GRAPEFRUIT

Q: Is there any difference between pink and white grapefruits?


A: While most people choose pink grapefruit over white because they think it will be sweeter, there is very little difference in actual taste. The grapefruit is pink because of beta carotene, a plant pigment that's abundant in dark green and deep yellow vegetables like carrots and squash. According to the USDA dietary guidelines and the National Cancer Institute, we need about five to six milligrams of beta carotene a day. Pink grapefruit only contains 0.2 milligrams, while white grapefruit contains trace amounts. While beta carotene-rich foods may be linked to reduced rates of cancer, the amount found in pink grapefruit will be of little benefit, so choose either pink or white depending on availability, freshness and preference rather than for any apparent health benefit.
May92IM

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WHAT DOES WATER DO?

Q: I always drink plenty of water, which everyone says is very good for me. What does water do?

A: Water accounts for 60 percent of the bodyweight of the average male and 50 percent of the average female. Every tissue in the human body contains water, but not all tissues contain the same proportion of it. Muscle tissue contains 72 percent water by weight, bones are about 25 percent water. And fat contains 20 to 35 percent water. Consequently, people who have a higher percentage of bodyfat have less water in their bodes than thinner people of the same age and sex because muscle tissue contains more water than fat tissue. Women generally contain less water because they have a greater proportion of fat tissue than most men.

Water is necessary for many bodily functions, including hydrolysis, the process by which proteins, fats and carbs are broken down with water for absorption. It also acts as a lubricant and cushion in saliva, tears and synovial fluid, which is the thick liquid that is encapsulated around many joints to cushion the joint.

Another of water's functions is to regulate body temperature. In maintains an even temperature better than other fluids because water temperature is not easily affected by changes in environmental temperature. Both blood and interstitial fluids, which are present throughout the body, have high water contents.

If your body is exposed to cold, it conceives heat by narrowing the blood vessels near the skin surface. This causes less blood to be circulate near the surface, which slows the loss of heat from the body. If your body is overheated from exercising, the blood vessels of the skin dilate, which brings a larger volume of blood close to the surface, where it loses heat to the environment. When you perspire, the skin excretes fluids, which results in a further loss of heat.

Water, as you can see, is a very important element to the human body-and not just to athletes' bodies. You should drink eight to 10 glasses a day.
Oct95IM

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WHY ARE CARBOHYDRATES SO IMPORTANT

Q: I like meat and eggs, but when I add a lot of carbohydrates to my diet, I eat too many calories. Why are carbohydrates so important?


A: Carbohydrates are the human body's fundamental source of fuel, but not all carbohydrates are major sources of energy. There are two different types of carbohydrates, available carbohydrates and dietary fiber. Available carbs include starches and sugars, which are hydrolyzed, or absorbed, in the human digestible process. Dietary fiber is a plant food component make of linked carbohydrate units that cannot be separated by human digestive secretions.

Sugars and starches are metabolized, or processed, by the body and broken down to glucose, which is used by all the body's cells to create energy. Inadequate carbs in your diet, thee fore, can cause the higher centers of your brain, as well as your muscles, to malfunction. Available carbs also play a role in metabolizing fat for energy. In fact even when you're burning away fat through diet and exercise, your body needs a byproduct of carbohydrate metabolism to function optimally during exercise. Therefore, if there are no carbohydrates, your energy production will be limited and you'll burn protein instead-an undesirable situation because your body has other specific needs for protein. Consequently, you should eat at least the minimum recommended amount of carbohydrates so the protein is spared from being used as energy. This is referred to as the protein-sparing effect of carbohydrates.

Dietary fiber, or unavailable carbohydrates, enhance the activities of the gastrointestinal, or digestive, tract. The human digestive tract doesn't use fiber, because it can't breaks it down. Instead, most dietary fiber remains a solid material in the large intestine after the other components of food are absorbed, and the intestinal muscles get a workout moving the solid waste through the colon. Fiber is also source of food for bacteria in the guy, and soluble fiber is believed to lower blood cholesterol because it reduces the absorption of cholesterol from the digestive tract.

