As a slight departure from the normal format of this newsletter, this special supplement is all Question And Answer -- an attempt to clear a backlog of questions.
(Q) The RDA for vitamin C is set at 60 mg, but many people take megadoses for one reason or another; mainly for colds, and usually based on research done several years ago by Linus Pauling, who recommended large doses as a cure for oncoming colds. What is the current thought about high doses of vitamin C?
J.J.A., Astoria, OR
(A) The RDA for vitamin C, as set by the Food and Nutrition Board, is 60 mg daily for adults. The World Health Organization recommends 30 mg per day. Either level is sufficient to prevent deficiency symptoms, but optimal intake levels are currently not known. Vitamin C is important in synthesis of collagen, part of the connective tissue in the body; is important for growth and repair of cartilage, and has many other important functions.
It is likely that the RDA for vitamin C will be increased to somewhere between 100 and 200 mg per day in the near future, based on the fact that plasma is saturated at that range. Expressed another way, taking more doesn't increase levels in the body. More is simply excreted in the urine.
The bottom line seems to be that while intake of vitamin C is important, there is no scientific evidence that supports taking mega-doses of vitamin C. In fact, mega-doses may interfere with the absorption of certain prescription drugs. It also increases the absorption of iron, which can be a problem for men.
(Q) What is the latest stand on secondhand smoke? I am a smoker, and don't want to quit, but my wife is adamant about me quitting, mainly because we are planning to have a baby.
G. A., Santa Clara, CA
(A) Do yourself, your wife, and your future child a big favor and QUIT.
For quite some time the evils of secondhand smoke have been well-known (and previously reported in an issue of this newsletter -- October 1998).The most comprehensive report to date links secondhand smoke to heart disease, nasal sinus cancer, sudden infant death syndrome and other diseases including lung cancer. The report, prepared by the National Cancer Institute (NCI), details 18 studies that have linked secondhand smoke with heart disease. It warns that exposure to secondhand smoke should be recognized as a major cause of death in the United States. Specifically for your attention, G.A., the report also confirms that exposure to secondhand smoke significantly increases the risk of death among children. [Note that infants (even while developing in a uterus) because of their size and evolving developmental stage, are especially susceptible to toxins like secondhand smoke.] Secondhand smoke also is linked to middle ear infections, asthma, bronchitis, and pneumonia.
As you can see, smoke, whether firsthand or secondhand, is a serious health risk for everyone exposed to it. Your child-to-be will thank you for giving up the smoking habit.
(Q) As I approach my mid-60s, I would like to try anything reasonable to keep my immune system running on all cylinders, if that is possible. Any suggestions?
"Gettin' Old," Del Rio, TX
(A) Way back in 1997 it was reported in the Journal of the American Medical Association (JAMA) that vitamin E supplements (i.e., more than the daily requirement) improves the immune system in the elderly.
Simin Nikbin Meydani, D.V.M., Ph.D., from the Nutritional Immunology Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, Mass., and her research team studied whether long-term supplementation with vitamin E enhances immunity in healthy elderly subjects.
In general an aging immune system is in decline, but the study demonstrated that supplementation of healthy elderly with vitamin E, an antioxidant vitamin, significantly improves some immune responses without any adverse effects.
For example, researchers found that subjects consuming 200 mg/day of vitamin E had a 65 % increase in delayed-type hyper-sensitivity skin response and a six-fold increase in the amount of antibody made in response to hepatitis B compared with placebo. The same group also had a significant increase in the amount of antibody produced in response to tetanus vaccine. No effect of vitamin E was found for diphtheria vaccine or on the total number of cells and proteins that fight infection, which substantiates the prior statement saying that vitamin E improves the immune response in some cases.
The authors of the study note that the U.S. recommended daily allowance for vitamin E, 30 mg/day, is based on studies in young subjects, but that 200 mg/day seemed to be the optimum level for the older test population.
The authors further state that since ageassociated decline in immune response is associated with increased morbidity and mortality in the elderly, they recommend increasing the intake of vitamin E for elderly .
