Optimal Nutrition

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What's the main purpose of electrolytes?

Dear Reader,

Electrolytes are vital to one's health and survival. They are positively and negatively charged particles (ions) that are formed when mineral or other salts dissolve and separate (dissociate) in water. Since electrolytes carry a charge, they can conduct electrical current in water, which itself in its pure form is a poor conductor of electricity. This characteristic of electrolytes is important because the current enables electrolytes to regulate how and where fluids are distributed throughout the body, which includes keeping water from floating freely across cell membranes.

Basically, cells need to be bathed in fluids — inside and out. To control fluid passage across cell membranes, cells regulate the movement of electrolytes into and out of them, which causes water to follow the charged particles around wherever they go. These actions help maintain a state of fluid balance. This is also how electrolytes transport nutrients into cells and wastes out of them. The difference in electrical balance inside and outside of cells also allows for transmission of nerve impulses, contraction or relaxation of muscles, blood pressure control, and proper gland functioning. In addition, the presence of electrolytes determines the acidity or pH of some fluids, especially blood.

As you can see, our bodies have developed mechanisms to keep electrolytes within specific ranges. If one loses large amounts of fluids quickly, however, electrolytes may become unbalanced. This imbalance can occur through vomiting, diarrhea, excessive sweating, serious burns, or wounds. In these cases, water and electrolytes need to be replaced. Life-threatening conditions may result if the losses are severe.

A well balanced diet usually supplies an adequate amount of electrolytes. The major ones are sodium, potassium, and chloride; others include calcium, magnesium, phosphate, and bicarbonate, to name a few. Most Americans get plenty of sodium and chloride from what they eat. Including five or more daily servings of fruits and veggies will provide sufficient potassium. Sports drinks containing these substances are usually only recommended for endurance events lasting over an hour.

Alice

Nuts about nuts: Are some better for health than others?

Dear Nuts for nuts,

What did one squirrel say to the other squirrel? "I'm nuts about you!" One variety of nut isn't necessarily healthier or better than another. All nuts are healthy, unless you have an allergy or sensitivity to one or more kinds. While individual types vary in nutrients, most nuts contain an array of vitamins and minerals, such as iron, magnesium, zinc, vitamin E, and small amounts of folate, copper, phosphorous, and calcium. Nuts may also contribute to one's daily protein and fiber needs.

The following chart provides nutritional information for some popular nuts. All numbers are for dry roasted, unsalted nuts. Some nuts are roasted in oil, which adds fat and calories without adding additional vitamins or minerals. In addition, some nuts are salted, which may greatly contribute to one's daily sodium intake. Based on that information alone, it seems that dry roasted, unsalted nuts are the way to get the best bang for your buck.

Nut type Calories(per oz.) Fat (g) Sat. Fat (g) Unsat. Fat (g) Protein (g) Fiber (g) Calcium
(% DRI)
Zinc (% DRI) Vit. E (% DRI) Magnesium (% DRI)
Peanuts 166 14 2 12 7 7 1.5 9 19 12
Walnuts 182 18 2 16 4 4 3 7 7 11
Pecans 189 19 2 17 2 2 1 15 8 9
Almonds 167 15 1 14 6 6 7 9 11 20
Cashews 163 13 3 10 4 4 7 15 1 18
Macadamia 200 21 3 18 2 2 2 4 1 7

Nuts are calorie dense foods, meaning they pack a lot of calories into a small amount of food. This can be helpful for people trying to gain weight, but also need not make them off limits to those watching their waistlines. For example, one ounce of most nuts equals about 18 to 24 nuts (a small handful for many, and a tiny handful for larger-handed folks), and contains between 165 and 200 calories. The majority of the calories in nuts is derived from their unsaturated fats — specifically, monounsaturated fat — which is more healthful than saturated fat.

Nuts offer so many valuable nutrients, and can be enjoyed in small servings as well. Why not try to:

  • Mix sliced nuts into plain rice, rice pilaf, or couscous.
  • Sprinkle slivered nuts onto vegetables or into salads.
  • Use slivered or chopped nuts as a yogurt topping.
  • Substitute diced nuts for croutons in salads.
  • Add chopped nuts to vegetable dips or soups.

In conclusion, it's great that you're nuts about nuts. No ifs, ands, or nuts about it!

Alice

What's that growing in the refrigerator?!? A guide for storing and eating leftovers

Dear Leftover lover,

Enjoying holiday leftovers is a favorite tradition. However, food-borne illness resulting from eating leftovers long past their prime can dampen holiday cheer. Typical symptoms of food-borne illness, caused by bacteria, include abdominal pain, diarrhea, and vomiting.

