Updated: Jun 16, 2021
Cachexia, often known as wasting disease, accounts for upwards of 40% of all cancer patient deaths.(1) Present in localized and metastatic cases alike, cachexia is clinically characterized by progressive weight loss, inflammation, insulin resistance, fatigue, and muscular degeneration.(2) Because few medications can counteract these deleterious changes, nutritional choices are especially important in clinician efforts to optimize outcomes. Although the carcinogenic effects of processed meat are well-established, significant controversy still surrounds red meat and fish as staples in Western diets.(3) Few foods garner more derision, with detractors inclined to cite public health officials’ testimonies linking meat to heart disease and cancer.(4) Such health concerns, in part, may be fueling the rising interest in veganism; the number of U.S. consumers identifying as vegans increased by 600% between 2014 and 2017.(5) While the vegan population remains a minority, the explosive growth of the movement warrants investigation, along with claims of meat acting as a source of cancer.
Seminal studies linking red meat with inflammation are largely observational in nature, which means that associations between findings do not necessarily establish causation. Unlike double-blind, randomized controlled trials, the standard in clinical research, observational studies have a greater propensity for bias and cannot control for confounding variables. In this context, the correlation between red meat consumption and inflammation in study participants could be explained by other factors like sleep deprivation, stress, smoking, alcohol consumption, chemical exposure, and general environment.(6) Furthermore, variation in meat processing can introduce additional confounding effects, along with the choice of study population.(7)
Further undermining the tenuous link between unprocessed red meat and cancer are data from controlled trials measuring inflammation markers in participants. In one study, authors concluded that substituting red meat for carbohydrates actually reduces inflammation in non-anemic individuals.(8) Data from a more recent study corroborate these findings, with study authors noting that there was little to no difference in inflammation markers in participants eating a diet high in red meat versus a diet high in oily fish.(9) Such results have prompted an international panel of researchers to reverse the conventional thinking that justifies the flight towards veganism. Bradley Johnston, the lead author of dietary guideline recommendations from the NutriRECS consortium, stated that “the certainty of evidence for these risk reductions was low to very low” and that “if there are health benefits from eating less beef... they are small". (4, 10) If anything, eliminating red beef entirely can increase the likelihood of long-term health problems – especially in cancer patients.
Nonie De Long, a licensed nutritionist from Canada, contends that “a vegan diet is one of the unhealthiest diets... the problems start with a lack of appetite, energy, and strength, and escalate over time to chronic fatigue, dental problems, muscle wasting, premature aging, digestive issues, and skin conditions.” Notably, problems can also sometimes extend into the psychological plane; anxiety, depression, mood swings, and eating disorders can manifest in vegans.(11) Although the absence of nutritionally dense red meat is somewhat problematic, the subsequent substitution of grains and vegetable-oil laden foods can prove damaging. Among the resulting problems, ironically, is inflammation – the very process by which some vegans sought to avoid by excluding dietary meat.(12) Even if vegans take proper precautions to avoid processed, empty-calories, they still have a higher likelihood of being deficient in key nutrients like Vitamin B12, iron, zinc, iodine, essential fatty acids (e.g., DHA), and vitamins A and D.(11) These nutritional shortfalls can exacerbate the core clinical features of cancer cachexia and should be avoided by adopting a diverse, anti-inflammatory diet.
