Plant-Based Eating: Getting the Right Nutrition
“It is the position of the American Dietetic Association that appropriately planned vegetarian diets, including total vegetarian or vegan diets, are healthful, nutritionally adequate, and may provide health benefits in the prevention and treatment of certain diseases. Well-planned vegetarian diets are appropriate for individuals during all stages of the life cycle, including pregnancy, lactation, infancy, childhood, and adolescence, and for athletes.” —Position Statement for Vegetarian Diets; American Dietetic Association, 2009.
Plant-based eating is growing in popularity because it’s increasingly backed by a wealth of scientific data supporting the health benefits. These benefits includes lower rates of heart disease, high cholesterol and blood pressure, obesity, type 2 diabetes and certain types of cancer. Vegetarian eating has even landed on the latest food and diet trends of 2014, but it’s important to know that a plant-based approach to eating is far more than a trend; it dates back to ancient times, and has been popular throughout history and around the globe. Today, there is a global push towards vegetarianism to save the world from hunger, fuel poverty and the impact of climate change, according to a 2010 report from the United Nations Environment Programme (UNEP).
A vegetarian diet can be the single most effective way to prevent chronic disease.
This report notes that as the global population escalates, the western taste for a diet rich in meat and dairy is becoming unsustainable. A worldwide diet shift away from animal products toward a plant-based approach to eating would help reduce the global impact on agriculture and fuel.
A vegetarian diet can be the single most effective way to prevent chronic disease. An estimated 70% of all diseases including one-third of all cancers are related to diet. A plant-based diet reduces the risk for chronic degenerative diseases including coronary heart disease, diabetes, obesity, high blood pressure and cancers such as prostate, breast, colon stomach, lung and esophageal cancer.
The Dietary Guidelines Advisory Committee states a plant-based diet emphasizes vegetables, fruit, cooked dry beans and peas, whole grains, nuts and seeds.
Types of Vegetarian Diets
Vegan: A vegetarian diet that excludes all animal products such as meat, poultry, fish, eggs, milk, cheese and all other dairy products.
Lacto-Vegetarian: A vegetarian diet that excludes meat, poultry, fish and eggs but includes dairy products.
Lacto-Ovo Vegetarian: A vegetarian diet that excludes meat, poultry and fish but includes eggs and dairy products (most vegetarians in the United States fall into this category).
Flexitarian: A semi-vegetarian diet with a focus on plant-based foods with occasional meat, poultry, or fish consumption.
The Dr. Dean Ornish Program for Reversing Heart Disease has demonstrated that heart disease can be reversed through a four-element approach that includes a lacto-ovo vegetarian style of eating. The diet, however, only allows eggs whites and nonfat dairy products and excludes added fats such as nuts, seeds, oils, avocados and coconut (see Ornish Lifestyle Medicine Guidelines). A plant-based, vegetarian approach to eating offers numerous nutritional benefits, including lower levels of saturated fat, trans fats, cholesterol, and animal protein. The diet is also nutrient rich and provides higher levels of complex carbohydrates, fiber, magnesium, potassium, folate, and antioxidants such as vitamins C and E with a spectrum of health promoting phytochemicals that protect and prevent disease.
An analysis of National Health and Nutrition Examination Survey (NHANES) data found that the average intake of fiber; vitamins A, C, and E; thiamin; riboflavin; folate; calcium; and magnesium by those following vegetarian diets exceeded that of non-vegetarians, suggesting that vegetarian diets are nutrient dense and consistent with dietary guidelines. Research supports the nutrition adequacy of a well-planned low-fat, vegetarian approach.
Nutritional Concerns
It’s easy to meet current recommendations for all nutrients through a vegetarian approach, but there are a few key nutrients for vegetarians that are important to highlight that could potentially be at risk of being low depending on one’s food choices. These nutritional concerns are protein, iron, zinc, calcium, vitamin D, riboflavin, vitamin B-12, vitamin A, n-3 fatty acids, and iodine.
Protein
Protein is an essential nutrient that is the part of every cell, tissue and organ in our body. Protein builds new cells, maintains tissue, muscle and bone mass, makes enzymes, supports our immune system and is critical for overall good health. The recommended intake for protein is 0.8gm of protein per kg of body weight (.36gm /lb) per day, which is equivalent to about 46 gm of protein for most adult women and 56 gm of most adult men. This helpful tool can help determine your individual protein needs. However, protein needs can vary based on your specific individual needs. There is also new research indicating that as we age, our need for protein may increase to maintain lean body mass and retain functional abilities.
