With aging (beginning in your forties don't forget - or even earlier) comes a slower metabolism and usually less physical activity - leading to bone loss (osteoporosis), increased amounts of body fat, and weaker muscles; with an ultimate consequence of increased risk for falls, heart disease, decreased physical function in general, diabetes and other medical conditions; not to mention decreased self-confidence and self-esteem (bad body image); potentially to the point of depression.
These problems are not exclusively "women's problems," but are certainly much more common among women, who typically start life with smaller, thinner skeletons (not to mention the vicissitudes of estrogen levels during a female life span - increasing susceptibility to osteoporosis; and less muscle mass, resulting in lower metabolic rates, which along with the need for more body fat than for men, makes weight (fat) gain easier. And don't forget the impact of less strength on falls - a major health risk for older women.
I would like to be more eloquent on this subject - to really fire up women to start weight training; but the best I can hope for is that all women who read this message will think about it and talk to their friends about it. And there is no age limit - from childhood to "elderlyhood", there are benefits to enjoy.
Vitamin D Deficiency - Everyone knows about the need for calcium to build and maintain strong bones, but not everyone is aware of the important role that vitamin D plays in the game. Calcium is an important element to the human body. It addition to its well-known bone building task, it is also pivotal to all muscle contractions - including the heart. A crucial issue is that you can ingest plenty of calcium, but still be calcium-deficient because of a lack of adequate vitamin D, which is essential for adequate calcium absorption. In the absence of adequate calcium, vitamin D will remove calcium from bones to use elsewhere - not good. But inadequate amounts of vitamin D, even with a plentiful supply of calcium, can have the same result - bone density loss.
A problem, especially among the elderly, is that the two primary sources of vitamin D are milk - it's fortified with vitamin D - and sunshine; and they frequently don't drink milk, or spend much time outdoors (a problem that is often exacerbated by living in nursing homes). Regardless of whether one is exposed to the sun or not, after about age 70 much less vitamin D is converted by the body from sunshine.
Also, above about 34° the vitamin D that can be produced from sunlight is diminished; and in more-northern areas no vitamin D can be produced during the winter - the sun angle is too low. Particularly cloudy/foggy areas have similar problems of poor vitamin D production.
Another factor in underproducing vitamin D is use of sunscreens. We use them to help ward off skin cancer, but an SPF of 8 reduces production of vitamin D by 95%. At SPF 30, almost NO vitamin D is produced.
Vitamin D underproduction is a problem more for the elderly than for younger people who tend to get more sunshine. Over the age of 70 people generate, roughly, only a third as much vitamin D as people in their twenties. Are supplements the answer? Maybe. There are some recommendations that people over the age of 50 need 400-600 IUs per day. Over age 70, 800 IUs may be appropriate.
Food sources of vitamin D are few after fortified milk. Fish is another one, but it frequently has no nutrition label, so vitamin content is unknown.
One final issue before moving on has to do with the question: is it necessary to ingest both calcium and vitamin D together? And the answer is, NO. It is only critical that when you eat calcium sources, you have some vitamin D ready-and- waiting (left over from sun exposure, or whatever) to play its absorption role. Together is good, but not necessary.
The preceding information comes primarily from the October 1997, Nutrition Action Health Letter.
Now that we have learned about vitamin D deficiency, let's turn our attention to vitamin D toxicity.
Ironically, there are people who are taking too much vitamin D as part of attempting to ward off osteoporosis. The calcium-vitamin D connection is now clear - the vitamin helps the body absorb calcium. In-other-words, you could take plenty of calcium in your diet, and still end up with osteoporosis due to a deficiency in vitamin D; but, too much (more than 1000 IUs per day) moves calcium from the bones, to the blood, then to the urine, and out. In addition to loss of bone density, liver toxicity may also occur. So use caution when taking vitamin D supplements. Ultimately, it is very important to get a sufficient level of both calcium and vitamin D, but not too much D.
Most of the previous information comes from the October 1997, issue of the Tufts University Health & Nutrition Letter.
