Optimal Nutrition

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Health benefits of fish oils

Dear Curious,

Somthing's fishy about your lab results. The improvement in your cholesterol levels may be due to the foods you replaced with the fish, rather than the fish in and of itself. The fats found in some varieties of fish, omega-3 fatty acids, reduce triglyceride levels in the blood, but generally do not affect cholesterol levels.

However, you're still doing yourself a favor by feasting on fish. Eating fish offers many major health advantages. The primary benefit found from including fish oils in your diet is the lowered risk for sudden cardiac death. This means that fish eaters decrease their chance of dying suddenly from a heart attack (keep in mind that there are different types of heart attacks).

Two mechanisms explain how eating fish reduces the chance of heart attack. First, it seems that fish oil fatty acids reduce blood clotting by decreasing the stickiness of blood platelets. Second, omega-3 oils may play a role in stabilizing heart rhythms. It could be that the electrical impulses that go awry during some heart attacks are preserved in fish eaters. These protective qualities may work together, resulting in the reduced risk of sudden cardiac death that has been observed among fish consumers. Other possible health benefits of omega-3 fatty acids are their potential to help lower blood pressure and protect against some forms of stroke.

Remember, it is possible to have too much of a good thing. There are certain risks associated with eating too much fish. The main risk has to do with the toxicity of environmental contaminants, primarily mercury, which ends up in fish due to environmental pollution. Because of this, women who are pregnant or breastfeeding are often advised to avoid fish. In addition, there are various recommendations for eating fish to avoid consuming dangerous levels of mercury, as its toxicity can damage the brain, kidneys, and lungs. Mercury levels may be especially high in shark, swordfish, king mackerel, and tilefish.

But in moderate amount, fish can be beneficial, especially for people eating a western diet that is often low in omega 3s. Good sources of omega 3 include:

  • Shrimp
  • Salmon
  • Mackerel (watch out for the higher mercury levels in king mackerel)
  • Rainbow and lake trout
  • Sardines
  • Halibut
  • Pollock
  • Oysters
  • Catfish
  • Albacore, blue fin, and yellow fin tuna (including the canned type)
  • Striped sea bass
  • Turbot
  • Swordfish (watch out for higher mercury levels)

Fish oil supplements, on the other hand, contain almost no toxic contaminants and thus are safe. However, they can cause gastric symptoms, so it is best to take them with food. People with low blood pressure or who are taking medication for low blood pressure should also be careful about eating too much fish, since the fish oil could lower blood pressure even more. In very high amounts, fish oils can have some anti-coagulant effects, causing nosebleeds in some people.

Eating these jewels of the sea even once or twice a week may lead to heart healthy benefits. Obviously an all-around healthy diet will provide even more protection from heart disease, and other maladies, too.

Alice

Eating at night = weight gain: Myth or fact?

Dear Reader,

You and your friends have picked up on a popular debate. One aspect of weight management that is vital to understand is that we gain and lose weight over periods of time — weeks, months, years — not hour by hour. This happens as we take in more calories than we expend. Another important fact of metabolism is that our bodies do not stop working, even when we are sleeping! Hearts are beating, blood is circulating, lungs are functioning, brains are even working. This all takes energy — meaning we are still burning calories.

There is no magic time after which the body stores fat. For instance, if you eat the same exact meal at 6 pm or at 8 pm, is one more caloric than the other? No, each meal has the same number of calories. What really matters is the total amount of food and drink you have over the course of a week, or a month or longer, and how much energy you expend during that timeframe. Excess calories will be stored as fat over time, regardless of whether they are taken in during the day or night.

When it comes to eating late at night and the potential for weight gain, there are several considerations:

  • Portion sizes — waiting to eat could lead to consuming larger portion sizes.
  • Quality of food — after a long day of work or school, a few slices of pizza or a fast burger may seem easier than steamed vegetables and broiled fish.
  • "Mindless snacking" — evenings spent studying, going out, or watching TV may lead to excess calories from fast, sugary, on-the-go options.
  • Health concerns — consistent periods of going without food followed by a large meal can negatively impact the interaction between blood sugar and insulin and make you more vulnerable to Type 2 diabetes.

