Journal Retracts Review Article that Claimed the Herbicide Glyphosate (Roundup) is Safe

The editors of the journal Regulatory Toxicology and Pharmacology have retracted a review article from the year 2000, which had concluded that the herbicide Roundup and its active ingredient glyphosate do not pose a health risk to humans. The retraction was based on several points. First, the article’s claim that glyphosate is not carcinogenic was based solely on unpublished studies from Monsanto (the manufacturer of Roundup). The review article failed to include at least five other studies on the carcinogenicity of glyphosate that had been completed at the time the review article was written. Second, lawsuits filed in the United States revealed that employees of Monsanto may have contributed to the writing of the article, and that these employees were not listed as co-authors of the paper. The retraction notice stated that the failure to disclose this authorship raises serious concerns about the independence of the authors and the integrity of the data that was presented. Third, information obtained during litigation suggested that Monsanto paid the authors to write the paper, and that these payments were not disclosed by the authors. The failure to disclose this financial conflict of interest calls into question the objectivity of the authors. Fourth, the review article has had a significant impact on government regulations related to the use of glyphosate and Roundup. Because it has played a key role in the assessment of glyphosate’s safety, there can be no room for doubt about the scientific integrity of the paper.

Comment: Glyphosate is the active ingredient in Roundup, the most widely used herbicide in agriculture. Several studies have found an association between glyphosate exposure and non-Hodgkin lymphoma. Some countries and some US cities have banned or restricted the use of glyphosate because of concerns about its safety. In addition, numerous lawsuits have been filed against Monsanto and its parent company Bayer, alleging that glyphosate exposure caused severe health problems. Although glyphosate is still being sold for agricultural use, Roundup products for home and garden use now contain other active ingredients.

Anonymous. Retraction notice to “Safety evaluation and risk assessment of the herbicide roundup and its active ingredient, glyphosate, for humans” [Regul. Toxicol. Pharm. 31 (2000) 117-165]. Regul Toxicol Pharmacol 2025;165:106006.

Can Food Allergy Cause Anemia?

Two hundred forty-four patients with functional gastrointestinal disorders who were found to have non-celiac wheat sensitivity (NCWS; diagnosed by double-blind placebo-controlled wheat challenge) were evaluated retrospectively. The prevalence of anemia was significantly higher in these patients than in 124 patients with irritable bowel syndrome who had not been found to have NCWS (34.8% vs. 17.4%; p = 0.03) and was nonsignificantly lower than in 174 patients with celiac disease (34.8% vs. 48.3%). The anemia of patients with NCWS had features consistent with iron deficiency. Thirty-one patients with NCWS and anemia were re-evaluated after being on a strict wheat-free diet for at least 12 months (mean, 21 months). In these 31 patients, the mean hemoglobin concentration increased from 9.6 g/dl to 12.0 g/dl, the mean ferritin level increased from 15 ng/ml to 24 ng/ml, and only 2 patients (6.5%) continued to be anemic. Twenty-five of these 31 patients were treated with iron supplements. However, in the past, all of these patients had been treated with similar or higher doses of iron without having any improvement of the anemia.

Comment: It is well known that celiac disease can cause anemia, which apparently results from malabsorption of iron and other nutrients. The results of the present study suggest that wheat allergy in the absence of celiac disease can also promote the development of iron deficiency and anemia. As with celiac disease, the likely mechanism is nutrient malabsorption secondary to intestinal inflammation. Allergy-induced gastrointestinal bleeding might also be a contributing factor, as has been demonstrated in infants allergic to cow’s milk. It would not be surprising if future studies found that allergies to other foods can also contribute to the development of anemia in some individuals.

Mansueto P, et al. Anemia in non-celiac wheat sensitivity: Prevalence and associated clinical and laboratory features. Dig Liver Dis. 2023;55:735-742.

Coffee Promotes Recovery from Postoperative Ileus

Seventy-nine patients who had undergone small-bowel resection were randomly assigned to consume 100 ml of caffeinated coffee or water 3 times per day (at 8 a.m., noon, and 4 p.m.). Treatment was started no later than the day after surgery and was continued until the time of first flatus or first bowel movement, whichever came first. The median time until the nasogastric tube was removed (3.4 vs. 4.0 days; p = 0.002) and the median time until hospital discharge (6.7 vs. 7.7 days; p = 0.01) was significantly shorter in the coffee group than in the water group.

Comment: Postoperative ileus is a temporary disruption of bowel motility that often occurs after bowel surgery. Prolonged ileus, which occurs in 10% to 24% of patients undergoing abdominal surgery, can lead to various complications and increased length of hospital stay. The results of the present study demonstrate that consumption of a modest amount of coffee can accelerate the return of bowel function and decrease the length of hospital stay in patients undergoing small-bowel resection. Previous studies have found that chewing gum after major surgery can also accelerate recovery of bowel function, prevent postoperative complications, and decrease the length of hospital stay.

