In This Issue

Heart Disease/Bacterial Infection

Exercise Builds Brain Cells?

Dietary Reference Intakes (DRI)

Prostate Health And Exercise

About Blood Types

Food Additives to Avoid

Questions And Answers

For quite some time some scientists have suspected that there is a link between heart disease and some form of bacterial infection.

Researchers now claim that the link has been confirmed, and that the study proving the link is to be published in the latest edition of the journal SCIENCE. If this discovery proves to be true, many lives could be saved each year by the use of antibiotics, or possibly by an immunization against specific "bugs." [Not bad considering there are close to 961,000 deaths in the U.S. each year from heart disease.]

The study was done at the Ontario Cancer Institute (OCI) in Toronto. Mice were injected with proteins from chlamidia bacteria, and were found to develop heart disease; and, up to 95% of people are exposed to chlamidia during their lifetimes.

The chlamidia protein is found on the surface of the bacteria, and closely resembles that found in a healthy heart. When the mouse's immune system prepares to do battle with the foreign proteins, some damage is done to the heart and coronary arteries.

Dr. Josef Penninger of the OCI says that this study is the first to demonstrate heart disease from a bacterial source. Dr. Paul Ridker of the Harvard Medical School is quick to add that all of the normal risk factors like high blood pressure, smoking, high cholesterol, and obesity remain important, but now a new one can be added to the list.

There is still some skepticism about the results of this OCI study, but those skeptics support clinical trials to verify whether or not antibiotics can prevent some heart disease. Part of the reasoning behind that thought is that roughly 20% of heart attacks are not linked to any known risk factors.

[The heart disease-bacteria link is similar to the recent finding of a bacteria-stomach ulcer link.]

Exercise apparently stimulates growth of brain cells. Two recent independent animal studies to be published in the March issue of "Nature Neuroscience" show that mental or physical activity can stimulate new brain cell growth as well as help existing cells live longer. One study was done at the Salk Institute for Biological Studies in San Diego, and dealt with the effects of physical exercise, running specifically, on the brain. The second study, done at Princeton University, revealed that mental tasks could increase the number of new neurons in the adult hippocampus (an area of the brain related to learning and memory), as well as help existing neurons (nerve cells) live longer.

The Salk study compared adult mice - one group housed in a cage containing a running wheel, and a second group housed in a standard no-wheel cage. The mice with the wheel developed twice as many new brain cells as the other group. It was theorized that, because it has now been verified that adult brain cells can be created, running (or other intense exercise?) might stimulate brain-cell growth in humans as well as in the mice in the study.

In the Princeton research mental tasks were found to provide similar results to those of the Salk research - new neurons in the hippocampus were doubled, and the life of existing neurons were extended.

Until recently it was thought that brain growth (increased neurons) was essentially complete in humans at birth. This new research suggests that memory improvement in the elderly may be stimulated by exercise - both mental and physical. That theory has been around for quite some time - part of the use-it-or-lose-it concept, but now there is more evidence to support the concept, and research in this area continues. It is certainly plausible that mental activity keeps your brain sharp as you age, but the exercise-brain connection is newer, and exciting.

An RDA (Recommended Dietary Allowances) revision is in progress, and has been since about 1997. The RDA designation is being replaced by DRI (Dietary Reference Intakes), and those 14 nutrients that have been completed are listed below in Tables 5-1a and 5-1b. The full list will be displayed when it is completed - date unknown, but the committee responsible for determining the new nutrition standards is composed of seven panels, two sub-committees, and representatives from both Canada and Mexico. In other words, don't hold your breath waiting for the new standards to be completed - well into the next millenium I would guess.

At one time the DRIs included four components: 1) RDA, the standard individual intake, 2) UL (Tolerable Upper Intake Level), the level of intake above which adverse effects may occur, 3) EAR (Estimated Average Requirement) - a level at which 50% of those actually consuming specified nutrients would be inadequate, and 4) AI (Adequate Intake), which seems to be a level deemed by experts to be adequate, but not quite as accurate as RDA or EAR. In the latest data that I have seen, only RDA and AI appear to have survived this seemingly highly bureaucratic process of setting new nutrition standards, but maybe they just aren't out yet, or I just haven't seen them.

To date, the most significant change may be increase in calcium intake during specific age ranges. Intake from age 9 -18 for both boys and girls has been increased from 1200 mg to 1300 mg. This is, of course, the time to maximize bone density in preparation for the later years when bone density tends to decrease, especially without preventative measures like ERT, weight bearing exercise, or other actions.