So, to settle the debate, you are correct that late-night calories won't change your metabolism or magically count more than calories eaten during the day. However, limiting late-night meals and snacks may be an effective weight management strategy for some because it helps them to control their overall calorie intake. Some people find that if they set a time that they can't eat past, it helps minimize or eliminate the possibility of munching on a lot of high calorie foods. Another useful tip may to be to eat four or five smaller meals and snacks spread evenly throughout the day so you don't become overly hungry at any point. Following these tips can keep your energy levels consistent for work and play and can provide some long-term benefits to help you reduce your chances for diabetes or other health issues. 

Bon appétit! 

Alice

June 29, 2007

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Dear Alice,

Though your metabolism IS constantly at work, it does slow down later in the day, especially if you are just dieting and not exercising. When you exercise your heart rate and...

Dear Alice,

Though your metabolism IS constantly at work, it does slow down later in the day, especially if you are just dieting and not exercising. When you exercise your heart rate and metabolism both increase. In addition it is better to eat more meals and take in the same amount of calories because in doing so you keep your metabolism working. On the other hand if you eat less or worse starve yourself for several hours your metabolism slows down and potentially puts your body into a "starvation mode" where more insulin is released causing the body to store more fat. This is the most simple answer to this question.

Where can I find easy vegetarian recipes?

Dear Reader,

Having some vegetarian (or vegan or gluten-free) recipes on hand can be helpful, whether or not you're a vegetarian yourself. There may be times when you have company over who are vegetarian, for cultural, religious, or other reasons, and you want to be prepared. In addition, people may choose to consume fewer animal foods and products in their eating plans, and desire to find suitable and tasty meat-less substitutes. Vegetarian eats are not the bland, boring fare some may traditionally consider (plain tofu, boiled carrots, or alfalfa sprouts!) — The flavors, colors, and textures can be lively and incredibly appetizing to many palates. And, similar to non-vegetarian meals, vegetarian eats can be simple or complicated to prepare.

Numerous vegetarian websites, blogs, and cookbooks exist. Let's start wtih some favorite websites and blogs:

Cookbooks are also terrific resources of recipes for vegetarians, including:

  • "How to Cook Everything Vegetarian," by Mark Bittman will appeal to those who want simple vegetarian recipes.
  • "Veganomicon: The Ultimate Vegan Cookbook," by Terry Hope Romero is a classic. While all the recipes are vegan, you could easily adapt and add some non-vegan, but still vegetarian ingredients, such as milk or cheese.
  • "Moosewood Restaurant Cooks at Home: Fast & Easy Recipes for Everyday," by the Moosewood Collective. Actually, all of the Moosewood cookbooks are excellent!

These books, as well as other vegetarian cookbooks, are available at on- and off-line bookstores. For more information about vegetarianism, check out the Related Q&As. If you're a Columbia student, give Becoming a vegetarian — Columbia Health resources a quick read. Readers: We would love to hear your suggestions! Leave 'em in the comments!

Happy (vegetarian food) hunting,

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

Forgot to refrigerate leftovers — still okay to eat?

Dear Sleepy cook,

Sounds like a very tasty meal — one that would be tragic to discard. Unfortunately, it is likely that while you were sleeping, bacteria were partying on your stove and reproducing at alarming rates. Bacteria thrive at 40 to 140 degrees F and reproduce quickly. Thus, you should probably toss the sauce. Perishable foods should not be away from the fridge for more than two hours; seven hours would really be pushing it. Here are a few basic guidelines to follow in re-heating and refrigerating leftovers:

  • Tempting as it may be, do not taste food to determine if it is spoiled. You may get sick even from a small taste and your taste buds may not always detect good sauce gone bad.
  • Invest in a meat thermometer.
  • When initially cooking beef, chicken, or pork, make sure the meat reaches a minimum internal temperature of 160 degrees.
  • Make sure fish reaches a minimum temperature of 145 degrees.
  • Reheat all leftovers to 165 degrees.
  • Bring leftover sauces, soups, and gravy to a boil.
  • When wrapping up freshly cooked leftovers, store in multiple smaller containers so they cool more quickly.
  • Know that eating perishable foods that have been away from the fridge longer than two hours can be risky.

