Considerations for a Low Carbohydrate Diet

As naturopathic physicians, we are passionate about addressing the root causes of chronic disease. It is common knowledge today that the leading causes of death worldwide are non-communicable chronic diseases. Non-communicable chronic diseases are broadly defined as conditions that are not passed directly from one person to another, last 1 year or more in length, and require ongoing medical attention and or limit activities of daily living₁.

The most common chronic diseases in Canada include cardiovascular disease, certain cancers, stroke, and diabetes₁. The prevalence of chronic diseases increase as we age, with 73% of individuals (almost 3 out of 4 people) 65 years or older have 1 more or more chronic diseases₂. However, these conditions are not only restricted to the older population, as 44% of adults 20 years and older have 1 or more chronic diseases₃. Taken together this illustrates the fact these conditions often occur earlier in life then persist and develop over decades.

This highlights the importance of making health-promoting choices earlier and throughout our lives to mitigate these disease processes from developing. The good news is that we can greatly delay the development of these conditions with the right diet and lifestyles choices.

I want to discuss the role of low carbohydrate diets as a tool for addressing three of the most common chronic diseases, obesity, diabetes, and cardiovascular disease.

In 2018, 26.8% of Canadians reported a height and weight that classified them as obese₄. Carrying extra body fat is a significant contributing factor in the development of other chronic diseases such as diabetes, high blood pressure, heart disease, stroke, arthritis and certain cancers₅. The connection between carbohydrates intake and fat storage in our body is complex and deserving of its own post. Nevertheless, I will offer an abbreviated explanation here.

Eating dietary carbohydrates stimulates the release of a hormone called insulin. Insulin is an “anabolic hormone” that indicates the presence of nutrients and signals to the body it is a time for storage and growth. Insulin is known mainly for its role in promoting the uptake of sugars from our blood and is dysregulated in patients with diabetes. However, another crucial role insulin plays is in regulating the breakdown of fats in our fat cells.  In the presence of high insulin, fat cells cannot effectively burn and use their stored fat.

As dietary carbohydrates are the strongest signal for the release of insulin, a reduction in carbohydrate intake leads to reduced levels of insulin and less time spent in energy “storage” mode, allowing more time for the breakdown of fats.

Two separate examinations of the current research done in 2012 and 2015, looking at over 1700 patients concluded that very low carbohydrate diets were more effective than low-fat diets as tools against obesity_{6, 7}.

Another review in 2018 looking at low glycemic index foods also determined that choosing foods that decrease the rate at which your blood sugars raise following meals also effectively lower body weight₈.

When it comes to diets for weight loss it is not as simple as calories in calories out.

Diabetes is a condition the occurs when the body loses its ability to produce (type 1) or properly use (type 2) insulin. Type 2 diabetes, accounts for roughly 90% of diabetes cases in Canada and is one of our nation’s fastest-growing chronic diseases₉.

As previously mentioned, insulin’s major function is to control blood sugar levels. In type 2 diabetes, if our body cannot effectively transport sugars throughout our body, it would be reasonable to suspect reducing the demand for insulin by decreasing the volume of carbohydrates we eat may be beneficial. The research shows exactly that. As early as 1983, type 2 diabetic patients on a very low carb ketogenic diet showed significant reductions in blood sugars, hemoglobin A1c and improved overall glucose metabolism reducing the demand on the sub functioning insulin to traffic carbs₁₀. More recent research has supported these findings and further demonstrates that patients on low carbohydrate diets have a decreased need for diabetic medications_11,12. Raising awareness and having tools in our kit to address this increasingly common problem of dysregulated blood sugars becomes ever more important.

Cardiovascular disease or heart disease is the best player on team chronic disease and is the leading cause of death globally₁₃. Cardiovascular disease refers to a group of disorders affecting the heart and vessels, many of which are related to a process called atherosclerosis. Atherosclerosis is a complex process involving fatty molecules and the immune system which leads to the deposition, retention, and accumulation of fatty molecules within the walls of our vessels. Over time this leads to the formation of plaques. These plaques are fibrous caps, like scabs within our vessel walls trapping excess fats and immune cells there. These plaques can dislodge and block downstream blood flow₁₄. If this occurs in the heart it is a heart attack, if in the brain it is a stroke. The fundamental role fats play in this process has been the target of much research over the last several decades.

This has led to the identification of a certain pattern of lipids markers leaving the individual more prone to the development of atherosclerosis and heart disease. This pattern is known as the “atherogenic lipid profile” or “atherogenic dyslipidemia” which involves elevated triglycerides and decreased high-density lipoprotein cholesterol (HDL-C), commonly referred to as “good cholesterol”₁₅. A very low carbohydrate ketogenic diet is one of the most effective tools for addressing cardiovascular disease risk.  A review in 2018 indicated a low carbohydrate diet improves all parameters of the atherogenic lipid profile, with a marked reduction in blood triglycerides and increases in HDL-C as well as positive reductions in total cholesterol and blood pressure_{11, 16, 17,18}. There is no other single intervention that so comprehensively improves our lipid profile. 

A low carb diet – causes a fundamental shift in the metabolism of our bodies by burning fats and using ketones as fuel as opposed to carbohydrates. This allows for many potential health benefits addressing the underlying mechanism of several of today’s more common chronic diseases. However, a very low carbohydrate diet can so effectively decrease your blood pressure and blood glucose it can be dangerous if done unsupervised for those with pre-existing high blood pressure and diabetes. It is important to speak with your health care provider prior to making significant dietary changes. For more information on if changing your carbohydrate intake is right for you and health goals reach out to us at the IHC.

