Methionine

1. What conditions has Methionine been studied for?

• Aging / lifespan and healthspan

  • Methionine restriction (MR/MetR) studied for lifespan extension across species (yeast to rodents) and for metabolic/inflammatory aging mechanisms.

  • Premature aging: Hutchinson–Gilford progeria syndrome (HGPS) mouse models.

  • Metformin-associated longevity mechanisms in C. elegans via microbial folate/methionine metabolism (metformin acting like a methionine-restriction mimetic in the host).

• Cancer (tumor growth, tumor metabolism, therapy sensitivity)

  • Methionine dependence (“Hoffman effect”) and methionine auxotrophy in cancer cells; dietary methionine restriction explored as a selective anti-tumor strategy.

  • Tumor-initiating cells (TICs): elevated methionine cycle/transmethylation driven by MAT2A; vulnerability to methionine-cycle inhibition.

  • Osteosarcoma subgroup with MTAP deletion: reliance on methionine metabolism; sensitivity to dietary methionine restriction or MAT2A inhibition; links to immune checkpoint therapy resistance.

  • Hepatocellular carcinoma (HCC) in mice: folic acid diet manipulation altered MAT2A expression/methionine cycle flux and cancer development.

• Metabolic health

  • MR studied for metabolic health improvements and reduced oxidative stress/inflammation in animal models.

  • Metformin’s metabolic effects potentially mediated partly through microbial folate/methionine metabolism (with relevance to therapeutic efficacy and side effects).

  • Review-level claims that methionine supplementation has been studied for hepatic steatosis, insulin resistance, inflammation, and fibrosis (not detailed in the studies reviewed here beyond the review statement).

• Depression (subthreshold depression)

  • S-adenosyl-methionine (SAMe; a methionine-derived methyl donor) combined with probiotics studied as a supplement approach for subthreshold depression.

• Developmental biology (mechanistic, not treatment)

  • Mouse pre-implantation embryo development: activation of the methionine cycle from 8-cell to blastocyst stage (metabolism–epigenetics link).

2. Does it work in treating those conditions? Summarize the evidence.

• Longevity/aging: Evidence supports methionine restriction (not supplementation) as beneficial in multiple model organisms.

  • A review abstract states MetR “extends lifespan across different species” and benefits metabolic health and inflammatory responses, but also notes mechanisms are not fully understood.

  • In two HGPS (progeria) mouse models, MR extended lifespan and reversed transcriptome alterations in inflammation and DNA-damage response genes; it also improved lipid profile and altered bile acids. Cholic acid treatment improved healthspan/lifespan in vivo, suggesting a bile-acid-linked pathway in MR benefits.

  • In C. elegans, metformin increased lifespan by altering microbial folate and methionine metabolism; genetic perturbation of worm methionine synthase (metr-1) and SAM synthase (sams-1) altered the longevity effect, consistent with metformin-induced methionine restriction in the host. Importantly, metformin could increase or decrease lifespan depending on bacterial strain sensitivity and glucose concentration (context-dependent effect).

• Cancer: Evidence in the studies supports targeting methionine availability/flux as a potential anti-cancer strategy in specific contexts, but it is not presented as a general “methionine supplement” treatment.

  • Tumor-initiating cells showed elevated methionine cycle activity driven by MAT2A, leading to “addiction” to exogenous methionine; pharmacologic inhibition of the methionine cycle (even transiently) was sufficient to cripple tumor-initiating capability in the reported study.

  • In osteosarcoma, an MTAP-deleted subgroup relied on methionine metabolism and was sensitive to methionine intervention via dietary restriction or MAT2A inhibition; methionine intervention also increased PD-L1-related signaling and immune pathway activation in those cells (suggesting a way to modify an immune-cold tumor microenvironment).

  • In a mouse HCC model, a high-folate diet promoted cancer development alongside increased MAT2A expression and accelerated methionine cycle activity; a folate-free diet reduced MAT2A and impeded HCC development. Liver-specific Mat2a knockout abolished folate’s tumor-promoting effect, supporting a causal role for MAT2A/methionine cycle flux in that model.