Two different families of bacteria are found in food: pathogenic bacteria and spoilage bacteria.

Pathogenic bacteria cause food-borne illness. Leaving food out at room temperature (about 72° F or 22° C) for extended periods of time encourages growth of these types of pathogens. These bacteria grow rapidly when in the "danger zone," which is between 40° to 140° F (4 to 60° C). They are difficult to detect, because they don't affect the taste, smell, or appearance of food. Safe food handling and proper food storage are the best defenses against pathogenic bacteria. For detailed instructions on how to keep food safe for consumption, check out the Partnership for Food Safety Education web site.

Spoilage bacteria can grow at lower temperatures, such as ones found in refrigerators. These bacteria cause food to taste, look, and/or smell badly. Most of the time, spoilage bacteria won't cause illness, but they do make food much less appealing to eat.

Leftovers need to be kept in airtight containers recommended for reuse and food storage in the refrigerator and/or freezer. Leftovers can also be wrapped in two layers of plastic wrap and/or foil or in a plastic storage bag (with the food inside wrapped in a layer of plastic wrap or foil) to maintain moisture and prevent absorption of odors from other foods. When freezing leftovers, adding freezer tape also helps keep air and moisture out, and protects from freezer burn. Here are some safe time limits for keeping some common meat and poultry leftovers:

Food Item

Refrigerator Storage Temp.
(40° F / 4° C)

Freezer Storage Temp.
(0° F / -18° C)

Cooked turkey or chicken, plain

3 to 4 days

4 months

Cooked turkey or chicken dishes

3 to 4 days

4 to 6 months

Turkey or meat broth, gravy

1 to 2 days

2 to 3 months

Lunch meat

Unopened, 2 weeks
After opened, 3 to 5 days

1 to 2 months

Cooked fried chicken

3 to 4 days

4 months

Cooked chicken nuggets or patties

1 to 2 days

1 to 3 months

Cooked meat and meat casseroles

3 to 4 days

2 to 3 months

For more information on the safe keeping of most foods, visit the U.S. Department of Agriculture (USDA) Food Safety and Inspection Service web site. Enjoy your holiday meal today, tomorrow, and the next day,

Alice

Time-release dietary supplements

Dear Reader,

It's easy to become confused with the whole array of dietary supplements on the shelves nowadays. One form may claim superiority in advertisements, but how are you to know for sure which ones are right for you?

First of all, vitamins and minerals are needed in our bodies in relatively small amounts. Vitamins may be present in our blood, organs, or other tissues. Although each micronutrient (scientific term for vitamins and minerals) has a specific function, here's a brief overview by category:

  • Water-soluble vitamins (all the B vitamins and vitamin C) and many minerals act as co-enzymes, meaning they aid in chemical reactions in the body. Excessive amounts don't make reactions occur faster or more efficiently than adequate or recommended amounts. Plus, too much of one mineral may actually inhibit the absorption and effectiveness of another.
  • Fat-soluble vitamins (vitamins A, D, E, and K) are involved in specific roles of maintenance and repair of body cells and tissues. Unlike water-soluble vitamins, extra amounts of fat-soluble vitamins are not excreted, so over-saturation of these may lead to toxicity.
  • Minerals have a variety of functions, ranging from water and acid-base balance, to bone structure and co-enzyme activity, as mentioned before.

As long as you consume a sufficient vitamins and minerals, a constant influx is not necessary, and may also be harmful. For example, time-release niacin is not recommended because it can cause liver damage. Time-release iron supplements are ineffective because the point of release in the intestinal tract does not absorb this mineral efficiently. Some time-release supplements contain coatings that prevent the absorption of fat-soluble vitamins. As you can see, time-release nutritionals are certainly not worth the extra money manufacturers often charge for them. Besides, Mother Nature has already provided us with a way to time-release our nutrients... by getting them from a variety of foods, eaten at various times throughout the day.

To get to your last question, you are among quite a number of men and women who have expressed concern over whether their multi-vitamin "works" or "doesn't work"; that is not really the point of these supplements. Their purpose is to help certain people fill in nutritional gaps when they are unable to eat enough food or obtain adequate vitamins and minerals from their diet. Multi-vitamins also might be recommended for some vegetarians, dieters, and others who have food allergies, intolerances, or other problems associated with eating particular foods. A supplement may benefit the elderly, too, because sometimes older people can't absorb nutrients as well as they did in their youth. Remember, the meaning of a dietary supplement is to add to a diet, not to take the place of food!

