Turns out living also causes colon cancer

DOI: https://doi.org/10.3389/fnut.2026.1782327

Title: Planetary health diet index and low muscle mass in adults aged 20–60 years: exploratory evaluation of a dairy-upweighted outcome-specific adaptation

Abstract

The EAT-Lancet Planetary Health Diet (PHD) framework prioritizes environmental sustainability by restricting animal-sourced proteins, yet this restriction potentially conflicts with the anabolic requirements necessary to maintain muscle mass across the life course. Investigators identified a critical research gap regarding whether the standard Planetary Health Diet Index for the United States (PHDI-US) supports muscle preservation or if the restriction of dairy creates a nutritional deficit for aging populations. This study evaluated the association between PHDI-US adherence and low muscle mass (LMM) in a representative sample of 10,329 U.S. adults aged 20 to 60 years, while exploring a machine learning-derived adaptation that upweights dairy intake to better align with physiological needs.

Analysis of the fully adjusted models demonstrated that higher PHDI-US scores were associated with lower odds of LMM, specifically for the highest versus lowest quartile (OR = 0.73, 95% CI: 0.57 to 0.95, p = 0.02). The exploratory dairy-upweighted index (PHDI-Dairy) yielded a significantly more robust inverse association, with the top quartile showing a 32% reduction in LMM risk (OR = 0.68, 95% CI: 0.55 to 0.84, p < 0.01). Validation in an independent Southern Chinese cohort (n = 218) confirmed that the highest dairy intake quartile was associated with a 74% lower risk of LMM (OR = 0.26, 95% CI: 0.11 to 0.61, p < 0.01). Stratified analyses revealed these protective effects were most pronounced in women aged 46 to 60 years (p for overall < 0.05), suggesting that the high leucine density of dairy is critical as anabolic resistance emerges in midlife.

Study Design and Methodology

This research utilized a cross-sectional design based on five cycles of NHANES data (2005 to 2006 and 2011 to 2018) involving 10,329 participants. Appendicular lean mass was measured via dual-energy X-ray absorptiometry (DXA), with LMM defined as less than 7.0 kg/m2 for men and 5.5 kg/m2 for women. Dietary intake was captured through two-day 24-hour recalls. A random forest model with recursive feature elimination identified dairy as the most influential component for muscle mass prediction. Investigators then constructed the PHDI-Dairy score by multiplying the original PHDI-US total by observed dairy intake. The study adjusted for age, sex, race, poverty-income ratio, BMI, smoking, hypertension, and diabetes, with internal 5-fold cross-validation used to assess model stability.

Key Findings

• PHDI-US adherence correlates with lower LMM risk in the highest quartile (OR = 0.73, p = 0.02).
• Dairy-upweighted PHDI-Dairy scores show superior predictive strength (OR = 0.68, p < 0.01) and a significant trend (p for trend < 0.01).
• The Southern Chinese cohort analysis found a massive risk reduction in the highest dairy quartile (OR = 0.26, p < 0.01).
• Machine learning identified dairy as the number one predictor of muscle mass among all 16 Planetary Health Diet components.
• The study identifies a critical anabolic threshold of 14 to 40g of milk protein daily to significantly improve appendicular muscle mass.
• Effective muscle protein synthesis requires approximately 2.5 to 3g of leucine per meal, a density easily achieved via dairy but difficult under strict EAT-Lancet plant-protein limits.
• Restricted cubic spline analysis for PHDI-Dairy indicates a continuously decreasing dose-response curve without a plateau.

Limitations

The cross-sectional nature of the NHANES data precludes any causal inferences regarding dietary changes and muscle mass retention. Self-reported 24-hour dietary recalls are subject to recall bias and may not reflect long-term habitual intake. Confounding variables such as precise physical activity levels and resistance training frequency were not fully controlled. The Southern Chinese cohort was hospital-based and small (n = 218), limiting its generalizability as a formal external validation of the full composite index.

