Submission for Next Canada Food Guide

Below is a copy of a letter I recently sent (with 78 others signing) to Health Canada and the Provincial ministers of health to support a plant-based option in the next version of the Canada Food Guide:

Health Canada is now in the unique position to influence the incidence and progression of hypertension, cardiovascular disease, strokes and diabetes by modifying the current guidelines for healthy eating based on recent controlled trials and prospective longitudinal studies.

We are practicing physicians and include investigators who have received grants for nutrition related projects from the CIHR. We provide diet advice to our patients and we would like to share with you the data we use to make our recommendations.

We would like to give our wholehearted personal support to the proposed guiding principles as stated:

1. 1. Regular intake of vegetables especially plant-based sources of protein
   2. Inclusion of foods that contain mostly unsaturated fat instead of saturated fat
   3. Limit intake of processed/prepared foods and sugar-sweetened beverages
   4. Selecting foods while being sensitive to cultural diversity and the effect of eating choices on the environment.

However, we feel that these guidelines do not go far enough.

In considering the evidence, a large randomized controlled trial (N Engl J Med2013;368:1279-90) is a strong basis for recommendations. In a study of over 7000 persons at high risk but free of cardiovascular disease lasting 4 years; it was shown that the so called Mediterranean based diet supplemented with Nuts or olive oil reduced a composite of cardiovascular events (myocardial infarction, stroke or death) by 30% in relation to the control which was a low fat diet. From Table 1, the effective diet was based on increases in fruits, vegetables, nuts, legumes, white meat and olive oil. The diet had more vegetable monunsaturated fats as compared with the low fat control. In particular it discouraged red meat, processed foods such as processed meats, commercial bakery goods, spreading fats, and soft drinks.

More recently two prospective longitudinal studies encompassing 47,994 women and 25,745 men followed for over 12 years showed that improvement in alternate healthy eating index, alternate Mediterranean diet index or improvement in the DASH diet index was associated with a significant reduction in mortality (N Engl J Med 2017;377:143-53).

The common feature of all these diets is that they were based on whole grains, vegetables, fruits and fish. Increases in Nuts and legumes improved the scores in general and red or processed meats reduced the scores. These longitudinal studies therefore confirm the pattern seen in the controlled trial.

Looking at obesity and type 2 diabetes, the following studies strongly support the role of a plant-based diet as the best option for obesity and diabetes prevention/treatment:

1. A 74 week randomised controlled trial showed that a plant-based diet is better than the American Diabetes Association diet (c). These results have been confirmed in multiple other studies (d).
2. In a large prospective cohort study (e), high animal protein intake was associated with a 49% higher rate of type 2 diabetes; conversely, a high plant protein intake was associated with a 9% lower rate of diabetes.

In terms of cardiovascular disease we agree with the advice to lower saturated fat intake as outlined in the recent American Heart Association Presidential Advisory on Dietary Fats and Cardiovascular Disease (a,k). In addition we personally support the role of a plant-based diet as the best option for cardiovascular disease prevention and treatment as supported by the following studies:

1. A plant-based low fat diet is the ONLY diet which has been shown to reverse coronary artery disease [ h] on angiography in a randomised controlled trial [i ]
2. There is a clear and significant dose-response relationship between intake of fruits and vegetables and mortality from coronary heart disease (16% reduction), stroke (8% reduction), and cancer (10% reduction). Similar associations were observed for fruits and vegetables separately. Dose-related reductions in risk were observed in all outcomes up to 600 g/day [j].
3. The DASH diet which is high in fruits and vegetables is highly effective in treating hypertension [ r]
4. Separate studies have shown that approximately 45% of cardio-metabolic deaths are due to deficiencies in diet including high sodium, high processed and red meats, high sugar-sweetened beverages, and low in fruits and vegetables [k]
5. Real world data shows that a plant-based diet is well tolerated and effective in reducing multiple cardiac risk factors (g,q)
6. A meta-analysis of 7 studies (124,706 participants) from around the world showed statistically significant reductions in ischemic heart disease mortality (29%) and cancer incidence (18%) and non-significant reductions in all cause mortality (9%), circulatory disease mortality (16%), and cerebrovascular disease mortality (12%)[f].

In addition we personally support a shift to a diet which is lower in fat, refined carbohydrates, sugars, and processed/ultra-processed foods based on the following:

1. A single high fat meal impairs vascular endothelial function while this is not the case with a low fat meal [k]
2. Substituting fat with processed carbohydrates and sugars does not decrease heart disease [b]
3. High sugar-sweetened beverage intake is a major cause of cardio-metabolic and diabetic mortality [m]
4. Added sugar intake is strongly associated with cardiovascular mortality [p]
5. The intake of processed and ultra-processed foods is clearly and strongly linked to energy intake from added sugars (l, o).

Many of us feel that the current Canadian guidelines reads like a dietitians manual. If your future efforts are to be understood by the user namely the public it needs to be an easily practiced set of concepts. May we suggest concepts like:

1. Avoid foods processed and sold in packets.
2. Buy and eat whole grain products, vegetables and fruits in any quantity.
3. Avoid sweet or sweetened drinks such as sodas, pop. Do not add sugar to beverages.
4. Limit red meat intake to once a week at the most.
5. Cook with olive or canola oil
6. Nuts and peanuts are good articles of food

Thank you for your consideration of this personal submission. We sincerely hope that Canada takes this opportunity to build on your currently stated Guiding Principles to develop a food guide which will best serve the health of our country and environment and serve as a leader throughout the world.

Signed,

Dr Subhas Ganguli MD FRCPC (Gastroenterology) – McMaster University

Click here for a list of the references.

You can give Health Canada you own feedback here

If you would like to see an overview of my Food as Medicine website, click here.