In that same issue of JAMA, Ranjit Kumar Chandra, O.C., M.D., from the Memorial University of Newfoundland, Janeway Child Health Centre, St. John's, supports using nutritional supplementation (like vitamin E) to improve health and reduce illness.
(Q) I have felt extra tired during/after exercise lately, and know it isn't a case of over-training, and I'm getting plenty of rest. Could my diet be the cause? My eating habits haven't been so great lately.
M. R., Whangarei, NZ
(A) Given that you have eliminated two of the possibilities, your diet certainly could be the culprit. Another possibility is a medical condition that would require a visit to your friendly doctor; but let's discuss the diet option.
First, dehydration is a major cause of fatigue. Active people need at least 2 liters of fluid a day, so drink before, during and after exercise, as fluid losses increase during exercise even in cold weather (it may also enhance your immune system). Use the urine color test: if your urine is frequently dark yellow, drink more; it should be relatively clear.
The food you eat should be relatively high in carbohydrates since they are your major energy source. Stick mainly to the less refined type of cereals and grains, and include plenty of legumes, vegetables, and fruits.
We used to talk about simple and complex carbohydrates, but now a lot of talk is concentrated on the glycemic index (GI), which is a ranking of foods from 0-100, which reveals how quickly a food will cause a rise in blood glucose levels. The lower the GI, the more gradual the rise in blood glucose, which provides a more sustained and satisfying energy supply.
Foods lower on the GI are good choices 1-2 hours before exercise, so you start out well-fueled. And, in the long run, diets rich in low GI foods, may help protect against heart disease, certain cancers and Type 2 diabetes. Higher GI foods like sports drinks, bananas, potatoes, white rice, white bread, scones, jelly beans, rice pudding, cereal bars, soft drinks and refined breakfast cereals, raise blood glucose levels more quickly. Thus, they can help maintain blood glucose levels if taken during exercise; and to refuel glycogen stores immediately after exercise.
Personally, I'm not a fan of eating according to the GI. There are too many anomalous situations. For example, potatoes are often bashed for being high on the GI, but preparation and type make a big difference. Mashing raises the GI, as does making them into French fries. Mealy Idaho spuds are relatively high, but the waxy red potatoes are lower. My advice is to concentrate on the amount of processing (e.g., long grained brown rice rather than Uncle Ben's instant white rice -- even fortified it's nutritionally inferior), and vary your diet.
The key is to regularly eat a variety of complex carbohydrates to maintain a fairly constant fuel source, and to consume some simple carbs (high GI) during and after exercise. The "during" part is only necessary for long duration or highly intense exercise, but the "after" part is important to restore energy expended during exercise, and the sooner after exercise, the more efficient the refueling.
(Q) I have been plagued by cluster headaches for years, have seen several doctors, and taken several medications; all to no avail. I am getting desperate, can you offer any suggestions?
R. R., Witchita, KA
(A) One option may be oxygen therapy. I'm not sure how much scientific research supports use of oxygen for cluster headaches, but there certainly is anecdotal evidence supporting its efficacy. At least some insurance companies will pay for it as long as it is ordered by prescription' which I think lends some credence to its use.
A company called "LinCare," which operates nationwide, rents oxygen tanks and related equipment, and seems to be well-thought-of by those who have signed up with them. I am slightly skeptical of this therapy, but talk to a physician about this option. And note that at least one user suggested finding a younger doctor, who may be more supportive of alternative therapies, to discuss this with.
(Q) Why is it that when I am out in the sun on a warm day, I feel lethargic even when I'm relatively sedentary, but well-hydrated? Like when I'm watching a baseball game in the hot sun.
A. L., Los Altos, CA
(A) The answer to your question is bound up in a body function called thermoregulation. The human body strives to maintain an internal temperature of about 99 °F ± 1°. Four mechanisms are used to do this: convection, conduction, radiation, and evaporation. In hot weather (which is affected by air temperature, direct sunlight, wind, and humidity); evaporation is the primary cooling mechanism. Body heat is moved toward the cooler skin from the warmer core by blood, which explains why our fair skinned friends get so red-in-the-face from exercise -- their capillaries are working overtime.