  • Review studies describe “methionine dependence” (Hoffman effect) and that decreasing dietary methionine can selectively suppress tumor growth in methionine-auxotrophic cancers, but these are general statements without trial-level details in the provided text.

• Depression (SAMe): The study describes a study aiming to demonstrate efficacy of a supplement combining SAMe 200 mg/day plus specific probiotics for subthreshold depression; however, the provided excerpt does not include outcomes, effect size, or comparator results, so efficacy cannot be concluded from the study text shown.

• Metabolic disease: MR is described as beneficial for metabolic health and oxidative stress in review studies, and metformin’s effects may involve microbial folate/methionine metabolism; however, the studies reviewed here do not give human clinical outcome data for methionine restriction or supplementation as a treatment for metabolic syndrome/diabetes.

3. What health benefits does it have?

• As an essential amino acid: Methionine is required for protein synthesis and supports one-carbon metabolism via the methionine cycle (review abstract).

• Methylation capacity (via SAM): Methionine supplies S-adenosylmethionine (SAM), a key methyl donor influencing gene regulation/epigenetics (multiple studies link methionine cycle flux to epigenetic state; embryo development abstract highlights methionine cycle activation during a key epigenetic remodeling window).

• Redox/antioxidant pathways: Methionine metabolism contributes to glutathione synthesis and oxidative stress regulation; MetR-associated benefits are described as partly mediated through reduced oxidative stress (review abstract).

• Potential longevity/metabolic benefits via restriction (not higher intake):

  • MetR/MR is repeatedly described as extending lifespan and improving metabolic and inflammatory profiles in model organisms; MR extended lifespan in progeria mouse models and improved lipid/bile acid profiles.

  • MetR may induce autophagy because SAM can activate mTORC1 and suppress autophagy; therefore lowering methionine/SAM is proposed to promote autophagy (review abstract; mechanistic framing rather than direct clinical proof).

• Potential cancer-therapy relevance (context-specific): Some tumors (or tumor subpopulations like TICs, and MTAP-deleted osteosarcoma) show vulnerabilities to methionine restriction or methionine-cycle inhibition (MAT2A-targeted), suggesting a potential therapeutic angle.

4. Does it have any downsides or side effects?

• Risks of long-term methionine restriction: A review abstract notes adverse events including bone-related disorders, stunted growth, and hyperhomocysteinemia with long-term dietary methionine restriction.

• Risks of high methionine intake: The same review abstract notes that high methionine intake can cause hyperhomocysteinemia, reduced body weight, and increased cholesterol levels.

• Microbiome/folate-related issues (indirectly connected): In the C. elegans metformin–microbe model, metformin altered microbial folate and methionine metabolism; the study notes that in humans metformin side effects include folate deficiency and gastrointestinal upset, and suggests microbial metabolism changes could contribute. This is not a methionine supplement side effect per se, but it highlights that perturbing folate–methionine pathways can have tolerability consequences.

• Cancer-context caution: Several studies emphasize that many cancers increase methionine cycle flux and can be dependent on exogenous methionine; this implies that increasing methionine availability could theoretically be unfavorable in certain cancer contexts, although the studies reviewed here do not directly test methionine supplementation worsening cancer outcomes.

5. Is it beneficial or harmful for any genetic variations (pharmacogenomics)?

• MTAP deletion (tumor genetic alteration): In osteosarcoma, MTAP-deleted tumors relied on methionine metabolism and were sensitive to methionine intervention (dietary restriction) or MAT2A inhibition; methionine intervention also modulated PD-L1-related signaling and immune pathways. This suggests MTAP deletion may be a predictive biomarker for benefit from methionine-targeting strategies (in that tumor context).

• MAT2A dependency/expression (tumor metabolic genotype/phenotype): Tumor-initiating cells had elevated methionine cycle activity driven by MAT2A, and MAT2A expression influenced sensitivity to therapeutic inhibition (as stated in the TIC abstract). In the HCC mouse model, Mat2a knockout abolished folate’s tumor-promoting effect, supporting MAT2A as a key determinant of response in that pathway.

