Dr. Jan Hajek (biography, no disclosures)
What I did before
As an infectious disease physician, I was concerned about the public health threats posed by animal agriculture. The emergence of antibiotic-resistant bacteria and the spread of zoonotic viral infections were of particular concern.[1] I was aware of the United Nations report “Livestock’s Long Shadow”, that identified animal agricultural as one of the most significant contributors to greenhouse gas emissions and global warming.[2] I was aware of the terrible conditions that sometimes occur on modern farms and, along with most of us, wished to minimize unnecessary suffering to animals.[3] I was aware that more and more people are making dietary choices that avoid meat and other animal products because of health, environmental, and animal welfare concerns. I saw many patients in clinic that struggled with complications of diabetes (diabetic foot infection) and recommend foot care, quitting smoking, and medication adherence. However, I did not recommend plant-based (vegan) diets to my patients.
What changed my practice
A recent essay by Dr. Kim Williams, the president of the American College of Cardiology, in which he described the potential health benefits of a plant-based diet and why he began to recommend a healthy, low-fat, plant-based diet to his patients.[4] In his essay, Dr. Williams described a patient’s anecdotal experience with a plant-based diet. He also referred to a clinical trial in which patients randomized to interventions including a plant-based diet had dramatic improvements in coronary angiography.[5] He explained that although this trial and other larger observational studies are not as rigorous as other cardiology trials, the data to support the health benefits of plant-based diets are very compelling. In fact, the data are so compelling that the U.S. Medicare system now covers a cardiac rehabilitation program that includes a plant-based diet. In 2013, Kaiser Permanente, one of the biggest HMOs in the U.S., published an article encouraging physicians to routinely recommend a plant-based diet to their patients.[6]
In evaluating the evidence, the 2015 US Government Scientific Report of Dietary Guidelines Advisory Committee concluded that: “Consistent evidence indicates that, in general, a dietary pattern that is higher in plant-based foods, such as vegetables, fruits, whole grains, legumes, nuts, and seeds, and lower in animal-based foods is more health promoting and is associated with lesser environmental impact (GHG emissions and energy, land, and water use) than is the current average U.S. diet.”[7] The newly released US Dietary Guidelines now promote a plant-based diet for both environmental and heath benefits. Although a quantitative cut-off of 300 mg per day of cholesterol is no longer included, the guidelines were clear in stating that “this change does not suggest that dietary cholesterol is no longer important to consider when building healthy eating patterns” … “individuals should eat as little dietary cholesterol as possible while consuming a healthy eating pattern.” 7
For diabetes in particular, observational studies suggest that persons who follow a plant-based diet have a lower risk for diabetes, and an RCT demonstrated reductions in HbA1c in patients with diabetes randomized to a vegan diet compared to the standard American Diabetes Association diet.[8]
What I do now
As well as foot care, smoking cessation, and medication adherence, I now recommend a healthy, low fat, plant-based diet to patients with complications related to diabetes.
I often start by saying that studies have shown that a plant-based, vegan diet that avoids meat, eggs and dairy products has shown health benefits, particularly in patients with diabetes. Many patients already have some experience with vegetarian and vegan diets and are happy to discuss and learn more about plant-based diets.
Although it takes planning, the guidelines for a plant-based dietary approach to improve diabetes care are generally straightforward:[9]
- Steer clear of meat and animal products like dairy and eggs;
- Limit high fat foods like oils and pastries;
- Choose whole grains, vegetables, legumes, and fruits;
- Favour low glycemic index foods; and
- Supplement with vitamin B12 [10]
Best of all, the diet does not require calorie counting; portion sizes of pasta, grains, legumes and vegetables do not need to be restricted.
The change to a plant-based diet low in saturated fats can lead to reduced insulin requirements. Patients should let their diabetes care providers know they are switching to a plant-based diet.
Despite the strong body of evidence supporting plant-based diets, many of us do not recommend a healthy plant-based diet and avoiding consumption of meat, dairy and eggs as a treatment option for diabetes or health promotion. This could be because of a lack of awareness of these diets or perhaps because our own personal eating habits affect our decisions about foods and how we counsel patients.
We should all consider recommending a healthy, low-fat, plant-based diet to our patients, particularly those with diabetes.
