Optimal Nutrition

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Milk — Bad or good?

Dear Cow lover,

Why does a milking stool have only three legs? Because the cow has the udder! Get it? Unfortunately, there’s not such a definitive answer to YOUR question. Research on the health effects of drinking milk has produced mixed results. As with any other food group, it is important to consider the pros and cons of dairy consumption.

Before a discussion of pros and cons, here is a run-down on recent milk research as it relates to osteoporosis. Although it is thought that drinking milk every day helps ward off osteoporosis, a small group of renowned researchers recently found that drinking too much milk can actually contribute to calcium loss. This is because the high amount of protein in milk thins blood and tissue, causing it to become acidic. In order to neutralize the acidity, the body draws out calcium from bones. As a result, the more milk you consume, the more calcium you need to process the protein intake. With that being said, drinking moderate amounts of milk each day (500 to 700 milligrams daily) is still thought to be good for your bones. More information on osteoporosis can be found in Calcium, milk, and osteoporosis?.

Moooving on, here is a list of the various pros and cons of drinking milk:

Pros:

  • Milk is high in calcium, which is important for healthy bones. Additionally, the calcium in milk is well absorbed by the digestive tract because the vitamin D and lactose found in milk facilitate calcium absorption. Still, it's possible to get ample calcium without drinking dairy milk — by eating foods such as tofu, soy milk, or greens such as kale. See Calcium — how much is enough? for more information.
  • Whole milk is brimming with protein, which is beneficial for muscle growth.
  • Studies have shown that drinking milk can help regulate weight gain.
  • Skim milk is very low in fat and cholesterol, and is a complete source of protein.
  • Milk is also a good source of phosphorous, magnesium, vitamin A, vitamin D, and riboflavin (a B vitamin).

Cons:                          

  • Whole milk is high in saturated fat, which can increase cholesterol level.
  • Milk is a common cause of food allergy (allergy to milk protein).
  • Many people lack the enzyme to digest lactose (milk sugar). This is called lactose intolerance, which causes bloating, gas, and diarrhea.
  • Milk may contain the antibiotics given to the cow while it is lactating. It has been argued that humans subsequently absorb these antibiotics upon drinking milk, potentially leading harmful bacteria to become more resistant to these antibiotics. As a result, when antibiotics are prescribed, they may not be as effective at killing the bacteria.
  • Some research has found a correlation between drinking milk that is produced by cows injected with the bovine growth hormone (rBST) and cancer. However, research shows highly mixed results.

As a side note, if you are concerned about the possible effects of antibiotics and rBST on your body, it is possible to buy antibiotic-free (and typically hormone-free, as well) milk from specialty grocers that carry natural foods. Alternatively, you can purchase USDA-certified organic milk, which is available at most supermarkets.

Overall, when researching the pros and cons of milk, it is important to take into account that there are two opposing sides — one that believes that milk is great for the body, and another that believes that milk does not aid against osteoporosis and is even harmful for the body. Whatever camp you choose to join, it is important to be informed. Seize every opportunity (to obtain information), and milk it for all its worth!

Alice

Creatine monohydrate supplement for strength?

Dear Reader,

Creatine is a substance manufactured in the human body by the liver and kidneys or obtained from meat in the diet. It is present in muscle, nerve, and sperm cells. In muscles, creatine is used to form phosphocreatine, which can be used to supply energy needed for muscle contractions. It has been suggested that by increasing creatine in the diet, one may increase the amount of phosphocreatine in the muscle, which would then provide a greater availability of high energy phosphate for energy production during muscle contraction. It also may cause the muscles to retain water, a proposed mechanism for the "bulking" effect of the supplement.

No one really knows how much creatine is too much. Some people experience muscle cramps, electrolyte imbalances, fever, or gastrointestinal symptoms like nausea and diarrhea when they take creatine. Long-term effects are much less well-studied. While there is little conclusive evidence for adverse affects, people who have liver or kidney problems or who take diuretics should avoid taking creatine because of the theoretical complications. People with diabetes or who take either medications or supplements that affect blood sugar should also use caution. If you start to notice any side effects, you should stop taking creatine and see your health care provider.

As for benefits, creatine can enhance performance for short bursts of anaerobic activity, like weightlifting. However, people doing aerobic activities, like running or cycling, probably won't see any improvement.  