Alice

Are yams an adequate alternative to hormone replacement therapy?

Dear Ana,

Wild yam (Dioscorea villosa) and Mexican yam have been marketed as alternatives to synthetic progesterone (not estrogen), which is a hormone taken by some women during menopause. These yams contain diosgenin, a plant substance that has a chemical structure similar to progesterone. In the laboratory, diosgenin can be converted to progesterone by using specific reagents and enzymes to carry out a series of chemical reactions. This transformation can only be performed in a lab — the same process does not occur in the human body. As a result, it's actually misleading for a manufacturer to term a wild yam supplement as "natural progesterone" because it is not progesterone, nor does it have any impact on a woman's hormone levels. Since diosgenin doesn't have hormonal activity itself, creams containing this substance are not effective.

In the United States, what is commonly referred to as a "yam" is actually a variety of sweet potato (ipomoea batatas). Yams are similar in shape to sweet potatoes, but are drier and starchier in taste, and are rougher and scalier in texture. Sweet potatoes are a good source of beta-carotene, vitamin C, folic acid, and some B vitamins. Predominantly grown in the Caribbean and Africa, yams are a good source of potassium, but contain no beta-carotene, and have lower levels of B vitamins, vitamin C, and folic acid than sweet potatoes. Eating sweet potatoes or yams will provide nutrients, but, as they contain neither progesterone nor estrogen, they won't affect a woman's hormonal balance.

Alice

Fiber supplements — Safe to use every day?

Dear Regular,

Some of the fiber supplements (available in powder and pill forms) you are referring to are designed to help alleviate constipation, and are to be used for a limited time only. That's because if a person has chronic constipation, the cause needs to be determined. Other products can be used as supplements, as long as there are no underlying medical issues, such as chronic constipation. Two steps to determine how you use supplements are 1) read the labels carefully to find a fiber product that can be used daily, and 2) speak with your health care provider to determine if you should be taking a daily supplement.

For people who experience constipation or other irregularity with their bowel movements, some causes may be: 

  • Inadequate fiber consumption
  • Lack of exercise
  • Insufficient fluid intake
  • Change in one's daily routine
  • Ignoring the urge to move one's bowels
  • Certain diseases
  • Some medications

Luckily for you and anyone who needs more fiber, fruits and vegetables aren't the only good sources for getting more fiber into your diet. Here are some fiber boosting tips:

  • Have a higher fiber cereal for breakfast — try to select one that contains at least 5 grams per serving.
  • Add beans to salad, or dine on a cup of chili for lunch. Each ½ cup of beans contains 3 to 4 grams of fiber.
  • Choose whole wheat bread, which has 2 grams of fiber per slice.
  • Munch on berries (one serving = ½ cup), pears (1 medium with skin), and oranges (1 medium). If you eat just two servings of these a day, you'll add 7 to 8 grams of fiber.
  • Snack on popcorn (go for air-popped). You get 1 gram of fiber per cup (equal to about 2 to 3 handfuls).
  • Have a baked potato, which has almost 4 grams of fiber.
  • Chomp on a medium carrot, which can add 2 grams of fiber.

Part of the benefit of getting fiber through food is that you will also take in the abundant vitamins, minerals, and plant chemicals (phytochemicals) that are present — you'll get lots of important nutrients, such as vitamin A, thiamin, riboflavin, niacin, folate, vitamin C, vitamin E, chromium, copper, iron, magnesium, potassium, and zinc; also in these foods are disease fighting plant chemicals, such as anthocyanins, alpha and beta-carotene, isoflavonoids, and phytosterols, among others.

If you do take a fiber supplement, you'll want to be careful because too much fiber can bind important minerals, such as calcium, iron, and magnesium, decreasing their absorption by the body. If you have more questions about your use of supplements, it would be a great idea to ask your health care provider, who knows your medical history and can recommend the best source of fiber for you. If you're a Columbia student, you can make an appointment with Medical Services (Morningside) or the Student Health Service (CUMC).

Wishing you continued regularity,

Alice

Helping a friend to eat healthier

Dear In a quandary,

Your friend definitely isn't alone, but in order for her to change her behaviors or ingrained patterns, she needs to acknowledge that a problem exists, or see a benefit from making a change. Because food and eating habits are such a personal aspect of our lives, it can be a sensitive area of discussion. To answer your first question, diets that are high in fat, sodium, and calories, and low in fruits, veggies, calcium, and other nutrients, may contribute to the development of diseases, such as heart disease, diabetes, hypertension, and osteoporosis, among others. If this factor is a concern to your friend, she may consider changing her patterns. However, if she is healthy now, the thought of developing any of these conditions in the far off future may not be motivation enough for her in the present time to change habits with which she's been comfortable.