It’s easy to obtain adequate protein from a vegetarian diet, including the low-fat, lacto-ovo vegetarian approach recommended by the Dr. Dean Ornish Program for Reversing Heart Disease. There are many plant protein sources that can contribute to adequate protein intake. Food choices that are rich in plant protein are beans, lentils and peas. Whole grains and vegetables such as kale, broccoli and spinach also contain protein.
Omega-3
EPA and DHA are essential omega-3 fatty acids that are important for cardiovascular, brain, and overall health. There are two major types of omega-3 fatty acids in our diets. One type is alpha-linolenic acid (ALA), which is found in some plant sources such as flaxseed, soy, walnuts and some vegetable oils such as canola, green vegetables, such as Brussels sprouts, kale, spinach, and salad greens. The other type of omega-3 fatty acids are eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) found primarily in fatty fish. The body can convert the plant-based omega-3 fatty acid ALA into EPA and DHA, but the conversion is limited. Since vegetarians avoid fish and seafood, there is risk for low levels of these essential omega-3 fatty acids in vegetarians. However, both vegetarians and vegans may obtain omega 3 from marine algae supplementation.
B12
B12 plays a role in red blood cell and DNA formation, metabolism and central nervous system maintenance. Since B12 is primarily obtained from animal sources, vegetarians, primarily vegans, can be at risk of a low B12. Vegan sources of B12 include nutritional yeast, fortified cereals and meat alternatives that are fortified. Taking a basic multivitamin and mineral that contains at least 2.4 mcg is recommended as part of preventative approach to deficiencies. Lacto or lacto-ovo vegetarian that include eggs and/or dairy are able to obtain adequate B12 from those animal sources. The Dr. Dean Ornish Program for Reversing Heart Disease includes optional sources of egg whites and nonfat dairy products, making it easier to maintain adequate levels of B12 from the diet.
Calcium
Calcium is important for bone health along with vascular, muscle and nerve function. Vegetarians that include dairy have similar levels of calcium as non-vegetarians. However, vegans need to rely on plant sources for calcium which include fortified soy milk, orange juice and other fortified products such as tofu, dark leafy greens such as collards, blackstrap molasses, broccoli and bok choy. Including a calcium supplement may also be helpful, but as always check with your doctor before adding any supplement.
Vitamin D
Vitamin D also plays an important role in bone, vascular, muscle and nerve function. We can obtain it from just 15 minutes of sunlight. However, vitamin D exposure can depend on the season, region of the country, cloud and smog cover, and level and amount of protective sunscreen a person wears. Researchers suggest that getting 5-30 minutes of sun exposure without sunscreen between 10am and 3pm twice a week can be a helpful strategy to keep up levels of vitamin D. Other ways to obtain Vitamin D can be from fortified foods such as soy milk, juice and cereals.
Iron
Iron is an essential mineral that is important for oxygen transport for body tissues. There are two types of iron, heme and nonheme. Heme iron is found in animal foods such as meat, poultry and fish. Nonheme iron is present in plant foods such as beans, lentils and soy products, and spinach. Only about 10-15 % of nonheme iron is effectively absorbed. For vegetarians relying primarily on plant sources, it is suggested to increase intake by 1.8 times. Nonheme iron can be sensitive to polyphenolics, and phytates that are found in legumes, and whole grains, that can bind with iron decreasing absorption. However, one strategy that can diminish phytate levels and enhance iron absorption is soaking, sprouting, fermenting and cooking beans and grains. Another benefit of a vegetarian diet is that a plant-based approach is high in vitamin C, enhances the absorption of iron. Research shows that most vegetarians do show lower levels of iron than non-vegetarians.
Zinc
Zinc is a mineral that plays a role in the immune system, and is present in cells throughout the body. Plant based sources of zinc that are part of the Dr. Dean Ornish Program for Reversing Heart Disease include whole grains, beans, and soy. Zinc is also sensitive to phytates as noted with iron and the same strategies of soaking, sprouting, fermenting and cooking beans and grains can promote bioavailability. Zinc levels have been shown to be lower in vegetarians, supporting the importance for vegetarians to include a multivitamin and mineral supplement as a nutrition insurance, along with increasing zinc rich foods. A low-fat, plant-based approach that includes a variety of whole grains, vegetables, fruits, legumes (and nonfat dairy and egg whites if you’re following the Dr. Dean Ornish Program for Reversing Heart Disease) will provide you with more than adequate nutrition as well as delicious food with a bounty of health benefits.
What health benefits have you experienced by making the shift to a vegetarian diet?