Garlic may be used to treat brain cancers, The Times reported on September 1 2007. The newspaper reported that scientists had found that certain organic compounds in garlic kill tumours. The type of tumour in question, glioblastoma, tends to kill people soon after they are diagnosed.
The article continues that it will be several years until this finding can be used for the treatment of cancer. In the meantime, the researchers recommend making the most of garlic’s “potential cancer-preventing powers”, by peeling it and leaving for 15 minutes before cooking to release the enzyme that contains the “anti-cancer” compounds.
This study is based on research looking at the effects of garlic compounds on brain cancer cells grown in the laboratory. The Times story correctly includes some note of caution about the fact that therapies based on these findings are a long way off. The study did not assess whether eating garlic could prevent cancer, or the effects of garlic compounds in people with tumours; it only looked at brain tumour cells grown in the laboratory.
This study cannot tell us what benefits we might gain from eating garlic, and we certainly should not change our consumption of garlic based on this study.
Where did the story come from?
Dr Arabinda Das, and colleagues from the Medical University of South Carolina carried out this research. The study was funded in part by the National Cancer Institute and the National Institute of Neurological Disorders and Stroke. The study was published in the peer-reviewed medical journal: Cancer.
What kind of scientific study was this?
This was a laboratory study assessing the effects of garlic compounds on brain tumour cells.
The researchers grew human glioblastoma (a type of brain tumour) cells in the laboratory. They then treated some of these cells with increasing concentrations of three compounds found in garlic. Other cells which were not treated with these compounds were used as controls. They then looked at whether the treated and control cells survived. They also looked at what changes were happening in the cells that might explain how and why they lived or died.
What were the results of the study?
The researchers found that all three compounds caused more glioblastoma cells to die (by a method known as apoptosis) than was observed in the untreated control cells. The higher the concentration of the compound used, the more cells died.
The researchers then reported their results and went into in-depth analysis about the biochemical changes occurring in these cells.
What interpretations did the researchers draw from these results?
The researchers concluded that garlic compounds cause human glioblastoma cells to die by apoptosis. They also drew conclusions about what biochemical changes might play a role in this cell death.
What does the NHS Knowledge Service make of this study?
This was a laboratory study, and no conclusions about the effects of garlic on human health can be drawn from it.
This study did not look at the effects of eating garlic in people who have glioblastoma; it also did not look at whether eating garlic prevents people developing cancer. In addition, this study did not look at the effects of these garlic compounds on healthy human cells; therefore it is possible that these compounds also kill healthy cells.
Based on this studies findings, we shouldn’t believe that eating garlic will prevent or cure cancer.
Sir Muir Gray adds…
Many powerful drugs have been developed from plants and it is to be hoped that many more will be discovered. Plants or plant extracts can now be more easily tested in laboratory studies with those that show promise being developed for human trials. For this reason, it is important that we try to prevent the loss of any more plant, or animal, species. It is also important to be realistic about the number of plants to be tested and the low probability that a promising lab result will become a successful human treatment.