Note the following:

• mg = milligrams (1,000 = 1 gram)
• µg = micrograms (1,000,000,000 = 1 gram)
• mg NE = milligrams of niacin equivalents; a measure of niacin activity (Note that for infants aged 0.0-0.5 yrs, the "2" is for mg of preformed niacin, not niacin equivalents.)
• µg DFE = 1 mg food folate or 0.5 µg folic acid taken on an
• empty stomach; or 0.6 µg folic acid taken with meals
• * = no special value; use the number for your age.

Risk of prostate cancer, that male nemesis, may be reduced by exercise, the Universal Palliative. In a recent issue of Cancer Causes & Control a study of nearly 30,000 men reported that those who walked on their jobs and participated in moderately intense leisure activities had their prostate cancer risk reduced by 60% when compared to those who were mostly sedentary. Even men who were inactive at work, but were activate during their leizure time had a 30% risk reduction relative to those habitual couch potatoes. If ultimately validated, this report simply adds to the tremendous benefits of exercise (physical activity).

Blood type is important, but many of us don't even know what our type is. But that may not be all that crucial. Even if you told the blood bank or a doctor, for example, what your type is, they would check it anyway - it's too important to just take your word for it.

Two areas where blood type is especially important are blood transfusions and blood donors.

Blood transfusions have been tried as far back in history as the 1600s - without much success until more recently. Very little success in the early history of blood transfusions motivated doctors to try some fairly creative ideas - animal blood, saline, milk, and even wine were used at one time or another for transfusions, obviously without success.

But, in the early 1900s, Dr. Karl Landsteiner of Austria discovered that humans have some distinctly different blood types identifiable by the presence of molecules called antigens on the surface of red blood cells.

The first group of blood types identified were called the ABO group, and identifiable by the presence of A or B antigens. The ABO group includes type A, B, AB, and O. Type A blood has only A antigens on its surface, type B has only B antigens, AB has both, and O has neither.

After Dr. Landsteiner's discovery of distinct blood types, more effective transfusions were finally done by "typing" blood of donor and recipient before transfusing to insure compatible types.

Since the initial discovery of the ABO group, others have been found, but none more significant than the original find.

One more stumbling block remained, but was solved when the Rh factor blood group was discovered - identified by Rh antigens on the surface of red blood cells. A further distinction within the Rh group was found. The presence of an Rh+ and Rh-. The difference being the presence or absence of the D antigen.

A combination of the ABO and Rh blood groups results in the most commonly known blood types: A+, A-, AB+, AB-, O+, and O-. With the definition of all of these types, transfusions have become quite safe.

About transfusions - closely following birth, humans start developing antibodies, part of the immune system, which defend against foreign invaders. Antibodies are formed to fight against A or B antigens, whether we happen to have them on our red blood cells or not. It turns out that, according to Mayo Clinic hematologist S. Breanndan Moore M.D., some plants produce them, so as soon as a baby starts to eat plant foods, A and B antigens start to develop, even if the baby has type O blood. If the child should later be transfused with a blood type other than O, disastrous consequences may result from the inevitable war (antigen vs antibody) that will break out. Hence, precise blood typing is critical, and now is quite routine.

Safe transfusions (compatible blood) for the normal types include:

• Type A can receive A or O,
• Type B can receive B or O,
• Type AB can receive A, B, AB, or O,
• Type O can only receive O, but it can be donated to anyone.

Rh incompatibility can present a problem. A person with Rh+ blood can be transfused with Rh- blood, but the reverse is not consistently true. In addition to transfusion problems, incompatible blood types can also cause problems during pregnancy. During birth some of the baby's blood may find its way into the mother's bloodstream. If their types are different, the mother may develop antibodies that could cause a problem with future pregnancies.

A further Rh complication that can occur is when a father is Rh+ and the mother is Rh- (about 15% of women). If the baby inherits the father's blood type, the mother and baby have incompatible types. An Rh- mother's first born usually isn't at risk because she hasn't yet developed Rh+ antibodies; however, with a second Rh+ baby, the newly formed antibodies can infiltrate the placenta and cause damage to the developing baby. Each succeeding Rh- incompatible pregnancy faces an ever increasing risk.

In modern times; however, the problem is not so widespread or severe because of blood screening for Rh-, and subsequent use of a serum that prevents an Rh- woman from producing antibodies. Also, more screening of both mothers and developing fetuses for potential blood incompatibilities, and ensuing use of other effective therapeutic techniques has made a difference.

