Nature Over Nurture: How Can Lifestyle Factors Really Effect Cancer Risk? Part 2

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Dr. Sarah LoBisco, ND
@DrLoBisco

Lifestyle and Cancer Risk

In the previous article, I discussed some statistics on cancer and how diet and lifestyle play a role in prevention. In this article, I continue with a focus on lifestyle and plant medicine.

One article wonderfully exemplified how lifestyle impacts health outcomes. It was a large Australian cohort study of middle-aged and older adults that was published in the PLOs One Journal in December 2015. The researchers used questionnaires to establish an index of health risk which included these seven factors: smoking, high alcohol intake, poor diet, physical inactivity, prolonged sitting, and unhealthy (short/long) sleep.

The 231,048 participants were followed for six years. The researchers found a strong relationship between the lifestyle risk index score and all-cause mortality. Specifically, combinations of either physical inactivity, prolonged sitting, and/or long sleep duration or combinations involving smoking and high alcohol intake had the strongest associations with all-cause mortality. This provided evidence that alcohol intake, smoking, sleep and movement could be predictors of health outcomes.1

Another study showed the impact of just one lifestyle factor, exercise, by investigating the relationship between aerobic fitness in late adolescence to early death. This December 2015 study was reported in the International Journal of Epidemiology. The researchers sought to determine if a high fitness level could compensate for the risk of being obese.

The study comprised of 1, 317, 713 Swedish men (mean age, 18 years) who were followed for 29 years. The research supported that individuals in the highest fifth of aerobic fitness were at lower risk of death from any cause in comparison with individuals in the lowest fifth. Interestingly, although low aerobic fitness in late adolescence is associated with an increased risk of early death, the risk of early death was higher in fit obese individuals than in unfit normal-weight individuals.2

This study provided support of the “unfit obese” hypothesis, in which regardless of fitness, obesity increased the risk of cardiovascular disease/all-cause mortality.2,3 For example, a 2013 review in Annals of Internal Medicine of eight studies categorized six patient groups by BMI category (normal weight/overweight/obesity) and metabolic status (healthy/unhealthy). The authors used the criteria for metabolic syndrome by Adult Treatment Panel III or International Diabetes Federation in their search. The review concluded that metabolically healthy obese individuals had an increased risk for events compared with metabolically healthy normal-weight individuals in studies with 10 or more years of follow-up. Furthermore, all metabolically unhealthy groups had increased risk. One limitation of this study was the researchers did not account for additional factors that could have contributed to the results, such as the healthy metabolically active participants having more smokers in their group. Another caution of interpretation of this study was the measurements of metabolic parameters across the reviewed articles.3 Still, these two studies provide some support for obesity in relationship to its association with cancer.3,4

The National Cancer Institute lists obesity, along with age, alcohol, cancer causing substances, chronic inflammation, diet, hormones, immunosuppression, infectious agents, radiation, sunlight, tobacco, and genetics, among its risk factors for cancer. Although obesity’s association to cancer varies by type, they listed some potential mechanisms for all cancer growth including:

  1. The excess amounts of estrogen produced by fat cells which are associated with the risk of breast, endometrial, and some other cancers.
  2. The increased levels of insulin and insulin-like growth factor-1 (IGF-1) known to promote the certain tumor types.
  3. Hormones from fat cells called adipokines can stimulate or inhibit cell growth. “For example, leptin, which is more abundant in obese people, seems to promote cell proliferation, whereas adiponectin, which is less abundant in obese people, may have antiproliferative effects.”
  4. There may be an effect on tumor growth regulators such as mammalian target of rapamycin (mTOR) and AMP-activated protein kinase by fat cells.
  5. Chronic low level inflammation may be linked to obesity which increases risk of cancer. This may include the effect on the transcription factor nuclear factor kappa beta.
  6. Altered immune responses
  7. Oxidative stress.5

Interestingly, all these factors can be addressed by diet, as noted in my previous article.

A little note on the reported link of sun exposure and cancer. A March 2016 20-year follow up prospective study of 29, 518 Swedish women published in the Journal of Internal Medicine women demonstrated that sun exposure did decrease incidence of melanoma but also lowered life expectancy by .6-2.1 years.6 They concluded:

Women with active sun exposure habits were mainly at a lower risk of cardiovascular disease (CVD) and noncancer/non-CVD death as compared to those who avoided sun exposure. As a result of their increased survival, the relative contribution of cancer death increased in these women. Nonsmokers who avoided sun exposure had a life expectancy similar to smokers in the highest sun exposure group, indicating that avoidance of sun exposure is a risk factor for death of a similar magnitude as smoking.7

Furthermore, a small 2013 study from the University of Edinburgh in the UK showed the sun may benefit heart health by more than vitamin D, but from nitric oxide release.7,8 So, healthy sun exposure may play a role in prevention of cancer death, maybe not cancer risk.