Cancer Is Driven By Inflammation
Inflammation arises from diets rich in sugar and refined starches. In her book, Keto for Cancer, Miriam Kalamian recommends a diet that ensures high intake of anti-inflammatory omega-3 and monounsaturated fats while reducing intake of unhealthy fats and oils.(13) Keeping glucose levels low is critical to stress cancer cell energy production, so cancer patients should also enjoy fruit sparingly and prioritize consumption of low glycemic ones like grapefruit, berries or green apples.(14) Other mindful replacements – like colored vegetables for sweet potatoes – can minimize carbohydrate consumption while ensuring that nutrients like beta carotene are consumed adequately. Clean red meat and fish provide valuable protein, which is needed to repair and maintain muscle mass. Regular exercise can also complement these dietary choices and slow down sarcopenia, or muscle wasting.(13) When in motion, fit muscles extract glucose from the bloodstream and store some in the form of glycogen to power future bursts of activity. Fit muscles can store between 350-500 grams of glucose, exceeding the liver’s storage capacity by a factor of roughly 3.5-5.(15) This sequestration of glucose from the bloodstream deprives cancer cells of their primary fuel, and it is also never made available to them again. When accessed for energy, glycogen stores can only be used by adjacent muscle tissue!
The 3 Lever Anti-Cancer Diet
When I discuss diet with cancer patients, I strive to always simplify by suggesting that they look at a scenario of 3 levers, or switches, at their disposal in thinking about their optimal, anti-cancer diet.
The First Lever - What You Eat
The first lever is the determination of what they eat preferentially in the balance of the three macros of carbohydrates, proteins, and fats. I remind our patients that there is much speculation about some tumor types usurping the use of amino acids or fats, but what we know more definitively is that the breakdown products of carbohydrates or sugars are the main metabolic drivers in cancer cells. Reduction of these byproducts in our diet is the first priority. I remind patients that natural grains and fruits do not get a pass and should be restricted as well. Additionally, I like reminding those in our care that normal cells can survive and thrive on fats, proteins, and limited carbohydrates, but cancer cells are generally challenged and sometime crippled in this nutrient environment
The Second Lever - When You Eat
The second lever to deploy is when we eat or do not eat. I remind patients we can dramatically lower insulin growth factor and insulin, the main proliferative driver at the top the pyramid of cascade of cell-to-cell cross talk for proliferation, by long periods of non-eating. I encourage patients to tighten the time window of their meals such that they have 14 to 16 hours of no significant substrate intake. Many patients elect to have their first meal in late morning or midday, so I also recommend that patients start their day with electrolytes, no or low carbohydrates beverages. The goal is to maintain sufficient caloric intake but compress it to a 6-8 eating window with flexibility dependent the day’s schedule. This intake modification becomes progressively easier as the fat burning pathways upregulate and reset to our normal, evolutionary rhythm
The Third Lever - What You Do When You Eat
The third lever is what we do or do not do when we eat or do not eat. I remind patients that the muscles are the “escape valve” for directing our diet variance to safety and benefit. After high carbohydrate intake, people should consider walking the dog or an imaginary dog to activate non-insulin glucose uptake and lower glucose levels. If one consumes a high protein or amino acid meal, consider some muscle activation activity (10 minutes of strength exercise) before or after to drive proliferation in the muscles rather than possible cancer cell stimulation. A third option is to incorporate exercise into a fasting option to prolong and enhance ketosis and autophagy. Essentially, the two options on exercise (muscle or aerobic) can modulate dietary strategies and enable more flexibility and control.
The three levers are a simple primer on adding nutrition to the care and prevention in our cancer patients. When our patients want to dial in on more nutrition goals, we have referral options available to consider with our nutritionist colleagues where glucose and ketone monitoring are considered.
Cachexia demonstrating sarcopenia (muscle loss) and lymphopenia (immune depletion) all can spell the demise of cancer patients. Strict attention to combining protein intake cleanly sourced combined with muscle activation exercises can trigger maintenance of muscle mass and slow the decline. Attention to this threat need to be addressed early well before major signs and symptoms arrive. I encourage patients to create some measure of their muscle function (number of push-ups, squats, or whatever one can monitor) and verify you are holding your ground or even improving.
