How to Lower Your Risk for Colorectal Cancer: Part 2

Making healthy lifestyle choices can help to prevent the development of CRC for both the young and the old.  But modifications in daily activities, such as what you put into your body and how much you move it, can only be generated by yourself.  No on else can do it for you.

Here are some recommended goals to aim for. (1,2)

 

Eat a healthy diet rich in high fiber foods.

It’s not just about avoiding the foods that are harmful; it’s also about emphasizing the foods that actively help your body to thrive.  This means including a large variety of foods sourced from plants in your diet.  This doesn’t mean you must eat only plants (although that is a beneficial step to take) but you do need to concentrate on making foods sourced from animals only a minimal part of your diet. Fill your plate with high fiber vegetables, legumes, fruits, whole grains, nuts and seeds.  The fiber in these foods promotes the growth of healthy microbes in the gut.  It is their main fuel for themselves but they also produce health-enhancing chemicals like short-chain fatty acids that in turn support the well-being of the whole human body in which they live.  These chemicals are crucial for maintaining a strong gut barrier, strengthening the immune system, lowering body inflammation, reducing the risks of developing obesity, diabetes, cancer, cardiovascular disease and liver disease, and protecting the nervous system. As an added bonus, high fiber foods are very filling and help to keep body weight at a healthy level.  (7)

Only about 5% of North Americans get enough fiber in their diets; most people ingest only about 16 grams per day.

Canadian recommendations for middle-aged adults call for at least 25 grams a day for women and at least 38 grams a day for men. (25)  But even these levels are only a minimum amount.  More fiber is even better and there is no upper limit. Our ancestors ate a diet containing 100 grams of fiber daily and more.  (8)  The preponderance of evidence points to consuming about 50 grams of fiber daily for health in both men and women.  This is the amount found in the traditional diet in Africa and it has been linked to the prevention of numerous chronic illnesses in human beings.  (8,24)

 Each 10 grams of fiber eaten daily is associated with a 10 to 17% reduction in the risk of CRC.

 

Strive to enjoy at least 150 minutes of physical activity every week. 

Strong evidence from multiple studies reveals that high levels of recreational physical activity can support an approximate 20% reduction in the risk of developing CRC and a 42% decrease in both all-cause death and CRC-specific death.  Investigators postulate that the reason for this effect is multifactorial and includes shrinking the amount of adipose tissue (fat-carrying cells) in the body; lowering chronic inflammation, blood glucose and insulin levels; reducing insulin resistance; and increasing the speed of movement of food through the intestinal tract, a factor that reduces the contact time between the lining of the intestine and the food carrying potential carcinogens.

Recreational physical activities can include many behaviours but some examples are brisk walking, hiking, jogging, cycling, swimming, playing tennis and pushing a lawn mower.

 

Reduce or eliminate your intake of alcohol, meat, processed foods and refined sugars.

Eat no more than 18 ounces (the size of a deck of cards) of red meat (beef, pork, lamb) per week.

Avoid processed meats, foods high in refined sugars (including sugary drinks, candies, sweet baked goods, white flour and white bread) and highly processed foods.

If you must drink alcohol, do it in moderation – two drinks or less per week.  When it comes to alcohol, the less the better.  (9)

 

Do not smoke

 

New Science on this Subject

With the recent discovery that young people are experiencing CRC at a higher rate than their parents, research in this field has blossomed.

A prospective study published in April 2019 demonstrated that even very small amounts of processed meats increase the risk of CRC.  A single slice of bacon or ham (about 25 grams of processed meat) eaten every day raises the risk by 20%.  So do red meats with the addition of 50 grams of a red meat like roast beef or lamb every day increasing the CRC risk by 19%.  On the other hand, those who ingest more fiber reduce their risk by 14%.  (10)

In 2019 a study from Spain looked at diets high in red and processed meats that promoted inflammation and an upsurge in the risk of developing CRC.  The researchers examined the antioxidant contents and inflammatory effects of the dietary habits of their study participants.  They found that those who consumed the highest amounts of inflammatory foods, including red and processed meats, significantly increased their risk for CRC when compared to those who ate the fewest inflammatory foods and foods high in fiber and antioxidants.  Also, diets highest in pro-inflammatory foods were associated with a rise in the risk for breast cancer. (11)

2019 saw the publication of a review in Current Gastroenterology Reports which revealed that high-fat low-fiber diets boost the risk of cancer while diets high in fiber reduce cancer development, including that of CRC.  The researchers suggest that fiber seems to encourage the growth of friendly microorganisms in the gut microbiome that protect against the risk of cancer.  (12)

Two reviews from 2021 found that (13,14)…

  • Red meat consumption was significantly associated with higher risk of many cancers including breast cancer, endometrial cancer, colorectal cancer, colon cancer, rectal cancer, lung cancer and hepatocellular carcinoma.
  • Processed meat consumption was significantly associated with a 6% higher risk of breast cancer, an 18% higher risk of CRC, a 21% higher risk of colon cancer, a 22% higher risk of rectal cancer and a 12% higher risk of lung cancer.