According to the March 1999 Nutrition Action Health Letter, there are several food additives to be avoided because of poor testing or known to be unsafe at normal consumption levels -

• Acesulfame K
• Artificial Colorings (Blue 1, Blue 2, Green 3, Red 3, Yellow 6
• Olestra (Olean)
• Potassium Bromate
• Saccharin
• Sodium Nitrate/Nitrite

(Q) Do vegetarians need creatine supplementation?
A. B., Mountain View, CA

(A) Generally speaking, meat eaters have a higher level of creatine in their muscles than do vegetarians. Although everyone has different levels, vegetarian athletes, especially, might benefit from creatine supplements, at least in the short term (since the effect of very long term use is unknown).

(Q) A friend of mine said that vitamin K can help prevent hip fractures in aging women. I though calcium intake was the key to strong bones.
J. R., Palo Alto, CA

(A) Calcium (and don't forget vitamin D) is certainly an important ingredient in bone health, but research at Harvard and Tufts universities found that vitamin K also promotes bone health. Its protective effect is thought to be caused by enabling osteocalcin, a bone protein, to enter bones. Without osteocalcin in bone structures, it seems that skeletal weakening occurs.

Vitamin K is important for helping blood to coagulate, and the RDA is enough for that function, but it seems that the RDA should be increased in view of the new findings about its connection to bone health. Any RDA increase will surely require further research. In the mean time, the Lead investigator of the research, Diane Feskanich, ScD, recommends that people should consume at least one daily serving of the highest natural source of vitamin K - dark green vegetables like collard greens, spinach, Brussels sprouts, or broccoli.

(Q) When should I take my multi-vitamin/mineral pill?
D. B., Spokane, WA

(A) Take them with meals. Their absorption is improved when they are broken down at the same time as food.

The same goes for iron supplements. Anyone taking them should do so on a full stomach, or with a glass of juice. Iron-rich foods like meat, fish, and poultry, along with vitamin C-rich juice, fruits, or vegetables help increase absorption of iron from iron-containing supplements.

However, if you are a coffee or tea drinker, don't drink them with an iron-rich meal, they inhibit iron absorption. Allow about 90 minutes between the two.

(Q) I know I should cut down on caffeine, but are there any other additives to cut back on? D.B.F., Roseburg, OR

(A) You are right about caffeine. It is a flavoring and stimulant - mildly addictive, and may cause insomnia or jitteryness. Coffee drinkers who suddenly quit, can get headaches, irritability, sleepiness, or other withdrawal symptoms. Also, caffeine increases risk of miscarriages and maybe birth defects, and retards fetal growth, so women who are pregnant, or are thinking about getting pregnant, should eliminate it from their diet. In addition, it may reduce chances of getting pregnant in the first place.

Another additive to cut down on is dextrose (glucose, corn sugar) - a sweetener/coloring agent. It is a natural sugar found in fruit and honey. But when it is added as a sweetener, it accounts mainly for empty calories and promotes tooth decay.

Corn syrup, a sweetener, thickener without any nutritional value, but not without calories - empty ones, is often used in foods that contain little nutritional value, and promotes tooth decay as well.

Invert sugar is another sweetener - a mix of dextrose and fructose - with the same empty calories and tooth decay promoting characteristics.

Manitol, another sweetener, contributes only half as many calories as sugar; but large amounts (A box car full?) may act as a laxative.

Then there is partially hydrogenated vegetable oil, which contains trans fats that function as saturated fat to help create heart disease.

Salatrim is next. It is modified fat, supposedly with only half as many calories as normal fat, but in large amounts may cause stomach cramps and/or nausea.

Salt - yes plain old salt (sodium chloride), used as a flavoring or preservative. For salt sensitive people, it raises high blood pressure, or at least the risk of it; which of course increases the risk for a stroke or heat attack.

The last item on this "cut back on" list is sugar (sucrose - table sugar). Sugar, corn syrup, and their bretheren make up about 15-20% of the average diet, and their lack of nutrition - no vitamins, protein, minerals, or fiber - account for their deserved reputation for promoting obesity, dental problems, and maybe even heart disease, under certain conditions.

(Q) What's a good butt exercise?
L. B., Holy City, CA

(A) Try "bentleg deadlifts." In a standing position, hold a barbell across the front of your thighs; bend forward from the hips and simultaneously bend your knees. Lower the barbell toward the floor while maintaining a "flat" back. Then stand up again. That's one.

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Send questions or comments to Michael Fenner: e-mail to Mike Fenner
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