What Not To Eat When You Have Brain Metastases?

Brain metastases patients should maintain their diet to avoid nutritional deficiency due to the side-effects of cancer treatment and also to minimize them.

Patients should avoid dairy products (milk, cheese), gluten, corn, preservatives, soy, chemical food additives, red meat, caffeine, alcohol, tobacco, saturated fats and trans-fatty acids along with processed foods. Thus, the diet should consist of foods rich in green vegetables, fruits, fish, lean protein, whole grains, healthy fats and herbs and spices.¹

Nausea should be alleviated by eating smaller and frequent meals, eating digestible proteins, staying hydrated. To avoid nausea overeating should be avoided along with excessive fats (especially saturated fats) and dehydration. Hot, spicy foods, strong odor foods, greasy, fried, excessive sweet foods should be avoided too.²

Adequate nutrition is an important part of diet to avoid fatigue. Brain metastases patients should eat consistently and at no point avoid food. They should eat lean proteins and high fiber and unsaturated fats to avoid fatigue.

Brain metastases patients also suffer from constipation as a side-effect of treatment and to prevent that they should eats foods that are high in fiber such as fresh fruits and vegetables, whole grain foods along with staying hydrated and doing gentle exercises.³ Doctors can also prescribe laxatives to combat side-effects of medications.

Ketogenic diet has been touted to be helpful for brain metastases. It is a diet that consists of very low carbohydrate, high fat (unsaturated) and calorie restricted diet. This diet works on the principle that cancer cell growth depends on glucose level in the body and when instead of glucose body utilizes ketones for energy needs, the cancer cells become more susceptible to treatment as they are depleted of glucose for growth.^{4, 5}

Brain metastases differ from primary cancers in terms that they do not originate from the brain tissues, rather they are a result of spread of tumor from distant organs, such as lung cancer when metastasizes to brain consists of lung tissue, not brain tissue. Therefore, brain metastases are known as secondary tumors as their primary origin is not the brain cells or tissues. Interestingly, primary brain tumors are quite rare and occur in the ratio of 1:10 to brain metastases. In the recent times, brain metastases have been on the rise owing to the fact that patients now have a greater availability to MRI and other advanced imaging techniques as well as advanced treatment modalities due to which patients are living longer than in the past.⁶

The growth of cancer cells in the brain causes pressure in and around the brain tissues leading to various signs and symptoms including headache, nausea, vomiting. Brain metastases patients may even experience seizures, behavioral changes, cognitive changes, visual changes, weakness, motor and sensory function changes, which depends on the location and number of tumors inside the brain. The most common cancers that metastasize to brain are lung cancer followed by breast cancer, melanoma, colorectal cancer, and renal cancer.

The main consideration on the treatment of brain metastases is the type of primary tumor as some tumors are more susceptible to treatment and some are more resilient. For example, lung tumors are more amenable to radiation therapy whereas melanomas are less sensitive to radiation therapy.⁷ It is a well-known fact that chemotherapy is found to be ineffective for brain metastases due to the blood-brain barrier. Therefore, most of the focus on the treatment of brain metastases depends on radiation and surgical management.

Not only the cancer itself, but also the treatment takes a toll on the patient’s health and diet. The cancer and its treatment lead to decreased appetite, weight loss, and nausea, changes in taste, fatigue, skin changes and pain. If the brain tumor is excised, then it can cause severe protein depletion leading to decrease in total protein, albumin, and transferring and in turn cause significant elevation of nitrogen loss.⁸

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