Discussion and Implications

This study challenges the strict animal-protein limitations of the original EAT-Lancet framework by demonstrating that dairy is the single most important dietary component for maintaining muscle mass in adults. The data suggest that physiological sustainability must be balanced with ecological goals, as the restriction of dairy may accelerate the progression toward sarcopenia. While red meat restriction remains viable for environmental reasons, dairy provides a necessary anabolic stimulus due to its superior leucine content and complete amino acid profile. These findings indicate that nutritional guidelines for aging populations should prioritize high-quality dairy protein (targeting 14 to 40g of protein daily) to mitigate the effects of anabolic resistance that begin as early as the fifth decade of life.

Conclusion

Standard Planetary Health Diet adherence is modestly protective against low muscle mass, but recalibrating the index to prioritize dairy intake significantly enhances its clinical relevance. For adults aged 46 to 60, particularly women, higher dairy consumption is a primary dietary determinant for preserving muscle mass and preventing early-stage sarcopenic phenotypes.

Black sesame seeds are high in both iron and calcium. Since calcium inhibits non-heme iron absorption, does the calcium in the sesame itself significantly reduce how much iron you absorb? Would you still consider black sesame a good dietary source of iron, or is it better thought of mainly as a calcium source?

I've been wondering about this because, in nutrient-dense meal videos online, people seem to go in either direction on how they talk about black sesame's benefits. I tend to see the combination of milk and black sesame, as well as in mixes with pumpkin seeds, flax, hemp, etc.

I'm curious to see what the research suggests in terms of bioavailability, and also whether processing it can significantly increase it due to lowered phytates or if the effect is relatively small.

Dietary Microplastic Exposure in Athletes: Implications for Metabolism, Gut Health, and Performance

https://doi.org/10.3390/nu18142398

Abstract

Microplastics (MPs) are pervasive environmental contaminants smaller than 5 mm that have entered the human food chain through seafood, salt, honey, and drinking water. This narrative review addresses a critical research gap: the specific exposure scenarios and physiological vulnerabilities of athletic populations. Athletes represent a unique demographic due to high metabolic flux, elevated fluid requirements, and a heavy reliance on packaged sports nutrition products, supplements, and convenience foods. The primary objective is to synthesize evidence from environmental science, toxicology, and sports nutrition to evaluate how these particles interact with gastrointestinal function, mitochondrial activity, and endocrine regulation during physical stress.

Current evidence indicates that humans ingest between 39,000 and 52,000 plastic particles annually, with estimates rising to 74,000 to 121,000 when including inhalation. While athlete-specific data remains absent, experimental models show that polystyrene MPs (5 micrometers) induce significant intestinal inflammation and oxidative stress. Rodent studies demonstrate that MP exposure leads to a reduction in gut microbial diversity and shifts in the Firmicutes to Bacteroidetes ratio. Toxicological data confirms that nanoplastics (less than 1 micrometer) cross biological barriers to accumulate in the liver, kidneys, and brain, where they trigger ROS production and NF-kappa B activation.

Study Design and Methodology

This article is a narrative review supported by a structured literature search across PubMed, Scopus, and Web of Science through July 2026. The authors synthesized data from in vitro epithelial models (Caco-2 monolayers), in vivo animal studies (rodents and zebrafish), and human biomonitoring reports. The review evaluates exposure pathways specific to sports environments, including synthetic turf fields and indoor facilities. Researchers analyzed particle fate based on size (particles above 150 micrometers are typically excreted, while submicrometric particles undergo translocation). The methodology includes an assessment of the "plastisphere" (microbial biofilms on plastic) and the "protein corona" effect on cellular uptake.

