Is oil a healthy part of a whole food plant-based diet?

As you’ve learnt throughout this course, transitioning to a whole food plant-based (WFPB) diet is widely recognised for its health benefits, particularly in preventing and reversing chronic diseases.

A key consideration in this dietary approach is whether or not the inclusion of added oils is needed or necessary. The WFPB community holds varying opinions on this matter, but focusing on the overall quality of the diet is paramount.

Some proponents of adding fat to the diet in the form of refined oils argue that it enhances the absorption of fat-soluble vitamins and other phytonutrients like carotenoids found in fruits and vegetables. The good news is that consuming added oils is not necessary to achieve this effect.¹

Whole plant foods, such as avocados, nuts, seeds, and olives, naturally contain the fats required for nutrient absorption, along with fibre, antioxidants, and other beneficial compounds absent in isolated oils. Eating a variety of whole, plant-based foods ensures that nutrient absorption is optimised without the need for processed oils, which can introduce excess calories and lack the synergistic nutrients found in their whole-food counterparts.²

There is no argument that oils, even those derived from plants, are highly processed and calorie-dense, offering minimal nutritional value compared to their whole food counterparts. For instance, turning olives into olive oil removes fibre and many beneficial phytonutrients, leaving a product rich in fat and calories but lacking the comprehensive benefits of the whole olive.

Notably, pioneers in the whole food plant-based movement, like Dr Caldwell Esselstyn and Dr Dean Ornish, recommend avoiding added oils altogether, including olive oil, especially for individuals with heart disease. Their clinical experience suggests that eliminating added oils can arrest and potentially reverse the progression of heart disease.^3,4

A recent randomised crossover trial examined the cardiometabolic effects of extra virgin olive oil (EVOO) within a whole-food, plant-based (WFPB) vegan diet. Participants at risk for cardiovascular disease followed two dietary interventions: one high in EVOO (four tablespoons per day) and one low in EVOO (less than one teaspoon per day), each for four weeks.

The study found that while both diets improved cardiovascular risk factors, the low-EVOO diet led to more significant reductions in low-density lipoprotein cholesterol (LDL-C) levels.⁵ These findings suggest that minimising added oils, even those considered heart-healthy like EVOO, within a WFPB diet may enhance cardiovascular health benefits.

Some nutrition experts suggest that small amounts of oil can be included in moderation for those without chronic disease or excess weight within a WFPB diet without negating its health benefits. They emphasise that the focus should be on the overall dietary pattern rather than individual components. There is no denying however that a diet centred around whole plant foods, whether it contains added oil or not, is considered the healthiest choice.

Eating out in restaurants and cafes is difficult enough when it comes to switching to a plant-based diet. When reducing or avoiding oils is involved, it becomes even more tricky to choose the best options on the menu. However, cooking at home is easy without using oil. Remember, it’s what you do most of the time that counts, so don’t lose motivation when you happen to eat something less than ideal. See our doctors and dietitians’ lessons on this specific topic for further information.

While reducing or eliminating added oils is the ‘gold standard’ in WFPB nutrition and may offer additional health benefits, especially for those with specific health conditions, the primary goal should be to adopt a diet rich in whole plant foods. With or without added oils, this approach is a significant step towards transitioning to better health and preventing and reversing chronic diseases.