On the subject of strength training for kids (pre-pubescents): so, your 10-yr old son (or daughter) wants to lift weights? What should you do? First, who wants him (Take it easy, I'm not a misogynist or a sexist, "him" just happens to be my choice.) to train, and why? If you want him to "fill-out" some - forget it. As he reaches puberty, he will start to grow naturally. In fact, in the not too distant past, it was commonly thought that pre-pubescents shouldn't bother with weight training because they couldn't increase muscularity or strength before the testosterone flood. It's true that weight training seems not to increase size prior to puberty, but profound increases in strength can be achieved. The increases in strength reflect neuromuscular development. When adults start weight training (true beginners) large strength gains are typically made quite quickly. These strength gains are also neuromuscular in nature - as opposed to strength gains resulting from muscle growth. In essence, muscles are learning how to lift weights, and as they become more efficient, you get stronger.
It is now well-accepted that prepubescent children can achieve positive results from weight training. Increased levels of strength, improvements in sports, improvements in self-confidence, to name a few.
There are some cautions to observe with prepubescent training. For one, bone growth hasn't been completed yet, so maximal lifts in general are contraindicated; and shoulder exercises in particular should NOT include heavy weights.
As you all know, the shoulder joint is a particularly vulnerable part of human anatomy. The Designer made a compromise when it came to the shoulder joint - great mobility for relative instability. The head of the humerus (arm bone) fits into a shallow depression (Glenoid Fossa) in the shoulder girdle, and it is lashed in place with ligaments and tendons; unlike the hip joint, where the head of the femur (thigh bone) fits into a deep socket (acetabulum) in the hip girdle - not very mobile, but very stable. [Regular readers of the Newsletter are probably sick of hearing about this shoulder/hip instability/stability thing, but it just keeps coming up.]
Here is a brief but important note for girls. It is healthy for them to weight train because of one of its well-documented benefits - it increases bone density (stress on the skeleton caused by resistance/weight training results in bone growth) - thereby lessening the potential ravages of osteoporosis; a scourge for postmenopausal women, but far from unknown in young girls/women - especially athletes (like gymnasts and distance runners).
Weight training stimulates bone growth in both males and females. Bone injuries that have resulted from weight training have typically been caused by using too much weight and/or poor exercise technique. There once was a lot of talk about stress on the epiphysial (growth) plates potentially causing stunted or uneven bone growth, but there is now much less emphasis on this issue. It seems that this can still be a problem area, but by avoiding heavy lifting, it is an unlikely occurrence. All-in-all, it seems that the benefits of weight training on bone growth far exceeds the risk of injury.
One thing to bear in mind is a child's tolerance for exercise. Adult-imposed exercise may turn a child away from exercise. Whatever the source behind a child starting an exercise program, it has to be tolerable - fun. An easy start works best; with progression to higher levels best achieved when at least partially self-motivated. It is important that your child focuses on him/her- self, and not others. Growth rates are so variable at a young age, that a child might easily be discouraged at being smaller, weaker, and slower than others of the same age. The child should be taught inner-focus (to work toward his unique capabilities).
Another thought - some parents are so intense about their child's athletic success that they try to push them beyond their genetic fences. It may be more productive to support the "do-what-you-can-do" philosophy.
One thing that is a very important aspect of any child's weight training program is that it be supervised - always. Supervision would commonly come from a parent (or maybe a teacher or coach). It is important that anyone who undertakes the task of strength training a child should be diligent about proper techniques, including exercise selection and form, and proper rest intervals.
Some considerations for a child's exercise program are:
Remember that, for children, it is important to encourage exercise, but don't force it. Make it fun.
Does hyperplasia (growth of new muscle fibers) actually occur? For quite some time - years, actually - it has been said that development of new muscle fibers (hyperplasia) seemingly does not happen; only hypertrophy (growth of existing fibers) is possible. An article by Jose Antonio, PhD, in the November '97 issue of Muscle & Fitness magazine: however, suggests that hyperplasia does occur under some conditions, and explains the mechanism by which it happens.
