Tag Archives: Food

Monosodium Glutamate (MSG)

Q: What is ‘MSG’ and is it harmful?

A: Monosodium glutamate (MSG) is a compound added to foods to enhance natural flavors. It’s made of glutamate, water and sodium. As a building block of proteins, the amino acid glutamate is found naturally in a wide variety of foods. Glutamate is also produced by the human body.

Glutamate from MSG is metabolized in our system in the same way as naturally-occurring glutamate. American consumption of MSG is estimated to be about 0.55 grams per day, though Taiwanese intake averages roughly 3 grams daily. A U.S. government committee on food additives evaluated MSG in the late ‘80s and concluded that the substance does not represent a health hazard for the general population. In one study, adult men consumed diets containing up to 147 grams MSG daily (200-300 times higher than normal consumption) for up to 42 days and researchers observed no adverse reactions to this dosage (Bazzano et al, 1970).

Surprisingly, MSG contains less sodium than table salt. MSG is 14% sodium, while the salt shaker holds 40% sodium. Therefore, MSG can actually be used instead of salt to obtain the same palatability.

So why the bad reputation? The late 1960’s saw a flurry of reports that consumption of large amounts of MSG causes flushing, lightheadedness, facial pressure and chest tightness. This cluster of reactions has been dubbed Chinese Restaurant Syndrome (CRS). However, well-designed experiments of the past decade have not been able to attribute CRS symptoms to MSG. It is possible, however, that some individuals may, in fact, be sensitive to MSG after ingesting greater than 3 grams in the absence of food.

Asian cuisine is not the only place you will find MSG! Even Italian dishes contain it and some highly-seasoned restaurant meals may contain up to 5 grams. MSG is available for purchase in the spice section of many supermarkets, and on packaged foods labels, you can find the ingredient listed as “monosodium glutamate.”

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Antioxidants: Free radical scavengers

Q: What’s an “antioxidant”?

A: Antioxidants are compounds that offset damage to the body’s cells. Antioxidants, including certain vitamins, minerals and phytochemicals, defend against injuries caused by free radicals. But what’s a free radical? Simply, free radicals are oxygen molecules floating around in your system that contain an unpaired electric charge. This single “electron” looks for a buddy to gain stability and so it destructively steals a second electron from substances like cell membranes and DNA.  Free radicals form naturally during the metabolism of food, but are also caused by cigarette smoke, air pollution and UV sun rays. While there are some benefits to free radicals, these highly reactive, unstable molecules are implicated in aging, neurodegenerative diseases and cancer. Fortunately, antioxidants can destroy free radicals, limit their formation and stimulate repair activity at the site of damage.

Antioxidant Food sources Recommended Daily Amount
Vitamin C Orange, grapefruit, mango, strawberries, broccoli 90 mg for men75 mg for women
Vitamin E Wheat germ oil, sunflower seeds, peanut butter 15 mg
Beta-carotene (Vitamin A  precursor) Carrots, sweet potatoes, broccoli None established
Selenium Brazil nuts, tuna, turkey, rice 55 µg
Lycopene Tomatoes, ketchup, watermelon None established
Lutein Dark, leafy greens (e.g. spinach) None established
Resveratrol Red grapes None established
Anthocyanin Blueberries, raspberries, plums, red grapes None established

There is no set daily recommendation for most antioxidants; however, eating more fruits and vegetables is the best way to boost your intake. Rely on whole foods, not supplements, since popping high dose capsules can have negative health effects. For example, beta-carotene supplements are associated with higher rates of lung cancer in men; however, smokers are recommended to increase vitamin C intake, due to smoke-induced oxidative damage. My take? Get your antioxidants from food sources, steer clear of mega-dose pills and stick to recommended daily amounts of vitamins & minerals.

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Are There “Negative-Calorie” Foods?

Q: A “negative-calorie diet” seems too good to be true. Is it?

A: A negative-calorie diet causes you to expend more calories chewing, digesting and absorbing certain foods than the food actually contains. As an example, proponents of this diet claim that if you eat a cup of chopped lettuce that has 10 calories, you’ll burn that off and then some! While this sounds great, I haven’t found any research validating this theory. The “thermic effect of food” refers to the energy spent processing food in our system for storage and use, but we do not yet have the metabolic tools to determine this value for single food items.

Other purported negative-calorie foods include celery, carrots, cucumber, onion, spinach, apple, cranberry, orange, peach, strawberry and watermelon. The eBook The Negative Calorie Diet states that you can lose up to 14 pounds in two weeks by eating these foods! At that drastic rate, it must mean that you can only eat these foods and nothing else. But, a prolonged diet of only fruits and vegetables lacks several key nutrients, including protein and essential fats. Weight loss should always be gradual (1-2 pounds per week) and accomplished by exercising and eating smaller portions of well-balanced meals, including several daily servings of fruits and vegetables. Weight management is a delicate balance between calories in and calories out. The foods deemed “negative-calorie” are nutritious, low-energy fibrous fruits and veggies that fill you up and leave less room for higher-calorie items. If including these foods in your diet induces any weight loss, it’s likely only due to the fact that you’re eating fewer calories in general, not because your body’s digestive tract is working overtime.