The amount taken in through commercially marketed supplements is far greater than one would be able to ingest via food. Some regimes call for a loading period — perhaps 20 to 25 grams for five days, followed by daily doses of about 5 grams. Non-meat eaters (vegans) may respond better since their natural creatine stores are probably lower than meat-eaters. Since any long-term effects from these high levels are uncertain, your best bet is to let your health care provider know that you take creatine. That way, if you ever do experience side effects, he/she will be better able to help you decide whether to keep pumping up.

Alice

Non-meat proteins

Dear Veggie,

As vegetarianism, veganism, and even just eating less meat become more popular dietary and lifestyle choices for a growing number of people, adequate protein sources are always a topic of discussion. There have been scores of arguments about protein in all its facets: how much you need, what kinds are most useful to the body, and how to prepare it. But what it comes down to is: every body is different, has different needs, and digests foods uniquely, so the best non-meat sources of protein for one person might be the worst for someone else.

The recommended daily protein intake for healthy adults is about 0.4 grams per pound of body weight. Vegans (those who avoid all animal products, including dairy and eggs) may require a bit more at 0.5 grams per pound of body weight. Protein facilitates growth, metabolism, immune system functioning, repair, muscle contraction, and the transmission of nerve impulses and hormones in the body. It can also be a source of energy when the body runs out of carbohydrates and fat for fuel. And protein's not that hard to find, even for vegetarians. Almost every food contains protein: nuts, seeds, beans, soy products (tofu, soy milk, tempeh), grains (wheat, oats, rice), eggs, and dairy products all being excellent vegetarian sources (many of which tend to be low in saturated fat, cholesterol, and sodium).

The list below gives the protein content of some of the highest protein and/or most popular vegetarian foods:

  • Tempeh — 1 cup — 31 g
  • Lentils — 1 cup — 18 g
  • Chickpeas — 1 cup — 15 g
  • Tofu (firm) — 4 oz — 11 g
  • Peanut butter — 2 tbsp — 8 g
  • Soymilk — 1 cup — 7 g
  • Soy yogurt — 1 cup — 6 g
  • Whole wheat bread — 2 slices — 7 g
  • Broccoli, cooked — 1 cup — 4 g

Protein is a macronutrient made up of smaller parts, called amino acids. There are different amino acids, many of which the body can produce, but nine which the body cannot. These nine must be eaten, and are therefore called essential. Animal proteins contain all nine of these essential amino acids in appropriate proportions, while the proteins found in plants often do not. Plant-based sources of protein have various amounts of amino acids in them. As such, it was previously thought that certain ‘complimentary proteins’ or combinations of plant-based proteins were needed in order to get all essential amino acids. However, rather than planning specific food combos at each meal, eating a variety of plant-based proteins over the course of a day should ensure that you get the essential amino acids you need.

You might find it helpful to consult with a registered dietitian if you want a more specific evaluation of your diet and unique nutritional needs. Columbia students can contact Medical Services (Morningside) or the Student Health Service (CUMC) to schedule an appointment. There is also a wealth of information online about vegetarian recipes, philosophies, and nutritional facts about specific foods.

People decide to eat less meat or no meat for myriad reasons that include health, animal rights, environmental sustainability, and religion. You can rest assured that your decision will further any or all of these goals without depriving you of the protein you need. Enjoy!

Alice

Avocados are fatty — are they healthy?

Dear Guacamole,

No need to pause that chip in midair, or order sushi sans avocado! Avocados are indeed high in fat, but they're high in monounsaturated fat, the good fat, the kind of fat that may actually help lower blood cholesterol levels. And as you rightly said, avocados contain no cholesterol — no plant foods do.

You may have heard the term low-density lipoproteins (LDL) in the discussion of different types of cholesterol. LDL cholesterol is often referred to as bad cholesterol because when the body has too much it can form plaque on the walls of arteries and veins which can cause heart attack or stroke. In contrast, high-density lipoproteins (HDL) clear the blood stream and artery walls of LDL and transport it to the liver where it can be broken down and eliminated. Lowering LDL and increasing HDL is considered desirable in terms of preventing heart disease and stroke. The good news in terms of those tasty avocados is that eating monounsaturated fats, especially while decreasing intake of carbohydrates and saturated fats, may decrease levels of LDL and raise HDL cholesterol.