The original question hasn't been answered yet, has it? But it will be. Thermoregulation requires the use of energy. During exercise in heat, roughly 55% of energy is converted to heat, which then has to be dissipated. Even in the absence of exercise, energy in a hot environment is being spent at a higher than normal rate -- to reduce heat. And don't overlook the flip side of thermoregulation. Shivering is the primary technique the body uses for warming up when its cold. And shivering uses energy too.
There are also other important factors involved; e.g., loss of electrolytes. You may remain fully hydrated by drinking frequently, but if water is your drink of choice, you will likely end up with an electrolyte imbalance. This is one case where a sports drink (whether commercial or home-made) makes sense.
Clothing is another issue. Typically, less is better; and avoid pure cotton, it doesn't breath. Of course there is another issue here -- sun damage. So avoid exposure during the hottest part of the day (about 10:00 a.m. to 2:00 p.m., I think), but if you can't, use sun screen liberally and wear a hat, and more if you can -- cover up.
(Q) Functional fitness is a term that I have heard bandied about recently. I gather that it is a type of exercise, but can you tell me what exactly it is, and whether it's just another passing fad or not?
A. P., Dodge City, Kan
(A) Functional Fitness (FF) in its broadest sense is using a system of Functional Training (FT) to improve one's quality of life. The concept of FF/FT is nothing new, but now has a catchy name and is being packaged in some gyms as the fitness concept of the future -- starting right now. Its proponents claim that it is far superior to exercise machines because they force the user to work in one plane only, and therefore many smaller muscles used for stability are bypassed. So balance balls, the Pilates system, yoga, tai chi, tubes, bands, climbing walls, plyometrics, spinning, etc. are popping up all over at gyms which are currently populated widely by traditional exercise machines. [Another concept used a lot currently is development of "core" strength -- basically the same as FF, I think.]
My personal impression of FF is that it has some legitimacy, but isn't the exercise panacea that many of its promotors imply that it is. They often dismiss current exercise systems for not training the whole body, for ignoring balance, for not training for specific movements (functionality), so the implication is that for sports training especially it is inefficient, and that it can actually cause injuries.
I am cynical enough to think that FF is promoted more to fill up gyms than for any real exercise benefits. That is not to say that I don't believe that FF has a plus side. It does promote balance, it can be fun and therefor break up the potential monotony of traditional weight training (whether with machines or free weights).
I find myself, somewhat irrationally perhaps, trying to defend the current exercise environment against the onslaught of FF largely because of the often inaccurate criticism of weight training -- primarily, buŻ not exclusively, of exercise machines.
"They" seem to imply that weight training by machine is almost a worthless endeavor, but in my opinion they can be useful, especially for beginners. But I will acknowledge that not everyone can accomodate every body size, and they sometimes put one in an inappropriate position, but machines are constantly evolving to more accurately match normal human movement, and become safer in terms of body position. In most cases dumbbells are my preference for the very fact that they promote balance and symmetrical strength; i.e., they require each side of the body to do its share of the work, where many machines allow the dominant side to take on a disproportionate part of the load. Balance is improved by exercises like walking lunges. And squats are not just up/down movements without balance requirements and use of smaller muscles to maintain stability. Cable crossovers done one arm at a time turn out to be excellent abdominal exercises. For the back (erector spinae muscles) try "back twists," which are done on a back extension stand (sometimes called a Glute-Ham Developer). Once you are installed, you will be in a prone position with a pad over your ankles, and your hip bones (illiac crests) supported by another pad. You are in a horizon position parallel to the floor. In this position, back extensions are normally performed, but, instead, you twist from side to side, under control, with an unsupported trunk. The point I'm trying to make is that the quality (both the design and effort made) of your overall program is, in my opinion, more important than what equipment/techniques you use.
