Brain Fog During Chemotherapy and Radiotherapy - Magaziner

Brain Fog During Chemotherapy and Radiotherapy

Often a patient will come into our office during or after chemotherapy treatments. One of the first things their loved ones will say is “I wish they told us about these side effects so we could be prepared.”

One side effect is chemo brain. This is a “brain fog sensation,” a loss of memory and cognitive function.

Most research reports that these are temporary conditions caused by chemotherapy treatments. Symptoms should be treated with various methods including memory and brain exercises when needed. Also included in the treatment methods are certain Alzheimer medications and those medications for attention-deficit disorder. However, new research is suggesting doctors look at how to manage post chemo and radiation therapy for possible answers.

Let’s Look At The Research

Initially, it was thought that the side effects of chemotherapy were solely responsible for “chemo brain.” This limitation to chemotherapy causing effects was challenged by a research team from the Moffitt Cancer Center and Research Institute working with associates from the University of South Florida and the University of Kentucky. In a study they published in the medical journal Cancer, changes in cognitive functioning over time were compared in:
(1) breast cancer survivors treated with chemotherapy plus radiotherapy,
(2) breast cancer survivors treated with radiotherapy only, and
(3) women with no history of cancer.

The researchers noted cognitive problems for up to three years post chemo. What they also found in test subjects was that not only did chemotherapy lead to what is commonly referred to as “Chemo Brain,” but radiotherapy did as well. (1)

Inflammation as treatment and its side effects

Somehow a proinflammatory radiotherapy treatment was causing brain problems. This added to speculation that inflammation does play a role in brain fog. The problem for the patient and the doctor is that inflammation also plays a role in tumor shrinkage.

In the cancer journal, Oncotarget, researchers noted that treatments combining radiotherapy and immunotherapy demonstrated remarkable efficacy with respect to tumor outcomes by enhancing the proinflammatory environment in the tumor. (Immunotherapy enhances the immune response to invading cells like cancer, flu or cold, by increasing inflammation).

However, a proinflammatory environment in the brain causes and induces cognitive impairments and may affect brain function in cancer patients receiving these treatments.

The research team from Oregon Health and Science University, who is behind this research, concluded that, “Although combined treatment achieved tumor growth control, it affected the brain and induced changes in measures of anxiety, cognitive impairments, and neuroinflammation.”(2)

Inflammation opens a door for neurotoxicity and cognitive dysfunction
The focus here is on cytokines – a small protein that communicates with immune cells to get them to the site of injury, infection, and inflammation. The thinking is that cytokines are somehow opening a doorway in “blood-brain barrier” the blood filtering mechanism that carries blood to the brain while blocking many harmful substances. It is through that it is through this doorway that “unfiltered” chemicals are getting through into the brain.

In research from the International Journal of Cancer, doctors looked at the neurotoxicity side effect of chemotherapy treatment.

Here is what they wrote:

Clinical studies suggest that the most frequent neurotoxic adverse events affect memory and learning, attention, concentration, processing speeds and executive function.

Emerging preclinical research points toward direct cellular toxicity and induction of neuroinflammation as key drivers of neurotoxicity and subsequent cognitive impairment. (The research suggests that the chemicals used in chemotherapy are somehow bypassing the blood-brain barrier., as we mentioned above.)

Emerging data now show detectable levels of some chemotherapeutic agents within the central nervous system, indicating potential disruption of blood-brain barrier integrity.

Blood-brain barrier disruption is a key aspect of many neurocognitive disorders, particularly those characterized by a proinflammatory state.(3)

In research from doctors in the Czech Republic, it was reported that cognitive impairment (impairment of memory, attention, or concentration) is documented in 17-75% of patients with various malignancies treated with chemotherapeutic agents that worsen quality of life.

Changes occur mainly in the ability to learn and remember, in the speed of reactions, and in attention and executive functions.

Although chemo-related cognitive impairment’s complexities are not yet fully understood, the involvement of neurotoxicities, such as that induced by treatment, anemia, higher levels of oxidative stress and inflammatory responses, genetic factors, and reduced brain connectivity should be discussed. (4)

Omega 3 and sugar reduction can help

The link between inflammation post chemotherapy and radiotherapy has been shown. Is there anything that can help. Research suggests dietary changes may offer some benefit.

In the medical journal, Breast cancer research and treatment, a paper entitled Clearing the fog: a review of the effects of dietary omega-3 fatty acids and added sugars on chemotherapy-induced cognitive deficits.

Doctors from Ohio State University suggested that:

Dietary approaches that modify inflammation and neurogenesis (growth of nervous system tissue) are promising strategies for reducing chemotherapy-induced cognitive deficits in breast cancer survivors.

Omega-3 fatty acids administered concurrently with doxorubicin chemotherapy have been shown to prevent depressive-like behaviors and reduce neuroinflammation, oxidative stress, and neural apoptosis (nerve cell death) in animal studies.

In contrast, diets high in added sugars may interact with the Omega-3s to diminish their anti-inflammatory activity. The sugars may also act independently to increase neuroinflammation and promote cognitive deficits.

A diet rich in long-chain, marine-derived omega-3 fatty acids (fish oils) and low in added sugars may be an ideal pattern for preventing or alleviating neuroinflammation and oxidative stress, thereby protecting neurons from the toxic effects of chemotherapy.

Research testing this hypothesis could lead to the identification of modifiable dietary choices to reduce the long-term impact of chemotherapy on the cognitive functions that are important to the quality of life in breast cancer survivors. (5)

Come See Us For Help

At the Magaziner Center for Wellness, we see a lot of patients post-cancer treatment. These include cancer patients already undergoing conventional treatment by an oncologist or radiotherapist who wishes to give themselves the added benefits of nutritional and immune-function support.

These patients have reported reduced side effects and better therapeutic results while on our program. The challenges of “Brain fog,” or “Chemo brain,” can be helped with a customized program of various methods that we offer here.

Call us at 856-424-8222 OR email us at


1. Cognitive functioning after cancer treatment: A three-year longitudinal comparison of breast cancer survivors treated with chemotherapy or radiation and non-cancer controls.” Phillips KM, Jim HS, Small BJ, et al. CANCER; Published Online: December 12, 2011.
2 McGinnis GJ, Friedman D, Young KH, et al. Neuroinflammatory and cognitive consequences of combined radiation and immunotherapy in a novel preclinical model. Oncotarget. 2017;8(6):9155-9173. doi:10.18632/oncotarget.13551.
3. Wardill HR, Mander KA, Van Sebille YZ, Gibson RJ, Logan RM, Bowen JM, Sonis ST. Cytokine-mediated blood brain barrier disruption as a conduit for cancer/chemotherapy-associated neurotoxicity and cognitive dysfunction. Int JCancer. 2016
4. Fayette D, Gahérová Ľ, Móciková H, Marková J, Kozák T, Horáček J. Chemotherapy-related Cognitive Impairment in Patients with Hodgkin Lymphoma-Pathophysiology and Risk Factors. Klinicka onkologie: casopis Ceske a Slovenske onkologicke spolecnosti. 2017;30(2):93-9.
5. Orchard TS, Gaudier-Diaz MM, Weinhold KR, DeVries AC. Clearing the fog: a review of the effects of dietary omega-3 fatty acids and added sugars on chemotherapy-induced cognitive deficits. Breast cancer research and treatment. 2017;161(3):391-398. doi:10.1007/s10549-016-4073-8.

Sign Up for Our Newsletter

Get the latest news, research and articles.

Site Design Rebecca Pollock
Site Development Alchemy + Aim