Caffeine during chemo?

Will drinking caffeine while on chemotherapy affect my treatment?

Caffeinated drinks can be a part of a healthy lifestyle and contribute to our daily fluid intake when consumed in moderation. Nevertheless, since chemotherapy medication is tailored to specific cancers, and symptoms vary, you might need to reduce your intake of caffeine if it worsens the side-effects you are experiencing.

What is caffeine and how does it affect the body?

Caffeine is a stimulant that acts primarily on the central nervous system, reducing the sensation of tiredness and fatigue (1). No wonder that 90% of the world’s adult population consumes it daily, mainly in the form of coffee or tea (2). Caffeine also occurs naturally in cocoa beans (chocolate), guarana, yerba mate and kola nuts, and it is synthetically added to beverages such as sodas and energy drinks (3). It is also present in medications, including headache or pain remedies, and over-the-counter stimulants.

Contrary to the general believe that caffeine is a strong diuretic, scientists have concluded that caffeinated beverages and water hydrate to the same degree over a period of 24 hours (4, 5 & 6). According to the European Food Safety Authority, intakes up to 400mg from all sources (approximately four cups of coffee or eight cups of tea), consumed throughout the day, do not raise health concerns (7). More specifically, among the general healthy adult population, no health risks related to toxicity, hydration, bone status, cardiovascular health, male fertility or cancer, have been found within this daily limit (7).

Nonetheless, caffeine consumption can increase the likelihood of headaches, anxiety, and nausea among non and low consumers (1, 8). It can also interfere with sleep, act as a laxative or increase the likelihood of acid reflux, especially in the case of coffee (8).

“Since chemotherapy medication is tailored to specific cancers, and symptoms vary, you might need to reduce your intake of caffeine if it worsens the side-effects you are experiencing.” Julia Correcher

Best fluids to keep hydrated during chemotherapy

Chemotherapy side effects such as high fever, infections, diarrhoea, and vomiting can lead to excessive fluid loss. This can result in dehydration if the losses are not replenished by our fluid intake (9).

The American Cancer Society recommends consuming at least eight to ten glasses of fluid a day, prioritising drinks that help restore sodium, potassium, and other important ions for the body, such as clear soup, broth, or stock, fruit drinks, and weak warm tea (9, 11). Juicing or smoothies may be a good option for those struggling with weight loss, swallowing, or digestive problems, to complement their overall diet.

While caffeinated drinks, ice cream, and sodas can be consumed to replace fluid loss during chemotherapy, you should be mindful of sugar content and avoid those that contain more than 15 g per 100 ml (12).

Best fluids to drink during chemo: Water, clear broth/soup, milk, jelly, fruit juice, weak tea or coffee

The intake of sugar-sweetened beverages has been shown to negatively affect cell’s DNA, increasing risk of obesity (13). Obesity is, in turn, linked to other diseases such diabetes or cancer. This is because our cells have not yet developed the necessary mechanisms to deal with the high sugar content of our modern diets. Failure to use/detoxify this excess, results in harm to their delicate mechanisms, and, over time, contribute to many chronic diseases such as cancer (14). Always check the label for sugar content and choose the low option when possible.

When should caffeine be avoided?

You should avoid or cut back caffeine if it worsens the chemotherapy side effects you are experiencing. The National Cancer Institute suggests avoiding caffeinated drinks or foods such as dark chocolate if you experience diarrhoea (11, 15). Water, sports drinks (without xylitol or sorbitol), and fat-free broth could be consumed instead, preferably at room temperature (11, 15).

Likewise, if you are facing loss of appetite and weight, high-calorie content drinks, like juice or milk, might be recommended over low-calorie options, like tea or coffee. If you have problems sleeping, caffeine should be avoided after 5pm or close to your bedtime, and if you find yourself feeling more anxious, irritable, or nervous, avoiding caffeine might help (8).

How to beat fatigue during chemotherapy?

Cancer-related fatigue (CRF) is a common side effect from treatment. Even so, it can also be a consequence of problems related to the disease itself, such as anaemia or hormonal changes (16). Each patient is different, as it is their treatment, thus CRF patterns vary. It is important to discuss changes in energy levels with your clinician to identify the main contributing factors.

An increasing number of studies have assessed the benefits of exercise during cancer treatment, concluding that it can improve fatigue, body functionality and quality of life (17). Developing an activity/rest program will help. The idea is to design a daily routine that allows the best use of your energy. The type of exercise and intensity will depend on your preferences and ability. Some clinicians advise to first assess physical response to chemotherapy before choosing your exercise program. For those who had sedentary lifestyles before diagnosis, low‐intensity activities such as stretching or slow walks are recommended to start with (17).

If fatigue is related to anaemia, nutritional interventions might be helpful, including the intake of iron-rich foods and supplements (16). This will need to be supervised by a medical professional, such as an oncology dietitian. Dehydration can also cause fatigue, so drinking enough fluids through the day as discussed in this article can be crucial.

In conclusion, you can consume caffeine as long as you do so in moderation, and do not experience diarrhoea as a side effect of your treatment. Some drinks are better than others, drinking warm and weak tea or coffee is best, and considering sugar content (less than 15 g per 100 ml) is important due to its effects over our DNA health. If you experience CRF, exercise might help increase your energy levels, as well as maintaining yourself hydrated by consuming 8 to 10 glasses of fluid a day. Everybody is different, if you are unsure, talk to your doctor or dietitian to help you choose the most appropriate drinks for your personal circumstances.

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(9) Yasko JM, Greene P. Coping with problems related to cancer and cancer treatment. CA: a cancer journal for clinicians 1987;37(2):106-125.

(10) University of Pittsburgh Cancer Institute. Chemotherapy Information for Patients and Families. Patient booklet 2012.

(11) National Cancer Institute. Eating Hints: Before, during, and after Cancer Treatment. U.S. Department of Health & Human Services 2018:1-60.

(12) FDA. Using traffic lights to make healthier choices. Food Standards Agency 2007. Available from: http://www.resourcesorg.co.uk/assets/pdfs/foodtrafficlight1107.pdf

(13) Qi Q, Chu AY, Kang JH, Jensen MK, Curhan GC, Pasquale LR, Ridker PM, Hunter DJ, Willett WC, Rimm EB, Chasman DI. Sugar-sweetened beverages and genetic risk of obesity. New England Journal of Medicine. 2012 Oct 11;367(15):1387-96

(14) Houghton, C. Switched on: Harnessing the power of nutrigenomics to optimise your health. 1st ed. Integra Publishing; 2010.

(15) PDQ® Supportive and Palliative Care Editorial Board. Nutrition in Cancer Care (PDQ®) – Health Professional Version. Summary 2003.

(16) PDQ® Supportive and Palliative Care Editorial Board. Fatigue (PDQ®)– Health Professional Version. Summary 2017.

(17) Doyle C, Kushi LH, Byers T, Courneya KS, Wahnefried W, Grant B, et al. Nutrition and physical activity during and after cancer treatment: an American Cancer Society guide for informed choices. CA: a cancer journal for clinicians. 2006;56(6):323-353.