cholesterol spike on a low-carb, high-fat diet

Can a low-carb diet cause your cholesterol to skyrocket? This question has vexed researchers and influencers alike as the popularity of low-carbohydrate diets has surged, yet the evidence has remained mixed. New research suggests that the answer depends on your genes.

According to the study, the high saturated fat intake that tends to accompany a low-carb diet interacts with genetic factors in ways that can increase low-density lipoprotein (LDL) cholesterol, considered a key driver of heart disease risk. The role of genes explains why different individuals can follow the same diet but see different outcomes. 

“Our findings suggest that some individuals may be more sensitive to the LDL cholesterol-raising effects of saturated fat, particularly in the context of a low-carbohydrate diet, because of their genetic background,” said Alexa Barad, PhD, RDN, a postdoctoral scholar at Stanford University School of Medicine.

“These findings highlight that there is real heterogeneity in how people respond to diet. Dietary conversations can sometimes become overly simplified. One person may say, ‘Low-carb diets always raise LDL cholesterol,’ while another says, ‘My LDL cholesterol did not change at all.’ Our findings suggest that both experiences can be true, depending, at least in part, on the individual’s genetic makeup,” said Barad.

Previous studies have shown healthy low-carbohydrate diets can support weight loss and blood sugar control for some people, but these diets have inconsistent effects on LDL cholesterol. Researchers sought to find a way to predict who would likely benefit from a low-carb diet and who may see a dangerous spike in LDL cholesterol.

The research is based on data from DIETFITS, a randomized controlled trial in which over 600 adults followed either a healthy low-carb or healthy low-fat diet for a year. The primary study found that neither diet was superior to the other in terms of weight loss. For the new analysis, researchers assessed the relationships among genotype, saturated fat intake, diet type and change in LDL cholesterol from baseline to 6 months in 431 DIETFITS participants with available genetic data.

Among participants following the low-carb diet, the results showed that those with a genetic predisposition toward elevated LDL cholesterol were more likely to see their cholesterol rise. The results also showed that this was driven by a greater sensitivity to saturated fat, meaning that people at higher genetic risk had the largest increases in LDL cholesterol when they consumed more saturated fat. People following a low-fat diet did not show the same patterns.

Unlike prior studies, which have mostly focused on single genetic variants, researchers combined thousands of genetic variants across the genome (creating what is known as a polygenic score) to estimate each participant’s overall tendency for higher or lower LDL cholesterol. In the future, Barad said clinicians could potentially use polygenic scores to help identify people who are more likely to experience adverse LDL cholesterol responses to certain dietary modifications.

However, even without genetic testing, the study offers an important lesson that the response to diet can vary from person to person, underscoring the need to monitor how your body is responding to a dietary change rather than assuming the results will be the same for everyone, Barad added.

Further studies could help to confirm the findings and ensure they apply broadly to diverse populations. General dietary guidance suggests limiting saturated fat to less than 10% of daily calories and favoring unsaturated fats. For those choosing a low-carbohydrate diet, emphasizing healthier fat sources such as nuts, seeds, olive oil and avocado over foods high in saturated fat such as butter, beef tallow, fatty cuts of meat and processed meats may help reduce the risk of adverse cholesterol responses, Barad noted.

Prebiotic sodas typically contain as much sugar as fiber

While healthier than regular sodas and fruit drinks, prebiotic sodas do not necessarily compare favorably with other alternative

 Prebiotic sodas have become more popular in recent years, with a wave of new products promising gut health benefits and low-calorie enjoyment. According to a new analysis, however, many of these beverages contain relatively little prebiotic fiber content and more sugar than marketing claims might imply.

“Many products include nutrition and functional claims that may overstate their nutritional quality. For example, some labels claim ‘no added sugar,’ yet the product may still contain around 10 grams of total sugars from sources like juice,” said Carlos R. Soto Díaz, MPH, a PhD candidate at the University of North Carolina at Chapel Hill. “This raises concerns that such claims may create a ‘health halo,’ leading consumers to believe the product is healthier than its overall nutritional profile suggests.”

Prebiotic sodas represent one of the fastest growing beverage segments in the U.S. market, with estimated sales of $777 million in 2025. Using data from the Mintel Global New Products Database, researchers analyzed 108 prebiotic sodas launched in the U.S. between 2021-2025.  These were defined as carbonated beverages that contain fiber and use the term “prebiotic” in the product name, package claims or ingredient lists. They compared prebiotic sodas’ nutritional contents to regular sodas, diet sodas, fruit drinks and flavored sparkling waters introduced during the same time period.

