It's no secret: A diet rich in fruits and vegetables can play a key role in preventing chronic diseases and improving health.
As Americans strive to lead healthier lifestyles, different eating trends become more popular. The raw food diet is an example of one such trend.
What is the raw food diet? Is it just another fad diet or can it really be beneficial to your health?
What Is the Raw Food Diet?
Although there are different versions of the raw food diet, they all have one thing in common: Foods can't be heated above 118° F.
Uncooked vegan foods make up most of the diet. These include:
Food processing is limited to blenders and dehydrators. Sometimes a process called fermentation is used to add flavor to food. In this process, yeast or bacteria is added to foods high in sugars and carbohydrates.
Although rare, when animal products are included they are eaten raw.
Why Go Raw?
Through the 19th, 20th and 21st centuries, various doctors used raw foods as a form of alternative medicine to treat diseases. In 1986, Harvey and Marilyn Diamond published Fit for Life, a book promoting this idea. Since then, the raw food diet has gained popularity.
Heat destroys some enzymes in food. Enzymes help our bodies break down nutrients so the body can absorb them. By avoiding heat, enzymes are left unchanged. Many people who favor raw food diets believe that this makes digestion and absorption of nutrients in food easier. However, there is little to no scientific research to support this theory.
Are There Health Benefits to Eating Raw Food?
There's very little research on the raw food diet. Many health aspects of the raw food diet have come from conclusions drawn from research on vegetarian and vegan diets. (Vegan diets omit all animal products including meat, poultry, fish, eggs and dairy.)
Due to strict preparation guidelines, raw food dieters are less likely to eat meals outside of the home. This may mean that they eat less sodium and saturated fat.
Here's what the preliminary research on the raw food diet has found:
More research is needed to draw solid conclusions.
Are There Drawbacks?
Followers of the raw food diet are at risk for several nutrient deficiencies.
Preliminary studies have shown a significantly lower intake of protein among raw food dieters than the what is recommended for vegetarian adults (0.6 g/kg compared with 1.1 g/kg). To date, no recommendations for protein exist for the raw food diet.
The raw food diet meets approximately 73% of calorie needs required for adults. There are more underweight individuals in the raw food population than in the average population. In addition to decreased caloric intake, women experienced decreased or missed menstrual periods when starting the raw food diet.
Omega-3 fatty acids
No research has been done to look at levels of omega-3's among people who follow this diet. However, vegan diets often do not meet the requirements for omega-3 fatty acids. Sources include fish, eggs, flaxseed, walnuts, canola oil, olive oil and flax oil. People on the raw food diet may need to take supplements.
Vitamins and minerals
The raw food diet is often lacking many of the vitamins and minerals found in food from animal sources. These include B12, iron and vitamin D.
Lack of vitamin B12 in the raw food diet has been linked to higher levels of homocysteine, a risk factor for heart and blood vessel disease. Supplements are recommended.
Non-heme iron (from plants) is harder for the body to absorb than heme iron (from animals). However, many food preparation techniques used in the raw food diet may actually increase iron absorption from plant sources. Examples include soaking and sprouting beans, nuts, seeds and other legumes. Pairing vitamin C with plant sources of iron also aids absorption.
The Institutes of Medicine recently increased recommendations for vitamin D. Vitamin D is found in some food sources such as eggs, fatty fish (salmon), liver and eggs. Some vitamin D is also found in fortified milks and juices, which are not included in the raw food diet because they are processed foods. If raw meat products are consumed, the recommendation for vitamin D intake is more likely to be met. Supplementation may be necessary.
Zinc and calcium are commonly deficient in the raw food diet.
What About Food Safety?
Heat kills disease-causing microbes, according to the Centers for Disease Control and Prevention. Heating food to an internal temperature above 160° F, for even a few seconds, is enough to kill parasites, viruses or bacteria, except for Clostridium bacteria."
The foods most likely to be contaminated are raw animal foods, such as raw milk, eggs and meat. Recent outbreaks of foodborne illness have also been traced to raw fruits and vegetables. People especially at risk for foodborne illness include young children, pregnant women and the elderly.
Preparing food without heat requires time, planning and special equipment. Not everyone may be able or willing to put in the time and effort this strict diet requires.
Certain nutrients are actually absorbed better when treated with heat. Lycopene, a carotenoid found in tomatoes, is absorbed more efficiently when cooked. Raw egg whites contain a compound called avidin, which decreases the absorption of biotin.
The Bottom Line
The major advantage of the raw food diet is the high intake of fruits and vegetables. However, there are nutritional gaps that need to be filled. Therefore, strict adherence to the raw food diet may not be the best way to improve your health. Until more research is done, a balanced diet combined with daily physical activity remains the key to a healthy lifestyle.
Alexandra Kuznetsov, B.S. is a Dietetic Intern at Brigham and Women's Hospital. She graduated with a B.S. in Nutrition and Dietetics from New York University.
Category: Food for Thought
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