Does Microwave Cooking Reduce Nutrition?

I’m sure you’ve heard plenty of friends, family and random strangers speaking of how microwave cooking can be unhealthy, how it reduces nutrition in our food and so on. I have too, and thought a little research may help all of us make more informed decisions.

Does cooking food in microwaves reduce it’s nutritional value or content? Apparently not.

I looked up multiple papers and the conclusion was hard to miss. Here’s a tabulated summary. The papers I referenced conducted research in the context of different foods, as illustrated below.

CONTEXT	OUTCOME
Legumes	No nutritional changes based on cooking method. [1]
Water soluble vitamins	Microwave heating caused less nutrient loss than other methods. [2]
Rice	Not much difference, though pressure cooking is slightly better. [3]
Vegetables	Nutrition loss happens across cooking methods, varying according to the cooking method, nutrient and vegetable. On the whole, microwave cooking didn’t significantly degrade nutritional value. [4]
Peas	No significant changes to fat, protein, beta-carotene or ascorbic acid. Greater retention of Thiamin and Riboflavin. [5]
Green Leafy Vegetables	No significant difference in nutrient content based on cooking method. [6]
Courgettes / Zucchini	Better preservation of nutrients using microwave cooking, lower energy expenditure and lesser time taken. [7]
Vegetables	Highest nutrient retention in vegetables cooked by microwave steaming. [8]
Liquid Foods	No major differences found. [9]
Oats	“… properly applied microwave heating can provide substantial support for nutritionally valuable meal preparation.” [10]

Conclusion: The use of microwave ovens for cooking food appears to be beneficial for the retention of nutritional content, as compared to conventional methods of cooking.

References:

1. Nutritional quality of microwave-cooked and pressure-cooked legumes
2. Effect of microwave processing on water soluble vitamins: Kinetic parameters
3. Nutritional Quality of Microwave and Pressure Cooked Rice (Oryza sativa) Varieties
4. Nutritional composition and sensory profile of microwave and conventionally cooked vegetables
5. Effect of Microwave and Conventional Cooking on the Nutritive Value of Colossus Peas
6. Nutrient Composition and Sensory Profile of Differently Cooked Green Leafy Vegetables
7. Optimization of microwave cooking of courgette in terms of nutrient preservation and energy consumption
8. Sensory attributes and nutrient retention in selected vegetables prepared by conventional and microwave methods
9. No Major Differences Found between the Effects of Microwave-Based and Conventional Heat Treatment Methods on Two Different Liquid Foods
10. Comparison of Conventional and Microwave Assisted Heating on Carbohydrate Content, Antioxidant Capacity and Postprandial Glycemic Response in Oat Meals

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