{"doi":"10.1001/jamanetworkopen.2023.44457","title":"Cardiometabolic Effects of Omnivorous vs Vegan Diets in Identical Twins","abstract":"<jats:sec><jats:title>Importance</jats:title><jats:p>Increasing evidence suggests that, compared with an omnivorous diet, a vegan diet confers potential cardiovascular benefits from improved diet quality (ie, higher consumption of vegetables, legumes, fruits, whole grains, nuts, and seeds).</jats:p></jats:sec><jats:sec><jats:title>Objective</jats:title><jats:p>To compare the effects of a healthy vegan vs healthy omnivorous diet on cardiometabolic measures during an 8-week intervention.</jats:p></jats:sec><jats:sec><jats:title>Design, Setting, and Participants</jats:title><jats:p>This single-center, population-based randomized clinical trial of 22 pairs of twins (N = 44) randomized participants to a vegan or omnivorous diet (1 twin per diet). Participant enrollment began March 28, 2022, and continued through May 5, 2022. The date of final follow-up data collection was July 20, 2022. This 8-week, open-label, parallel, dietary randomized clinical trial compared the health impact of a vegan diet vs an omnivorous diet in identical twins. Primary analysis included all available data.</jats:p></jats:sec><jats:sec><jats:title>Intervention</jats:title><jats:p>Twin pairs were randomized to follow a healthy vegan diet or a healthy omnivorous diet for 8 weeks. Diet-specific meals were provided via a meal delivery service from baseline through week 4, and from weeks 5 to 8 participants prepared their own diet-appropriate meals and snacks.</jats:p></jats:sec><jats:sec><jats:title>Main Outcomes and Measures</jats:title><jats:p>The primary outcome was difference in low-density lipoprotein cholesterol concentration from baseline to end point (week 8). Secondary outcome measures were changes in cardiometabolic factors (plasma lipids, glucose, and insulin levels and serum trimethylamine <jats:italic>N</jats:italic>-oxide level), plasma vitamin B<jats:sub>12</jats:sub> level, and body weight. Exploratory measures were adherence to study diets, ease or difficulty in following the diets, participant energy levels, and sense of well-being.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>A total of 22 pairs (N = 44) of twins (34 [77.3%] female; mean [SD] age, 39.6 [12.7] years; mean [SD] body mass index, 25.9 [4.7]) were enrolled in the study. After 8 weeks, compared with twins randomized to an omnivorous diet, the twins randomized to the vegan diet experienced significant mean (SD) decreases in low-density lipoprotein cholesterol concentration (−13.9 [5.8] mg/dL; 95% CI, −25.3 to −2.4 mg/dL), fasting insulin level (−2.9 [1.3] μIU/mL; 95% CI, −5.3 to −0.4 μIU/mL), and body weight (−1.9 [0.7] kg; 95% CI, −3.3 to −0.6 kg).</jats:p></jats:sec><jats:sec><jats:title>Conclusions and Relevance</jats:title><jats:p>In this randomized clinical trial of the cardiometabolic effects of omnivorous vs vegan diets in identical twins, the healthy vegan diet led to improved cardiometabolic outcomes compared with a healthy omnivorous diet. Clinicians can consider this dietary approach as a healthy alternative for their patients.</jats:p></jats:sec><jats:sec><jats:title>Trial Registration</jats:title><jats:p>ClinicalTrials.gov Identifier: <jats:ext-link xmlns:xlink=\"http://www.w3.org/1999/xlink\" ext-link-type=\"uri\" xlink:href=\"https://clinicaltrials.gov/study/NCT05297825?term=NCT05297825&amp;amp;amp;rank=1\">NCT05297825</jats:ext-link></jats:p></jats:sec>","journal":"JAMA Network Open","year":2023,"id":618426,"datarank":0.6952093482344455,"base_score":4.634728988229636,"endowment":4.634728988229636,"self_citation_contribution":0.6952093482344455,"citation_network_contribution":0.0,"self_endowment_contribution":0.6952093482344455,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":102,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":null,"is_data_producer":false,"deposit_databanks":null,"is_oa":false,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":null,"fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":1595401,"name":"Catherine