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Planning A Vegetarian diet

The quality of any diet – inclusive of meat or not – depends on whether nutritionally-sound food choices are made. The term ‘vegetarian’ refers to people who steer clear of most or all animal-derived foods, including eggs and dairy. Lacto-ovo vegetarians, on the other hand, consume milk products and eggs, but exclude meat and seafood. Ovo-vegetarians include eggs, but do not eat meat, seafood or dairy. Lastly, pesco-vegetarians eat seafood, eggs and dairy, but not meat or poultry. Depending on what type of “vegetarian” you are, a carefully planned diet must include good sources of calcium, iron, zinc and B12:

Calcium: If you don’t eat dairy products, you should select calcium-fortified juices, soy milk and breakfast cereals. Other good sources of absorbable calcium include figs, fortified tofu, some beans, and certain green vegetables, such as broccoli, kale and turnip greens.

Iron: The iron in plant foods, such as beans, dark green leafy vegetables and whole-grain breads is poorly absorbed.Luckily, vegetarians tend to eat produce that’s rich in vitamin C, which helps the body absorb iron more efficiently.

Zinc: Meat is the richest source of bioavailable zinc. Since soy interferes with zinc absorption, it’s important to include whole grains, nuts, and beans such as black-eyed peas, pinto beans and kidney beans in your diet.

B12: This vitamin, also known as cyanocobalamin, is only found in animal products. While soy products may contain some B12, it is not in the active form. The recommended daily intake for male and female adults is 2.4µg/day, although percent daily values (% DV) on food labels are based on 6µg. Your body stores about 5 years of B12, after which a deficiency in this vitamin can be extremely detrimental to your health. Strict vegetarians should not ignore this nutrient. B12 is absorbed with the help of intrinsic factor (IF), which is produced in your stomach. If you’re 60 or older, the loss of IF and low stomach acid levels may lead to B12 deficiency, whether or not you adhere to a vegetarian diet. If the deficiency is due to the loss of IF, you may need an intramuscular B12 injection.  If you’re younger, low B12 levels are more likely due to inadequate dietary intake and an oral vitamin supplement and careful food planning will help. Depending on what type of vegetarian you are, non-meat sources high in B12 include mollusks (e.g. clams), salmon, trout, tuna, egg, yogurt, American cheese and fortified cereal.

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Benefits of Fiber

Q: What exactly is ‘fiber’ and why is it so good for you?

A: Fiber is an indigestible carbohydrate, or a string of sugar units held together by bonds that human digestive enzymes cannot break. There are two types: soluble and insoluble fiber.

Food Sources

Soluble fiber: barley, oats, oat bran, rye, fruits (especially apples and citrus), beans, vegetables, seeds

Insoluble fiber: Brown rice, fruits, beans, seeds, vegetables (cabbage, carrots, brussels sprouts), wheat bran, whole grains

While fiber does not provide energy, it has many other beneficial effects:

1. Lowers blood cholesterol: Soluble fiber reduces cholesterol and the risk of heart disease by several mechanisms. (Note: This is why General Mills is able to claim that eating whole grain oat Cheerios can help lower your cholesterol.)

2. Maintains bowel function: Insoluble fiber speeds up the transit of food through your system, while soluble fiber slows it down.

3. Assists blood glucose control: Soluble fiber slows the absorption of glucose from the intestine into the blood stream, thereby preventing a spike (and crash) in blood glucose after a meal. This can lower the risk of type 2 diabetes.

4. Promotes weight management: Fiber makes you feel full and lessens hunger

5. May defend against colon and rectal cancer: Scientific studies are mixed, but insoluble fiber speeds up the removal of cancer-causing agents from the colon, while resident bacteria in the colon ferment soluble fiber, producing a beneficial compound that may help colon cells resist injury.

Recommended Intake: Since most fiber-rich foods supply a mixture of soluble and insoluble fiber, recommendations are given without regard to type. The American Dietetic Association suggests 20 – 35 grams of fiber daily, which is about twice the average intake. That said, don’t overload on fiber and make sure to increase fluid consumption as you gradually increase fiber intake.

Fruits, vegetables, whole grains and beans are among the best sources of fiber! Also, remember that fiber supplements are not necessarily substitutes for whole, fiber-rich foods.

