- Some dietary components are converted by gut bacteria into compounds that show significant links to the development of aggressive prostate cancer.
- Prostate cancer is more likely in men who have higher levels of these metabolites.
- These compounds might be used as early disease biomarkers.
- Men may be able to lower their chance of fatal prostate cancer by changing their food and lifestyle.
According to a research, there is a link between diet, the gut microbiota, and fatal prostate cancer.
The Cleveland Clinic research was published in Cancer Epidemiology, Biomarkers & Prevention.
Researchers analyzed data from the PLCO cancer screening trial, a 148,000-person randomized control trial. It included screening 76,685 men aged 55 to 74 for prostate cancer and following up with them for up to 13 years.
Nearly 700 males were studied for their baseline levels of specific dietary components and metabolites. Prostate cancer claimed the lives of 173 of them. For individuals who acquired deadly prostate cancer, the median period between baseline sample and death was 11.69 years.
“Men with higher levels of certain diet-related molecules are more likely to develop aggressive prostate cancer.”
– Dr. Nima Sharifi, MD, Director, Genitourinary Malignancies Research Center, Kendrick Family Endowed Chair for Prostate Cancer Research, Cleveland Clinic, lead researcher on the study
The researchers compared individuals who died with controls in a one-to-three ratio on factors such as age, race, time of blood sample collection, and date of enrollment. The control sample consisted of 519 males, 83.6 percent of whom remained healthy, and 16.4 percent of whom were diagnosed with non-lethal prostate cancer throughout the study’s term of observation.
All participants in the PLCO cancer screening experiment provided blood samples as part of the enrollment process. In the study, the researchers looked for numerous distinct metabolites in the blood serum, some of which are generated by gut bacteria as a result of food consumption. Data from individuals who eventually died from prostate cancer were compared to results from healthy men.
Increased risk
In their study, the researchers discovered a link between more aggressive prostate cancer and three metabolites, including phenylacetylglutamine, choline, and betaine.
Phenylacetylglutamine is formed as a result of the breakdown of phenylalanine, an important amino acid, in the gut flora. Choline and betaine may be found in various meals, as well as being produced by the bacteria that live in the gut.
Phenylalanine may be found in high-protein foods such as dairy, meat, chicken, soy, fish, beans, nuts, and diet drinks sweetened with aspartame, as well as in meals that contain a lot of fat. It is a necessary component of many proteins and enzymes in the body, and when converted to tyrosine, it is utilized to produce the neurotransmitter dopamine, which is then released into the body.
Choline is mostly found in animal products such as meat, fish, eggs, and dairy, while pulses, nuts, and seeds may provide a supply of choline for vegans who avoid animal products. Shellfish, wheat, spinach, and beets are just a few of the foods that are rich in betaine.
Men who had high phenylacetylglutamine levels in their blood serum at the start of the trial were 2.5 times more likely to die of prostate cancer than those who had the lowest levels, according to the findings of the researchers. Men who consumed more choline or betaine had almost double the chance of dying from prostate cancer as those who did not.
“[Our results] imply that food consumption interacts with gut bacteria in a sophisticated manner to influence the risk of fatal prostate cancer,” Dr. Sharifi said in his statement.
Trimethylamine and trimethylamine N-oxide (TMAO) are produced by certain gut bacteria and have been linked to an increased risk of cardiovascular and neurological diseases in a prior research. In this investigation, for the first time, a connection between precursors of TMAO and cancer was discovered.
“Betaine and choline are being converted into more toxic chemicals in some. This does not mean they are bad for everyone. It’s the diet-microbe interaction that leads to the cancer.”
— Prof. Tim Spector, Professor of Genetic Epidemiology, King’s College, London, and Zoe Study Lead.
Dietary modifications may be beneficial
According to research, lowering meat consumption is associated with a decreased risk of death from cardiovascular disease and cancer. According to the findings of this research, such message is reinforced in the case of prostate cancer.
According to Dr. Sharifi, “generally speaking, the metabolites linked with deadly prostate cancer are found to be elevated in meat and other animal-derived items.”.
The professor issued the following warning: “These metabolites are ubiquitous. It’s difficult to cut them out.”
The authors emphasize that, although this research demonstrates a connection between the three metabolites and deadly prostate cancer, it does not establish a causal relationship between the two. Dr. Sharifi and his colleagues are now doing more research to establish “how metabolism in people interacts with prostate cancer.”
Prof. Spector feels that the work “additionally contributes to the story-building on how diet influences cancer, which is mediated by the gut microbiome.” We are overturning decades of medical advice that “it really doesn’t matter what you eat.”