P. Ward","orcid":null,"position":1,"is_corresponding":false},{"id":1595402,"name":"Kristen M. Cunanan","orcid":null,"position":2,"is_corresponding":false},{"id":1595403,"name":"Lindsay R. Durand","orcid":null,"position":3,"is_corresponding":false},{"id":5637,"name":"Dalia Perelman","orcid":"0000-0003-3335-1950","position":4,"is_corresponding":false},{"id":428386,"name":"Jennifer L. Robinson","orcid":"0000-0003-4241-5290","position":5,"is_corresponding":false},{"id":661989,"name":"Tayler Hennings","orcid":"0009-0000-5068-9860","position":6,"is_corresponding":false},{"id":1595404,"name":"Linda Koh","orcid":null,"position":7,"is_corresponding":false},{"id":241991,"name":"Christopher Dant","orcid":"0000-0003-1599-3749","position":8,"is_corresponding":false},{"id":1595405,"name":"Amanda Zeitlin","orcid":null,"position":9,"is_corresponding":false},{"id":313976,"name":"Emily R. Ebel","orcid":"0000-0002-3244-4250","position":10,"is_corresponding":false},{"id":237037,"name":"Erica D. Sonnenburg","orcid":"0000-0001-8379-005X","position":11,"is_corresponding":false},{"id":36353,"name":"Justin L. Sonnenburg","orcid":"0000-0003-2299-6817","position":12,"is_corresponding":false},{"id":819,"name":"Christopher D. Gardner","orcid":"0000-0002-7596-1530","position":13,"is_corresponding":false},{"id":441517,"name":"Matthew J. Landry","orcid":"0000-0003-2285-7702","position":0,"is_corresponding":false}],"reference_count":0,"raw_metadata":{"has_enrichment":true,"resolved":true,"title":"Cardiometabolic Effects of Omnivorous vs Vegan Diets in Identical Twins","abstract":"<jats:sec><jats:title>Importance</jats:title><jats:p>Increasing evidence suggests that, compared with an omnivorous diet, a vegan diet confers potential cardiovascular benefits from improved diet quality (ie, higher consumption of vegetables, legumes, fruits, whole grains, nuts, and seeds).</jats:p></jats:sec><jats:sec><jats:title>Objective</jats:title><jats:p>To compare the effects of a healthy vegan vs healthy omnivorous diet on cardiometabolic measures during an 8-week intervention.</jats:p></jats:sec><jats:sec><jats:title>Design, Setting, and Participants</jats:title><jats:p>This single-center, population-based randomized clinical trial of 22 pairs of twins (N = 44) randomized participants to a vegan or omnivorous diet (1 twin per diet). Participant enrollment began March 28, 2022, and continued through May 5, 2022. The date of final follow-up data collection was July 20, 2022. This 8-week, open-label, parallel, dietary randomized clinical trial compared the health impact of a vegan diet vs an omnivorous diet in identical twins. Primary analysis included all available data.</jats:p></jats:sec><jats:sec><jats:title>Intervention</jats:title><jats:p>Twin pairs were randomized to follow a healthy vegan diet or a healthy omnivorous diet for 8 weeks. Diet-specific meals were provided via a meal delivery service from baseline through week 4, and from weeks 5 to 8 participants prepared their own diet-appropriate meals and snacks.</jats:p></jats:sec><jats:sec><jats:title>Main Outcomes and Measures</jats:title><jats:p>The primary outcome was difference in low-density lipoprotein cholesterol concentration from baseline to end point (week 8). Secondary outcome measures were changes in cardiometabolic factors (plasma lipids, glucose, and insulin levels and serum trimethylamine <jats:italic>N</jats:italic>-oxide level), plasma vitamin B<jats:sub>12</jats:sub> level, and body weight. Exploratory measures were adherence to study diets, ease or difficulty in following the diets, participant energy levels, and sense of well-being.