All of this means that carbs are very important to your body even though some of their functions are minor. The national Research Council and other experts recommend that 60 percent or more of your daily calories should come from carbohydrates, primarily a complex-carb and fiber intake of 25 to 40 grams a day.
Oct1995

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OAT BRAN: ISN'T IT SPECIAL

Since the early 1980s oat bran has been touted as a health breakthrough. Recently everything from muffins, cookies and cereals to breads has been advertised as containing oat bran. The medical community has endorsed oat bran's use based on its supposed cholesterol-lowering effects in the blood. This research is now being challenged.

In a recent study of individuals with normal blood cholesterol levels, including oat bran in a lowfat diet resulted in no greater reduction in blood cholesterol levels than a lowfat diet itself. Apparently, eating oat may only be beneficial for individuals with normally high blood cholesterol levels. Fiber seldom exerts much influence on serum cholesterol in people whose cholesterol levels are already low.
Aug90IM

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BREAKFAST: FOR CHAMPIONS

Q: I've heard that having a good breakfast is important for weight control, but does it do anything to promote good health?

A: In a study conducted in California, those who ate breakfast almost every day generally had better health and were sick less often than those who ate breakfast only some of the time. Furthermore, a good breakfast may be a prerequisite for good performances in your work and sports activities. Breakfast often comes 12 hours after your last meal of the previous day and is important for maintaining energy and cellular metabolism. A few researchers suggest that breakfast should be the largest and most important meal, and everyone agrees that it should include more than a cup of coffee and a doughnut. In related experiments erratic eaters had poorer health than those who ate regularly. So setting up a regular eating schedule will not only help you maintain you desired weight, but it will also help to maintain your health.
April92IM

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INCREASE LIFE EXPECTANCY 28 PERCENT

Q: My wife read that eating too much causes people to die sooner than they might otherwise. Is this true?

A: Some researchers feel that the most important factors determining life span are those that influence fatness. Animal studies have shown that eating fewer calories can extend survival time dramatically. Reducing calories by up to 40 percent increased life expectancy 28 percent.
Studies done on older people living in remote areas of the world found that their diets were low in fat and calories. These people were also physically active and had productive and respected roles in society. All of these factors are important for good health and long life.
While maximum life expectancy has changed little in recent years, you can increase your own life expectancy if you remain healthy and active. A lowfat, restricted-calorie diet may help you to extend your years and postpone chronic illness.
April92IM

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HEARTBURN

Q: What exactly is heartburn? Is it caused by something you eat?

A: Hiatal hernia, more commonly known as heartburn, is caused by a protrusion of part of the stomach above the diaphragm, the muscle that separates the chest from the abdomen. The result is an enlargement of the diaphragm opening that connects the esophagus to the stomach. There may be no symptoms, or there may be pain, swallowing difficulties and frequent, objectionable burping.
By reducing the amount of food you eat at any one time, you can keep the size of your stomach smaller so it will protrude less. In addition you should cut down on irritating foods, such as citrus fruits and spicy and greasy dishes, and limit your intake of coffee and antacids, as excessive amounts of those substances can lead to further problems. Rather than making the symptoms, the best treatment is to avoid large meals or those foods that promote acid development in the stomach, as discussed above. Instead, stick to more frequent meals of soft and bland foods to relieve the problems.
April92IM

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FOOD-CLAIM CRACKDOWN

Q: I recently read that food companies will have to change the claims they make about how healthy their products are. Do you know anything about this?

A: The Food and Drug Administration has indeed begun investigating manufacturer's labeling practices. The first issue it took up was the use of the word "fresh" on orange juice cartons. As the juice is frequently reconstituted from concentrate, manufacturers are no longer permitted to say "fresh from concentrate" and imply that it is fresh juice when it is not.