The American Heart Association recommends that total fat intake be kept to 25 to 35 percent of your daily calories and that saturated fat comprise less than seven percent of total daily calories. That means the remaining fat should come from monounsaturated and polyunsaturated fat sources like nuts, seeds, fish and vegetable oils. Translated into layman's terms this would mean that a typical 2,000 calorie a day diet would include 50 to 70 grams of fat, with about 34 to 50 grams of that fat from poly- or monounsaturated sources and about 16 grams or less from saturated sources. Because it's hard to keep track of exactly how many grams of fat are coming from which sources, it's a good rule of thumb to choose unsaturated over saturated fats whenever presented the option. Saturated fats come from animal products like meat, seafood, milk, butter, cheese, and ice cream. Monounsaturated fats come from vegetarian sources like nuts, seeds, vegetable oils, olives, and, drum roll please… avocados.

In addition to containing healthful fat, avocados are also high in beta carotene, fiber, folate (a B vitamin), and potassium (ounce for ounce, avocados have 60 percent more potassium than bananas). To put the fat in perspective, avocados have less fat than lean beef per ounce, and a whole Haas avocado has less fat than 3 tablespoons of Italian salad dressing. While it's a good idea to take all fats in moderation, rather than shun the guacamole bowl at the party, help yourself to some of the green gooeyness, along with plenty of veggies, fruits, and whole grains. Enjoy!

Alice

Bananas = fat?

Dear Banana Lover,

Nutritionally, bananas are packed with many good things. To get right to your question, according to the U.S. Department of Agriculture (USDA), one medium banana contains only 0.39 grams of fat. Compare that to a California avocado that has 21 grams of fat (with 3 grams of saturated fat). Like protein and carbohydrates, fat is an important macronutrient that plays a vital role in maintaining health. So while you don’t have to eschew avocados and olives, you can rest assured that eating a banana will provide some low-fat satisfaction in a balanced diet.

Bananas make a healthy and helpful snack choice for endurance athletes (and others) because they have higher carbohydrate content when compared to other fruits (by weight). They also provide a good source of potassium, which is vital for controlling the body's fluid balance, and regulating one's heartbeat and blood pressure, and preventing muscle cramping.

Think of it this way, if a contest called for designing an ideal food, you might just come up with a banana. They are neat (they come in their own wrapper!), they ripen best after harvest, they can be eaten at various stages of ripeness, there is a good supply all year, they tend to be inexpensive, and almost everyone can digest them. Chew on this, in an average year Americans consume about 25 pounds of bananas per person.

Perhaps you can help spread the word that people should just enjoy having their bananas and eating them, too!

Alice

Food Guidelines — How much is a serving?

Dear Trying to Eat Healthy,

Knowing what and how much to eat can feel overwhelming. In recognition of the fact that more Americans are overweight and obese than ever before, the U.S. Department of Agriculture (USDA)/U.S. Department of Health and Human Services regularly reviews and updates the food guide recommendations. The newest update by "Choose My Plate" and makes suggestions based on age, gender, and activity level. It no longer recommends amounts of food in terms of serving size, but rather suggests portions according to actual weights and amounts of specific foods. You can learn more about how to apply the new food guide recommendations to your lifestyle at ChooseMyPlate.gov.

Even though there is no single chart that details how much of a particular food constitutes a serving, you can click on each food group's heading (see below) for more information on common portion sizes. Also, here's a basic breakdown of the guidelines:

Grains
One serving equals 1 slice of bread; 1/2 cup of cooked rice, pasta, or cereal; or 1 cup of ready-to-eat cereal. All of these serving sizes are known as "ounce equivalents" in Choose My Plate-speak.

As a general rule of thumb,
1 serving size/ounce equivalent of bread = plastic CD case
2 servings/ounce equivalents of cooked brown rice = a tennis ball

Vegetables
Unlike the Grains group described above, cup size matters when it comes to vegetables. That is, vegetables servings are measured in cups rather than ounces. One serving equals 1/2 cup of raw or cooked vegetables or vegetable juice or 1 cup of leafy raw vegetables.