Handouts for Patients
There are many useful online resources, starter kits, and educational pamphlets available such as those from the Kaiser Permanente group [11] or the Physicians Committee for Responsible Medicine (PCRM). [12]
I found the PCRM website particularly useful. The website includes handouts and a 21-day vegan kickstart to support anyone interested in trying a 21-day trial of a low-fat plant based diet and also has information specific to patients with diabetes.
Additional reading
The nutritional update published by Kaiser Permanente provides an excellent overview of the evidence supporting plant-based diets and recommendations for how to discuss the dietary changes with patients.6
An article in the American Diabetes Association Spectrum journal has a very useful article on preparing to prescribe plant-based diets to patients for diabetes prevention and treatment.9
Finally a detailed, practical, evidence-based review of how nutritional requirements are met by following a plant-based diet – addressing concerns about protein, iron, calcium, and omega-3 fatty acid intake – has been recently published. [13]
References
- Liu, Y-Y, Wang, Y, Walsh, TR et al. Emergence of plasmid-mediated colistin resistance mechanism MCR-1 in animals and human beings in China: a microbiological and molecular biological study. Lancet Infect Dis. 2016;16: 161–168. (View with CPSBC or UBC) DOI: 10.1016/S1473-3099(15)00424-7
- Livestock’s Long Shadow: Environmental Issues and Options. United Nations Report (2006). View
- Hutchinson, B. Canada’s largest dairy farm crippled by abuse allegations from undercover animal rights worker on his first mission. June 10, 2014. National post. Retrieved July 29, 2016. <http://news.nationalpost.com/news/canada/canadas-largest-dairy-farm-crippled-by-abuse-allegations-from-undercover-animal-rights-worker-on-his-first-mission>
- Williams, KA. Cardio Buzz: Vegan Diet, Healthy Heart? July 21, 2014. Cardiobuzz. Retrieved 29 July, 2016. <http://www.medpagetoday.com/Blogs/CardioBuzz/46860>
- Ornish D, Brown SE, Scherwitz LW et al. Can lifestyle changes reverse coronary heart disease? Lifestyle Heart Trial. Lancet 1990; 336:129-133. (Request with CPSBC or view UBC) DOI: 1016/0140-6736(90)91656-U
- Tuso PJ, Ismail MH, Ha BP et al. Nutritional update for physicians: plant-based diets. Perm J. 2013 Spring; 17(2):61-6. View
- Dietary guidelines. 2016. US Office of Disease Prevention and Health Promotion. Retrieved 29 July, 2016. <http://health.gov/dietaryguidelines>
- Barnard ND, Cohen J, Jenkins DJ, et al. A low-fat vegan diet improves glycemic control and cardiovascular risk factors in a randomized clinical trial in individuals with type 2 diabetes. Diabetes Care 2006;29: 1777–1783. View
- Trapp C, Levin S. Preparing to prescribe plant-based diets for diabetes prevention and treatment. Diabetes Spectrum 2012;25:38–44. View
- What you need to know about vitamin B12. EatRight Onatrio. Retrieved 29 July, 2016. <http://www.eatrightontario.ca/en/Articles/Nutrients-(vitamins-and-minerals)/What-you-need-to-know-about-vitamin-B12.aspx#.V6DKQfmAOkp> From the article: Health Canada recommends that all adults 50 and older, regardless of dietary meat, egg and dairy consumption, take vitamin B12 supplements or include foods fortified with vitamin B12 in their daily food choices.
- The Plant-Based Diet. 2015. Kaiser Permanente. View
- The Physicians Committee for Responsible Medicine. <http://www.pcrm.org/health/diets/kickstart>
- Is a Vegetarian Diet Adequate? Medical Journal of Australia 2012; 1 Supplement 2. View
Loading ...
At our family practice clinic we have been actively educating our patients about the significant health benefits of a plant based diet for several years. Contrary to some opinions, it is my experience that many people are interested in making diet changes to improve their health and reduce medication burden. We have see some great successes in weight loss, diabetes and hypertension control.
I think we have to be careful to make dietary recommendations to our patients based on poor science. One study of 28 patients that looked at making global changes including regular exercise and a diet change, plus the anecdotal opinion of a cardiologist does not make for good science. We have been following a low fat diet for the last 50 years and it has caused nothing but trouble for North americans. Perhaps the work of Professor Tim Noakes is also of interest to you. The only thing I would agree with it that a diet with a lower glycemic index and regular exercise is going to to of benefit overall but I do not think we have good evidence that plant based protein diets are better or worse for us. Even the latest observational non randomized study of 130,000 does not prove the point.
