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Wednesday, April 21, 2021

2 Scholarly Articles - (1) Food intake diet and sperm characteristics in a blue zone: a Loma Linda Study & (2) Plasma, Urine, and Adipose Tissue Biomarkers of Dietary Intake Differ Between Vegetarian and Non-Vegetarian Diet Groups in the Adventist Health Study-2

Title:
Food intake diet and sperm characteristics in a blue zone: a Loma Linda Study
 
Authors:
Eliza M Orzylowska, John D Jacobson, Gihan M Bareh, Edmund Y Ko, Johannah U Corselli & Philip J Chan
All from the Loma Linda Uiversity School of Medicine, USA
 
Published:
European Journal of Obstetrics, Gynecology, and Reproductive Biology, Epub: 30 May 2016

Abstract:
Objectives: 
The study examined the effect the life-long vegetarian diet on male fertility and focused on vegetarians living in the Loma Linda blue zone, a demographic area known for life longevity. The objective was to compare sperm characteristics of vegetarian with non-vegetarian males.  
 
Study design: 
The cross-sectional observational study was based on semen analyses of 474 males from 2009 to 2013. Patients categorized themselves as either life-long lacto-ovo vegetarians (N=26; vegetable diet with dairy and egg products), vegans (N=5; strictly vegetables with no animal products) or non-vegetarians (N=443; no diet restrictions). Sperm quality was assessed using a computer-aided sperm analyzer and strict morphology and chromatin integrity were manually evaluated. 
 
Results: 
Lacto-ovo vegetarians had lower sperm concentration (50.7±7.4M/mL versus non-vegetarians 69.6±3.2M/mL, mean±S.E.M.). Total motility was lower in the lacto-ovo and vegan groups (33.2±3.8% and 51.8±13.4% respectively) versus non-vegetarians (58.2±1.0%). Vegans had lowest hyperactive motility (0.8±0.7% versus lacto-ovo 5.2±1.2 and non-vegetarians 4.8±0.3%). Sperm strict morphologies were similar for the 3 groups. There were no differences in rapid progression and chromatin integrity.  
 
Conclusions: 
The study showed that the vegetables-based food intake decreased sperm quality. In particular, a reduction in sperm quality in male factor patients would be clinically significant and would require review. Furthermore, inadequate sperm hyperactivation in vegans suggested compromised membrane calcium selective channels. However, the study results are cautiously interpreted and more corroborative studies are needed.
 
Also see
 
Title:
Plasma, Urine, and Adipose Tissue Biomarkers of Dietary Intake Differ Between Vegetarian and Non-Vegetarian Diet Groups in the Adventist Health Study-2
 
Authors:
Fayth L Miles, Jan Irene C Lloren, Ella Haddad, Karen Jaceldo-Siegl, Synnove Knutsen, Joan Sabate & Gary E Fraser

Published:
The Journal of Nutrition, 1 April 2019
https://pubmed.ncbi.nlm.nih.gov/30770530/

Abstract:
Background: 
Differences in food composition, nutrient intake, and various health outcomes have been reported for vegetarians and non-vegetarians in the Adventist Health Study-2 (AHS-2) cohort.  
 
Objective: 
We sought to determine whether biomarkers of dietary intake also differed between individuals classified as vegetarian (vegan, lacto-ovo-vegetarian, pesco-vegetarian, semi-vegetarian) and non-vegetarians based on patterns of consumption of meat, dairy, and eggs.  
 
Methods: 
Fasting plasma, overnight urine, and adipose tissue samples were collected from a representative subset of AHS-2 participants classified into 5 diet groups (vegan, lacto-ovo-vegetarian, pesco-vegetarian, semi-vegetarian, non-vegetarian) who also completed food-frequency questionnaires. Diet-related biomarkers including carotenoids, isoflavones, enterolactone, saturated and polyunsaturated fatty acids, and vitamins were analyzed in 840 male and female participants. Multiple linear regression was used to examine the association between diet pattern and biomarker abundance, comparing each of 4 vegetarian dietary groups to non-vegetarians, and adjusted mean values were calculated. Bonferroni correction was applied to control for multiple testing.  
 
Results: 
Vegans had higher plasma total carotenoid concentrations (1.6-fold, P < 0.0001), and higher excretion of urinary isoflavones (6-fold, P < 0.0001) and enterolactone (4.4-fold) compared with non-vegetarians. Vegans had lower relative abundance of saturated fatty acids including myristic, pentadecanoic, palmitic, and stearic acids (P < 0.0001). Vegans had higher linoleic acid (18:2ω-6) relative to non-vegetarians (23.3% compared with 19.1%) (P < 0.0001), and a higher proportion of total ω-3 fatty acids (2.1% compared with 1.6%) (P < 0.0001). Results overall were similar but less robust for lacto-ovo- and pesco-vegetarians. 1-Methylhistidine was 92% lower in vegans, and lower in lacto-ovo- and pesco-vegetarians by 90% and 80%, respectively, relative to non-vegetarians (P < 0.0001).  
 
Conclusion: 
AHS-2 participants following vegan, and lacto-ovo- or pesco-vegetarian diet patterns have significant differences in plasma, urine, and adipose tissue biomarkers associated with dietary intakes compared with those who consume a non-vegetarian diet. These findings provide some validation for the prior classification of dietary groups within the AHS-2 cohort.