November 23, 2011
The recent boon in backyard and community gardens, farmers markets, and availability of organic foods offer evidence of increased consumer demand for more wholesome, sustainable, and environmentally-friendly foods. This growing trend to eat more fruits and vegetables and less processed foods combined with Americans’ favorite past-time of adopting restrictive, hard-to-maintain, weight-loss inducing diets at the turn of the New Year, creates a perfect storm for a surge in interest and popularity of the raw food diet.
The raw food diet emphasizes intake of foods in their natural, unprocessed, uncooked form. Raw fruits and vegetables top the list of food options. Add to that a mix of beans and legumes and it seems like you should have a nutrient-dense, filling, and weight-loss inducing “perfect diet.” After all, each of these foods is packed with nutrients, light on calories, and high in fiber. In a nation known for massive portion sizes and ready access to highly processed foods, this way of eating should be a welcome change. But a closer looks reveals a more complicated, expensive, and questionable eating plan.
Beyond promoting every nutrition expert’s mantra of “eat more vegetables and fruits”, the standard raw food diet is true to its name – most, if not all, foods need to be “raw”. This means dieters are prohibited from cooking food. The only allowed “cooking” is dehydration which requires a special machine that blows hot air through the food and increases the temperature to no more than 118F. Since grains are indigestible raw and the diet prohibits boiling them, raw grains must be soaked overnight or allowed to sprout before consumption. Proponents argue that avoiding heat exposure keeps food enzymes intact leading to better digestion; however, this argument does not physiologically hold merit since the acid in the stomach inactivates the enzymes once the food is eaten. Plus, the body already makes all the enzymes it needs to digest and absorb food. Since food can’t be cooked, meat and most animal products are off limits (unless a dieter chooses to put the risk of severe foodborne illness aside and eat raw meat). For this reason, the raw food diet typically resembles a vegan diet that is free of processed and cooked food. Most raw food devotees also consume a mostly organic foods to avoid exposure to pesticides and other synthetic chemicals. The extent of adherence to these tenants is pending the level of commitment to adopting a “pure” version of the diet.
Few published studies evaluate risks and benefits of a raw food diet. The limited available research suggests a variety of potential benefits such as improved “bad” LDL cholesterol and triglyceride levels (Koebnick et al, 2005), weight loss (Koebnick et al, 1999), improvement in fibromyalgia symptoms (Donaldson et al, 2001) and decreased blood pressure (Douglass et al, 1985) as well as potential harmful effects including decreased “good” HDL cholesterol (Koebnick et al, 2005), decreased bone density (Fontana et al, 2005), and vitamin B12 deficiency (due to elimination of animal products) (Koebnick et al, 2005). Extremists who do not adopt the vegan approach but instead consume raw animal products risk serious foodborne illness. Plus, as with any restrictive diet, strict adherence to a raw food diet is challenging. But it turns out that this imperfect adherence may be its major redeeming feature. After all, an overall concerted effort to eat a healthier, more wholesome, mostly plant-based diet should be the goal of any dietary overhaul.
- Koebnick C., et al. (2005). Long-term consumption of a raw food diet is associated with favorable serum LDL cholesterol and triglycerides but also with elevated plasma homocysteine and low serum HDL cholesterol in humans. Journal of Nutrition, 135, 10, 2372-2378.
- Koebnick C., et al (1999). Consequences of a Long-Term Raw Food Diet on Body Weight and Menstruation: Results of a Questionnaire Survey. Annals of Nutrition and Metabolism, 43, 2, 69-79.
- Donaldson M.S., et al (2001). Fibromyalgia syndrome improved using a mostly raw vegetarian diet: an observational study. BMC Complementary and Alternative Medicine, 2001, 1, 7. Douglass, J. M., et al (1985). Effects of a raw food diet on hypertension and obesity. Southern Medical Journal, 78, 7, 841-844.
- Fontana L., et al (2005). Low bone mass in subjects on a long-term raw vegetarian diet. Archives of Internal Medicine, 165, 684-689.
By Natalie Digate Muth
Natalie Digate Muth, MD, MPH, RD, FAAPNatalie Digate Muth, MD, MPH, RD, FAAP is the Senior Advisor for Healthcare Solutions for the American Council on Exercise, a board-certified pediatrician and Fellow of the American Academy of Pediatrics, a Diplomat of the American Board of Obesity Medicine, registered dietitian and board-certified specialist in sports dietetics, and ACE Certified Health Coach. She is the author of "Eat Your Vegetables and Other Mistakes Parents Make: Redefining How to Raise Healthy Eaters" and the textbook "Sports Nutrition for Health Professionals." She has been ACE certified since 1998.