One thing is for sure — criticizing and nagging don't work! So, what can you do? First of all, you can suggest spending time together doing some sort of activity. If you can get your friend moving, she may become interested in eating more healthfully. Try to disguise exercise into a fun pursuit. Some ideas include:

  • Going for a walk
  • Swimming
  • Hiking
  • Bike riding
  • Flying a kite
  • Playing Frisbee
  • ice skating
  • Borrowing a dog to bring to the park (or bringing your own) and playing ball

Another tact you can try is to determine something that is important to her, and show her that eating better can help improve the matter. While many people aren't motivated by diseases they can't relate to or that seem intangible, immediate concerns can hold more relevance. For example, skin problems, low energy levels, or stomach discomfort can promote a greater incentive or inclination to change. If she complains about any of these conditions, some appropriate suggestions could include drinking more water than diet soda, substituting a juicy piece of fruit for the chips, or heading over to an enticing salad bar rather than making a quick trip for fast food. Considering and implementing any changes or new patterns are only part of the challenge; maintenance is also key, and can be easier to follow-through when done together with a peer than by one's self. Your can demonstrate your support by bringing over some farm fresh apples, cooking a healthy meal together, going to lunch together at an eatery where healthy choices are available, walking together regularly during lunch breaks, etc.

Remember, gentle suggestions are better received than harsh criticism. Advice that begins with "You should..." may fall on deaf ears. Instead you can try to initiate a discussion, saying something like, "You know, I just read an article that said drinking water is important for keeping skin healthy... and I'm drinking more water as a result." Having a conversation about this subject may get your friend to think, and perhaps try, to take steps leading to healthier patterns of eating and activity. Then again, she may decide not to pursue anything at this time. If this is the case, you can express your concern to your friend, and let her know that if she would ever like to pursue healthier eating habits you are ready to support her. In the mean time, remember why you're friends in the first place and enjoy your time together!

Alice

November 7, 2008

21262

To the reader:

I think you could try to teach your friend about enjoying healthy food. It only works if you are subtle, so work in small steps. Try inviting her over for dinner and cooking...

To the reader:

I think you could try to teach your friend about enjoying healthy food. It only works if you are subtle, so work in small steps. Try inviting her over for dinner and cooking a healthier version of pizza or lasagne or some other food she might recogize. Or take her out for a healthy but filling meal at a good quality restaurant (Italian is often good for this). By doing this the aim is to lead by example: show her that healthy food tastes great, fills you up and can contribute to a fun meal, as well as being good for you. Then she will see that living a healthy lifestyle needn't be torture, in fact it is something that a lot of people (chefs, gourmet food lovers, etc.) deliberately seek! Good Luck!

Is margarine really better than butter?

Dear Baffled Over Butter,

You may be baffled over butter, but it sounds like you've got a good grip on chemistry! Some of the margarines sold in stores today are still made from oil that has been infused with hydrogen atoms, firming it up into a semi-hard or solid form at room temperature. This process is known as hydrogenation, and it allows the margarine to contain less saturated fat than butter. Unfortunately, hydrogenation also forms something known as trans fat, which actually does more damage to your body than saturated fat. (Both butter and margarine end up containing the same amount of total fat.)

Margarines made from hydrogenated oil usually appear in a solid stick form, similar to how butter is sold. Other kinds of margarines on the market today are made from non-hydrogenated oil, making them softer in texture and lower in calories, saturated fat, trans fat, and total fat. These soft margarines, which are commonly packaged in tubs and known as "soft-tub margarines," replace the hydrogenation process with small amounts of modified palm kernel and palm oil in order to make it softer and easier to spread.

Unlike margarine, butter isn't made from vegetable oil. Instead, butter is prepared from cream, contains saturated fat, and, because it's made from an animal source, also has cholesterol. Both saturated fat and cholesterol raise unhealthy cholesterol or LDL (low-density lipoprotein). Margarine is manufactured from vegetable oils, such as corn, soybean, or safflower oil, among others. Since margarine is based on plant sources, it doesn't contain cholesterol.

Because margarines don't contain cholesterol and are now made without trans fat, the American Heart Association recommends that soft margarine can be used instead of butter in recipes. Choose a margarine that contains less than two grams of saturated fat per tablespoon, no trans fat, and has liquid vegetable oil as the first ingredient.

If all this chat about fat has made you curious (or confused), check out Good vs. bad fats and "Good" and "bad" cholesterol in Alice!'s archives for more information.