If you find the science and stories of diet and physiology interesting, you may find the recently released book “A Case for Keto” by Gary Taubes is a fascinating read.

Dr. Luke Mountjoy, ND

References.

1. Centers for Disease Control and Prevention. (2021, April 28). About chronic diseases.
2. Centers for Disease Control and Prevention. https://www.cdc.gov/chronicdisease/about/index.htm.
3. Canada, S. (2020, December 24). Government of Canada. Canada.ca. https://www.canada.ca/en/services/health/publications/diseases-conditions/prevalence-chronic-disease-risk-factors-canadians-aged-65-years-older.html.
4. Canada, P. H. A. of. (2019, December 9). Government of Canada. Canada.ca. https://www.canada.ca/en/public-health/services/chronic-diseases/prevalence-canadian-adults-infographic-2019.html.
5. McDiarmid, C. (2019, June 25). This is a HEALTH fact sheet about Canadians aged 18 and older who are overweight or Obese, based on self-reported height and weight that has been adjusted with CORRECTION FACTORS. the results shown are based on data from the CANADIAN community HEALTH SURVEY. Overweight and obese adults, 2018. https://www150.statcan.gc.ca/n1/pub/82-625-x/2019001/article/00005-eng.htm.
6. Obesity. Public Health Ontario. (n.d.). https://www.publichealthontario.ca/en/diseases-and-conditions/chronic-diseases-and-conditions/obesity.
7. Bueno, N. B., de Melo, I. S., de Oliveira, S. L., & da Rocha Ataide, T. (2013). Very-low-carbohydrate ketogenic diet v. low-fat diet for long-term weight loss: A meta-analysis of randomised controlled trials. British Journal of Nutrition, 110(7), 1178–1187. https://doi.org/10.1017/s0007114513000548
8. Sackner-Bernstein, J., Kanter, D., & Kaul, S. (2015). Dietary intervention for overweight and obese ADULTS: Comparison of low-carbohydrate and low-fat Diets. a meta-analysis. PLOS ONE, 10(10). https://doi.org/10.1371/journal.pone.0139817
9. Zafar, M. I., Mills, K. E., Zheng, J., Peng, M. M., Ye, X., & Chen, L. L. (2018). Low glycaemic index diets as an intervention for obesity: A systematic review and meta-analysis. Obesity Reviews, 20(2), 290–315. https://doi.org/10.1111/obr.12791 https://www.canada.ca/content/dam/phac-aspc/documents/services/reports-publications/canada-communicable-disease-report-ccdr/monthly-issue/2020-46/issue-11-12-nov-5-2020/ccdrv46i1112a02-eng.pdf. (2020). Canada Communicable Disease Report, 46(1112), 380–383. https://doi.org/10.14745/ccdr.v46i1112a03
10. Phinney, S. D., Bistrian, B. R., Evans, W. J., Gervino, E., & Blackburn, G. L. (1983). The human metabolic response to chronic ketosis without caloric restriction: Preservation of submaximal exercise capability with reduced carbohydrate oxidation. Metabolism, 32(8), 769–776. https://doi.org/10.1016/0026-0495(83)90106-3
11. Gershuni, V. M., Yan, S. L., & Medici, V. (2018). Nutritional ketosis for weight management and reversal of metabolic syndrome. Current Nutrition Reports, 7(3), 97–106. https://doi.org/10.1007/s13668-018-0235-0
12. Meng, Y., Bai, H., Wang, S., Li, Z., Wang, Q., & Chen, L. (2017). Efficacy of low carbohydrate diet for type 2 diabetes mellitus management: A systematic review and meta-analysis of randomized controlled trials. Diabetes Research and Clinical Practice, 131, 124–131. https://doi.org/10.1016/j.diabres.2017.07.006
13. World Health Organization. (n.d.). The top 10 causes of death. World Health Organization. https://www.who.int/news-room/fact-sheets/detail/the-top-10-causes-of-death.
14. Crowther, M. A. (2005). Pathogenesis of atherosclerosis. Hematology, 2005(1), 436–441. https://doi.org/10.1182/asheducation-2005.1.436
15. Kutkiene, S., Petrulioniene, Z., Laucevicius, A., Matuzeviciene, G., Kasiulevicius, V., Petrulionyte, E., Staigyte, J., Saulyte, A., Gargalskaite, U., Skiauteryte, E., Kovaite, M., & Rinkuniene, E. (2018). Cardiovascular risk profile of patients with atherogenic dyslipidemia in middle AGE Lithuanian population. Lipids in Health and Disease, 17(1). https://doi.org/10.1186/s12944-018-0851-0
16. O’Neill, B. J. (2020). Effect of low-carbohydrate diets on cardiometabolic risk, insulin resistance, and metabolic syndrome. Current Opinion in Endocrinology, Diabetes & Obesity, 27(5), 301–307. https://doi.org/10.1097/med.0000000000000569
17. Volek, J. S., & Feinman, R. D. (2005). Carbohydrate restriction improves the features of metabolic syndrome. metabolic syndrome may be defined by the response to carbohydrate restriction. Nutrition & Metabolism, 2(1). https://doi.org/10.1186/1743-7075-2-31
18. Volek, J. S., Fernandez, M. L., Feinman, R. D., & Phinney, S. D. (2008). Dietary carbohydrate restriction induces a unique metabolic state positively affecting atherogenic dyslipidemia, fatty acid partitioning, and metabolic syndrome. Progress in Lipid Research, 47(5), 307–318. https://doi.org/10.1016/j.plipres.2008.02.003