Trimethylglycine (TMG), a naturally occurring compound, is a subject of active research due to its complex relationship with cancer. While some studies suggest potential benefits, others highlight considerations that warrant careful examination. TMG’s role in cancer prevention and progression is not straightforward and continues to be investigated.
Understanding Trimethylglycine
Trimethylglycine, often referred to as TMG or betaine, is an amino acid derivative found naturally in various foods. It is particularly abundant in wheat germ, wheat bran, spinach, and beets, with smaller amounts in seafood like shrimp and mussels. The human body can also produce TMG from choline, a nutrient found in foods such as eggs, liver, and fish.
TMG functions primarily as a methyl donor in the body. It donates methyl groups to other molecules, influencing their structure and function. This process, called methylation, is involved in numerous bodily processes, including gene expression, protein function, neurotransmitter synthesis, and detoxification. TMG also regulates homocysteine levels by converting excess homocysteine into methionine, which reduces its potentially harmful buildup.
TMG’s Dual Role in Cancer Research
Research into TMG’s effects on cancer presents a complex picture, with studies indicating both potential anti-cancer and pro-cancer effects. TMG’s influence on methylation processes is a central theme in these findings.
TMG may exhibit anti-cancer properties through its involvement in maintaining DNA integrity and influencing cell differentiation. By supporting proper methylation, TMG can contribute to the healthy functioning of genes and potentially inhibit uncontrolled cell growth or encourage programmed cell death, known as apoptosis. TMG also possesses antioxidant and anti-inflammatory properties, which may contribute to its anti-cancer effects. For instance, TMG has been shown to decrease inflammation that can promote tumor growth.
Conversely, some research suggests that TMG or its metabolic products might promote cancer cell proliferation or metastasis. Sarcosine, a metabolite related to TMG, has been linked to promoting the growth and progression of prostate cancer in certain models. Elevated sarcosine levels have been shown to induce cancer cell invasion. These pro-cancer effects are often observed in laboratory or animal models and require further investigation in human populations.
Key Research Findings by Cancer Type
The effects of trimethylglycine have been investigated across various cancer types. Much of this research remains in preclinical stages, involving laboratory or animal studies, with human data still being collected.
Liver Cancer
In liver cancer, TMG (betaine) has shown protective effects. Studies indicate that betaine can help prevent alcohol-induced hepatic steatosis and metabolic-associated fatty liver disease, both of which can progress to hepatocellular carcinoma. This protective action is linked to TMG’s role in regulating methionine metabolism and reducing oxidative stress and inflammation in the liver.
Colorectal Cancer
For colorectal cancer, some studies suggest a reduced risk associated with higher plasma concentrations of betaine. In laboratory models of colitis-associated colon cancer, TMG significantly reduced tumor growth. TMG was observed to inhibit inflammation, increase markers of cell adhesion, and decrease markers associated with aggressive phenotypes.
Breast Cancer
In breast cancer, studies linked TMG production from increased choline and betaine consumption to greater breast cancer survival and reduced mortality. TMG has also been shown to retain the anti-cancer effects of cisplatin, a chemotherapy drug, in laboratory settings, suggesting a potential role in enhancing treatment efficacy.
Prostate Cancer
Prostate cancer research presents a more complex picture. While some studies suggest that increased dietary methyl donors, including betaine, might be protective against the progression of prostate cancer when consumed before tumor formation, other research indicates that higher levels of betaine in blood serum have been associated with an increased risk of lethal prostate cancer. This association may be influenced by how gut bacteria convert choline and betaine into other metabolites.
TMG Supplementation and Safety Considerations
Trimethylglycine is available as a dietary supplement, often referred to as betaine anhydrous. A typical Western diet provides approximately 0.5 to 2.5 grams of TMG daily, though cooking can reduce its content.
While TMG is considered safe in doses up to 20 grams per day, most human studies on TMG supplementation have used amounts ranging from 500 to 9,000 milligrams daily, often divided into multiple doses. Long-term safety data for TMG supplementation is still emerging. Some research has indicated that TMG supplements might slightly increase total and LDL (“bad”) cholesterol levels, which could potentially counteract other cardiovascular benefits.
Given the complex research findings regarding TMG and cancer, individuals, especially those with a cancer diagnosis or undergoing cancer treatment, should consult with healthcare professionals before considering TMG supplementation. Specific therapeutic dosages are not well-defined, and the safety profiles for certain populations, such as pregnant or nursing individuals and children, have not been fully established. The scientific understanding of TMG’s interactions with cancer is still evolving.