Can Eating Eggs Prevent Alzheimer’s Disease?

The association between egg consumption and incidence of Alzheimer’s disease was examined in a prospective cohort study of 39,498 Seventh-day Adventists (mean age, 64 years) participating in the Adventist Health Study 2. During a mean follow-up period of 15.3 years, 2,858 individuals developed Alzheimer’s disease. Egg consumption was inversely associated with Alzheimer’s disease risk. Compared with never or rarely consuming eggs, hazard ratios (95% confidence intervals) after adjusting for demographic factors, lifestyle factors, intake of various food groups, and comorbidities were 0.83 (0.75-0.92) for 1-3 times per month, 0.83 (0.74-0.94) for once per week, 0.80 (0.71-0.90) for 2-4 times per week, and 0.73 (0.60-0.89) for 5 or more times per week.

Comment: In this observational study of a health-conscious population, moderate egg consumption, as compared with never or rarely eating eggs, was associated with a significant reduction in risk of developing Alzheimer’s disease. While observational studies do not prove causation, the findings are consistent with the possibility that eating eggs can help prevent Alzheimer’s disease. Eggs are a rich source of various nutrients that enhance brain function, including choline, lutein, zeaxanthin, docosahexaenoic acid, and high-quality protein.

Oh J, et al. Egg intake and the incidence of Alzheimer’s disease in the Adventist Health Study 2 cohort linked with Medicare data. J Nutr. 2026;156:101541.

The Importance of Adequate Iodine Intake During Pregnancy

In a study of 1,211 mother–child pairs in the United Kingdom, lower iodine status during the first trimester of pregnancy (as measured by the urinary iodine-to-creatinine ratio) was associated with lower verbal intelligence in the children at 15 years of age, and in severe iodine deficiency was also associated with reduced full-scale intelligence quotient in the children.

Comment: Iodine deficiency during pregnancy can lead to hypothyroidism in the fetus, which can result in developmental deficits, including mental disability. The results of the present study suggest that the deficits in brain function associated with iodine deficiency persist at least into the teen years.

The prevalence of mild-to-moderate iodine deficiency has increased in the United States over the past several decades, as a result of decreased salt intake and discontinuation of the use of iodates as dough oxidizers in commercial bread making. In a survey of pregnant U.S. women participating in the National Health and Nutrition Examination Survey (2005-2010), more than half had evidence of “less than adequate” iodine status during the first and second trimesters.¹ Inadequate iodine status during pregnancy is also common in the United Kingdom,² primarily because iodized salt is not widely available. In some parts of the world the prevalence of insufficient iodine intake during pregnancy is as high as 86%.³ 

The American Academy of Pediatrics and the Endocrine Society recommend that women receive prenatal vitamins that provide 150 µg per day of iodine during preconception, pregnancy, and lactation. Good food sources of iodine include fish, other animal products, seaweed, and iodized salt.

Keestra SM, et al. Iodine deficiency in the first pregnancy trimester and intelligence in adolescence. Eur J Nutr. 2026;65:111.

Bromelain Helps Promote Recovery After Tooth Extraction

Forty-two individuals undergoing extraction of a single mandibular third molar under local anesthesia were randomly assigned to receive 200 mg of pure bromelain, a pineapple extract containing 200 mg of bromelain, or placebo every 6 hours for 3 days, then every 12 hours for 4 days. Treatment was started on the morning of surgery. Compared with the placebo group, both bromelain groups required less ibuprofen (p < 0.0001), had less pain and swelling (p < 0.0001), and had significantly better scores on a scale that measured quality of life. The effects of the two different forms of bromelain were similar.

Comment: Bromelain is a group of substances present in pineapple stems and to a lesser extent in the pineapple fruit. Bromelain contains at least 5 proteolytic enzymes. It is believed to promote the healing of surgical wounds and soft-tissue injuries by enhancing the removal of fibrin from the inflamed areas, thereby restoring drainage and reducing swelling. Although proteolytic enzymes are protein molecules that would be expected to be destroyed by digestive enzymes after oral administration, the results of most studies suggest that at least a portion of orally administered proteolytic enzymes is absorbed into the bloodstream intact.