He introduces a "satellite cell" as the vehicle for hyperplasia. It is a cell (not a muscle cell) that just kind of "lurks" on the periphery of muscle cells. They function to repair damaged muscle cells, or can fuse with another existing cell to cause hypertrophy. Satellite cells can also apparently form a new muscle cell - hyperplasia. Satellite cells are stimulated into action by muscle damage, stretching, and contraction. The stimulation consists of microtears in your muscles - like from intense exercise. Changes to your exercise - the exercise itself, reps, rest intervals, exercise order, increased weight, etc. - seem to keep the satellite cells active.
(Q) I am eating more fruit to improve my diet, but what should I buy to get more bang for my buck?
J.L., Willow Glen, CA
(A) In terms of nutritional density, numero uno is kiwifruit (yes, that little fuzzy thing); then come papayas, mangoes, and oranges. Also high on the list are strawberries, blueberries, and guavas.
(Q) As a woman, do I really need to be concerned about a heart attack?
L.S., San Jose, CA
(A) Yes, heart attacks are now the #1 killer among women. After menopause estrogen basically removes women's long-known resistance to heart disease. The risk of death from heart disease in older women actually exceeds that of men.
The fear of breast cancer among women has been very high recently, but heart disease has actually become a more significant health risk.
(Q) Are fresh vegetables really more nutritious than frozen or canned? I say yes, but my friend says not necessarily.
M.B., Eureka, CA
(A) Yes, if you are out in a field eating them where they grow, but if you aren't, your friend is right. It is all a matter of timing - the fresher the better. However, lots of "fresh" produce isn't so fresh by the time you get it in a store. Frozen or canned produce can be fresher if processed quickly. At any rate, there isn't that much of a loss between canned or frozen, as opposed to truly fresh.
(Q) I like to use dried beans in my culinary expeditions, but cooking them is pretty time consuming, do you think they are worth it - nutritionally?
J.R., Los Gatos, CA
(A) Yes, they are. They are a good source of fiber, protein (incomplete), iron, zinc, and B vitamins: and are very cost-effective. Here are some cooking tips:
1- Presoak them overnight, and dump the water to help reduce flatulence - especially Navy or lima beans.
2- For improving flavor, cook with herbs and spices - like cumin, dill, fennel, cardamom, and/or cayenne.
3- When using prepared beans, pay attention to nutrition labels and select those low in fat and sodium.
4- For prepared beans, rinse to reduce sodium.
(Q) Do peanuts have any nutritional value? I like them and do eat them, but would feel better about it if I knew they had some value.
A.B.C., Klamath Falls, OR
(A) They are high in fat, but also contain protein, fiber, and an assortment of vitamins and minerals. But a plant physiologist at the U.S. Dept. of Agriculture, Timothy Sanders, likes them for their resveratol, a phenolic - considered to be a heart-saving chemical (also found in red wine). They are thought to fight cancer, and to diminish the affect of cholesterol on artery walls. It takes about 11 handfuls of peanuts to get as much resveratol as a glass of red wine, but it is thought that a handful of peanuts a day won't provide too much fat, and will still benefit the heart.
(Q) Are sports drinks bad for your teeth, as I have been told?
N.J., Atascadero, CA
(A) They can be. A study done in England found that the top eight brands were all acidic enough to damage tooth enamel It was suggested that you use a straw or a bicycle squirt-bottle, and not to swish the drink around in your mouth. It was also suggested to choose brands containing calcium, phosphate, or fluoride - they help prevent tooth damage.
(Q) I have a friend who recently had a heart attack. It was a surprise because he had a very normal cholesterol level. Are there other indicators of a potential problem?
G.A., Walla Walla, WA
(A) There are some new tests on their way. Tests for levels of: 1) Homocysteine, a product of protein-rich diets, and is thought to be related to atherosclorosis; 2) Lipoprotein (a), related to the better known HDL/LDL pair, seems to accelerate action of LDL and slows the breakup of clots in the blood; 3) Fibrinogen, which is an intimate part of clotting and seems to be part of artery clogging; and 4) C-reactive protein, found in high levels, seem to indicate a higher risk of heart attack.
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