Health 30/2025

Weekly roundup (21. July - 27. July)

Food

The U.S. Department of Health and Human Services, Department of Agriculture, and Food and Drug Administration are working together to create a single, official definition of “ultra-processed foods.” This will help make food labels clearer and allow health research and policies to be more consistent. Right now, about 70% of packaged foods in U.S. stores fall into the ultra-processed category, and 60% of the calories eaten by children come from them. These foods have been linked to serious health issues like heart disease, type 2 diabetes, cancer, obesity, and even some brain disorders. [source]

A study looked at 51 adults with prediabetes who ate about two ounces of pistachios every night for 12 weeks, instead of a typical carbohydrate snack with 15–30 grams of carbs. The pistachio eaters showed big changes in their gut bacteria: “good” bacteria like Roseburia and Lachnospiraceae increased, while harmful bacteria linked to poor metabolic health dropped. These changes suggest pistachios could help improve metabolism and reduce inflammation. [source]

Researchers found that drinking soft drinks made with white sugar can change the DNA of certain gut bacteria (Bacteroides thetaiotaomicron). This affects the immune system by altering T-cell levels, cytokine activity, and the gut’s barrier function. The good news? These changes reverse once sugar intake stops. [source]

Erythritol, a common sweetener in “sugar-free” products, was shown to stress and damage cells that make up the brain’s protective barrier, at levels you might get from just one serving of a soft drink. It also narrows blood vessels, which can cut off oxygen and nutrients to the brain. People with the highest erythritol levels in their blood were about twice as likely to have a heart attack or stroke compared to those with the lowest levels. [source]

A stevia leaf extract, when fermented with a specific bacteria (Lactobacillus plantarum SN13T), became far more toxic to pancreatic cancer cells than the non-fermented version—without harming healthy cells in lab tests. This is because fermentation changed certain plant chemicals into a form more powerful against cancer cells. Future studies will check if it works in living animals. While this is still early research, it shows the potential of fermented plant-based products. Including more naturally fermented foods like yogurt, kefir, sauerkraut, or miso in your diet may bring broader health benefits. [source]

In a study of over 10,000 older Americans, eating between 1.22 and 1.65 mg of copper daily was linked to better memory and focus, but going higher didn’t give extra benefits. Copper helps protect the brain, make neurotransmitters, and produce energy. Too much copper, especially when combined with a diet high in saturated fat, might raise dementia risk. Brain copper levels—not just dietary intake—are linked to slower cognitive decline and fewer Alzheimer’s plaques. Aim for a moderate copper intake through foods like nuts, seeds, whole grains, and seafood. Avoid over-supplementing, and pair copper-rich foods with a balanced, low-saturated-fat diet to protect brain health. [source]

A study of 151,543 UK adults found that vitamin D deficiency (<25 nmol/L) or insufficiency (25–49 nmol/L) is linked to a higher risk of being hospitalized with COVID-19, though it doesn’t increase the chance of catching the virus. 1 billion people worldwide have low vitamin D. People with low levels—especially Caucasians—were more likely to require hospitalization, while no significant risk increase was seen in Black or Asian populations. [source]

Beyond diet, gut and vascular health can be further supported with targeted interventions. Not all probiotics help after antibiotics—and some can even cause harm. In mice, Lactobacillus acidophilus increased the risk of C. difficile infection, while Lactobacillus gasseri helped protect the gut by producing natural antibacterials and boosting healthy bacteria. In people, probiotics preserved gut diversity and reduced antibiotic resistance genes, while a placebo group lost 30% of their bacterial diversity and saw resistance genes rebound. [source]

Similarly, certain foods can directly influence vascular function. Older adults who drank a concentrated beetroot juice shot twice a day for two weeks saw their blood pressure drop—an effect that didn’t happen in younger adults. The study, involving 36 older and 39 younger participants, found that nitrate-rich beetroot juice changed the mix of bacteria in the mouth: harmful bacteria like Prevotella decreased, while helpful bacteria like Neisseria increased. This likely boosted the body’s ability to turn dietary nitrate into nitric oxide, a compound that helps blood vessels relax and supports healthy blood pressure. [source]

Physical Activity

Staying active has powerful effects on overall health. A large review of 57 studies involving 36,383 people from over 10 countries found that walking 7,000 steps a day can cut the risk of death by 47%, almost the same as doing 10,000 steps. At 7,000 steps, dementia risk dropped by 38%, with only a small extra benefit from going to 10,000. For type 2 diabetes, risk fell 22% at 10,000 steps and 27% at 12,000. The biggest health boost came when increasing steps from 2,000 to 5,000–7,000, with smaller gains beyond that. [source]