Alice

Hints for holiday stomach stuffers

Dear Stuffed,

Put down your fork and raise your glass. Here's to feasting sensibly, moderately, and contentedly:

Before the meal:

  • Eat your regular daily meals rather than skipping to save room for a big holiday meal. Being overly hungry is a potential recipe for too much holiday cheer. Instead, eat a snack before you head out (vegetables or a piece of fruit are good options) so you will be less likely to overeat when you arrive.
  • If you need to bring a food to share, bring a healthier option. You can also try using ingredient substitutions to reduce the fat, sugar, salt, and calorie content of some of your favorite holiday recipes.
  • ChooseMyPlate.gov also has a guide for making healthier choices during the holidays that you can review. 

As you’re deciding what to put on your plate:

  • Focus more on the people, less on the fare. Try to spend time talking with other guests. Play a game, go for a walk, or try to engage in other activities that are not focused on eating.
  • Take a moment to think about the food options in front of you before deciding what to put on your plate. For example, if you choose stuffing and mashed potatoes, consider balancing your meal with some veggies instead of grabbing a roll with butter.
  • Foods that are high in fat make us feel full. If your holiday table is filled with fried foods or dishes with rich sauces, enjoy a limited amount of these. If the meal is served family style (passed around the table in serving dishes), it's fine to decline some items. For items you do select, take portions that are the amount you usually eat. Many people pile up their plates, and then feel obliged to eat everything.
  • If the holiday meal is served buffet-style, check out all the offerings before getting in line. You can avoid overloading your plate by taking only the items you really want to eat. Buffets are invitations for over-sampling the savories and sweets.
  • If it's appropriate to do so, get up between courses. An extra pair of hands clearing the table is often appreciated and will give you a chance to digest.

Some food for thought while you chew:

  • It can take 20 minutes or more to feel full. During the meal, eat slowly, chew thoroughly, chat with your neighbors, and sip water regularly to let your brain catch up with your stomach and register your fullness. Check in with yourself to see how you're feeling. Are you starting to get satiated? Try to become more in tune with your fullness cues and listen to them.
  • Watch out for the effects of alcohol. It increases one's appetite, setting the stage for overeating (it is also high in calories).

Actions to take after the holiday repast:

  • Take a stroll after the meal to get some exercise and help the food settle in your stomach.

Enjoying the holiday season doesn't have to mean overindulging in holiday cheer. Being mindful of your eating (and drinking) doesn't have to be limiting; it can actually enhance your experience. 

Happy Holidays!

Alice

A sweetener called stevia

Dear Skeptical,

Your skepticism is warranted, considering the label "all natural" does not have one, standard definition or imply “risk-free.” In order to be approved by the Food and Drug Administration (FDA), sweeteners marketed as “Stevia” may contain only one highly refined component of the stevia rebaudiana plant, called Rebaudioside A. Due to potential health risks, no other components of the stevia plant have been approved by the FDA as food additives or sugar substitutes. Non-food products (often labeled as dietary supplements) containing less refined stevia ingredients are available, and some are even deemed “safe for consumption.” However, the FDA recommends waiting for more conclusive research before consuming large quantities of supplements containing stevia-derived ingredients other than Rebaudioside A.

In addition to Rebaudioside A, most FDA-approved stevia sweetener products also contain fructooligosaccharide, a sugar extracted from non-stevia fruit sources. Some studies show that fructooligosaccharide may actually promote the growth of healthy bacteria, relieve constipation, regulate lipid metabolism, and promote immune system health. Additionally, these sugars may be less detrimental to oral health than table sugar, and may help to treat glucose intolerance. Rebaudioside A and fructooligosaccharide are both approved by the FDA as food additives.

Although some empirical studies show no negative side effects of consuming unrefined stevia plant products and deem them “relatively safe” and “nontoxic,” the FDA has expressed safety concerns related to these products. Such concerns include negative effects on the reproductive, cardiovascular, and renal systems as well as blood sugar regulation issues. Other concerns include the stevia plant’s potential ability to damage genetic material, but independent scientific studies have determined that this type of gene damage is only possible in a laboratory environment, not in the human body. Stevia proponents also cite the plant’s inability to be digested (hence, the reason why it is calorie-free) as evidence that it simply passes through the body without causing any damage.

When it comes to sweeteners and food additives, Rebaudioside A is the only FDA-approved component of the stevia plant. Considering the inconclusiveness of existing research, unrefined stevia supplements and other non-food products should be consumed cautiously. Good work keeping yourself informed before you ingest!

Alice

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