Holland C, et al. Coffee administration to promote return of bowel function after small bowel resection: A randomized, controlled trial. Am J Surg. 2023;226:156-160.

Mediterranean Diet for Psoriasis

Thirty-eight Spanish individuals (mean age, 46 years) with mild-to-moderate psoriasis who were receiving stable topical therapy were randomly assigned to consume a Mediterranean diet (intervention group) or a low-fat control diet for 16 weeks. Participants in the intervention group were given extra-virgin olive oil (EVOO) and were encouraged to consume at least 4 tablespoons per day. At baseline, the median Psoriasis Area and Severity Index (PASI) was 4.8 in the intervention group and 3.8 in the control group. The mean PASI decreased (improved) by 3.4 in the intervention group and did not change in the control group (p < 0.001 for the difference in the change between groups). A PASI reduction of at least 75% was achieved by 47% of patients in the intervention group and 0% of patients in the control group.

Comment: The Mediterranean diet emphasizes high intake of extra-virgin olive oil (EVOO), fruit, nuts, vegetables, legumes, and whole-grain cereals; moderate intake of fish and poultry; and low intake of whole-fat dairy products, red or processed meat, and sweets. This diet is known to have anti-inflammatory effects and might therefore be beneficial against inflammatory conditions such as psoriasis. In the present study, consumption of a Mediterranean diet supplemented with EVOO decreased disease severity in people with mild-to-moderate psoriasis. The beneficial effect may have been due in part to EVOO, since EVOO contains several polyphenolic compounds that are known to have anti-inflammatory activity. Consumption of refined sugar is also known to increase inflammation, so the reduction in sugar intake by study participants may have contributed to the improvement.

Perez-Bootello J, et al. Mediterranean diet and patients with psoriasis: the MEDIPSO randomized clinical trial. JAMA Dermatol. 2025;Sep 25:e253410.

Pregnant Women are not Consuming Enough Iodine

Dietary surveys were conducted in 750 pregnant women living in the United States. The median intake of iodine from diet was 109 µg per day, and 63% were consuming less than the Estimated Average Requirement (EAR) of 160 µg per day. Sixty-five percent of the women took a supplement containing iodine, but only 32% took at least 150 µg per day of supplemental iodine. Forty-one percent of the women were below the EAR, even with supplementation. Forty-eight percent of the women had a urinary iodine concentration below 150 µg/L, which is consistent with the findings from the dietary survey.

Comment: Iodine is an essential nutrient for fetal neurodevelopment. The EAR for iodine during pregnancy is 160 µg per day. The Recommended Dietary Allowance (the level of intake that would be expected to meet the needs of 97.5% of healthy pregnant women) is somewhat higher, at 220 µg per day. Most experts recommend that pregnant women take a supplement that provides 150 µg per day of iodine. The present study found that a large percentage of pregnant women in the US are not consuming enough iodine, which could have negative consequences for fetal and infant development. A recent study found that inadequate maternal iodine intake during the first trimester of pregnancy was associated with decreased intelligence of the child during adolescence.¹ Good food sources of iodine include milk, cheese, meat, fish, poultry, eggs, and iodized salt. Pregnant women should make sure that their prenatal multivitamin contains an adequate amount of iodine. In addition to reading the label, they should request a laboratory analysis of the product, since a substantial number of prenatal multivitamins have been found to contain less than 50% of the iodine listed on the label.²

Griebel-Thompson AK, et al. Iodine intake from diet and supplements and urinary iodine concentration in a cohort of pregnant women in the United States. Am J Clin Nutr. 2023;118:283-289.

Can Lutein and Zeaxanthin Improve Myopia, or is this More Research Fraud from China?

A meta-analysis was conducted on 10 randomized controlled trials, including a total of 1,035 adolescents with myopia (nearsightedness), that examined the effect of lutein and zeaxanthin supplementation on the progression of myopia. Supplementation with lutein and zeaxanthin resulted in a significant reduction in axial length elongation (suggesting an improvement of myopia) and an enhancement of visual sensitivity. Subgroup analyses revealed that higher doses of lutein and zeaxanthin and longer treatment periods were associated with significantly greater improvement, when compared with lower doses and shorter treatment periods.