On average, prebiotic sodas contained about 35 calories, 5 grams of sugar and 5 grams of fiber per 12-ounce can. In terms of calories and sugar, they ranked lower than regular sodas and fruit drinks but higher than diet sodas and flavored sparkling waters. In addition, nearly two-thirds of prebiotic sodas contained non-nutritive sweeteners such as stevia. By comparison, over 90% of diet sodas contained non-nutritive sweeteners, while less than 28% of fruit drinks, 16% of flavored sparkling waters and 12% of regular sodas contained them.

Prebiotic sodas consistently contained more fiber than other beverages, ranging from about 2 to 9 grams of fiber per can. In the U.S. market, the term “prebiotic” is not tied to a specific amount of fiber, so researchers cautioned that consumers should not assume a product contains a meaningful amount simply because it is labeled as prebiotic, and sodas should not be relied upon as a primary source of dietary fiber.

“I would encourage consumers not to be swayed by marketing claims and to carefully review the Nutrition Facts label,” said Soto Díaz. “While certain types of prebiotic fibers have been shown to support gut health, the extent to which the amounts found in these beverages provide meaningful benefits is still unclear. Any potential benefits should be considered alongside the product’s overall nutritional profile, including calories, sugars and non-nutritive sweeteners.”

When considering the healthfulness of prebiotic sodas, the researchers say it is important to consider what they are replacing. For people who regularly consume sugary beverages, switching to prebiotic sodas could help to reduce overall calorie and sugar intake. On the other hand, switching to prebiotic sodas might not be as beneficial for people who typically choose low- or no-calorie beverages.

Plant-forward planetary health diet linked to lower heart disease risk

 A 20-year study of more than 65,000 postmenopausal women found that higher adherence to the Planetary Health Diet was associated with a lower risk of overall cardiovascular disease, coronary heart disease, stroke and heart failure.

The findings showed that women whose diet most closely followed the Planetary Health Diet had about a 28% lower risk of cardiovascular disease compared with women in the group scoring the lowest for adherence. However, even moderate adherence to the diet was linked with lower risk.

The Planetary Health Diet emphasizes foods such as fruits, vegetables, whole grains, legumes, nuts and unsaturated fats while limiting foods such as red and processed meats, added sugars, refined grains and saturated fats.

“Our results suggest that people may not need to follow a perfect or very restrictive diet to see potential heart-health benefits,” said Donya Shahamati, a doctoral student in public health at the University of California, Irvine. “This is especially important for postmenopausal women, because cardiovascular risk increases with age and tends to rise after menopause.”

“Moving toward a more plant-forward, higher-quality diet can be accomplished through small, realistic changes,” said Shahamati. “These changes might include filling half the plate with vegetables more often; using avocado or olive oil in place of butter; choosing oatmeal or whole-grain cereal for breakfast; or trying a meatless meal once per week.”

For the new research, the investigators followed 66,892 participants in the Women’s Health Initiative (WHI), a long-term national health study funded by the National Heart, Lung and Blood Institute at the National Institutes of Health. All the women included in the analysis were free of cardiovascular disease at the start of the study (1994-1998) and had complete information on diet and other important health and lifestyle factors.

Using information collected through a food frequency questionnaire administered at the beginning of the study, the researchers calculated a Planetary Health Diet Index score for each study participant, with higher scores indicating a diet was more aligned with the Planetary Health Diet. The researchers then divided the women into five groups based on how closely their diets aligned with the Planetary Health Diet.

The women, who were around 63 years old at the start of the study, were followed for about 20 years to see who developed cardiovascular disease. When analyzing the data, the researchers adjusted for several factors that could affect cardiovascular risk, including age, race and ethnicity, education, income, smoking, alcohol intake, physical activity, body mass index and total calorie intake.

“We did not only look at overall cardiovascular disease,” said Shahamati. “We also looked separately at coronary heart disease, stroke and heart failure. This helped us see whether the pattern was similar across different types of cardiovascular outcomes.”

Overall, the results showed that women in the group whose diets were more closely aligned with the Planetary Health Diet had the lowest risk of cardiovascular disease. These women also showed a decreased risk of heart disease, heart failure and stroke risk compared to the women in the lowest-adherence group.

However, even moderate adherence to the diet was associated with a decrease in risk, with each 10-point increase in Planetary Health Diet Index score linked to further risk reduction.

The researchers caution that an observational study like this cannot show that diet directly caused the lower risk in women.