The results of the present study are consistent with previous research demonstrating that proteolytic enzymes can decrease pain and accelerate healing following a tooth extraction.

Colletti A, et al. An evaluation of the effects of pineapple-extract and bromelain-based treatment after mandibular third molar surgery: a randomized three-arm clinical study. Nutrients. 2024;16:784.

Tomatoes are Beneficial for People with Fatty Liver

Seventy-nine Italian adults (mean age, 58 years) with metabolic dysfunction-associated steatotic liver disease (MASLD), with a body mass index of 30 kg/m² or lower, were randomly assigned to consume 200 g per day of raw tomatoes and 50 g per day of tomato sauce for 6 weeks, or to a control group that consumed a tomato-free diet. The degree of hepatic steatosis decreased in both groups; the decrease was greater in the tomato group than in the control group (p = 0.003). Tomato consumption had no effect on body weight or liver enzymes.

In a second study, 98 Italian patients (mean age, 55 years) with MASLD were randomly assigned to receive, in double-blind fashion, a carotenoid-enriched tomato sauce (OsteoCol) or a standard commercial tomato sauce (control) for 12 weeks. The dosage was 80 g per day or 160 g every other day. OsteoCol was produced from vine-ripened organic Calabrian tomatoes, harvested at full physiological maturity. The product contained 247 parts per million (ppm) of all-trans lycopene (52% more lycopene than in the control sauce, which was present as 3 different lycopene isoforms) and 78 ppm of beta-carotene (over 8 times that of the control). Both types of tomato sauce were cooked before consuming. The mean reduction in liver fat content was greater in the OsteoCol group than in the control group (-11% vs. -3%; p = 0.014).

Comment: MASLD (formerly known as nonalcoholic fatty liver disease) is characterized by fatty infiltration of hepatocytes (hepatic steatosis). In some people, hepatic steatosis is accompanied by hepatic inflammation, in which case it is called metabolic dysfunction-associated steatohepatitis (MASH), formerly known as nonalcoholic steatohepatitis. MASH may progress to hepatic fibrosis, cirrhosis, or hepatocellular carcinoma. In contrast, hepatic steatosis without an inflammatory component does not typically progress to more severe liver disease. However, hepatic steatosis appears to be an independent risk factor for cardiovascular disease and is associated with increased all-cause mortality.

In the first study described above, daily consumption of raw tomatoes and tomato sauce decreased the amount of liver fat in adults with MASLD. In the second study, a high-carotenoid tomato sauce was more effective than a standard tomato sauce for reducing hepatic steatosis. The greater efficacy of the former product could have been due to the higher carotenoid content or to the different content of lycopene isoforms, compared with the standard tomato sauce. It is also possible that vine-ripened tomatoes contain higher concentrations of other biologically active compounds. The results of these studies demonstrate that including tomato products in a healthful diet may be beneficial for patients with MASLD.

Tatoli R, et al. Effect of tomato consumption on liver steatosis in MASLD: a randomized controlled trial (POMOSANO Study). Nutrients. 2026;18:2476.

Mare R, et al. A carotenoid-rich functional tomato sauce (OsteoCol) reduces liver fat content in adults with metabolic dysfunction-associated steatotic liver disease: a randomized clinical trial. Eur J Nutr. 2026;65:189.

Meta-Analysis of Studies on Coenzyme Q₁₀ for Treatment of Depression: Therapeutic Breakthrough or “Garbage in, garbage out?”

