Choosing a more plant-based diet was named as one of the food trends for 20181. Diets that limit or exclude meat, dairy products, and eggs used to be on the fringe of the general population, however these days more people are choosing to be vegetarian, vegan or eat mainly plant-based food than ever before. Although there aren’t many statistics for South Africa, in the US last year it was reported that 39% are actively trying to eat more plant-based foods, 30% of adults eat meatless protein alternatives at least once a week, 6% are strict vegetarians, while 3% follow a strictly vegan lifestyle2,3.
Search data from Google trends show a worldwide increase in the interest in veganism from 2004 to 2018, while vegetarianism stayed relatively constant4,5. Big organisations have also named the Vegetarian diet along with the Mediterranean as one of the dietary patterns that promote health6,7. There are many reasons why people choose a more plant-based diet such as the associated health benefits but also for ethical, religious and environmental sustainability reasons.
CHARACTERISTICS OF A PLANT-BASED DIET
This diet focuses on plant foods such as legumes (dried beans, peas, lentils and chickpeas), fruits, vegetables, nuts, seeds and grains. There are variations of plant-based diet, these include:
Lacto-ovo vegetarians include milk (Lacto) products such as yoghurt, milk and cheese as well as eggs (ovo), and exclude meat, poultry, fish and seafood6,8.
Lacto-vegetarians include milk products but exclude eggs, poultry, meat, fish and seafood6,8.
Vegans only consume plant foods and exclude all meat and animal products. They also do not use animal by-products, such as leather, silk, fur, honey, wool, cosmetics or soaps derived from animals6,8.
Pescatarians do not eat meat, however they will eat fish6,8.
There are many variations of the above though, with a new trend being the flexitarian or semi-vegetarian diet, which is mainly plant-based but does occasionally include meat but often better quality8.
WHAT DOES THE RESEARCH SAY?
Vegetarian diets are high in fibre, vitamins, minerals and phytochemicals and low in saturated fat (SFA) and cholesterol6. They are associated with several health benefits, such as lower cholesterol and blood pressure levels, decreased risk of heart disease, hypertension and type 2 diabetes. Vegetarians also tend to have a lower body mass index (BMI) and lower overall cancer rates6. Results from three big prospective Cohort studies, found that a diet that emphasized plant foods and was low in animal foods was associated with a 20% reduction in the risk of developing diabetes9. They further concluded that healthy plant foods (whole grains, fruits, vegetables, nuts, legumes, vegetable oils, tea/coffee) was associated with a 34% decreased risk of diabetes. While consumption of less healthy plant foods (fruit juices, sweetened beverages, refined grains, potatoes, sweets/desserts) was associated with a 16% increased risk of diabetes9. In a more recent paper, authors concluded that a dietary pattern which include more plant and less animal based foods resulted in a lower risk of insulin resistance, prediabetes and type 2 diabetes10.
When looking at studies in people with diabetes, the results aren’t so clear cut with inconsistent results in glycaemic control6,12. Some show a beneficial effect in HbA1c but only a small, non-significant change in fasting blood glucose concentration11. Others concluded that those receiving a vegetarian diet showed significant reductions in diabetes medication, greater weight loss, increased insulin sensitivity but no significant difference in HbA1c compared to those on a conventional diabetic diet12.
Although research seems inconsistent, most of the foods associated with a plant-based diet (higher intakes of vegetables, whole-grain high fibre foods, legumes, and nuts) are well researched and associated with a substantially lower risk of insulin resistance, type 2 diabetes as well as improved glycaemic control in either normal or insulin-resistant individuals6. We know that the consumption of certain animal foods such as red meat is positively associated risk of type 2 diabetes. This risk is further increased for frequent consumption of processed meats such as bacon and hot dogs6,9.
POINTS TO CONSIDER FOR THOSE LIVING WITH DIABETES
From the above you can see that following a plant-based diet has many beneficial effects, in both the prevention and management of diabetes. As many of the foods consumed in this type of dietary pattern consists of plant foods, careful attention must be placed on the amount of carbohydrate in the meal, as carbohydrates affect our blood sugar levels the most. Make sure that you choose whole grain, high fibre carbohydrates, lots of non-starchy vegetables and watch fruit portions. For all those loving with diabetes, but especially those following a plant-based diet, counting the total carbohydrates in your meals becomes important. Although there are many health benefits, there is also an increased risk of lower than recommended intakes of protein and certain vitamins and minerals. These include vitamin B12, calcium, vitamin D, iron, zinc and omega-3 fatty acids – particularly in vegan or certain vegetarian diets6.
Whether you choose a vegetarian, vegan or flexitarian diet, what the literature has in common is that a healthy dietary pattern includes a high intake of vegetables, fruits (watch portions), whole grains, legumes, nuts in moderation, plant fats and liquid vegetable oils, and may include or exclude limited quantities of lean meat, fish, low-fat and non-fat dairy products7. Chat to your local dietitian for more information on how to include more plant-based foods in your diet as well as to ensure that it is nutritionally balanced.
- Huffington post (2018). ‘Plant-Based’ Will Be The Hottest Food Trend Of 2018: Report Available at: https://www.huffingtonpost.ca/2017/11/24/plant-based-food_a_23287312/ (Accessed: October 2018)
- Nielsen (2018). Plant-based food options are sprouting growth for retailers. Available at: https://www.nielsen.com/us/en/insights/news/2018/plant-based-food-options-are-sprouting-growth-for-retailers.html (Accessed: October 2018)
- Food network (2018). These Vegetarian Trends are Going Mainstream. Available at: https://www.foodnetwork.com/healthyeats/restaurants/2018/these-vegetarian-trends-are-going-mainstream (Accessed: October 2018)
- Google Trends. Veganism. Available at: https://trends.google.com/trends/explore?date=all&q=%2Fm%2F07_hy (Accessed: October 2018)
- Google Trends. Vegetarianism. Available at: https://trends.google.com/trends/explore?date=all&q=%2Fm%2F07_jd (Accessed: October 2018)
- ADA (2009). Position of the American Dietetic Association: Vegetarian Diets. Available at: https://jandonline.org/article/S0002-8223(09)00700-7/fulltext (Accessed: October 2018)
- Science Direct (2017). Trending Cardiovascular Nutrition Controversies. Available at: https://www.sciencedirect.com/science/article/pii/S0735109717300360?via%3Dihub (Accessed: September 2018)
- Futurelife Dietitian Ashleigh Smith (2017). Best diets for those living with Diabetes. Available at: http://futurelife.co.za/best-diet-people-living-diabetes/ (Accessed: October 2018)
- PLOS Medicine (2016). Plant-Based Dietary Patterns and Incidence of Type 2 Diabetes in US Men and Women: Results from Three Prospective Cohort Studies. Available at: https://journals.plos.org/plosmedicine/article/file?id=10.1371/journal.pmed.1002039&type=printable (Accessed: July 2016)
- NCBI (2018). Plant versus animal-based diets and insulin resistance, prediabetes and type 2 diabetes: the Rotterdam Study. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6133017/ (Accessed: October 2018)
- NCBI (2014). Vegetarian diets and glycaemic control in diabetes: a systematic review and meta-analysis. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4221319/ (Accessed: October 2018)
- Wiley Online Library (2011). Vegetarian diet improves insulin resistance and oxidative stress markers more than conventional diet in subjects with Type 2 diabetes. Available at: https://onlinelibrary.wiley.com/doi/full/10.1111/j.1464-5491.2010.03209.x (Accessed: October 2018)