1 serving size = 1/2 cup of broccoli = a light bulb
1 serving size = 1/2 cup of potato = a computer mouse

Fruits
Like the vegetable group, cup size matters here, too. One serving equals 1 cup of fruit or 100 percent fruit juice, or 1/2 cup of dried fruit. Because fruits come in so many different shapes and sizes, it's hard to say how many pieces of fruit count as a serving.

Generally, 1 serving size of whole fruit = 1 tennis ball
1 serving size of cut fruit = 7 cotton balls

Dairy
One serving equals 1 cup of milk or yogurt, 1.5 to 2 ounces of cheese, and even 1.5 cups of ice cream. Choose low-fat options from this group whenever possible.

1 serving size of cheese = 2 9-volt batteries

Protein
Like the Grains group, serving sizes are also measured in ounce equivalents. One serving or ounce equivalent equals 1 ounce of cooked lean meat, poultry, or fish; 1/4 cup cooked beans; 1 egg; 1 tablespoon of peanut butter; or 1/2 ounce of nuts or seeds.

3 servings/ounce equivalents of fish = 1 checkbook
3 servings/ounce equivalents of meat or poultry = 1 deck of cards
2 servings/ounce equivalents of peanut butter = 1 roll of 35 mm film or 1 ping-pong ball

Oils
Choosemyplate.gov measures serving sizes in teaspoons.

1 serving/teaspoon of margarine and spreads = 1 dice
2 serving/teaspoons of salad dressing = 1 thumb tip

Because these oils are found in many of the foods we eat, there may not be a need to add this group to your diet. For example, half of a medium avocado or 2 tablespoons of peanut butter provide 3 and 4 teaspoons or servings of oil respectively, while also counting towards your vegetable or nuts allowance.

Remember, also, that most portions in the U.S. are oversized and contain several servings of the recommended categories. Ideally you want most of your food to be whole grains, plenty of fruits and vegetables, low-fat calcium fortified foods (such as milk and cottage cheese), and lean sources of protein (such as fish, turkey, and chicken).

If you're hungry for more information on dietary recommendations, check out the Dietary Guidelines for Americans 2010 and the American Academy of Nutrition and Dietetics’ Food and Nutrition Information web site. At Columbia, you can make an appointment with a registered dietitian to discuss your concerns and get more individualized information by contacting Medical Services (Morningside) or the Student Health Service (CUMC).

Alice

Risks of aspartame?

Dear Diet Coke,

Aspartame — how sweet it is! A common artificial sweetener used in various foods and drinks, aspartame is about 200 times sweeter than sugar. However, it contains fewer calories than sugar, making it a substitute for individuals who wish to cut back on sugar. To date, the U.S. Food and Drug Administration (FDA) considers aspartame safe to use, though it recommends maximum levels of acceptable daily intake (ADI) for children and adults.

An adult weighing 150 pounds (70 kilograms) can have up to 3,500 milligrams per day of aspartame. In terms of diet soda, this translates into no more than 19 cans of diet soda per day (diet soda typically contains 180 milligrams of aspartame per can). A child who typically weighs 66 pounds (30 kilograms) could drink up to 8 cans of diet soda before going over the ADI for children. That's still quite a lot of soda! There may be other considerations, such as caffeine and the acid in soda that can damage teeth, to weigh before drinking a case a day.

There is no conclusive data demonstrating that aspartame poses a safety risk to humans. However, the FDA has noted some possible, but uncommon, side effects of aspartame consumption. These complaints have included headaches, dizziness, stomach problems, and changes in mood. One particular safety risk of aspartame involves individuals with phenylketonuria (PKU). PKU is a rare genetic disease characterized by the inability to break down the amino acid phenylalanine, which is found in aspartame. People with PKU should avoid all products that contain aspartame. These products are labeled for easier recognition.

You may want to keep in mind that aspartame and other artificial sweeteners are not exactly a green light to consume excessive amounts of foods and drinks that contain it, as the calories still add up. Research suggests artificial sweeteners may stimulate a person's appetite. Because they have no caloric content, they don't seem to activate the same food reward signals in the brain that induce feelings of satiety. As a result, craving a sweet flavor after eating artificially sweetened foods but not feeling full or satisfied by them may lead to overeating.

