There are so many myths and misinformation around food, so I suspect you might have a question or two. Here are the ones most commonly asked, answered by Dr. Neal Barnard of the Physicians Committee for Responsible Medicine. And if you have more questions, you can consult their website at www.pcrm.org.
Where do I get iron if not from red meat?
The most healthful sources of iron are "greens and beans." That is, green leafy vegetables and anything from the bean group. These foods also bring you calcium and other important minerals. Vegetables, beans and other foods provide all the iron you need. In fact, studies show that vegetarians and vegans tend to get more iron than meat eaters. Vitamin C increases iron absorption. Meanwhile, dairy products reduce iron absorption significantly.
To go into a little more detail, there are actually two forms of iron. Plants have nonheme iron, which is more absorbable when the body is low in iron and less absorbable when the body already has enough iron. This allows the body to regulate its iron balance. On the other hand, meats have heme iron, which barges right into your bloodstream whether you need it or not. The problem is that many people have too much iron stored in their bodies. Excess iron can spark the production of free radicals that accelerate aging, increase the risk of heart disease and cause other problems.
So while it's important to avoid anemia, you also do not want to be iron overloaded. It's probably best to have your hemoglobin on the low end of the normal range. If your energy is good and your hemoglobin and hematocrit are at the low end of normal, that is likely the best place to be.
Having said that, you will want your doctor to review your laboratory results and to track them over time. If your hemoglobin and hematocrit are dropping, that may be a sign of blood loss. That can be from benign causes, such as menstrual flow, but can also reflect more dangerous health issues, such as intestinal bleeding.
What is the best source of calcium, and how does it compare with dairy?
The same green leafy vegetables and legumes that provide iron are also good sources of calcium, for the most part, and absorption is typically better from these sources than from dairy products. One common exception is spinach, which has a great deal of calcium, but its absorption is poor. But broccoli, brussels sprouts, kale, and other common greens have highly absorbable calcium.
If you like, you can also use calcium-fortified products such as breakfast cereals and juices, although these products provide more concentrated calcium than is necessary. It pays to put some thought into keeping your bones healthy. Studies have shown that the following factors are helpful in building and maintaining strong bones:
- Getting plenty of exercise. Studies have concluded that physical exercise is the key to building strong bones (it's more important than any other factor). For example, a study published in the British Medical Journal that followed 1,400 men and women over a 15-year period found that exercise may be the best protection against hip fractures and that "reduced intake of dietary calcium does not seem to be a risk factor." And at Penn State University, researchers found that bone density is significantly affected by how much exercise girls get during their teen years, when 40 to 50 percent of their skeletal mass is formed.
- Getting enough vitamin D. If you don't spend any time in the sun (about 15 minutes on the face and arms each day is enough), be sure to take a supplement or eat fortified foods.
- Eliminating animal protein. For a variety of reasons, animal protein causes calcium loss.
- Limiting salt intake. Sodium tends to cause the body to lose calcium in the urine.
- Eating plenty of fruits and vegetables. People who eat lots of vegetables and fruits are less likely to have bone breaks. Part of the reason may be that they contain vitamin C, which is essential for building collagen, the underlying bone matrix.
- Not smoking. Studies have shown that women who smoke one pack of cigarettes a day have 5 to 10 percent less bone density at menopause than nonsmokers.
Is it healthy for a pregnant or nursing mother to eat a plant-based diet? How about kids?
According to the American Dietetic Association:
Well-planned vegan and other types of vegetarian diets are appropriate for all stages of the life cycle including during pregnancy, lactation, infancy, childhood, and adolescence. Vegetarian diets offer a number of nutritional benefits including lower levels of saturated fat, cholesterol and animal protein as well as higher levels of carbohydrates, fiber, magnesium, potassium, folate, antioxidants such as vitamins C and E and phytochemicals. Vegetarians have been reported to have lower body mass index than non-vegetarians, as well as lower rates of death from ischemic heart disease, lower blood cholesterol levels, lower blood pressure, lower rates of hypertension, Type 2 diabetes and prostate and colon cancer.
—American Dietetic Association position
paper on vegetarian and vegan diets.
In the seventh edition of Dr. Benjamin Spock's Baby and Child Care—the last edition published during Dr. Spock's lifetime—he spelled out some good advice for children's diets. He recommended that children be served plant-based diets—vegan diets—and that, to deal with finicky eaters, the best approach was not to arm-wrestle with children but rather to simply find healthful foods they will eat. For example, children may not like cooked spinach, but they might like fresh spinach as part of a salad. They often are not keen on more exotic vegetables, but they are fine with corn, carrots, green beans, etc. Virtually all children like the following:
Legumes: baked beans (okay to add cut-up veggie hot dogs), lentil soup, split pea soup, peas, bean burritos, bean tacos
Vegetables: carrots, green beans, vegetable soup, salads
Grains: rice, whole grain bread, oatmeal, cold cereals with soy milk or rice milk, corn, vegan pizza, spaghetti with chunky tomato sauce
Fruits: apples, bananas and all others
Meat analogues: veggie burgers, veggie hot dogs, etc. (Soy-based ones have a cancer-preventing effect for girls and are healthful for all children.)
It is also important to provide a pediatric multivitamin. PCRM has a book called Healthy Eating for Life: For Children, which is very detailed on veganism and kids.
Do I need to take any particular vitamins or minerals because of eating this way?