The FDA is currently looking into the widespread use of several other terms, including "light," "nonfat" and "cholesterol-free." As there are no regulations regarding the use of such words, the uneducated consumer is often misled. An example is vegetable oils that are labeled "cholesterol-free." Cholesterol is only found in foods of animals origin, so any product that has a vegetable origin would be cholesterol-free. Furthermore, describing an oil as "cholesterol-free" implies to the consumer that the oil is healthier than oils that contain cholesterol, which isn't completely true. Remember that most medical groups recommend a diet that is low in total fat, not just cholesterol.
While the FDA is just beginning to control labeling practices, it is gratifying to see that both the government and consumers are interested in eliminating such deceptive advertising.
Sept91IM

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MILDLY ANEMIC

Q: After reading one of your columns about iron deficiency, I had a blood test done to check out my hemoglobin and iron stores, as you suggested, before taking any supplements. I was found to be mildly anemic, and my physician recommended eating more red meat and taking an iron supplement. Now I'm afraid of overloading on iron. Is this a real danger?

A: Your concern is valid. Excessive and random supplementation will always leave you open to the possibility of overdose and toxicity. A mild oral overdose of iron typically causes gastrointestinal distress, nausea and/or black diarrhea. Having a second blood test taken will alert you to changes in your hemoglobin levels and iron stores. You have indicated in another part of your letter that you are a premenopausal female, so it is likely you will need to take a supplement for an extended period and then intermittently during periods when you're menstruating. Your doctor should be able to give you more individual advice after seeing the results from your next blood test. To maximize your absorption of iron, remember to take your iron supplement with orange juice or vitamin C and avoid eating foods that are high in calcium, such as dairy products.
Sept91IM

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FOR BASIC FOOD GROUPS

Q: In school we were taught about the four basic food groups. Have they changed much since then?

A: while the four food groups of meat, dairy, vegetables and fruits, and grains still exist as they always have, you can expect changes in diet-planning guidelines based on those groups. The four foods group plan was designed in the '40s primarily as a means of encouraging people to get adequate nutrition. Since that time additional standards have been formulated, and during the past year the U.S Department of Agriculture and the Department of Health and Human Services created new guidelines based on a pyramid scheme: Vegetables and fruits are on the bottom tier, grains are on the next tier and so on, with salt, sugar and oil on the top.

The point is to eat foods from each group in quantities based on their position in the pyramid, with those on the bottom being the most desirable and those on top being more restricted. Unfortunately, many people misinterpreted the pyramid diagram, thinking that the foods on the top level were the most important. The government is currently rethinking the scheme to emphasize foods from the two carbohydrate groups-grains and vegetables and fruits-with fewer servings coming from the meat and dairy groups and very limited servings of items containing salt, sugar and fats.
Sept91IM

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HIGH-FRUCTOSE CORN SYRUP AND INVERT SUGAR

Q: I often see high-fructose corn syrup and invert sugar listed as ingredients on food labels. Are they the same as sugar, or are they better or worse for you?

A: Both high-fructose corn syrup (HFCS) and invert sugar contain the same molecules as sucrose (table sugar), glucose and fructose. HFCS is the predominant sweetener found in processed foods today. While ordinary corn syrup, which is produced from cornstarch, contains mostly glucose, HFCS contains mostly fructose, with glucose making up the balance. Many nutritionists believe that fructose is healthier than glucose, since fructose does not require the body to metabolize insulin.

Invert sugar is a mixture of glucose and fructose that forms when sucrose is split in a chemical process. It's sold only in a liquid form, and, like HFCS, is sweeter than sucrose. Invert sugar is used as an additive to preserve food freshness and prevent shrinkage.

There are numerous sweeteners besides sugar substitutes on the market. Since JFCS and invert sugar are sweeter than sucrose, manufacturer must use less in processed foods. It is important to remember, however, that unlike sugar substitutes, these sweeteners contain calories.
Sept91IM

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IMPORTANCE OF DIETARY CARBOHYDRATES

We've known about the importance of dietary carbohydrates for quite some time. Research shows a direct relationship between the carbohydrate content in a person's diet and the amount of glycogen stored in his or her skeletal muscle. By simply raising the amount of carbohydrate calories in your diet from 50 to 70 percent, you can practically double your muscle glycogen stores, going from 18 to 37 grams per kilogram of muscle. Along with the increase in muscle glycogen stores comes an increase in endurance-exercise performance.