If you are concerned about the safety of aspartame, you can always check the labels of the foods and drinks before you buy them. You may also want to consider discussing any concerns with a health care provider, who may be able to suggest other sweetening alternatives. If you are a student at Columbia, you can make an appointment to see a health care provider by contacting Medical Services (Morningside) or the Student Health Service (CUMC).

Here's hoping that this response didn't sugarcoat your concerns!

Alice

Egg substitutes

Dear Yolking it Up,

Egg powder is usually simply dehydrated eggs, a substitute that people may use when they're camping, or in other situations where there is a lack of refrigeration. Egg powder may also be added to some cake mixes, pancake mixes, and the like, so that the home baker doesn't have to add whole eggs to the mix. A large egg contains about 6 grams of high quality protein, making both eggs and egg powder good sources of protein. Eggs are also an important source of vitamins B12 and E, riboflavin, folacin, iron, and phosphorus. These make it one of nature's near perfect foods, except for the cholesterol — its yolk contains a significant portion of the total daily maximum intake of cholesterol.

Many people experiment with egg whites in order to lower the cholesterol content of their favorite recipes. There are numerous egg substitutes on the market, which come in frozen, refrigerated, and powdered form (this may be what you are referring to in your question). Most of the substitutes have egg whites as their main ingredient. The white of the egg is almost pure protein, containing a near complete balance of complementary amino acids. So, these substitutes are definitely a good source of protein, but not of fat or cholesterol, or B vitamins and minerals.

With the variety of egg substitutes on the market, it's important to read the label carefully. Some have vegetable oil, flavoring, or color added to give the effect of yolk. Other products contain no eggs at all, and are intended to be used in baked products to produce the leavening effect, but would taste terrible as scrambled eggs. The products range in caloric content from 15 to 60 calories per serving, as compared with about 80 calories for a whole egg. Most have little or no cholesterol, but some contain as much as 4 gms of fat per serving.

The American Heart Association recommends limiting average daily cholesterol intake to less than 300 milligrams. If you have heart disease,  the recommendation drops to less than 200 milligrams daily. It may make sense to consult with a nutritionist or your health care provider if you already have elevated levels of cholesterol. 

As with many foods, moderation is the key to getting "eggs-actly" what is best for your health.

Alice

Becoming a vegetarian — Columbia Health resources?

Dear Future Veggie,

Yes, absolutely! Columbia Health has lots of resources for you as you prepare to make the switch. When planning out a healthy vegetarian diet, it is certainly helpful to have some guidance. Get Balanced! Columbia University's Guide for Healthier Eating provides a ton of great information on making healthy food choices as a vegetarian or vegan. Columbia students can also meet with a registered dietitian through Columbia Health. Before meeting with a professional, it may be helpful to do some background research. Check out the related questions below for a plethora of useful information!

It's a great idea to plan consciously when switching over to a vegetarian diet. Not eating meat can offer many health benefits, as well as addressing environmental and ethical concerns. However, people who make the change without learning about proper nutrition can very easily become deficient in certain nutrients, experience undesired weight gain or loss, and fall into the famous trap of becoming a "pasta" vegetarian who lives on carbs and sweets and not much else.

Have you thought about to what degree of vegetarianism you will pledge? There are many variations on the vegetarian diet, including: lacto-ovo, vegetarians who avoid all meat but eat milk and eggs; pescatarians, who eat fish, and do not eat other types of meat; vegans, who avoid all animal products including milk, eggs, and even honey (produced by bees); raw foodists, who eat only raw fruits, veggies, sprouted nuts and grains; and even fruititarians, who only eat fruits, nuts, and seeds. Wherever you fall on the vegetarian spectrum, here are some general tips on converting to a vegetarian diet:

  • Plan to incorporate into your diet a wide variety of whole grains, fruits, vegetables, legumes, nuts, seeds, vegetable oils, and of course leave room for some decadent delights (think: vegan triple chocolate cake).
  • Ensure that you are eating adequate amounts of non-meat proteins, necessary for long-term sustained energy, and to repair and replace worn-out body cells. High protein veggie foods include beans, nuts (including peanuts and almonds), and milk.
  • Vitamins B-12 and D, calcium, iron, and zinc are other nutrients important to pay attention to, as they are abundantly found in meat, but not as easy to find in plant foods. Some strategizing with a nutritionist or educating yourself about vegetarian sources for these nutrients will help you make sure you're getting enough of these important nutrients.
  • Because vegetarian diets are often high in fiber, remember to drink lots of water to ensure all that roughage is moving through and out of your system efficiently. Six to eight glasses per day is the general recommendation.