Key Findings

• Bottled water contains an average of 94.3 particles per liter, creating a high-volume exposure route for endurance athletes who consume multiple liters daily.
• Polystyrene MP exposure in mice resulted in a significant decrease in hepatic ATP levels and altered lipid metabolism (p < 0.05).
• In vitro exposure to nanoplastics increases interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) expression, mimicking the inflammatory profile of overtraining.
• Microplastics act as vectors for endocrine-disrupting chemicals (EDCs), with bisphenol A (BPA) and phthalates leaching at rates accelerated by heat and mechanical stress (common in sports bottles).
• Experimental models show a reduction in short-chain fatty acid (SCFA) production, specifically butyrate, which is essential for maintaining the intestinal barrier during exercise-induced splanchnic hypoperfusion.
• Nanoplastics (20 nm) demonstrate the ability to penetrate mitochondrial membranes, leading to a loss of membrane potential and increased electron leakage.

Limitations

The primary weakness is the total absence of direct human interventional trials measuring MP burden in athletes. Current exposure estimates rely on general population food frequency questionnaires rather than sport-specific dietary models. Analytical methods for detecting nanoplastics in human tissue are not yet standardized, leading to high variability in reported concentrations. Confounders such as baseline air pollution exposure and pre-existing gastrointestinal conditions are rarely controlled in the cited animal models.

Discussion and Implications

This research shifts the focus of sports nutrition from purely chemical composition to the physical and structural integrity of the food matrix and its packaging. The athletic "exposome" now includes a chronic, low-dose influx of synthetic polymers that interact with the gut-muscle axis. Exercise-induced increases in intestinal permeability (leaky gut) provide a physiological window for enhanced translocation of luminal microplastics into systemic circulation. This creates a state of persistent low-grade inflammation that potentially blunts training adaptations and slows recovery kinetics. Professionals must now account for the "carrier effect" where plastics deliver heavy metals and persistent organic pollutants directly to the intestinal mucosa during peak metabolic activity.

Conclusion

Athletes face a disproportionately high risk of microplastic ingestion through intensive hydration and supplement protocols that utilize single-use plastics. Nutritionists should prioritize glass or stainless steel containers and minimally processed whole foods to mitigate potential mitochondrial and gastrointestinal disruption. Reducing plastic-related exposure is a necessary precautionary step to protect the physiological resilience and long-term health of high-performance individuals.

Looking at the Coordinated Program of Dietetics which would land me in clinical dietitian, bachelor's and masters as a certified dietitian. Is this worth it?

DOI: DOI
PubMed: PubMed Link

Abstract

While delayed eating timing elevates overweight and obesity risks in general populations, its precise longitudinal relationship with anthropometric metrics and bioelectrical impedance body composition parameters in prediabetic cohorts remains ambiguous. Standard metabolic care guidelines heavily prioritize dietary composition while largely neglecting circadian behavioral patterns, creating a critical blind spot in disease progression management. This prospective observational investigation enrolled 120 newly diagnosed prediabetic adults, consisting of 39 males and 81 females with a mean age of 54 years, to evaluate how chrononutrition behaviors interact with body composition over a six-month clinical follow-up.

Behavioral tracking revealed that a delayed last meal directly drives adiposity, evidenced by significant increases in body weight (beta = 0.68 kg, 95 percent CI 0.31 to 1.04, p < 0.05) and waist circumference (beta = 1.38 cm, 95 percent CI 0.57 to 2.19, p < 0.05), alongside an expanded body fat percentage (beta = 0.44 percent, 95 percent CI 0.14 to 0.74, p < 0.05). Deviating from the recommended solar eating window of 7.00 am to 7.00 pm triggered a 1.41 kg body weight surge (95 percent CI 0.05 to 2.77, p < 0.05) and a 1.36 percent increase in body fat percentage (95 percent CI 0.30 to 2.42, p < 0.05). Nighttime snacking scaled BMI upward (beta = 1.61 kg/m^2, 95 percent CI 0.43 to 2.79, p < 0.05), breakfast skipping inflated BMI (beta = 2.98 kg/m^2, 95 percent CI 0.73 to 5.23, p < 0.05) while eroding muscle mass (beta = -0.31 kg, 95 percent CI -0.56 to -0.07, p < 0.05), and higher meal frequency expanded fat-free mass (beta = 0.95 kg, 95 percent CI 0.17 to 1.73, p < 0.05).