Conversely, if you don't get enough carbohydrates from your diet, your muscle glycogen levels will be depressed and your performance hindered. The adequate supply of dietary carbohydrates become critical during training, when successive days of exercise lead to depletion of muscle glycogen levels. If you're also not taking in enough carbohydrates your muscle glycogen stores may remain depressed, and performance will be hindered during training or competition on subsequent days. Even so, the question remains as to how much carbohydrate is enough.

While the answer will vary from individual to individual and depends on numerous factors including exercise intensity, duration and frequency, several studies suggest that everybody needs a substantial amount. It is important to note that these studies were done on cyclist and runners. Bodybuilders probably create an ever-greater degree of muscle glycogen depletion due to the anaerobic nature of weight training coupled with the typical one or more forms of aerobic exercise that they do. In the case of runners and cyclists, researchers found muscle glycogen depletion in their leg muscles by the third consecutive day of training for as little as 30 minutes at 70 percent of their maximum capacity.

There was significantly less glycogen in the leg muscles of both groups even though the athlete consumed 3,500 calories and from 450 to 625 grams of carbohydrate per day. These levels corresponded to five to eight grams of carbohydrate intake per kilogram of bodyweight per day. Apparently an even higher intake of carbohydrate would be required to resupply muscle glycogen levels following additional successive days of training. While these athletes were not doing excessive amounts of exercise, their muscle glycogen levels were still depressed by the start of the third daisy's training. This could be critical for a bodybuilder on a calorie-restricted percents diet. Most bodybuilders are apparently in a state of partial glycogen depletion throughout their entire preoccupation phase and so they should not expect to be able to perform high-intensity exercise on successive days during that periods. A large athlete may need 3,000 to 4,000 calories in the form of carbohydrate in order to fully restore muscle
glycogen stores after intense training. Total caloric intake would have to be substantially higher.

While the caloric and carbohydrate intakes of endurance athletes often meet these requirements, those of competitive bodybuilders and other athletes whose bodyweight is a factor seldom do. Current thinking on the subject of weight loss and fat loss must change before bodybuilders will be able to meet the nutritional requirements for optimal training and performance in order to reap maximum benefits in terms of muscle hypertrophy and fat loss.
April91IM

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AVOID SUGAR LIKE IT'S THE PLAGUE

Q: Why do bodybuilders avoid sugar like it's the plague? Isn't it okay to eat a certain amount every now and then?

A: For some reason table sugar, or sucrose, has gotten a bad reputation. Purists who forgo all processed foods consider it to be no less than poison. Many nutritionists recommend avoiding sugar both by itself and in food products. Diabetics are often warned to limit their intake of simple sugars, and individuals who have high blood triglycerides can control their plasma lipid levels by reducing their intake of sucrose and other simple sugars.

While sucrose is a highly processed food that has little vitamin or mineral content and is considered by some to have no nutritional value, it does provide calories and a concentrated source of carbohydrate. For athletes who are involved in intense training and whose intake and expenditure are between 5,000 and 10,000 calories a day, sucrose is a viable source of carbohydrate and calories. Sucrose also has lower glycemic index value than some other complex carbohydrates have, including rice, potatoes and bread.

Research has shown that dietary saturated fat and cholesterol are the main culprits in the development of numerous diseases, such as heart disease, cancer, obesity and diabetes. Limiting your dietary fat intake goes a lot further in controlling these diseases than does limiting sucrose intake. While it's never a good idea to eat excessive amounts of calories or any nutrient, sucrose can play a role in a healthy diet, particularly that of an athlete involved in regular, intense training.
Feb92IM

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LOWFAT: NOT WHERE IT'S AT





Q: I tried to follow a lowfat, Pritikin-type diet, and it was impossible. Maybe this kind of regimen is okay for you fanatics, but for myself and many others it's just not worth it! I still want to eat healthy, so could you cut me some slack and give me some reasonable recommendations?