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>A total of 22 pairs (N = 44) of twins (34 [77.3%] female; mean [SD] age, 39.6 [12.7] years; mean [SD] body mass index, 25.9 [4.7]) were enrolled in the study. After 8 weeks, compared with twins randomized to an omnivorous diet, the twins randomized to the vegan diet experienced significant mean (SD) decreases in low-density lipoprotein cholesterol concentration (−13.9 [5.8] mg/dL; 95% CI, −25.3 to −2.4 mg/dL), fasting insulin level (−2.9 [1.3] μIU/mL; 95% CI, −5.3 to −0.4 μIU/mL), and body weight (−1.9 [0.7] kg; 95% CI, −3.3 to −0.6 kg).</jats:p></jats:sec><jats:sec><jats:title>Conclusions and Relevance</jats:title><jats:p>In this randomized clinical trial of the cardiometabolic effects of omnivorous vs vegan diets in identical twins, the healthy vegan diet led to improved cardiometabolic outcomes compared with a healthy omnivorous diet. Clinicians can consider this dietary approach as a healthy alternative for their patients.</jats:p></jats:sec><jats:sec><jats:title>Trial Registration</jats:title><jats:p>ClinicalTrials.gov Identifier: <jats:ext-link xmlns:xlink=\"http://www.w3.org/1999/xlink\" ext-link-type=\"uri\" xlink:href=\"https://clinicaltrials.gov/study/NCT05297825?term=NCT05297825&amp;amp;amp;rank=1\">NCT05297825</jats:ext-link></jats:p></jats:sec>","is_dataset_classified":null,"base_score":4.634728988229636,"endowment":4.634728988229636,"datacite_reuse_total":0,"file_count":0,"downloads":0,"views":0,"has_version_chain":false,"is_dataset":false,"is_oa":false,"pmid":"38032644","pmcid":null,"openalex_id":"https://openalex.org/W4389180633","authors":[],"funders":[{"funder_name":"NCATS NIH HHS","grant_id":"UL1 TR003142","title":null},{"funder_name":"NCATS NIH HHS","grant_id":"UL1 TR001085","title":null},{"funder_name":"NHLBI NIH HHS","grant_id":"T32 HL161270","title":null}],"total_grants":3,"fwci":21.2948,"citation_percentile":0.99784148,"influential_citations":0,"citation_trend":[{"year":2023,"count":2},{"year":2024,"count":27},{"year":2025,"count":50},{"year":2026,"count":23}],"oa_status":"gold","license":"cc-by","oa_locations":[{"url":"https://jamanetwork.com/journals/jamanetworkopen/articlepdf/2812392/landry_2023_oi_231297_1700251908.10956.pdf","host_type":"journal"},{"url":"https://jamanetwork.com/journals/jamanetworkopen/articlepdf/2812392/landry_2023_oi_231297_1700251908.10956.pdf","host_type":"publisher"},{"url":"https://jamanetwork.com/journals/jamanetworkopen/articlepdf/2812392/landry_2023_oi_231297_1702500348.50261.pdf","host_type":"publisher"},{"url":"https://doi.org/10.1001/jamanetworkopen.2023.44457","host_type":"journal"},{"url":"https://pubmed.ncbi.nlm.nih.gov/38032644","host_type":"repository"},{"url":"https://www.ncbi.nlm.nih.gov/pmc/articles/10690456","host_type":"repository"},{"url":"https://escholarship.org/uc/item/2vv090fg","host_type":"repository"}],"fields_of_study":["Agriculture Sustainability and Environmental Impact","Food Waste Reduction and Sustainability","Urban Green Space and Health","Adult","Female","Humans","Male","Body Weight","Cardiovascular Diseases","Cholesterol, LDL","Diet, Vegan","Insulins","Twins, Monozygotic","Vegetables","Middle Aged","Diet, Healthy"],"mesh_terms":["Diet, Vegan","Diet, Healthy","Adult","Body Weight","Cardiovascular Diseases","Female","Humans","Cholesterol, LDL","Male","Middle Aged","Twins, Monozygotic","Vegetables","Insulins"],"keywords":["Vegan Diet","Omnivore","Medicine","Randomized controlled trial","Meal","Population","Biology","Internal medicine","Environmental health"],"sdg_mappings":[],"linked_datasets":[],"clinical_trials":[],"software_tools":[],"database_accessions":[],"source":"live","citation_network_status":"fetched"},"created_at":"2026-08-03T04:21:31.776731Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}