When planning a vegetarian diet, it is important to take into consideration a number of variables, such as body size, activity level, health status, and food preferences. But standing behind your ethical beliefs with the food you take in and the industries you support is an admirable and worthwhile undertaking. With the right guidance, education, and support, you could enjoy great health, a happy and clean conscience, and the joy of being an inspiration and teacher for others who wish to join you!

Alice

Difference between olive oil and corn oil

Dear Three-in-one,

There is a bit of debate about the pros and cons of olive oil vs corn oil. Some newer research suggests when included in a well-balanced diet, corn oil may have comparable or possibly greater, health benefits when juxtaposed with olive oil. Both corn and olive oil are made up of mostly unsaturated fats. Monounsaturated fats and polyunsaturated fats are often described as “healthy fats”. Research suggests that these two types of fatty acids may help lower cholesterol, normalize blood clotting, and also possibly improve insulin and blood sugar levels — and they are healthier choices to cooking with butter or lard. Good vs. bad fats can provide some more detailed information about the different types of fat found in food.

Olive oil has a higher percentage of monounsaturated fats when compared to corn oil. The exact ratios are as follows:

  • Corn oil: 59% polyunsaturated 24% monounsaturated 13% saturated, which give a 6.4:1 unsaturated/saturated fat ratio
  • Olive oil: 9% polyunsaturated 72% monounsaturated 14% saturated, which gives a 5.8:1 unsaturated/saturated fat ratio

For quite some time monounsaturated fats were credited with lessening the hardening of arterial walls and thus reducing risks of heart and kidney disease. Recent clinical studies seem to lean more heavily towards the positive impact of polyunsaturated fats over monounsaturated fats in protecting against heart disease.

Also of note when cooking with oils, corn oil tends to be more stable at higher heats, whereas olive oil is more stable at lower heats and tends to burn at high heats. So, depending on your recipe, one may be more suitable on the stove than the other.

Olive oil also has the most nutritional value when it is freshest, according to researchers. As soon as olive oil is exposed to air and light it begins to degrade and lose its heart-healthy benefits. While many of us are accustomed to expiration dates on bottles and cans, olive oil can also have both an expiration date and a harvest date — checking for those is advised by industry leaders. Olive oil enthusiasts and experts suggest using oil within about six months of harvest, if possible. When you store olive oil between uses, try to keep it in a cool environment away from light.

When shopping for corn oil, some consumers may be concerned with finding sources that are free of genetically modified organisms (or GMO-free). Corn is one of a handful of crops that are more likely to be genetically engineered than others. To learn more about GMO debate, check out GMO’s — okay for consumption?

While the existing research on olive and corn oil has certainly shaped nutritional recommendations we may have heard for years, it’s also worth noting that even clinical studies have limitations. And just like the evolving understanding of monounsaturated fatty acids vs. polyunsaturated fatty acids, what we know about olive oil and corn oil today may evolve with new research and deeper understandings of how these oils play a role in our bodies and health. 

Perhaps equally if not more important than the type of oil itself, is what you are sautéing, dressing, or marinating. Eating a well-balanced diet in addition to choosing dishes and snacks with healthy fats may make the bigger impact on overall health. Some research suggests that diets with an emphasis on vegetables, fruits, legumes, and whole grains (and less emphasis on meat, poultry, and dairy) when partnered with healthier fats from sources like nuts, corn oil, and olive oil can promote heart health and lower cholesterol.

If you are looking for more individualized advice on diet and nutrition, you may want to speak with a registered dietician, or a health care provider. If you’re a Columbia student, both the Morningside campus Medical Services and the Student Health Service on the Medical Center campus have registered dieticians on staff for nutritional consultations. You can also access nutritional information through Alice! Health Promotion Nutrition Initiatives.

Here’s to good eating and good health!

Alice

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