While it's ultimately up to you whether you eat or toss, wise eaters are wary of food that has been out a couple hours or more. Best of luck with future leftovers,

Alice

August 6, 2013

534185
Thank you! That was very helpful. I made a large batch if stew and had it in a large container. It would have taken a long time to cool down. I used 4 different containers after reading this post so...
Thank you! That was very helpful. I made a large batch if stew and had it in a large container. It would have taken a long time to cool down. I used 4 different containers after reading this post so it would cool down faster instead of one so bacteria would less likely grow ! Thank you!

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

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

Iron, calcium, and constipation, oh my!

Dear Calcium and Iron Maiden,

It seems like you're approaching a supplement regimen with a healthy consideration of various factors like absorption and affects on your system — a great idea! You're right that there are certain foods that can inhibit iron absorption, like the oxalic acid in spinach, phosphates primarily in milk, other dairy products, and egg whites, phytates in beans, and tannins in tea and coffee. While it would take a lot of these foods to seriously impair your ability to absorb iron, you might want to consider going easy on them while trying to boost iron levels.

On the opposite side of the spectrum, there are many foods that are rich in iron, and it's usually preferable to get your essential nutrients from food rather than supplements. The body has an easier time digesting and absorbing nutrients like iron and calcium in the amounts and forms in which they occur naturally. You can check out Sources of Iron in Alice's Fitness & Nutrition archives for a list of these iron-boosting foods (sneak preview: meat, fish, dark leafy greens, dried beans, and nuts are all healthy iron-rich foods). Another dietary tactic to boost iron absorption is to eat a vitamin C rich food with your iron-rich food or supplement, as vitamin C aids in iron absorption. For example, eating citrus (oranges, grapefruits, lemons) along with your spinach salad will help unlock the iron in spinach. You can also cook your food in cast iron pots and pans to enrich your food with iron.

In terms of your sensitive GI system, the least constipating iron formula is hydrolyzed protein chelate, but again, diet can come into play here. In addition to looking for gentle and non-constipating types of iron supplements, you can also alleviate constipation by drinking plenty of water and by eating fibrous foods like whole grains, fresh fruits, fresh vegetables, and other foods as unprocessed as you can find them (whole grain bread instead of white, whole grain pasta instead of white, brown rice instead of white). It's a good idea to increase fiber intake slowly — too much too soon can cause gas and bloating. And to underscore again, when increasing fiber it's important to drink even more water than you think you need to make sure all that bulk moves through your system smoothly.

As for calcium, the two most common forms in supplements are calcium citrate and calcium carbonate. Studies show that calcium citrate is the most absorbable supplement form, and may be taken between or with meals. Vitamin D helps to assimilate calcium into bones. When exposed to sufficient sunlight, the human body synthesizes its own vitamin D. Fatty fish like salmon, tuna, and sardines are great food sources of vitamin D. If you want a D supplement, which might be a good idea for folks who live in northern climates and don't get adequate sun exposure during the winter, or for people who don't eat a lot of fish, look for supplements that contain vitamin D3 (cholecalciferol), rather than vitamin D2 (ergocalciferol) — vitamin D3 is more potent. You might also want to consider taking a magnesium supplement with your calcium at a ration of two-parts calcium to one part magnesium, as magnesium is needed to fully absorb and utilize calcium.

Finally, see if you can avoid taking your calcium and iron supplements together, as they compete for absorption. It may seem like a lot of juggling of different foods, supplements, and timing of the two, but hopefully this kind of careful consideration and knowledge will boost your iron and calcium levels to new heights.

Farewell, fair Iron (and calcium) Maiden,

Alice

Are plastic wrap and containers safe for microwaving food?

Dear Reader,

You are quite right that some questions have been raised about whether microwaving food using plastic wrap and plastic containers is harmful to our health. Much of the focus has been on plasticizers (chemicals used to make plastic more flexible), polyvinyl chloride, and polycarbonate. More recently, bisphenol-A (BPA), primarily used in hard plastics like polycarbonate, has also been called into question.