What About Plant Medicne?

A 2013 review in African Journal of Traditional, Complementary, and Alternative Medicines stated that plant medicine is not just for treatment, but has a role in prevention of many chronic diseases.9

I am honored to be part of an upcoming summit sponsored by NDNR. My talk on this Natural Cancer Prevention Summit in May focuses specifically on the use of essential oils and how they may modulate our immune response, thereby effecting cancer risk. For example, here’s a teaser from a 2014 article in BioMed Research International which reviewed 130 studies:

Exploring natural plant products as an option to find new chemical entities as anticancer agents is one of the fastest growing areas of research. Recently, in the last decade, essential oils (EOs) have been under study for their use in cancer therapy and the present review is an attempt to collect and document the available studies indicating EOs and their constituents as anticancer agents. This review enlists nearly 130 studies of EOs from various plant species and their constituents that have been studied so far for their anticancer potential and these studies have been classified as in vitro and in vivo studies for EOs and their constituents. This review also highlights in-depth various mechanisms of action of different EOs and their constituents reported in the treatment strategies for different types of cancer. The current review indicates that EOs and their constituents act by multiple pathways and mechanisms involving apoptosis, cell cycle arrest, antimetastatic and antiangiogenic, increased levels of reactive oxygen and nitrogen species (ROS/RNS), DNA repair modulation, and others to demonstrate their antiproliferative activity in the cancer cell. The effect of EOs and their constituents on tumour suppressor proteins (p53 and Akt), transcription factors (NF-κB and AP-1), MAPK-pathway, and detoxification enzymes like SOD, catalase, glutathione peroxidase, and glutathione reductase has also been discussed.10

There’s even more ways that were discussed in the interview! Phew. Make sure you tune in May 16th-23rd at the Natural Cancer Prevention Summit.

LoBisco041lowresSarah Lobisco, ND, is a graduate of the University of Bridgeport’s College of Naturopathic Medicine (UBCNM). She is licensed in Vermont as a naturopathic doctor and holds a Bachelor of Psychology from State University of New York at Geneseo. Dr. LoBisco is a speaker on integrative health, has several publications, and is a certification candidate in functional medicine. Dr. LoBisco currently incorporates her training as a naturopathic doctor and functional medicine practitioner through writing, researching, private practice, and through her independent contracting work for companies regarding supplements, nutraceuticals, essential oils, and medical foods. Dr. LoBisco also enjoys continuing to educate and empower her readers through her blogs and social media. Her recent blog can be found at www.dr-lobisco.com.

References:

  1. Traditional and Emerging Lifestyle Risk Behaviors and All-Cause Mortality in Middle-Aged and Older Adults: Evidence from a Large Population-Based Australian Cohort. PLOS One. December 8, 2015
  2. Aerobic fitness in late adolescence and the risk of early death: a prospective cohort study of 1.3 million Swedish men. Int. J. Epidemiol. December 20, 2015. doi: 10.1093/ije/dyv321
  3. Kramer CK, Zinman B, Retnakaran R. Are metabolically healthy overweight and obesity benign conditions?: A systematic review and meta-analysis. Ann Intern Med. 2013 Dec 3;159(11):758-69. doi: 10.7326/0003-4819-159-11-201312030-00008.
  4. The National Cancer Institute. Obesity and Cancer Risk. NIH: National Cancer Institute Web Site. January 3, 2012. http://www.cancer.gov/about-cancer/causes-prevention/risk/obesity/obesity-fact-sheet
  5. American Cancer Society. Cancer Research UK. Obese women 40 per cent more likely to get cancer. ScienceDaily. March 16, 2015. www.sciencedaily.com/releases/2015/03/150316214820.htm.
  6. Lindqvist PG, Epstein E, Nielsen K, et al. Avoidance of sun exposure as a risk factor for major causes of death: a competing risk analysis of the Melanoma in Southern Sweden cohort. J Intern Med. 2016; doi: 10.1111/joim.12496.
  7. Paddock, C. Sun Exposure Benefits May Outweigh Risks Say Scientists. Medical News Today. May 8, 2013. http://www.medicalnewstoday.com/articles/260247.php
  8. The University of Edinburgh, UK. Sunshine could benefit health. The University of Edinburgh Web Site. Available at: http://www.ed.ac.uk/news/2013/sunshine-080513. May 22, 2013.
  9. Sofowora A, Ogunbodede E, Onayade A. The Role and Place of Medicinal Plants in the Strategies for Disease Prevention. African Journal of Traditional, Complementary, and Alternative Medicines. 2013;10(5):210-229.
  10. Gautam, N, Mantha AK, Mittal S. Essential Oils and Their Constituents as Anticancer Agents: A Mechanistic View,” BioMed Research International, vol. 2014, Article ID 154106, 23 pages, 2014. doi:10.1155/2014/154106

 

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