Research from 2022 showed that eating a plant-based diet reduces the risk of CRC by 22% compared with those eating the least plant-based. (15)

Studies published in 2022 and 2023 found that a diet high in processed foods and sweets raises the risk of developing CRC.  In addition, they discovered that a diet of mostly animal-sourced foods (eggs, fish and seafood, and dairy products) can also increase CRC risk.  Contrarily, a diet high in fruits and vegetables does not escalate the risk of developing CRC. (16,17)

In 2023, findings from the Singapore Chinese Health Study indicated that a low-carbohydrate diet with a high level of animal protein and fat was related to a significant increase in the risk of colon cancer among Chinese Singaporeans while a low-carbohydrate diet centered around eating plants showed a much lower risk. (18)

From January 2024 a new analysis of over 50,000 people determined that (19)…

  • Replacing 100 grams (3.5 ounces) of red meat every week with an equal amount of whole grains, fruits or vegetables was linked with a reduced risk of CRC.
  • Replacing 50 grams of processed meat every week with an equal amount of fruits and vegetables was associated with a reduced risk of CRC.

In August 2024, to tease out CRC-related microbes that may be contributing to an increased risk of CRC, researchers investigated the effects of a dietary pattern, rather than specific foods or nutrients, on the attributes of the microscopic inhabitants of the gut microbiome. Using a group of 519 men and women they analyzed stool samples and dietary information to come up with a dietary pattern that encouraged the growth of gut microbes related to the onset of CRC.   This dietary pattern was called the CRC Microbial Dietary Score (CMDS) and it was characterized by high levels of industrially processed food and low levels of unprocessed fiber-rich food. They then investigated the association between the CMDS and the risk for CRC in almost 260,000 participants of three large US cohorts (the Health Professionals Follow-up Study, and Nurses’ Health Study I and II), in which health professionals supplied detailed information on health and lifestyle factors over long time periods.  Results showed that a higher CMDS was linked with a 25% rise in risk for CRC.  This research provides evidence for the potential role of the diet to modulate the gut microbiome into one which reduces the risk for developing CRC.  (20)

A study from December 2024 analyzed CRC tumours and found that they contained high amounts of inflammation-producing compounds which were associated with diets high in processed foods.  Additionally, these tumours were lacking in molecules related to healing and the lowering of inflammation.  This information could illuminate tools that can fight cancer by slowing or stopping tumour growth through the reduction in the diet of inflammatory compounds and the increase of healthy bioactive compounds derived from healthy plant-sourced foods.  (21)

 

For young and old alike….warning signs of CRC (22)

The diagnosis of CRC is often delayed in younger people.  They may have noticed mild symptoms but are unaware of the rise of this disease in their age group.  However, medical practitioners are now seeing early CRC in patients as young as the mid-20s.

The warning signs are the same, no matter how old or young you might be.

  • Changes in bowel habits
  • Blood in the stool
  • Tiredness
  • Abdominal pain

 Such symptoms can be easily mistaken for a less serious condition such as irritable bowel syndrome.  But people of all ages who are experiencing these symptoms should see their doctor to determine what is their cause.   Early detection can improve outcomes.

 

 

SOURCES:

https://connect.mayoclinic.org/blog/cancer-education-center/newsfeed-post/the-relationship-between-nutrition-and-colon-cancer

https://www.ncbi.nlm.nih.gov/books/NBK585999/

https://www.cbc.ca/news/health/colorectal-cancer-keeps-rising-among-younger-adults-no-one-s-sure-why-1.6772096

4  https://health.clevelandclinic.org/colon-cancer-in-young-adults

https://www.cancer.gov/news-events/cancer-currents-blog/2020/colorectal-cancer-rising-younger-adults

https://www.npr.org/sections/health-shots/2023/03/20/1163697875/colon-cancer-signs-screening-young-adult

7  Xiong, R.G., Zhou, D.D., Wu, S.X., Huang, S.Y., Saimaiti, A., Yang, Z.J., Shang, A., Zhao, C.N., Gan, R.Y., Li, H.B. Health Benefits and Side Effects of Short-Chain Fatty Acids. Foods. 2022 Sep 15;11(18):2863. Doi: 10.3390/foods11182863. PMID: 36140990; PMCID: PMC9498509.

8  Tuohy, K.M., Gougoulias,C., Shen, Q., Walton, G., Fava, F., Ramnani, P. Studying the human gut microbiota in the trans-omics era–focus on metagenomics and metabonomics. Curr Pharm Des. 2009;15(13):1415-27. Doi: 10.2174/138161209788168182. PMID: 19442166.

https://www.ccsa.ca/canadas-guidance-alcohol-and-health

10  Bradbury ,K.E., Murphy, N., Key, T.J. Diet and colorectal cancer in UK Biobank: a prospective study. Int J Epidemiol. Published online April 17, 2019.