Research suggests that plasticizers, BPA, and other chemicals may leach into food while being heated in a microwave. Plastics tend to break down and release chemicals when exposed to high temperatures, and the fear is that some plasticizers could mimic or compete with our hormones, producing a hormonal imbalance. This imbalance has been associated with the development of cancer, birth defects, and fertility difficulties. The United States Food and Drug Administration (FDA) does consider BPA to be an endocrine disruptor, meaning it can alter hormonal levels if present in high enough quantities. What is in dispute, however, is whether BPA and other chemicals leach into food in amounts high enough to cause serious health issues. Recently the FDA updated its stance on BPA to indicate moderate concern about its harmful effects during fetal development and for infants and young children. However, the FDA has not taken the same position regarding adults, who are generally less susceptible to chemicals.

While time and more testing will show whether or not heated plastics pose a health threat, limiting exposure to plastic containers with BPA, and all plastics when heated in a microwave, is a precaution some people have decided to take recently. Infants and developing embryos are especially vulnerable to potential chemical leaching, so pregnant and breastfeeding women and parents with young children might want to be particularly careful not to heat plastics in the microwave.

Here are some hints for safe microwaving:

  • Choose microwave-safe plastic wrap and never let it directly contact food.
  • Try using waxed or parchment paper instead of plastic wrap.
  • Only use containers that have been designated as microwave-safe. Best to use microwaveable glass and ceramic cookware. Otherwise, choose those made of polyethylene plastic which is plasticizer-free.
  • Never use microwave convenience food trays and containers more than once.
  • Do not microwave plastic containers used for cold food storage. They often melt and warp because they are not designed to withstand the high heat of microwaving.
  • Avoid microwaving food in freezer cartons and on Styrofoam trays.

Since microwaves are so common this is information everyone can use. Thanks again for the heads up!

Alice

How can I eat well at college?

Dear Confused and College Bound,

You are not alone with your concerns. Going to college is a big step in a person's life involving major changes. You and those around you may be living on your own for the first time, making decisions on a buffet of issues, including what to eat.

Eating healthy at college is possible. Many college dining services are offering more healthy choices and are often quite receptive to students' concerns and dietary preferences. But, this is only part of the challenge. In an environment where time, friends, and finances may combine in new ways, having options available only solves some of the puzzle. It's important to experiment with what works best for you. For example, that traditional idea of three square meals a day has been updated with a more contemporary concept of eating five smaller meals spread throughout the day. Steer clear of diets or fads, especially those that drastically limit a particular nutrient. Remember, balance, moderation, and variety win out over trendy and extreme. For some practical tips, navigate through the many options on Choosemyplate.gov. Columbia students can also take advantage of the resources from the get balanced! initiative. Plan ahead when possible so you don't have to rely on vending machines when you're hungry; think of ways to incorporate fruits, vegetables, and whole grains on a daily basis. Eating more of these will fill you up and possibly even enhance your already stellar brain power.

Making time for physical activity is important, too. Most college fitness centers have a variety of movement classes and options. When the weather is right, grab a friend and walk, run, bike, or blade outdoors. If you are Columbia affiliated, you can connect with the CU Move initiative.  CU Move encourages members of the Columbia community to engage in active lives that include regular physical activity. The program provides participants with motivation, incentives to be active throughout the year, and event calendars with access to plenty of free and low-cost physical activity options on campus and around NYC. 

Now, to address the second part of your question: an eating disorder, such as anorexia nervosa, is less about food, eating, and body weight. It has more to do with mental health, emotional, physical, socio-cultural, and family issues. If this is a particular concern of yours, you might want to take a look at Eating disorders vs. normal eating. Additionally, if you are a Columbia student, you can make an appointment with a health care provider or a registered dietitian to discuss your concerns by contacting Medical Services (Morningside) or the Student Health Service (CUMC).

Give yourself some time to adjust to a new environment and ask for help when you need it. Everything in moderation, even moderation. 

Enjoy your time at college,

Alice

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