Actually, vegans generally have better overall vitamin intake, compared with meat eaters. Meat has essentially no vitamin C and is low in many other vitamins as well. In contrast, vegetables, fruits and legumes (beans, peas and lentils) are vitamin-rich. In controlled studies, people switching to vegan diets typically increase their intake of several vitamins and reduce their intake of the undesirables—saturated fat and cholesterol, in particular. Even so, two vitamins deserve special comment:
Nowadays, some health authorities recommend high vitamin D intakes—up to 2,000 IU (50 micrograms) per day, because of its reputed cancer-fighting properties. To get there, you’ll need to take a vitamin D supplement. Vitamin D2 (ergocalciferol) is plant-derived, while vitamin D3, or cholecalciferol, typically comes from lanolin in sheep's wool.
- Vitamin B12 is made, not by plants or animals, but by bacteria. Animal products contain B12 made by the bacteria in their intestinal tracts. A more healthful source is any common multivitamin. B12 supplements are also widely available.
- Vitamin D normally comes from exposure to the sun. About fifteen minutes of direct sunlight on your face and arms each day gives you all the vitamin D you need. However, if you are indoors much of the day or live in an area where sunlight is limited, it is important to take a supplement. Any common multivitamin is fine. Most foods have little or no vitamin D. Certain fish contain some vitamin D, but they also harbor cholesterol, mercury, and other things you don’t want. Surprisingly, mushrooms (for example, shiitakes and chanterelles) contain vitamin D. Five dried shiitakes provide roughly 5 micrograms of vitamin D. You’ll also find it in fortified soy milk.
A plant-based diet easily provides all the protein the body needs. There is no need for meat, dairy products or eggs for protein, and you are better off without them. Vegetables, grains and beans give you plenty of protein, even if you are active and athletic. And there is no need to eat these foods in any special combinations. The normal mixtures of food people choose from day to day easily satisfy protein needs.
For people who like technical details, protein is made up of amino acids. Each amino acid molecule is like a bead, and many amino acids together make up the protein chain. There are many different amino acids, and all of the essential ones are found in plants.
And by all means, do not fret about protein grams or feel any need to count them. But if you are interested in the numbers, simply divide your body weight (in pounds) by three. That gives you an approximation of the number of grams of protein your body needs, plus a margin for safety. So, for example, for a person who weighs 120 pounds, 40 grams of protein is more than enough on a daily basis. Some experts believe that the actual amount of protein required is actually much less than this figure.
The bottom line is to have a healthful mix of vegetables, beans, whole grains and fruits, and protein takes care of itself.
This bears repeating, so that you can feel really clear. Soy products have been around for thousands of years and are a dietary staple in many regions of Asia. Research has shown that people in these regions have lower rates of heart disease, breast and prostate cancer, fewer hip fractures and fewer hot flashes. In addition, dozens of clinical studies have indicated the health benefits of diets rich in soy.
Some have raised the question as to whether soy has untoward effects. Happily, these concerns have been set aside. Girls who consume soy products in adolescence have about a 30 percent reduction in breast cancer risk as adults. Women previously diagnosed with breast cancer have a significantly greater survival if they include soy in their diets, compared with women who tend not to use soy products.
However, if a person is uncertain or simply does not want to include soy, I always remind them that a vegan diet does not mean joining the Soy Promotion Society. A vegan diet can mean many things: a Latin American tradition with beans, rice and tortillas; a Mediterranean tradition emphasizing vegetables, pasta, beans and fruit. Soy products come from an Asian tradition and are entirely optional.
What if I think I???m allergic to soy?
Again, eating a diverse diet of whole grains, beans and legumes, fruits and vegetables will give you everything you require in terms of protein. As for allergies, in some cases, they will change over time. For example, it is very common for children to have allergies that disappear as they get older, and that occurs in adulthood too. Also, quite often, allergic responses diminish when people stop consuming dairy products. For example, a person who is allergic to cats or has asthma symptoms in response to pollen will find that these symptoms diminish when they leave dairy products aside.
Where can I get my omega-3s if not from fish or fish oil?
ALA (alpha-linolenic acid) is a basic omega-3 fat that can be converted in the body to the other omega-3s the body needs. ALA occurs in small amounts in beans, vegetables and fruits, and this should be all the body needs. If more is desired, it is also found in walnuts, soy products and, in high concentration, flax seeds and flax oil. If these are used, there is no need for more than minimal amounts. If you are looking for more, for whatever reason, health food stores sell vegan omega-3 supplements.
Sometimes, eating lots of vegetables, beans or soy products gives me uncomfortable gas. How do you avoid this?
The problem with gassiness can often be found with beans. They should not be excluded from the diet, however, because they are great sources of protein, calcium and iron, among other nutrients. But if you are new to beans, it is good to have them in small portions and always very well cooked. A well-cooked bean is very soft, with no hint of crunchiness. As time goes on, your digestive tract adjusts, so a bean that may cause a problem today may be better tolerated later on.
Also, cruciferous vegetables can cause indigestion for some people. The answer is simply to cook them well. This group includes broccoli, cauliflower, brussels sprouts, kale and cabbage, among others. It is common for people to eat them raw or only slightly cooked, but they can easily cause gassiness or bloating. Cook them well, and the problem usually disappears. Later on, you can experiment again with less-cooked vegetables.
On the good side, rice is very easily digested, and a great food to emphasize. Brown rice is best. Also, cooked green, yellow, and orange vegetables are very easily digested. Fruits vary. Some people do very well with raw fruit; others
have more difficulty at first. If you are new to any particular fruit, you might have smaller servings at first, then gradually increase.
Printed from Oprah.com on Saturday, March 8, 2014
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