Exercise also matters for people with chronic conditions. A study of nearly 52,000 adults with diabetes found that “weekend warriors”—those doing all 150 minutes of moderate-to-vigorous exercise in just one or two weekly sessions—had a 21% lower risk of death from any cause and a 33% lower risk of heart-related death compared to inactive people. Those who spread workouts over three or more days had slightly smaller benefits (17% and 19% lower risk, respectively). Even people doing less than the recommended amount still saw some improvement. [source]

Pollution

An analysis of 51 studies covering over 29 million people found that air pollution significantly raises dementia risk. Every 10 μg/m³ increase in fine particulate matter (PM2.5) raises risk by 17%. For nitrogen dioxide (NO₂), each 10 μg/m³ increase raises risk by 3%. Soot exposure is even more concerning—every 1 μg/m³ increase raises dementia risk by 13%. [source]

A long-term study of 1,761 people followed over 26 years found that higher exposure to air pollution from midlife slows thinking speed, lowers cognitive test scores, and changes brain structure later in life. Specifically, high levels of nitrogen dioxide (NO₂) and particulate matter (PM10) were linked to slower processing and worse cognitive performance between ages 43 and 69. Brain scans of participants aged 69–71 showed that higher NOx exposure was tied to a smaller hippocampus, while higher NO₂ and PM10 were linked to larger brain ventricles—both signs of tissue loss related to dementia. [source]

Exposure to PFAS—“forever chemicals” found in many everyday items—is linked to a 31% higher risk of developing type 2 diabetes. A study of 180 people with newly diagnosed diabetes and 180 controls found that PFAS can disrupt metabolism, including amino acid production and drug processing, which may affect blood sugar regulation. These chemicals resist heat, oil, water, and stains, and they build up in both the environment and the human body. [source]

A study of over 70 reusable feminine hygiene products found that most—71.2%—had PFAS levels low enough to be considered “non-intentionally fluorinated.” However, 33% of period underwear and 25% of reusable pads showed intentional PFAS use. Researchers tested 323 product layers using advanced spectroscopy to measure total fluorine. While PFAS are persistent “forever chemicals” linked to health risks, the study shows that many brands do not need PFAS to make these products. [source]

In a study with rats, daily exposure to the pesticide rotenone for three weeks caused major changes in brain areas linked to Parkinson’s disease. In the substantia nigra, genes related to the immune system were strongly activated, and brain immune cells (microglia) became overactive. In the motor cortex, genes controlling communication between brain cells were disrupted. The study also found mitochondrial dysfunction and oxidative stress, showing that different brain regions respond differently to pesticide exposure—mechanisms tied to Parkinson’s disease. [source]

Chronic Health Issues & Aging

A study of 20,195 U.S. adults found that following a combination of healthy lifestyle habits—not smoking, moderate alcohol use, regular exercise, a healthy diet, and a healthy waist size—is linked to a lower risk of overactive bladder (OAB). About 14.6% of participants had OAB. People with four to five healthy habits had a 46% lower risk compared to those with zero or one habit. Each additional healthy habit lowered risk by 17%. [source]

A study of 111 dementia patients with newly diagnosed inflammatory bowel disease (IBD) compared to 1,110 dementia patients without IBD found that having both conditions led to nearly 1 extra point of cognitive decline per year on the Mini-Mental State Exam (MMSE). Cognitive decline accelerated noticeably after the IBD diagnosis, and this change is considered clinically significant—similar to differences seen in patients taking the Alzheimer’s drug donanemab versus those untreated. [source]

A study of 6 million women in the UK found that the bone-protecting benefits of menopausal hormone therapy (MHT) largely disappear within about one year of stopping treatment. Fracture risk rises after stopping, peaking around three years, then gradually drops to the level of women who never used MHT by 10 years, and continues to decline afterward. Women who used less than 5 years of estrogen-progestogen MHT had 14 extra fractures per 10,000 women-years in the first 1–10 years after stopping, while those using it for 5 or more years had only 5 extra cases. More than 10 years after stopping, fracture rates were actually lower than never-users, showing long-term bone benefits. [source]

Chronic kidney disease (CKD) is linked to a higher risk of tooth loss. A study of 16,125 Korean adults aged 40 and older found that people with CKD were more likely to have fewer than 20 teeth, with an odds ratio of 1.34, even after accounting for age, sex, income, education, lifestyle, and other health conditions. [source]

For people with chronic non-cancer pain, regular opioid use is linked to a higher risk of dementia. Compared to non-users, opioid users have a 20% increased risk of all-cause dementia and a 49% higher risk of vascular dementia. Those taking strong opioids face even higher risks: 72% for all-cause dementia and 155% for vascular dementia. Brain scans show that strong opioid use is associated with smaller hippocampal, white matter, and total brain volumes, and users tend to have lower fluid intelligence, though memory for future tasks isn’t significantly affected. [source]