• Host genetics in a model organism (mechanistic, not human pharmacogenomics): In C. elegans, mutations in methionine synthase (metr-1) and SAM synthase (sams-1) altered metformin-induced longevity, consistent with methionine restriction being part of the mechanism. This supports gene–nutrient/drug interaction in principle, but it is not directly translatable to human supplement guidance from the study alone.

• Limitations: The studies reviewed here do not discuss common human inherited variants in methionine/one-carbon metabolism (e.g., in folate-cycle genes) in relation to methionine intake or SAMe response; therefore, clinically actionable pharmacogenomic guidance for the general population cannot be concluded from this set of studies.

References

1. Metformin retards aging in C. elegans by altering microbial folate and methionine metabolism.
   Filipe Cabreiro, Catherine Au, Kit-Yi Leung, Nuria Vergara-Irigaray, Helena M Cochemé, Tahereh Noori, David Weinkove, Eugene Schuster, Nicholas D E Greene, David Gems (2013) - Cell
2. Dietary methionine influences therapy in mouse cancer models and alters human metabolism.
   Xia Gao, Sydney M Sanderson, Ziwei Dai, Michael A Reid, Daniel E Cooper, Min Lu, John P Richie, Amy Ciccarella, Ana Calcagnotto, Peter G Mikhael, Samantha J Mentch, Juan Liu, Gene Ables, David G Kirsch, David S Hsu, Sailendra N Nichenametla, Jason W Locasale (2019) - Nature
3. Methionine metabolism in health and cancer: a nexus of diet and precision medicine.
   Sydney M Sanderson, Xia Gao, Ziwei Dai, Jason W Locasale (2019) - Nature reviews. Cancer
4. Methionine is a metabolic dependency of tumor-initiating cells.
   Zhenxun Wang, Lian Yee Yip, Jia Hui Jane Lee, Zhengwei Wu, Hui Yi Chew, Pooi Kiat William Chong, Chin Chye Teo, Heather Yin-Kuan Ang, Kai Lay Esther Peh, Ju Yuan, Siming Ma, Li Shi Kimberly Choo, Nurhidayah Basri, Xia Jiang, Qiang Yu, Axel M Hillmer, Wan Teck Lim, Tony Kiat Hon Lim, Angela Takano, Eng Huat Tan, Daniel Shao Weng Tan, Ying Swan Ho, Bing Lim, Wai Leong Tam (2019) - Nature medicine
5. Methionine metabolism and methyltransferases in the regulation of aging and lifespan extension across species.
   Andrey A Parkhitko, Patrick Jouandin, Stephanie E Mohr, Norbert Perrimon (2019) - Aging cell
6. Methionine intervention induces PD-L1 expression to enhance the immune checkpoint therapy response in MTAP-deleted osteosarcoma.
   Haoran Mu, Qi Zhang, Dongqing Zuo, Jinzeng Wang, Yining Tao, Zhen Li, Xin He, Huanliang Meng, Hongsheng Wang, Jiakang Shen, Mengxiong Sun, Yafei Jiang, Weisong Zhao, Jing Han, Mengkai Yang, Zhuoying Wang, Yu Lv, Yuqin Yang, Jing Xu, Tao Zhang, Liu Yang, Jun Lin, Feng Tang, Renhong Tang, Haiyan Hu, Zhengdong Cai, Wei Sun, Yingqi Hua (2025) - Cell reports. Medicine
7. Methionine Dependence of Cancer.
   Peter Kaiser (2020) - Biomolecules
8. Metabolic control of histone acetylation for precise and timely regulation of minor ZGA in early mammalian embryos.
   Jingyu Li, Jiaming Zhang, Weibo Hou, Xu Yang, Xiaoyu Liu, Yan Zhang, Meiling Gao, Ming Zong, Zhixiong Dong, Zhonghua Liu, Jingling Shen, Weitao Cong, Chunming Ding, Shaorong Gao, Guoning Huang, Qingran Kong (2022) - Cell discovery