While research continues on the best approach to nutrition, cancer patients and ordinary people alike should take caution interpreting scientific data. Authors can have angles, and readers often readily accept results that support their existing attitudes towards anything, including food. Although vegans deserve some commendation for their earnest efforts to reduce their carbon footprint, increasing amounts of evidence suggest that such a lifestyle can prove unsustainable. When evaluating foods, consumers should weigh more heavily the source and quality of the food, rather than the food itself. Eaten in moderation, clean red meat and fish supply essential protein to the body and form the foundation of a healthy diet – even in patients with cancer.
Stay strong and keep smiling and be your own best doctor,
Charles J. Meakin MD, MHA, MS
Chief Medical Executive Care Oncology
Facebook Page: https://www.facebook.com/CareOncology/
1 - Fox KM, Brooks JM, Gandra SR, et al. Estimation of cachexia among cancer patients based on four definitions. J Oncol. 2009;2009:693458.
2 - Argiles JM, Busquets S, Felipe A, et al. Muscle wasting in cancer and aging: cachexia versus sarcopenia. Adv Gerontol. 2006;18:39-54.
3 - Otis BO. WHO report says eating processed meat is carcinogenic: understanding the findings. Harvard School of Public Health. https://www.hsph.harvard.edu/nutritionsource/2015/11/03/report-says-eating-processed-meat-is-carcinogenic-understanding-the-findings/ Published November 3, 2015. Accessed January 25, 2021.
4 - Kolata G. Eat less read meat, scientists said. Now some believe that was bad advice. The New York Times. https://www.nytimes.com/2019/09/30/health/red-meat-heart-cancer.html Published September 30, 2019. Updated October 4, 2019. Accessed January 25, 2021.
5 - Forgrieve J. The growing acceptance of veganism. Forbes. https://www.forbes.com/sites/janetforgrieve/2018/11/02/picturing-a-kindler-gentler-world-vegan-month/ Published November 2, 2018. Accessed January 25, 2021.
6 - Kay S. Does meat cause inflammation? Stephanie Kay Nutrition. https://www.kaynutrition.com/does-red-meat-cause-inflammation/ Published September 13, 2018. Accessed January 25, 2021.
7 - Ley SH, Sun Q, Willett WC, et al. Associations between red meat intake and biomarkers of inflammation and glucose metabolism in women. Am J Clin Nutr. 2014;99(2):352-360.
8 - Hodgson JM, Ward NC, Burke V, et al. Increased lean red meat intake does not elevate markers of oxidative stress and inflammation in humans. J Nutr. 2007;137(2):363-367.
9 - Navas-Carretero S, Perez-Granados AM, Schoppen S, et al. An oily fish diet increases insulin sensitivity compared to a red meat diet in young iron-deficient women. Br J Nutr. 2009;102(4):546-553.
10 - Johnston BC, Zeraatkar D, Han MA, et al. Unprocessed red meat and processed meat consumption: dietary guideline recommendations from the Nutritional Recommendations (NutriRECS) Consortium. Ann Intern Med. 2019;171(10):756-764.
11 - De Long N. Here’s why vegans have one of the most unhealthy diets. New Market Today. https://www.newmarkettoday.ca/local-news/ask-the-nutritionist-heres-why-vegans-have-one-of-the-most-unhealthy-diets-1559005. Published July 7, 2019. Accessed January 25, 2021.
12 - Kiecolt-Glaser JK. Stress, food, and inflammation: psychoneuroimmunology and nutrition at the cutting edge. Psychosom Med. 2010;72(4):365-369.
13 - Kalamian e-mail correspondence on nutrition.
14 - Carey E. 10 low-glycemic fruits for diabetes. Healthline. https://www.healthline.com/health/diabetes/low-glycemic-fruits-for-diabetes Published August 27, 2019. Accessed January 25, 2021.
15 - Yeager S. Everything you need to know about glycogen: your primer on the foremost fuel you need when you want to go fast. Bicycling. https://www.bicycling.com/health-nutrition/a20032965/everything-you-need-to-know-about-glycogen/ Published April 13, 2017. Accessed January 25, 2021.