As far as injuries go, it seems that improper form: too much weight, carelessness (like leaving dumbbells/barbells scattered all over the floor, dropping weights, overuse, etc.) are more responsible than lack of "core" strength/balance. Even injuries outside of gyms (or more accurately, formal exercise) may often be related to things like improper lifting technique/body dynamics more than weakness of core muscles. For example: lifting a heavy object out too far from the body.
So, does FF have anything to recommend it? Of course. Plyometric exercises, for example, can be especially helpful for some sports since they are designed to enhance development of speed and power. Jumping and medicine ball/Plyoball exercises, at lower levels can even be good for simple fitness enthusiasts by simply providing exercise alternatives.
Stability balls and balance boards can help improve, surprise, surprise -- balance.
Tubes and bands are good especially for travel -- they are very portable, and can be used for a wide variety of exercises; although an advanced exerciser won't get maximum tension out of these aids.
More benefits come from Yoga and tai chi -- a potentially improved mental state, flexibility, balance, strength ...
It seems that the Pilates System is the only FF exercise mode that is kind of an either/or exercise -- either Pilates, or conventional plus other FF modes; since Pilates has its own set of instructors and equipment, and usually isn't integrated into conventional clubs/gyms.
(Q) I come from a large family, several adults and lots of kids, that likes to get together at one house for major holidays. After getting overstuffed, we usually end up in a touch football game al la the Kennedys. Its a good way to work off a heavy meal, if you can avoid throwing up that is. But lately I've heard that might not be such a good idea, from a health standpoint. Have you heard anything about that?
R. R., Abilene, TX
(A) There is at least one study, presented at the 2000 American Heart Association's Scientific Sessions which suggests that exercise within two hours of a large meal increases one's risk of a heart attack, although the overall risk is still low.
It is proposed that risk is elevated by large meals in the following ways: 1) Eating and digesting food increases heart rate, blood pressure, and oxygen requirements; all of which, together, force the heart to work harder. 2) High blood pressure can cause plaques in an arterial wall to break loose and form a clot that may block a vessel. 3) After a large meal an increased amount of insulin is secreted by the pancreas, which interferes with normal relaxation of coronary arteries.
It isn't a good idea to draw conclusions based on a single study, but it certainly provides food for thought, and further research. And overeating is never a good idea anyway. This study just provides a little more incentive to cut back on the "stuffing." Even if overeating doesn't directly cause heart attacks, there is still the obesity issue as well as other health risks.
(Q) Does Maximin really do what its manufacturers say: prevents serious diseases like cancer, hepatitis, diabetes, and many more?
D. K., Ogden, UT
(A) Of course not. It is produced from clay silicates -- dirt, albeit fine dirt, since it is processed through a special high energy grinding process, according to the makers. It is claimed to stimulate the immune system, to be a "super antioxident." Don't believe the unproven claims.
Exercise Corner -- Ab Roller/Torso Trainer/???. For this supplemental issue the subject is an exercise "gadget" more than a specific exercise. This gizmo has been around for years in one configuration or other. Essentially it is an axle (bar) about 12 to 15 inches long with a couple of wheels near its center. They are about seven inches in diameter and are either side-by-side or spaced apart a few inches. The axle projects beyond the wheels enough to be used as grips (handles), that are covered with a plastic/rubber-like cover to enhance gripability.
Now for execution using the Ab Roller, assume a hands and knees position while grasping the handles. Now push forward (the wheels will roll freely) while maintaining straight arms. Extend your arms as far forward as you can without experiencing shoulder or low back pain. Pause, then pull back to the initial position where your arms will be more-or-less vertical.
Using this very simple piece of equipment will particularly work your abdominal muscles, shoulders (at least the anterior deltoids), triceps, the major back muscles, and to a lesser degree, several other muscles/muscle groups.
To stimulate more muscle involvement and increase overall intensity, include diagonal movements. For even greater intensity and muscle recruitment, perform the exercise in a pushup position -- knees off the floor. And, of course, the length of extension controls intensity.
Be especially aware of your shoulders and lower back, extreme extension can cause pain and increase risk of injury.
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Send questions or comments to Michael Fenner: e-mail to Mike Fenner
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