A meta-analysis was conducted on 5 randomized controlled trials (with a total of 474 participants) that examined the effect of coenzyme Q₁₀ (CoQ₁₀) in patients with depression, either as a primary disorder or in the context of an underlying medical illness. Three trials enrolled patients with depression associated with significant medical conditions (multiple sclerosis, breast cancer, or polycystic ovary syndrome), while two trials included patients with primary depression. In the pooled analysis, CoQ₁₀ significantly decreased depressive symptoms compared with the control groups (p < 0.01). The authors of the meta-analysis concluded that CoQ₁₀ may be beneficial in the treatment of depressive symptoms.

Comment: The great song writer and satirist Tom Lehrer once quipped, “Life is like a sewer: what you get out of it depends on what you put into it.” To paraphrase Lehrer’s comment, if a meta-analysis is based largely on studies of questionable or uncertain validity, then the conclusions from the meta-analysis might also be of questionable or uncertain validity.

Of note, four of the five trials cited in the meta-analysis came from Iran. In the only study that did not come from Iran, CoQ₁₀ was not more effective than placebo for relieving depressive symptoms. Concerns have been raised about the integrity of much of the research coming from Iran. It has been reported that numerous companies in Iran offer to write scientific papers for a fee,⁴ and that fabrication of data is common.⁵ In one paper included in the meta-analysis described above, Maryam Karamali was one of the authors. A PubMed search revealed that Karamali has coauthored 31 papers with Zatollah Asemi. Serious concerns have been raised about the integrity of Asemi’s work.⁶ At least 23 of Asemi’s papers have been retracted and Expressions of Concern have been issued for 85 of his papers. Among the 31 papers co-authored by Karamali and Asemi, there have been 6 retractions and 12 Expressions of Concern. Because of these issues, I have doubts about whether CoQ₁₀ is really an effective treatment for depressive symptoms.

Magalhaes PL, et al. Effects of coenzyme Q₁₀ supplementation on depressive symptoms and fatigue: a systematic review and meta-analysis of randomized controlled trials. J Clin Psychopharmacol. 2026;46:93-100.

Iron Therapy for Heart Failure: Results Differ According to Sex

The Intravenous Iron in Patients with Systolic Heart Failure and Iron Deficiency to Improve Morbidity & Mortality (FAIR-HF2-DZHK05) trial included 1,105 heart failure patients with a left ventricular ejection fraction of 45% or lower and iron deficiency. A total of 368 women and 737 men were randomly assigned to receive intravenous ferric carboxymaltose (a form of iron) or placebo. The 3 primary endpoints were 1) time to cardiovascular death or first heart failure hospitalization, 2) total heart failure hospitalizations, and 3) time to first event of cardiovascular death or heart failure hospitalization only in patients with transferrin saturation less than 20% at baseline. The hazard ratio for the first primary outcome was 1.07 (p = 0.80) in women and 0.74 (p = 0.016) in men, The rate ratio for the second primary outcome was 1.06 (p = 0.86) in women and 0.79 (p = 0.14) in men. The hazard ratio for the third primary outcome was 1.21 (p = 0.58) in women and 0.73 (p < 0.03) in men. The hazard ratio for all-cause mortality was 1.46 (p = 0.24) in women and 0.86 (p = 0.33) in men.

Comment: Iron plays a key role in myocardial function, both as a component of hemoglobin and as a cofactor for an enzyme in the electron-transport chain. Observational studies have found that iron deficiency in heart failure patients is associated with increased risk of hospitalization and increased mortality. Most, but not all, randomized controlled trials have found that intravenous administration of iron to iron-deficient patients with systolic heart failure resulted in sustained improvement in functional capacity, symptoms, and quality of life, and decreased the number of hospitalizations for worsening heart failure.

In the present study, the beneficial effects of iron therapy were seen only in men. In contract, iron therapy resulted in worse outcomes, compared with placebo, in women (although the differences were not statistically significant). Based on these findings, we should re-evaluate the wisdom of administering intravenous iron to iron-deficient women with heart failure. There has been little research on the effect of oral iron in heart failure patients. 