9. Functional properties of amino acids: improve health status and sustainability.
   Jason T Lee, Sam J Rochell, Ruben Kriseldi, Woo K Kim, Randy D Mitchell (2023) - Poultry science
10. Methionine Restriction Extends Lifespan in Progeroid Mice and Alters Lipid and Bile Acid Metabolism.
    Clea Bárcena, Pedro M Quirós, Sylvère Durand, Pablo Mayoral, Francisco Rodríguez, Xurde M Caravia, Guillermo Mariño, Cecilia Garabaya, María Teresa Fernández-García, Guido Kroemer, José M P Freije, Carlos López-Otín (2018) - Cell reports
11. Efficacy of a food supplement based on S-adenosyl methionine and probiotic strains in subjects with subthreshold depression and mild-to-moderate depression: A monocentric, randomized, cross-over, double-blind, placebo-controlled clinical trial.
    Hammad Ullah, Alessandro Di Minno, Cristina Esposito, Hesham R El-Seedi, Shaden A M Khalifa, Alessandra Baldi, Agostino Greco, Salvatore Santonastaso, Valeria Cioffi, Raffaele Sperandeo, Roberto Sacchi, Maria Daglia (2022) - Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie
12. Effect of Methionine Restriction on Aging: Its Relationship to Oxidative Stress.
    Munehiro Kitada, Yoshio Ogura, Itaru Monno, Jing Xu, Daisuke Koya (2021) - Biomedicines
13. Selective Oxidation of Methionine and Tryptophan Residues in a Therapeutic IgG1 Molecule.
    Emilien Folzer, Katharina Diepold, Katrin Bomans, Christof Finkler, Roland Schmidt, Patrick Bulau, Jörg Huwyler, Hanns-Christian Mahler, Atanas V Koulov (2015) - Journal of pharmaceutical sciences
14. Methionine as a double-edged sword in health and disease: Current perspective and future challenges.
    Umashanker Navik, Vaibhav G Sheth, Amit Khurana, Snehal Sainath Jawalekar, Prince Allawadhi, Ravinder Reddy Gaddam, Jasvinder Singh Bhatti, Kulbhushan Tikoo (2021) - Ageing research reviews
15. Dietary folate drives methionine metabolism to promote cancer development by stabilizing MAT IIA.
    Jin-Tao Li, Hai Yang, Ming-Zhu Lei, Wei-Ping Zhu, Ying Su, Kai-Yue Li, Wen-Ying Zhu, Jian Wang, Lei Zhang, Jia Qu, Lei Lv, Hao-Jie Lu, Zheng-Jun Chen, Lu Wang, Miao Yin, Qun-Ying Lei (2022) - Signal transduction and targeted therapy
16. Inhibiting G6PD by quercetin promotes degradation of EGFR T790M mutation.
    Zehe Ge, Miao Xu, Yuqian Ge, Guang Huang, Dongyin Chen, Xiuquan Ye, Yibei Xiao, Hongyu Zhu, Rong Yin, Hua Shen, Gaoxiang Ma, Lianwen Qi, Guining Wei, Dongmei Li, Shaofeng Wei, Meng Zhu, Hongxia Ma, Zhumei Shi, Xiuxing Wang, Xin Ge, Xu Qian (2023) - Cell reports
17. Calorie restriction and methionine restriction in control of endogenous hydrogen sulfide production by the transsulfuration pathway.
    Christopher Hine, James R Mitchell (2015) - Experimental gerontology
18. Targeting Methionine Addiction of Cancer Cells with Methioninase.
    Vadim S Pokrovsky, Louay Abo Qoura, Elena A Demidova, Qinghong Han, Robert M Hoffman (2023) - Biochemistry. Biokhimiia
19. Targeting the methionine addiction of cancer.
    Joni C Sedillo, Vincent L Cryns (2022) - American journal of cancer research

This article summarizes published research for educational purposes. It is not medical advice. Talk to your doctor before starting, stopping, or changing any supplement or medication.