Check the nutrition facts on the back of products to find out how much fiber is in one serving! Here are some examples:

½ cup whole grain barley – 3g fiber

½ cup instant oatmeal – 2g fiber

1 slice whole wheat bread – 3g fiber

1 slice white bread – 1g fiber

½ cup cooked brown rice – 2g fiber

½ cup cooked white rice – less than 1g fiber

¾ cup (2 oz) whole wheat penne pasta, dry – 6g fiber

¾ cup (2 oz) regular penne pasta, dry – 2g fiber


1 medium apple (with skin) – 3g fiber

1 medium pear (with skin) – 5g fiber

½ cup blackberries – 4g fiber

½ cup strawberries – 2g fiber

1 medium orange – 4g fiber

½ cup orange juice – less than 1g fiber

½ cup American grapes – less than 1g fiber


½ cup lentils – 8g fiber

½ cup chickpeas (garbanzo beans) – 5g fiber

½ cup black beans – 7.5g fiber


½ cup cooked broccoli – 2.5g fiber

1 medium artichoke – 10g fiber

1 medium baked potato (with skin) – 4.5g fiber

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Combating cold sores

Q: Can certain foods exacerbate cold sores?

 

A: Cold sores, or fever blisters, are caused by the herpes simplex virus. While the virus cannot be cured, cold sores can be treated. Along with avoiding triggers, such as excessive sun exposure, stress and colds, there is some evidence that nutrition plays a role in cold sore prevention.

Studies have shown that topical zinc oxide cream shortens the duration of a herpes outbreak, while oral zinc tablets are associated with reduced frequency and duration of flare-ups. In addition, lemon balm may speed up the healing process, but has no impact on prevention. 

Lysine and arginine are amino acids – building blocks of proteins – that have been implicated in cold sore management. Lysine has been shown to inhibit normal replication of the virus, thereby lessening outbreak duration, while arginine seems to promote growth of the virus.   Thirty years ago, a multi-centered study gave patients 1,200mg daily oral lysine doses, which appeared to accelerate recovery from infection and suppress recurrence of outbreaks (Griffith et al., 1978). It is difficult, however, to make a recommendation for daily lysine supplementation, because more recent studies have supplied participants with anywhere from 500 to 3,000mg lysine per day and long-term research is inconclusive.

In short, there does seem to be some consensus that diets high in lysine and low in arginine are beneficial for those who suffer from cold sores. See below for a list of potentially beneficial foods and a list of foods to avoid. If you find that limiting certain foods makes no impact on your cold sore symptoms, add those items back into your diet! Very restrictive diets may not supply adequate amounts of certain necessary nutrients. 

Beneficial: Foods high in lysine & low in arginine

Dairy (e.g. milk, cheese, yogurt)

Meat, chicken, fish

Mango, apricots, pears, apples, figs

Beets

Papaya

Avocado

Tomato, tomato juice, tomato paste

 

Foods to avoid: High in arginine & low in lysine

Coconut

Grape juice, orange juice

Rice

Peanut butter

Chocolate

Caffeine

Puffed wheat, corn, rice and oats

Nuts

Onions

Oatmeal

Plantains

Yams

Tahini

Lastly, in the midst of an outbreak, it may be best to avoid acidic foods, such as soda, citrus fruits, tomatoes, vinegar and alcohol, which may exacerbate the blisters.

For additional food information click here.

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Making Sense of the Food Pyramid

Q: How do I interpret the USDA’s food pyramid? What are appropriate portions for each food group?

A: The food pyramid consists of six major categories: grains, fruits, vegetables, meat & beans, milk and oils. The guidelines below are based on a diet containing roughly 2,000 calories per day – enough for the average adult. By visiting MyPyramid.gov, you can create a personal food pyramid and menu plan! Try keeping a food diary for a day or two and see how your diet matches up to the following recommendations. Then you’ll be able make substitutions and adjustments where necessary.

Food Group Single Serving Size
Grains – 6 servings per day 1 slice of bread = ¼ typical bagel = ½ English muffin = 1 cup of cereal = ½ cup cooked oatmeal, rice or pasta = ¼ cup granola 
Fruit – 4 servings per day ½ cup fruit slices = 1 medium-sized banana/apple/peach = ¼ cup dried fruit = ½ cup fruit juice 
Vegetables – 5 servings per day ½ cup cooked veggies = ½ cup raw veggies = ½ cup vegetable juice = ½ cup legumes = 1 cup raw, leafy greens (e.g. spinach, lettuce) 

Note: Legumes will also appear in the meat group because of their high protein content, but technically, they are vegetables.

 

Dairy – 3 servings per day 1 cup (8 fl oz) milk = 2 oz processed cheese (e.g. American) = 1 cup yogurt = 1.5 oz natural cheese (e.g. cheddar, mozzarella) 
Meats, poultry, fish, nuts – 6 servings per day 1 oz lean meat, chicken or fish = 1 slice of deli meat = 1 egg = ¼ cup legumes or tofu = 1 tbsp peanut butter = ½ oz nuts or seeds 
Oils – 6 servings per day 1 tsp oil = 1 tbsp mayonnaise = 2 tbsp light salad dressing = 1 tsp margarine

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