Because you’ll likely have a lot of questions about health stuff, I wanted you to hear the answers directly from the doctor so you feel really good about eating a plant-based diet! Neal Barnard, MD is a doctor, clinical researcher, and founding president of the Physicians Committee for Responsible Medicine, an international network of doctors and scientists. The below answers come directly from him, unless otherwise indicated.
How much protein do I need and where is the best place to get it?
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.
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. 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 it’s absorption is poor, unlike broccoli, Brussels sprouts, kale and other common greens, which 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 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 losses.
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.
What’s the scoop on soy?
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 supported 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 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, etc. Soy products come from an Asian tradition and are totally optional.
KF: I hear so many concerns about soy, so here are a few of the tweets and blogs that might help you make your decision about whether or not to eat it (I certainly do!).
Soy Tweets and Blogs (These are a few that I compiled; but there are so many!)
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 as asthma symptoms in response to pollen will find that these symptoms diminish when they leave dairy products aside.
Where can I get my Omega 3’s 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, in 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.
Is it ok to eat eggs, health wise? What about just egg whites?
There are major health issues with eggs. First, the yolk is where cholesterol lurks—more than 200 milligrams in one egg. That’s more cholesterol than you’ll find two quarter-pounders. There is also about 5 grams of fat in a single yolk.
Egg white is essentially solid pure animal protein. Its main problem is that the kidneys have trouble eliminating animal protein by-products. An 11-year Harvard study showed that kidney deterioration is accelerated by animal protein (for anyone who has already lost any degree of kidney function), whereas plant protein does no harm to the kidneys. It also tends to cause the body to lose calcium, just as other animal proteins do.
If it is hard to believe that there really is so much fat, cholesterol, and animal protein inside a single egg, keep in mind that an egg contains all the parts to make a complete chicken. The building blocks for the beak, bones, feathers, and everything else are inside that egg when it is laid, and they simply rearrange before the egg hatches. The cholesterol is used to build cell membranes, among other things, and there is, of course, no fiber, complex carbohydrate, or other healthful ingredients, because they are not part of a chicken’s biochemistry.
Will a plant-based diet affect my blood sugar?
Yes, avoiding meat definitely helps improve blood sugar. People who avoid meat are much less likely to develop diabetes and those who avoid all animal products are even less likely to do so. And, in clinical trials, people who make these same diet changes have dramatic improvements in blood sugar control. The most comprehensive study was our NIH-funded study, but other teams have found similar results. In 2010, the American Diabetes Association reported, as part of its official Clinical Practice Recommendations, that vegetarian and vegan diets have “metabolic advantages,” and one of the key ones is improved blood sugar.
Diabetes is obviously a serious condition, and a healthful diet is key to its management. If you have type 2 diabetes, a low-fat vegan diet is the diet of choice. It offers the best chance of reducing or eliminating your medications, and will help prevent complications.
Many people with diabetes are nervous about the fact that a plant-based diet increases their carbohydrate intake. The answer is not to turn to fatty, high-protein foods that increase the risk of cardiovascular and renal complications. Rather, the answer is to choose whole grains, legumes, vegetables, and fruits, focusing on low-glycemic index foods (ie, those that have minimal effect on blood glucose). The details are found in Dr. Neal Barnard’s Program for Reversing Diabetes.
I am just beginning to eat vegan but am experiencing a lot of gas; how do I deal with this?
If the problem is gassiness, beans are a common culprit. 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.
Fruit 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.
Digestive enzymes, such as Beano, can be used, but are usually unnecessary.
I am new to eating a plant-based diet but am nervous on the amount of carbohydrates I feel I am eating…coming from the Atkins diet, I am very aware of counting carbs. What should I do?
Keep in mind that the thinnest people on the planet—and who have the least diabetes—eat high-carbohydrate diets. That is, people in Japan and China and, of course, vegetarians tend to be slim and healthy.
The key is to think about which carbohydrate foods are best.
The first key is to choose those that are lowest in added fats. So rice is better than a cookie, and a baked yam is better than a baked potato that is drowning in butter and sour cream—and better than French fries dripping with grease.
Second, use the glycemic index. You’ll find all the details in Dr. Neal Barnard’s Program for Reversing Diabetes, but here it is in a nutshell.
Instead of sugar, have fruit. Yes, fruit is sweet, but it has little effect on blood sugar.
Instead of white and wheat breads, favor rye or pumpernickel.
Instead of white baking potatoes, have yams and sweet potatoes.
Instead of typical cold cereals, have oatmeal or bran cereal.
Rice and pasta are fine. Although whole-grain pastas are best, even white pasta has a low glycemic index. The real issue is to skip the meat and cream sauces, and stick to a low-fat tomato sauce.
How I can get enough of B vitamins and vitamin D from a vegan diet? The only option I see is to take vitamin supplements which don’t seem natural to have to take. How do I make sure I am getting all of the nutrients I need?
Actually, vegans generally have better overall vitamin intakes, 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.
Two vitamins deserve special comment:
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 multiple vitamin. B12 supplements are also widely available.
Vitamin D normally comes from the sun. About 15 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 have rather small amounts of vitamin D, but they also harbor cholesterol, mercury, and other things you don’t want. Surprisingly, mushrooms (eg, shitakes and chanterelles) contain vitamin D. Five dried shitakes provide roughly 5 mcg of vitamin D. You’ll also find it in fortified soymilk.
Nowadays, some health authorities recommend high vitamin D intakes—up to 2,000 IU (50 mcg) 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.
Is it healthy for kids to eat a plant based diet?
In the 7th edition of Dr. Benjamin Spock’s Baby & 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 children will eat. For example, children may not like cooked spinach, but they will 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 soymilk 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. The soy-based ones have a cancer-preventing effect for girls, and are healthful for all children.
It is also important to provide a pediatric multiple vitamin.
PCRM also has a book, called Healthy Eating for Life: for Children which is very detailed.
I have had breast cancer; are soy foods ok to eat for me?
Several recent studies have been very reassuring about soy products. Girls who have soymilk, tofu, or similar products on a regular basis during adolescence have about 30% less risk of developing breast cancer as adults, compared with those who tend not to have soy products. And a large JAMA study of women previously treated for breast cancer showed that they benefited, too. Those who consumed soy products regularly had about 30% reduced risk of recurrence, compared to women who did not include soy products in their routines. They also had significantly reduced mortality. So the evidence so far is strongly in favor of soy’s benefits.
Having said that, soy products are completely optional. A person who adopts a plant-based diet from a Mediterranean tradition would favor vegetables, fruits, pasta, and beans. From a Latin American background, it would mean beans, rice, tortillas, and plenty of fruit. Soy products reflect an Asian tradition. They have many attractions, but a person who, for whatever reason, prefers to skip them can certainly do so.