5 anti-cancer diets and their scientific evidence under examination

Cancer arises from a interaction of complex factors. A review by researchers at the Anderson Cancer Center in Houston (USA) concluded that hereditary genetic factors are the cause of 5-10% of cancers, while environmental causes account for 90%.

Therefore, we could say that cancer is mostly preventable. It has been estimated that between 40 and 50% of all cancers could be prevented by adopting a healthy lifestyle.

And what the studies show is also the importance of nutrition in prevention and during treatment to reduce the recurrence of cancer.

It has been estimated that between 32 and 35% of cancers could be attributed to dietary factors, despite the fact that the contribution of the diet varies according to the type of cancer: from 10% in lung cancer to 80% in large intestine cancers.

What science says about each diet and cancer

For years there have been a number of diets that are advertised as anti-cancer. Let’s see what relationship they have and the level of their evidence.

1. Mediterranean diet, the most studied

He nutritionist Ancel Keys He observed in 1945 that the largest number of centenarians in the world were concentrated in southern Italy. Likewise, cardiovascular diseases, widely present in the US, were less frequent in that part of Italy.

In the study, Keys verified that the diet traditionally consumed by the population of the Mediterranean Sea was low in animal fat and rich in fruitvegetables, legumes, whole grain, fish and olive oil.

Associations have been observed between increased consumption of olive oil and a lower risk of cancer breast and colorectal cancer. The main protective effects of olive oil consumption are attributable to the presence of monounsaturated fatty acids (MUFA) and phenolic compounds.

The oldest meta-analysis associated with a Mediterranean diet ever performed, based on twelve prevention studies and more than half a million people followed (The European Prospective Investigation into Cancer and Nutrition), found a significant reduction in the risk of overall mortality and a lower incidence and mortality of cancer and Parkinson’s and Alzheimer’s.

The PREDIMED (Prevention with Mediterranean Diet) study has provided the highest quality scientific evidence to be able to affirm that the Mediterranean diet is a useful pattern in the primary disease prevention cardiovascular diseases, type 2 diabetes, metabolic syndrome, cognitive impairment and breast cancer.

2. Vegetarian diet, with still scarce data

It includes those who consume dairy products and eggs (lacteo-ovegetarian) and those who follow the most restrictive patterns, without any products of animal origin (vegans).

Is a antioxidant-rich diet, mono- and polyunsaturated fatty acids, and should decrease cancer incidence and mortality. However, the scientific evidence on the anticancer effect of vegetarianism remains scant compared to the data available for the Mediterranean diet.

The results are difficult to explain due to the great heterogeneity between the dietary patterns defined as vegetarianism, which can confuse the results. But despite the diversity of data, this eating pattern is also interesting as a preventative diet.

In the case of strict vegans, If you exclude all animal products, including eggs, dairy, and honey, from your diet, it is important that you supplement with vitamin B12, zinc, iron, and omega-3s.

3. Low-carb diets or ketogenic diet, great potential

This diet began to be used successfully in the early 1920s to treat epilepsy patientsbut due to the rapid development of new anticonvulsant drugs, it fell into disuse until, in 1996, thanks to the American Epilepsy Society and the research and clinical trials carried out, it was used again in several hospitals, becoming more effective in the control of refractory epileptic seizures than many new drugs.

today is opening to new therapeutic possibilitiesas in some types of cancer, especially brain tumors, although there is still preliminary evidence.

The ketogenic diet is rich in healthy fats from avocado, olive oil, nuts, oily fish, seeds and coconut oil, moderate in protein (not hyperproteic): prioritize fish, eggs, some dairy products and lean meats such as animal proteins, and tofu, tempeh, nuts and hemp as a source of vegetable protein.

The diet is low in carbohydrates, prioritize vegetablesand limit the consumption of whole grains and fruits.

The goal is to get a metabolic state similar to that of a fast: the body produces ketone bodies from fat metabolites (hence the name ketogenic diet), such as beta-hydroxybutyrate or acetoacetate, for a new source of energy.

It should be the oncologist who recommends follow a diet of these characteristics, and the patient must have the advice of a dietitian-nutritionist trained in a ketogenic diet.

Studies of this diet have been carried out mainly in animals and in patients with brain tumors, and we also found studies in other types of cancer, such as prostate, pancreatic, breast and advanced cancers. Studies have always been done along with chemotherapy or radiotherapy treatmentTherefore, the recommendation initially focuses on these patients.

Studies have shown the next:

can induce epigenetic changes (silences oncogenes and activates healthy genes); lowers blood glucose and improves insulin resistance;reduces the inflammation markers;prevents angiogenesisthat is, it prevents the creation of new blood vessels, something necessary for the cancer cell to grow;increases GABAa neurotransmitter that has an essential relaxing effect; presents a pro-apoptotic action or, in other words, it promotes cell death; it increases the glutathione levels in healthy cells; increases the oxidative stress of the tumor cell.

does not heal by itself and this diet should not be recommended to all people with a cancer process. One of the myths that circulates is that it fights cancer by itself, but there are no studies to support this claim.

In fact, the studies carried out conclude that it provides a synergistic and protective effect together with oncological treatments usual chemotherapy and radiotherapy.

4. Alkaline diet, no evidence yet

The alkaline diet theory It is based on the existence of a series of foods that acidify the urine, such as meat, fish, cheese, eggs, refined sugar, nuts and cocoa; and foods that alkalize, such as vegetables and fruits.

This diet has been attributed the ability to modify the pH of urine and prevent acidification of the body, the most optimal environment for tumor cells to develop. But a more alkaline urine pH does not ensure alkalinization of the extracellular medium.

The reality is that the basis of this diet lacks scientific evidenceand even more if we take into account the research of Dr. Otto Warburg, who proposes that it is the cancer cell that generates an acid environment to develop, and not the other way around.

5. Therapeutic fasting, valuable in prevention and to enhance longevity

In our society there is a belief that fasting weakens us and slows down our metabolism. But scientific evidence is showing that periodic fasting is a healthy routine.

Has benefitsantiaginghelps increase energy and mental clarity, and promotes hormonal balance.

Besides, decreases markers of inflammation and autophagocytosis or cell repair; improves blood glucose levels, blood lipids and neuronal plasticity.

On the other hand, experts such as Valter Longo (of the University of Southern California), Thomas Seyfried (of Boston), Domingo D’Agostino (of the University of South Florida), and the Max Plank Institute show that fasting can play an important therapeutic role in cancer treatment: slows down tumor growtheliminates cancer cells, improves the effect of chemotherapy and the effectiveness of radiotherapy and reduces side effects.

Of course, fasting should always be supervised and assessed by a health professional.