11  Obón-Santacana, M., Romaguera, ,D., Gracia-Lavedan, E., et al. Dietary inflammatory index, dietary non-enzymatic antioxidant capacity, and colorectal and breast cancer risk (MCC-Spain Study). Nutrients. 2019;11:1406-1426.

12  Ocvirk, S., Wilson, A.S., Appolonia, C.N., Thomas, T.K., O’Keefe, S.J.D. Fiber, Fat, and Colorectal Cancer: New Insight into Modifiable Dietary Risk Factors. Curr Gastroenterol Rep. 2019;21:62-69.

13  Farvid MS, Sidahmed E, Spence ND, Mante Angua K, Rosner BA, Barnett JB. Consumption of red meat and processed meat and cancer incidence: a systematic review and meta-analysis of prospective studies. Eur J Epidemiol. 2021;36(9):937-951. doi:10.1007/s10654-021-00741-9

14  Huang Y, Cao D, Chen Z, et al. Red and processed meat consumption and cancer outcomes: Umbrella review. Food Chem. 2021;356:129697. doi:10.1016/j.foodchem.2021.129697

15  Kim, J., Boushey, C.J., Wilkens, L.R., Haiman, C.A., Le Marchand, L., Park, S.Y. Plant-based dietary patterns defined by a priori indices and colorectal cancer risk by sex and race/ethnicity: the Multiethnic Cohort Study. BMC Med. 2022;20(1):430-444. Doi:10.1186/s12916-022-02623-7.

16  Abd Rashid, A., Ashari, L., Shafiee, N., et al. Dietary patterns associated with colorectal cancer risk in the Malaysian population: a case-control study with exploratory factor and regression analysis. BMC Public Health. 2023;23:1386. Doi:10.1186/s12889-023-16283-6.

17  Wu, B., Zhou, R., Ou, Q., Chen, Y., Fang, Y., Zhang, C. Association of plant-based dietary patterns with the risk of colorectal cancer: a large-scale case-control study. Food Funct. 2022;13:10790-10801. Doi:10.1039/d2fo01745h.

18 Yu, Y.C., Paragomi, P., Jin, A., Wang, R., Schoen, R.E., Koh, W.P., Yuan, J.M., Luu, H.N. Low-Carbohydrate Diet Score and the Risk of Colorectal Cancer: Findings from the Singapore Chinese Health Study. Cancer Epidemiol Biomarkers Prev. 2023 Jun 1;32(6):802-808. Doi: 10.1158/1055-9965.EPI-22-0683.

19 Tammi, R., Kaartinen, N.E., Harald, K., et al. Partial substitution of red meat or processed meat with plant-based foods and the risk of colorectal cancer. Eur J Epidemiol. Published online January 23, 2024. Doi:10.1007/s10654-024-01096-7

20  Wang, K., Lo, C.H., Mehta, R.S., Nguyen, L.H., Wang, Y. et al.  An Empirical Dietary Pattern Associated With the Gut Microbial Features in Relation to Colorectal Cancer Risk. Gastroenterology. 2024 Dec;167(7):1371-1383.e4. Doi: 10.1053/j.gastro.2024.07.040. Epub 2024 Aug 6. PMID: 39117122; PMCID: PMC11581916.

21  Soundararajan, R., Maurin, M.M., Rodriguez-Silva, J., et al   Integration of lipidomics with targeted, single cell, and spatial transcriptomics defines an unresolved pro-inflammatory state in colon cancer.  Gut.  Published Online First: 10 December 2024. Doi: 10.1136/gutjnl-2024-332535

22  https://www.newsweek.com/doctors-colon-cancer-rise-gen-z-millennials-1986245

23 Genua, F., Raghunathan, V., Jenab, M., Gallagher, W.M., Hughes, D.J. The Role of Gut Barrier Dysfunction and Microbiome Dysbiosis in Colorectal Cancer Development. Front Oncol. 2021 Apr 15;11:626349. Doi: 10.3389/fonc.2021.626349. PMID: 33937029; PMCID: PMC8082020.

24  O’Keefe, S.J.D. Plant-based foods and the microbiome in the preservation of health and prevention of disease. Am J Clin Nutr. 2019 Aug 1;110(2):265-266. Doi: 10.1093/ajcn/nqz127. PMID: 31268135; PMCID: PMC6669048.

25  https://www.canada.ca/en/health-canada/services/nutrients/fibre.html

 

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My name is Debra Harley (BScPhm) and I welcome you to my retirement project, this website. Over the course of a life many lessons are learned, altering deeply-rooted ideas and creating new passions.

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