Specifically designed diets show a “potent ability” to prevent cancer, slow its progression and improve treatments, CNIO researchers say in a study
Diet helps prevent up to a third of the most common cancers, according to study authors Published in Trends in Molecular Medicine. The Growth Factors, Nutrients and Cancer group at the National Center for Cancer Research (CNIO), led by Nabil Djouder, published this review on the use of diet in cancer treatment, with Carlos Martínez-Garay as first author. In it, they defend the importance of taking diet into account in treatments. “The incorporation of dietary interventions into cancer therapies will open ‘a new era’ in cancer care,” says Nabil Djouder, senior author of the study.
‘Precision’ nutrition seeks to design diets adapted to each patient and their disease, to increase the effectiveness of therapy and reduce its side effects. The article also looks at why dietary interventions have not reached cancer patients despite good results from clinical trials.
Diet influences the incidence, growth and development of cancer to such an extent that one-third of the most common cancers can be prevented, at least in part, by changes in diet. And indeed, preclinical studies using food as a tool against cancer have shown promising results. However, these results have not yet reached the clinic.
A third of the most common cancers can be prevented, at least in part, through dietary changes.
Djouder explains: “Diets can directly target cancer metabolism, depriving the tumor of the nutrients it needs, or they can affect other key elements for cancer survival and development, such as growth signaling, oxidative stress, or the patient’s immunity. .
For the authors, one of the reasons why these nutritional therapies are still not being applied to cancer patients is that the clinical studies carried out so far have limitations. For example, many of these studies group together patients with highly heterogeneous tumor profiles. There is also a lack of strict standards for the implementation of diets as a treatment.
Caloric restriction, ketogenic diet and intermittent fasting
The present work reviews the possible therapeutic nutritional interventions against cancer and the remaining steps for them to be considered standard treatment. With this review, the authors hope to contribute to the design of new clinical trials and translational studies in this area.
The work focuses on caloric restriction, the ketogenic diet and intermittent fasting, analyzing how they can influence the appearance and development of tumors. After reviewing preclinical studies and recent or ongoing clinical trials on these diets, he offers a new perspective on the physiological rationale behind them.
The authors provide an in-depth review of what is known about nutrient metabolism and its relationship to tumor development and progression. The data suggest that the growth of some cancers may be highly dependent on specific amino acids, and that avoiding foods high in these amino acids may limit tumor growth.
Obesity and microbiome
In addition, many of the pathways related to tumor proliferation are linked to hormones that are sensitive to certain nutrients. This could explain the relationship between obesity and cancer, due precisely to the increased signaling of estrogens (hormones) produced by adipose tissue (fat).
The researchers also reviewed publications linking gut flora to cancer. The intestinal flora or microbiome groups the population of microbes present in the intestinal tract and is one of the main responsible for the interaction between what a person eats and their health.
“Many of the oncogenic effects attributed to the intestinal microbiome -explains Carlos Martínez-Garay- are related to inflammation of the digestive tract and, in fact, the presence of certain populations of bacteria is linked to chronic inflammation associated with cancers. gallbladder, bile duct and stomach.
Interaction with the immune system
One of the main factors responsible for tumor growth, and for the success or failure of the therapy chosen to fight each cancer, is the interaction between tumor cells and the patient’s immunity, and in this case there is also a relationship with food. Most of our immune cells are present in the gut as a defense barrier against ingestion of toxic compounds or pathogens.
“Certain components of the diet can provoke important responses in the immune system –says Martínez-Garay- and this can cause a dysfunction in our defenses that makes us more vulnerable to the formation of tumors”.
Precision nutrition for every patient
The authors point to the need to develop precision nutrition, a new approach that proposes the use of targeted dietary regimens to treat specific tumors based on the patient’s tumor and metabolism. The current ability to analyze tumors in depth and classify them based on their molecular profile has enabled great advances in the effectiveness of therapies to combat them.
As Nabil Djouder explains: “This can also be applied to nutrition if clinical data, microbiome examinations, molecular diagnostics, nutrigenomics and metabolomics are combined to develop specific dietary regimens intended for the individual management of cancer patients. The preclinical studies and clinical trials we reviewed show the potent effects of dietary interventions and this makes us think that a new era in cancer therapy has arrived.”