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1 October 2010
The obesity epidemic in America is spreading at an alarming rate and the only way to modify this trend is by making weight loss and healthy living a public priority (Mokdad et al., 1999). Each year, “the $50 billion North American weight-loss industry comprises a morass of fantastical claims of products and programs promising quick, easy, long-lasting results” (Berzins, 1999). Many obese Americans fall victim to these false advertisements and forget that “obesity management requires long-term behavioral, medical or surgical intervention” (Lau, Douketis, Morrison et al., 2007).
The weight loss industry continues to capture the minds of Americans by presenting them with unreasonable results, which causes consumer frustration and feeds into the vicious cycle of unhealthy eating habits. At times, these new formed habits of medically unsupervised starvation, binging, and restriction have been fatal due to the lack of proper guidance from advertisers (Wadden, Van Italliem, Blackburn, 1990).
Amongst all of these myths and dramatizations, it can become difficult to determine which diets are actually beneficial for weight loss and long-term healthy eating habits. The raw food diet not only encourages weight loss but it is said to promote a lifestyle of healthy eating that can be continued forever. This literature review will discuss the side effects and benefits of the raw food diet as a long-term way of eating and determine if it is really offers positive results to its followers (http://www.living-foods.com/faq.html).
What is the Raw Food Diet?
Raw foods and living foods are foods that have not been heated over 116◦ F and still contain their natural enzymes, which help in the digestion of foods. Heating foods over 116◦ F destroys enzymes and alters the molecular structure of the food. Individuals that follow the raw food diet believe that by cooking foods, they become toxic and have dramatically less nutrients than in their raw state. In living foods, the enzyme level is much higher than raw foods and the enzymes are considered active. In contrast, raw foods have dormant enzymes. In some cases, enzymes in raw foods can be activated through soaking. These raw foods would be considered living foods once they sprout. In the raw food diet, it is best to have organic foods to prevent contamination from potentially harmful and toxic pesticides, herbicides, and synthetic fertilizers (http://www.living-foods.com/faq.html; http://altmedicine.about.com/od/popularhealthdiets/a/Raw_Food.htm).
In order for a person to be considered a follower of the raw food diet, 75% to 100% of their diet must be raw or living. Unlike vegetarians and vegans, who consume a plant based diet, raw foodists must limit themselves to “uncooked, unheated, unprocessed and organic” plant based foods. There are also subtypes of raw foodists such as fruitarians, sproutarians, and juicearians. These individuals consume mostly fruits, sprouts, or fresh juice (http://www.living-foods.com/faq.html).
Since food cannot be heated above 116◦ F, raw foods are often soaked or sunbaked. Nuts, seeds, and grains are a few of the items that are often soaked. Tea is also prepared by drying and brewing unprocessed and organic herbs in the power of the sun. It is also forbidden for raw foodist to drink tap water. All water must be purified and juice must be freshly made, not bottled (http://altmedicine.about.com/od/popularhealthdiets/a/Raw_Food.htm).
Speculated Benefits and Side Effects
Advocates of the raw food diet often proclaim that it increases energy, improves skin appearance, improves digestion, promotes weight loss, lowers cholesterol, and reduces the risk of heart disease (http://altmedicine.about.com/od/popularhealthdiets/a/Raw_Food.htm). It is supposed to contain fewer fats, less sodium, and provide potassium, magnesium, fiber, and health-promoting enzymes for the body. They also state that the body may react poorly to detoxification at first but the nausea, headaches, and cravings disappear after several days. Once a follower is past this point, their cravings decrease and they start enjoying the benefits of raw foodism.
Critics of the raw food diet argue that it requires a considerable amount of time, commitment, resources, and effort. It also causes a deficiency in calcium, iron, B-12, protein, and calories. Because of this, the raw food diet is not recommended for children, pregnant or nursing women, anemic individuals, or individuals at risk for osteoporosis. They also argue that cooking foods allows some phytochemicals to be absorbed more effectively by the body (Fontana, Shew, Holloszy, Villareal, 2005; Koebnick et al., 2005).
Studies of the Raw Food Diet
Dental Erosions in Subjects Living on a Raw Food Diet (Ganss, Schlechtriemen, Klimek, 1999)
The purpose of this study was to determine if there was an associating between the raw food diet and dental erosions. One hundred and thirty subjects, 64 females and 66 males, who consumed more than 95% raw foods, were used for this study. The duration of raw foodism varied from 17 months to 418 months. This averaged to be 39 months of raw foodism for the group of subjects. A control group of 76 sex and age matched patients were randomly selected. Subjects were selected by a dietary and health questionnaire. Only individuals whose diet was 95% raw foods for at least a year could be considered for the study. Subjects with eating disorders or gastrointestinal disturbances were not included in the study.
Subjects recorded their food intake for seven days prior to their dental examination. The results showed that raw food dieters were at an increased risk for dental erosion. The subjects on the raw food diet had a significantly greater amount of dental erosion than the control group. Compared to the control group 60.5% of raw food dieters had at least one tooth with a severe erosion, while only 31.6% of the control suffered from severe erosion on one tooth.