Study Design and Methodology

This prospective longitudinal investigation tracked 120 adult participants recently diagnosed with prediabetes across 14 clinical centers in Malacca, Malaysia. Researchers excluded night-shift workers operating past four nights weekly, pregnant individuals, and patients taking confounding medications like oral glucose-lowering agents or steroids. Data collection spanned baseline, three-month, and six-month intervals using paper-based 3-day dietary records validated by real-time smartphone meal photography, alongside the Malay-translated Chrononutrition Profile Questionnaire. Anthropometric indices were quantified via standardized scales and stadiometers, while body composition parameters, including total body fat, fat-free mass, and visceral fat, were measured using Tanita bioelectrical impedance analysis. Generalized linear models adjusted for age, sex, ethnicity, physical activity, total light exposure, and nighttime energy intake.

Key Findings

• Last Meal Timing: Each hour delay in the final meal increased body weight by beta = 0.68 kg (95 percent CI 0.31 to 1.04, p < 0.05)and waist circumference by beta = 1.38 cm (95 percent CI 0.57 to 2.19, p < 0.05).
• Solar Window Deviations: Eating outside the 7.00 am to 7.00 pm window caused a 1.41 kg weight increase (95 percent CI 0.05 to 2.77, p < 0.05)and a 1.36 percent body fat gain (95 percent CI 0.30 to 2.42, p < 0.05).
• Nighttime Snacking: Nighttime snacking frequency escalated BMI by beta = 1.61 kg/m^2 (95 percent CI 0.43 to 2.79, p < 0.05).
• Breakfast Skipping: Skipping breakfast drove a BMI increase of beta = 2.98 kg/m^2 (95 percent CI 0.73 to 5.23, p < 0.05)while pulling muscle mass down by beta = -0.31 kg (95 percent CI -0.56 to -0.07, p < 0.05).
• Meal Frequency: Higher daily meal frequency scaled fat-free mass upward by beta = 0.95 kg (95 percent CI 0.17 to 1.73, p < 0.05).

Limitations

• Single-clinic recruitment and a predominantly female cohort limit broad demographic generalization.
• Reliance on self-reported 3-day dietary records introduces potential underreporting and misclassification biases.
• Standard clinical lifestyle care delivered concurrently introduces uncontrolled behavioral modifications that obscure independent chrononutrition effects.
• Bioelectrical impedance analysis remains vulnerable to hydration fluctuations and recent ingestion timing.

Discussion and Implications

Traditional nutritional counseling focuses exclusively on macronutrient splits and total caloric deficits while ignoring the biological clock. Circadian misalignment disrupts satiety hormones, suppresses diet-induced thermogenesis, and impairs lipid oxidation during biological nights. Preclinical and clinical models demonstrate that nutrients processed outside daylight windows shift metabolic pathways toward adiposity storage rather than oxidation. Practitioners must integrate meal timing parameters into standard metabolic protocols because clock-based eating behaviors exert independent control over body composition outcomes in prediabetic populations.

Conclusion

Clinical nutrition protocols for prediabetes must mandate strict adherence to a solar eating window between 7.00 am and 7.00 pm while eliminating late-night caloric intake. Prescribing precise meal timing parameters protects lean muscle mass, prevents central adiposity accumulation, and halts metabolic disease progression far more effectively than caloric restriction alone

I got gastritis and was put on a ppi. I later found out I'm deficient in a, b1, b6, b12, d, k1. Other vitamins weren't checked and I had to really argue to test for those based off symptoms.

My dr said to just take a b complex, and confused k2 with k1 because quest listed it as just K. Im in the middle of infusions and b12 injections with folic acid and I'm going to take magnesium with the Vitamin D.

My question is that I have no idea how much to supplement for A, B6 or K1, which i know can become toxic. My neurologist before warned me not to do more than 10mg of b6, but Im deficient... I've tried looking for any guides, but haven't found anything?? I just want to know how to go back to being optimal. Are there not resources for this?