I would be extremely hesitant to ever recommend a plant-based diet to any patient, in particular to healthy ones. I am well aware of the difficulty in creating studies to evaluate dietary changes but putting emphasis on a single cardiologist’s opinion is, as described above, not good science. Also as mentioned above, the recent observational study found a plant-based diet to be of no benefit to healthy patients (ie without risk factors of an unhealthy lifestyle). Even in unhealthy people, when removing processed red meat from the equation, a plant based diet was only mildly better for those patients and we realize how often observational studies will over estimate risk or benefit.
Given that the initial article is referring to diabetic patients, I would certainly advocate for dietary changes if the patient is not eating healthy, however, encouraging them to follow a very difficult way of eating that could easily cause them to be deficient in certain nutrients does not seem to be the most ideal way to get them healthier. I encourage these patients to exercise up to 150 min/week and to increase their intake of vegetables, fruits, and whole grains while avoiding lots of red meat and eating chicken/fish instead. I provide them with a handout that has numerous dietary suggestions/tips and encourage them to see a dietitian.
Thank you for writing this great article and for all the resources. (disclaimer-I follow a plant based diet myself and find it to be an easy and very enjoyable way of eating). There is much compelling science showing that a plant based diet is one of the healthiest diets to follow (along with the Mediterranean diet and DASH diet) for well-being, disease prevention and management of chronic diseases. I advise patients to look at any of these diets. In reply to Dr Arduini; a plant-based diet that includes a wide variety of fruits, vegetables, whole grains, nuts and seeds will not make you deficient in nutrients other than Vitamin B12; the resources cited in Dr Hajik’s article will help patients on their way to know what to do to make the dietary changes. (The only reason vegans should take a B12 supplement is because our food is sanitised. B12 is obtained from bacteria in the soil).
Thank you for your article. I always enjoy seeing physicians concentrating more and more on using dietary approaches for chronic disease management. I am sure we all agree that switching from the standard North American diet to a diet rich in whole foods will lead to positive health outcomes for the general population.
Where I disagree with a vegan/vegetarian approach in managing diabetes is forgetting to focus on the root cause of the disease. Diabetes is primarily a disease of carbohydrate metabolism due to insulin resistance. Suggesting a diet naturally rich in carbohydrates (Wheat, grains and fruit) does not reverse the disease. Eliminating fats from the diet of a diabetic and suggesting ‘healthy carbohydrates’ makes about as much sense on a physiological level as eliminating grains from the diet of a lactose intolerant patient and recommending ‘healthy dairy’.
In my practice my patients have had great success in treating and reversing diabetes and medication load, positively reversing/improving triglyceride/HDL ratio, maintainable weight loss and better BP control. Our approach involves carbohydrate restriction with higher fat intake (saturated, monounsaturated).
Thank you for your comments,
Dr. Martin Andreae, please take another look at the literature supporting more healthy carbohydrates and less fat as a dietary measure to improve glucose tolerance and reduce insulin resistance.
There is physiologic evidence demonstrating that higher dietary fat intake results in insulin resistance and glucose intolerance. Conversely, clinical trial data has demonstrated that individuals with type 2 diabetes consuming a low-fat, plant-based diet have reduced their insulin requirements.
Hot of the press –
A Comprehensive Review of the Literature Supporting Recommendations From the Canadian Diabetes Association for the Use of a Plant-Based Diet for Management of Type 2 Diabetes
http://www.ncbi.nlm.nih.gov/pubmed/27476051
This article provides an informative review of evidence for plant-based diets as part of diabetes care and explores ways to address some of the barriers patients face in learning about and adopting plant-based diets (PBDs):
“The current Canadian CPGs recommend PBDs for the management of type 2 diabetes.”
“Practitioner and patient education is key to improve both clinicians’ confidence in recommending PBDs and patients’ abilities to adopt PBD diets.”
People interested in dietary advice for their patients should also read ‘ Eat Dirt’ by Dr Josh Axe. It makes for interesting reading and he makes a compelling argument for organic foods.
I realize this is not main stream and the Kaiser Institute has not verified this but age old traditional diets in Ayurveda and Chinese Medicine also gives us a wholistic picture of how to keep healthy.
Not included in this article – no chicken, turkey, fish or eggs to be eaten on this diet. I recommend the Mediterranean Diet – eating ‘meat’ only 2X/mo. Some nutritional needs are missing from the Plant Based Diet. Not enough evidenced based truth to support it.