Karakas M, et al. Intravenous ferric carboxymaltose in heart failure with iron deficiency (FAIR-HF2 DZHK05 trial): Sex-specific outcomes. Eur J Heart Fail. 2025;27:2328-2342.

Feeding Goat Milk Formula to Infants Instead of Cow Milk Formula May Prevent Atopic Dermatitis

A total of 2,132 healthy term infants (aged 3 months or younger) in Spain or Poland, who were not selected on the basis of risk for developing atopic dermatitis (AD), were randomly assigned to receive, in double-blind fashion, whole goat milk formula or whole cow milk formula. In intent-to-treat analysis, the incidence of AD during the first year of life did not differ between groups. In per protocol analysis, which included only children who did not interrupt formula feeding for more than 3 consecutive days and who did not introduce solid foods before the age of 4 months, the incidence of doctor-diagnosed AD was 34% lower with goat milk formula than with cow milk formula in the group as a whole, and 64% lower among infants with a parental history of AD.

Comment: This study found that consumption of whole goat milk formula, as compared with cow milk formula, reduced the incidence of AD in formula-fed infants in the first year of life. This effect was more pronounced in infants who had a parental history of AD. Goat milk formula is commercially available, although it is more expensive than more commonly used infant formulas. While the use of goat milk formula may be advisable for selected infants, plain unmodified goat milk is deficient in a number of important nutrients and should not be given to babies.

Grote V, et al. Whole goat milk versus cow milk formula and atopic dermatitis in infants: A randomized clinical trial. Clin Nutr. 2026;63:106707.

Unexplained Cirrhosis? Consider Celiac Disease

Of 232 patients in India with cryptogenic (unexplained) cirrhosis, 11 (4.7%) (mean age, 31.3 years) were found to have biopsy-proven celiac disease. These 11 patients were prescribed a gluten-free diet. During a follow-up period of 1 year, compared with 44 matched patients (mean age, 31.8 years) with cryptogenic cirrhosis without celiac disease, the patients with celiac disease improved significantly, as measured by the Model for End-stage Liver Disease Sodium (MELD-Na) score (p = 0.001) and the Child-Turcotte-Pugh classification (p < 0.001). In addition, further decompensation was less frequent, and the mortality rate was nonsignificantly lower (9.1% vs. 18.2%; p = 0.67) in the patients on the gluten-free diet than in the patients without celiac disease.

Comment: Liver involvement is common in patients with celiac disease. In the present study, the prevalence of celiac disease in people with cryptogenic cirrhosis was about 5 times higher than in the general population. In those individuals, commencement of a gluten-free diet resulted in improved liver outcomes. Patients with unexplained cirrhosis should be tested for celiac disease, even if they do not have the typical gastrointestinal symptoms, because a substantial minority of celiac patients do not have gastrointestinal symptoms.

Pachisia AV, et al. Celiac disease Is common in adults with cryptogenic cirrhosis and responds favorably to gluten-free diet. Am J Gastroenterol. 2025;120:2113-2124.

References

1. Caldwell KL, et al. Iodine status in pregnant women in the National Children’s Study and in U.S. women (15-44 years), National Health and Nutrition Examination Survey 2005-2010. Thyroid. 2013;23:927-37.
2. Combet E, et al. Iodine and pregnancy – a UK cross-sectional survey of dietary intake, knowledge and awareness. Br J Nutr. 2015;114:108-17.
3. Patriota ES, et al. Prevalence of insufficient iodine intake in pregnancy worldwide: a systematic review and meta-analysis. Eur J Clin Nutr. 2022;76:703-15.
4. Stone R. In Iran, a shady market for papers flourishes. Science. 2016;353:1197.
5. Anonymous. Academic misconduct: Are we progressing or going backwards? University World News, March 5, 2025.
6. Grey A, Avenell A, Gaby A, Bolland MJ. Inconsistency in publishers’ responses to integrity concerns about published research. Evidence and suggested improvements. J Clin Epidemiol. 2025186:111918.