Comment: Lutein and zeaxanthin are carotenoids that have shown great promise for the prevention and treatment of age-related macular degeneration. I was initially excited to come across a study demonstrating that these carotenoids could also be useful for preventing and treating myopia. However, for two reasons my excitement was tempered by a strong degree of skepticism. First, in my long career of reviewing the medical literature related to nutritional therapies, I had never seen even one study that examined lutein and zeaxanthin as a treatment for myopia. Could it be possible that I had missed all 10 of the studies in the meta-analysis? Second, the study came from China, and it has been my distinct impression that many research papers coming from this country appear to be fraudulent.

So, I took a closer look at the paper and found that none of the 10 studies included in the meta-analysis had anything to do with myopia. Most of the studies were related to cognitive function or age-related macular degeneration in older adults; some of the studies were meta-analyses rather than randomized controlled trials; and 2 of the studies were in rats or mice (not humans). In addition, I found no evidence that any of the cited papers studied adolescents. In Table 1 of the paper, the mean age of the participants in each of the 10 cited studies was said to be between 12 and 15 years. However, on examining the cited papers, it appeared that the age numbers listed in Table 1 were a complete fabrication.

I sent an email to the editors of the International Journal of Ophthalmology, expressing my concerns about this paper. The editorial office replied the next day, stating that they would look into my concerns and, if they turned out to be legitimate, the paper would be retracted, While awaiting the results of their investigation, I am left wondering how the peer reviewers for this supposedly reputable journal could have missed such obvious defects in the paper.

Pei L, Mo Y, Duan JG. The differential effects of lutein and zeaxanthin supplementation on myopia prevention in adolescents: a systematic review and Meta-analysis. Int J Ophthalmol. 2026;19:370-378.

Can GLP-1 Receptor Agonists Cause Wernicke Encephalopathy?

A 49-year-old woman being treated with semaglutide for obesity presented with Wernicke encephalopathy in the context of frequent vomiting and reduced food intake. Eighteen other cases of Wernicke encephalopathy have been reported in patients taking a glucagon-like peptide-1 (GLP-1) receptor agonist. In 68% of those cases, nausea and vomiting or reduced food intake were involved, and weight loss ranged from 3.5 to 13.2 kg per month for 3 to 6 months.

Comment: GLP-1 receptor agonists such as semaglutide (Ozempic), tirzepatide (Mounjaro), and liraglutide (Victoza) are being widely used to treat type 2 diabetes and to promote weight loss. These drugs reduce appetite and also frequently cause gastrointestinal side effects including nausea and vomiting. Wernicke encephalopathy is caused by severe thiamine deficiency. Because not much thiamine can be stored by the body, this vitamin can become rapidly depleted when a person is not eating much and is also experiencing repeated vomiting. Severe thiamine deficiency can cause irreversible neurological damage if it is not detected and treated in a timely fashion. Individuals who are at risk of developing thiamine deficiency should take a thiamine or B-complex vitamin supplement. If they are not able to keep the supplement down because of repeated vomiting, an intramuscular injection of thiamine should be considered.

Gras C, et al. Semaglutide-induced Wernicke encephalopathy: a comprehensive analysis. Eur J Clin Nutr, 2025;79:1160-1163.

Can Turmeric Supplements Cause Liver Damage?

In reviewing the pathology archives at several different institutions, the authors of this report identified 11 patients over a 10-year period who had biopsy-confirmed hepatitis associated with the use of turmeric supplements. Six patients were asymptomatic with abnormal liver function tests, while 5 patients presented with malaise and/or jaundice. Ten patients showed predominant transaminase abnormalities, while one had predominant alkaline phosphatase elevation. All patients stopped turmeric supplements, and 4 patients also received steroid therapy. Liver function tests became normal in all patients. Roussel Uclaf causality assessment method analysis estimated that turmeric was the probable cause of liver injury in 8 cases and the possible cause in 3 cases.

Comment: Supplements containing turmeric or curcumin (which is derived from turmeric) are widely used for their anti-inflammatory effects and other potential health benefits. Published research suggests that these supplements may be beneficial for treating inflammatory bowel disease, and preliminary evidence suggests that they may be useful for preventing dementia and age-related macular degeneration. It is often difficult to prove that a specific supplement was responsible for a specific adverse effect. It is possible that in some cases the adverse effects reported in this study were due to contaminants or other ingredients in the products, or to the concomitant use of other medications. Nevertheless, people taking turmeric or curcumin supplements should be alert to the possibility of liver damage and should avoid excessive doses.

Papke DJ Jr, et al. Turmeric supplement-associated hepatitis: a clinicopathological series of 11 cases highlighting pan-lobular and zone 3 injury. Histopathology. 2025;86:410-422.

References

1. Keestra SM, et al. Iodine deficiency in the first pregnancy trimester and intelligence in adolescence. Eur J Nutr. 2026;65:111.
2.  Leung AM, et al. Iodine content of prenatal multivitamins in the United States. N Engl J Med. 2009;360:939-940.