A: You are not alone. Most people find it impossible to follow a strict Pritikin diet. In fact, the follow-up studies reveal that once patients leave his live-in program, they start eating a diet in which approximately 15 percent of the calories come from fat. While it's true that the less cholesterol and fat you take in, the better, particularly saturated fat, and reduction is beneficial.

The American Medical Association recommends that less than 30 percent of your calories should come from fat and less than 10 percent should come from saturated fat, and you should take in less than 300 milligrams of cholesterol per day. It appears that these fat and cholesterol levels are beneficial in lowering your risk of heart disease, obesity, hypertension and diabetes. It also appears that keeping fat consumption at much less than 30 percent of calories-closer to 20 percent actually-can reduce the risk of breast, prostate and colon cancers. Obviously, the lower you reduce your intake of fats, the lower your risk of disease.

You need to find a level of fat consumption that you can stick with for the long term. Your diet should feature large quantities of fruits and vegetables, grains and nonfat dairy products; limited amounts of lean meats and virtually no added fats in the form of oils or butter. Start changing your eating habits slowly by eliminating visible fats such as butter or margarine on your bread or potato; limiting or eliminating mayonnaise, avocados, nuts and other high-fat foods; and experimenting with nonfat seasonings, sauces and products. You can make a modest reduction in your fat consumption without too much difficulty, and that will get you started on reducing your risk of disease and leading a healthier life.
Dec91IM
 

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QUALITY OF FISH





Q: I love to eat fish, but how do I know if it's fresh or not?

A: Unfortunately, to date there is little control over the quality of the fish we buy at the market. Although a package may be stamped with a "sell by?" label, many stores remove old labels, drain off excess accumulated fluid, rewrap and redate the packages and set them back out on the shelves. The Food and Drug Administration (FDA) imposes few regulations on the packaging and labeling of fish-one among many food products that the government does not regulate strictly. According to one Washington, D.C.-based consumer group, the risk of getting food poisoning from seafood is 25 times greater than the risk of getting it from beef and 16 times greater than from poultry.

So how do you know the fish is good? Seafood that is displayed in refrigerated cases is safer than that which is displayed on trays of ice. Prewraped fish is the last choice; if it smells fishy, pass. Fresh fish, Class 1 in FDA terminology, has no smell. Anything deemed Class 2 is decomposing and smells "fishy." Class 3 can make you sick, smells pungent and should obviously be avoided.
Always trim away skin and any dark parts of the flesh because these areas tend to contain the highest concentrations of contaminants. Eat raw fish only when it's extremely fresh, and when you cook fish, make sure you cook it thoroughly to kill bacterial contaminants.
March91IM

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CANCER-CAUSING CHEMICALS

Q: Is it true that many foods naturally contain cancer-causing chemicals? Am I in danger if I eat a lot of these foods?

A: Foods can contain carcinogens (substances that cause malignant tumors to develop in greater incidence than would occur spontaneously) as natural ingredients, accidental additives and on rare occasion, as in the case of saccharin, intentional additives. Carcinogens that occur naturally in foods include aflatoxin in corn and peanuts, solanin in potatoes and patulin in apple's and apple juice. Natural carcinogens are banned for use as additives but allowed when they appear in their natural state. For example, safrole, a natural ingredient of the sassafras root and a known carcinogen, cannot be added to root beer for flavor but occurs as a natural component of nutmeg, mace, ginger and black pepper.

It is unlikely that the amounts of these compounds that occur naturally in foods contribute to cancer development. Limiting your fat and cholesterol intakes, maintaining adequate fiber intake and avoiding tobacco are three proven methods for reducing your risk of cancer.
March91IM