Raw Food Diet: Is Raw More Nutritious than Cooked?
By Lynn Grieger, RDN, CDE, CHW, CPT
When considering a raw food diet, you may want to know which foods contain more nutrients – raw or cooked? The answer isn’t as clear as you might expect. One main consideration is that there are many different food preparation methods. Some methods involve heat to bake, steam, roast, or fry. Other foods we prepare and eat raw, and some foods dried or sprouted. Each food preparation method has their benefits. There is ongoing work being done to identify the best way to prepare foods to preserve as many nutrients as possible.
When Did We Start Cooking our Food?
No one knows exactly when humans started using fire to cook food, but historians believe that fire was first routinely used around 1 million years ago. All known human societies eat cooked foods. Many biologists believe that developing fire to cook foods was a key change. This allowed humans to develop a larger brain with a direct impact on how we evolved as a species.
The brain needs more energy for its size than any other organ in our body. Some scientists theorize that developing a larger brain depended on ancient humans being able to cook food. Cooking foods like meats, potatoes, and grains makes them much easier to chew and digest. This provides more calories for energy.
What is a Raw Food Diet?
The raw food diet has been around since the mid-19th century. A man named Sylvester Graham had the idea that people would never become ill if they only ate uncooked foods. Graham was an early supporter of a vegetarian diet to promote health and prevent disease. Several of his theories continue today in recommendations for an eating style that is based on whole plants and high fiber.
A raw food diet is based on a vegan diet that includes fruits, nuts, seeds, and sprouted grains and beans. The actual
amount of raw food consumed ranges from 50% to 100% of total calories. The only “cooking” that is allowed is with a food dehydrator that blows hot air through the food at temperatures no higher than 118°F.
People who support a raw food diet believe that cooking destroys the enzymes needed to digest food, making cooked food less nutrient-dense.
Cook or Eat Raw?
Cooking foods can decrease water-soluble and heat-sensitive nutrients like vitamin C and some types of antioxidants. Different types of cooking methods have varying effects. In general, more nutrients are lost with higher cooking temperatures, longer cooking times, and putting foods in water. For example, water-soluble antioxidants called glucosinolates in cauliflower and broccoli are lost during boiling, but unchanged with steaming.
However, there are some vegetables that when cooked, actually increases the ability of our body to digest some types of nutrients.
These nutrients are the carotenoids in carrots and lutein in tomatoes. Another benefit of cooking is that kills harmful microbes that can cause food poisoning.
The raw food diet theory that cooking destroys the enzymes in foods necessary for digestion and nutrient absorption is false. Our body produces enzymes to digest food and absorb nutrients, and the enzymes in foods are deactivated by stomach acidity.
A meta-analysis of nutrient intakes of people who eat raw food versus cooked food showed that some beneficial nutrients are higher when people eat a raw foods diet. These nutrients are fiber, vitamins A, B6, C and E; folate, copper and potassium. However, some nutrients are lower: protein, vitamin B12, phosphorus, and zinc.
People who eat a raw foods diet tend to consume less total fat, saturated fat, and cholesterol primarily because they are not eating animal products or dairy foods that are higher in these nutrients.
They also tend to consume less sodium because they are not eating processed foods.
There is currently no research on any nutrient differences between people who eat a raw diet and those who eat a cooked vegan diet. In general, people who eat a plant-based diet have lower rates of heart disease, high blood pressure, obesity and diabetes.
The Bottom Line
Numerous research studies show that eating more plant sources of food -- vegetables, fruit, grains, nuts and seeds and legumes -- is a key strategy to improved health. This includes conditions such as a decreased risk of cardiovascular disease, obesity, diabetes and cancer.
All nutrients except for vitamin B12 are found in plant foods. People who eat a cooked or raw plant-based diet need a B12 supplement or should choose foods that are fortified with B12. Vitamin D is less prevalent in plants, with the major food sources in fish, liver, and egg yolks. However, some mushrooms are high in vitamin D and our skin produces vitamin D from the sun’s ultraviolet light.
Because uncooked foods like sprouts, berries and lettuce are often linked to food-borne illness, all produce should be thoroughly washed before eating. Due to the increased risk of food-borne illness from some uncooked foods, pregnant women, young children, senior citizens, people with weak immune systems and anyone with a chronic medical condition should not eat a raw foods diet.
Eating more thoroughly-washed fruit and vegetables either raw or cooked is a priority health goal
Aim for at least 5 servings per day of a variety of fruits and vegetables and more is always better! Include fresh or frozen fruit with breakfast oatmeal or yogurt, add a salad or vegetable soup to lunch, include two different types of vegetables with dinner, and enjoy fruit for snacks or a healthy dessert.
Cook vegetables in as little water as possible unless you’re making a sauce from the liquid.
*These statements have not been evaluated by the Food and Drug Administration
This information is for educational purposes only. The statements have not been evaluated by the Food and Drug Administration and are not intended to diagnose, treat, cure, or prevent any disease. Consult your physician if you have any question regarding a medical condition
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1. Food for Thought: Was Cooking a Pivotal Step in Human Evolution? Alexandra Rosati. Scientific American. 2-26-18
Cooking Up Bigger Brains. Rachael Moeller Gorman. Scientific American. 1-1-2008. https://www.scientificamerican.com/article/cooking-up-bigger-brains/
2. Chan Q, Stamler J, Brown IJ, et al. Relation of raw and cooked vegetable consumption to blood pressure: the INTERMAP Study. J Hum Hypertens. 2014;28(6):353–359. doi:10.1038/jhh.2013.115
3. Carmody R, Wrangham R. The energetic significance of cooking. Journal of Human Evolution. 2009;57(4):379-391.
4. Cunningham E. What is a raw foods diet and are there any risks or benefits associated with it? J Am Diet Assoc. 2004 Oct;104(10):1623.
5. Suzzane Havala Hobbs. Raw Food Diets. Review of the literature. The Vegetarian Resource Group. published 2002. Accessed 10-20-19.
6. Link LB, Jacobson JS. Factors affecting adherence to a raw vegan diet. Complement Ther Clin Pract. 2008;14(1):53–59. doi:10.1016/j.ctcp.2006.12.005
7. Tuso PJ, Ismail MH, Ha BP, Bartolotto C. Nutritional update for physicians: plant-based diets. Perm J. 2013;17(2):61–66. doi:10.7812/TPP/12-085
8. Hever J. Plant-Based Diets: A Physician's Guide. Perm J. 2016;20(3):15–082. doi:10.7812/TPP/15-082
9.Kara Meyer Robinson. Raw Foods Diet. Web MD. accessed 10-21-19