Effects of Raw Food Diet on Hypertension and Obesity (Douglass et al., 1985)
One primary research study examined if the raw food diet had positive effect on hypertension and obesity in humans. In this study 32 patients were documented, 21 men and 11 women. Out of these patients, 5% to 15% were mildly overweight and 15% to 40% were moderately obese.
All of these patients volunteered for the program and their adherence with the raw food diet was self-documented, so accurate data was not guaranteed. The patients were advised to make 40% of their diet a raw food diet but no limits were put on their portions or meals. After a physical examination, they had checkups to record their weight, blood pressure, and dietary percentages of uncooked foods every four to six weeks. Compliance with the dietary requirements was by a patient questionnaire.
Over an average of 6.7 months the patient’s mean weight loss was 3.8 kg. The 28 patients who were overweight lost an average of 4.4 kg. The patients who lost the most were the patients who consumed the most amount raw food for the longest duration of time.
The patients also showed an average reduction in blood pressure by 17.8 mm Hg. Five patients who were on medication were able to stop using it and fourteen patients who were going to be prescribed medication were able to manage their blood pressure by increasing the amount of raw food in their diet.
Patients suffered from sensitivity to alcohol, tobacco smoke, chemical odors, and medication. Eighty percent of the patients who smoked or consumed alcohol discontinued use after following the raw food diet. Consuming large amounts of banquet style food at restaurants caused nausea, vomiting, and malaise in patients who ate a large amount of raw food.
In general, the raw food diet could be associated with weight loss and a decrease in blood pressure in this study.
Consequences of a Long-Term Raw Food Diet on Body Weight and Menstruation (Koebnick, Strassner, Hoffmann, Leitzmann, 1999)
The goal of this study was to look at the connection between long-term raw food diets, body weight, and the menstrual cycle. This cross-sectional study of 216 men and 297 women was divided into five groups based on the severity of their raw food diet, “70-79, 80-89, 90-94, 95-99, and 100%” raw food consumed. The participants had been on the raw food diet for an average of 3.7 years at a variety of intensities that were assessed through a survey.
There were 253 meat eaters, 184 vegetarians, and 135 vegans. The raw food dieters consumed small amounts of alcoholic beverages a day, only 2.1% smoked, and 89% participated in physical activity. The subjects practiced the raw food diet to promote health, “prevent illness and to live in a natural and healthy way for a long time” (Koebnick, Strassner, Leitzmann, 1997; Koebnick, Strassner, Leitzmann, 1995) and the raw food diet was used as therapy for allergies, hypertension and obesity (Bircher-Benner, 1947; Bircher-Benner, 1950; Douglass, 1985; Waerland, 1977).
On average, men lost 9.9 kg and women lost 12 kg. Body mass index (BMI) was below normal for 14.7% of males and 25.5% of females. Of these, 2.6% of men and 5.7% of women were diagnosed with chronic energy deficiency. Approximately “30% of the women under 45 years had partial to complete amenorrhea; subjects eating high amounts of raw food (>90%) were affected more frequently than moderate raw food dieters” (Koebnick, Strassner, Hoffmann, Leitzmann, 1999) and 70% noticed a change in their menstruation. Most of the raw food dieters lost a significant amount of weight then maintained a body weight that was below average.
Due to these facts, it was concluded that women with partial to total amenorrhea had a lower BMI and ate more raw food than other women in the study.
Evidence of Benefits and Side Effects of the Raw Food Diet
In the studies, it was apparent that the raw food diet had benefits but severe side effects when it was followed severely. A moderate raw food diet had the ability to decrease or eliminate tobacco or alcohol related addictions or habits. It promoted weight loss and helped to decreased hypertension in moderately to severely obese individuals (Douglass et al., 1985; Bircher-Benner, 1947; Waerland, 1977). The raw food diet could also serve as therapy for certain allergies. These subjects tended to have a diet that was 40% raw food and 60% un-raw food.
Unfortunately, the raw food diet had a negative effect on strict followers. Women who ate over 90% raw suffered from amenorrhea (Koebnick, Strassner, Hoffman, Leitzmann, 1999). Both men and women from this study were underweight and were diagnosed with chronic energy deficiency. Many individuals who decided to follow the raw food diet for health benefits became sensitive to alcohol, tobacco smoke, chemical odors, or medication (Douglass et al., 1985). Their bodies also rejected process foods and caused them to have nausea, vomiting, and malaise after eating at restaurants or banquet dinners. Raw foodists can also be at risk for low bone mass and conditions, such as osteoporosis, that are associated with it (http://news.wustl.edu/news/Pages/4971.aspx). Dental erosion was also found more often in subjects that consumed a raw food diet than subjects that consumed a regular diet (Ganss, Schlechtriemen, Klimek, 1999).
From the studies, it can be concluded that long-term raw foodism is only beneficial if it is followed in moderation. Severe raw foodism over a long period of time can cause health complications and malnutrition in the body. Periods of raw foodism can be used to cleanse the body of toxins and preservatives but this way of eating should not become a permanent lifestyle.
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Department of Operative and Preventitive Dentistry and Department of Pediatric Dentistry, Dental Clinic, Justus Liebig University, Giessen, Germany. 33: 74-80.
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