Archive for September, 2013

What’s All This Wail About Kale?

September 28, 2013

Andrew Siegel, MD   Blog #121

Kale, kale, kale…it’s all we hear about lately.  Is this large, crisp, coarse-leaved, crinkly, intensely green cousin of cabbage the “super-food” that it is cranked up to be, or is this mere hype?  Is it the nutritional powerhouse that it supposed is or is it really just a pretty bed for shrimp cocktail?

In response to Burger King’s new line of low fat French fries announced on September 24, Eric Hirschhorn, chief marketing officer of the company stated: “You live in Manhattan and might be having a kale smoothie on your way to work this morning, but a lot of people don’t even know what kale is, and if they do, they don’t want to eat it. You have to give people what they want.”

Kale is certainly the hottest ticket on the veggie scene—the vegetable de jour—but apparently not so yet in the world capital of cuisine. On the front page of the Sunday, September 23rd New York Times was an article entitled, “Trendy Green Mystifies France. It’s a Job for the Kale Crusader!”  The article detailed the quest of an American woman, Kristen Beddard, to help kale gain traction as a potential staple of French cooking.   Although considered a menu staple and an eagerly pursued super-food in the United States, apparently the French do not understand or seem all that interested in this leafy green vegetable.  However, Ms. Beddard seems to be making headway in her mission. Alain Passard, owner of a 3-star Michelin restaurant in Paris, describes kale “not as a cabbage but a seaweed with the feel of an algae, personality, character, a power that unlocks creativity and touches on all the senses.”   Wow…sounds too good to be true!

Kale-like cabbages with prominent stalks were first cultivated in ancient Greece and Rome. Kale ultimately became a staple in northern Europe because it grew so nicely in the cold climates of that region. It was one of Europe’s most commonly grown and consumed vegetables during the Middle Ages. In England during World War II, kale was promoted as an easy-to-grow source of nutrients at a time when rationing was rampant.

Kale is a versatile vegetable and can be eaten raw, or cooked by a number of techniques including sautéing, steaming, boiling, frying, or baking. It can be served in pasta, soups, and stews. It makes for a very hearty side dish. The most readily available kale is the curly variety, which is ubiquitous in farmers markets and supermarkets—its pungent flavor and texture are ideal for making kale chips.  The next most popular variety is dinosaur kale, which has narrow, tall, dark leaves and a wrinkled texture–it’s slightly sweeter and more delicate than the curly variety.

In terms of nutrition, 2 cups of kale (70 calories) packs a great deal of nutrition and provides more than 2.5 times the daily requirement of vitamins A and C, 20% of vitamin B6, and plenty of vitamin K, carotenoids, calcium, riboflavin, niacin, magnesium, iron, sulphur, and phosphorus.  It contains almost 50 antioxidants.  Kale contains the highest concentration of the anti-oxidant lutein of any source, and if you ask any ophthalmologist, this carotenoid is the most important defense against macular degeneration, the number one cause of blindness.

Kale is not solely used for dietary and nutritional purposes, as there are many types of flowering kale plants that are used for ornamental reasons.  They have leaves in a variety of colors including pink, red, blue, and lavender and it is the cold that is responsible for intensifying these rich hues. Although edible, these decorative kales are not as appealing to the taste buds as are the kales that are use for culinary purposes.

The following is a fabulous recipe for roasted kale chips with parmigiano-reggiano, courtesy of Whole Foods market.

Ingredients:

1 bunch kale

1 tablespoon extra virgin olive oil

½ teaspoon chili powder

¼ teaspoon kosher salt

2 tablespoons finely grated Parmigiano-Reggiano cheese

Preparation:  Preheat oven to 350°F.  Line 2 baking sheets with parchment paper. Trim tough stems from kale and discard.  Cut leaves into 2 inch pieces, place in a large bowl, drizzle with oil and toss.  Add chili powder and salt and toss again. Arrange kale on sheets in single layer; bake until crispy and edges begin to brown, about 12 minutes or so.  Remove from oven and let cool for 2 minutes. Transfer to a bowl and toss with the cheese.  Store in an airtight container for up to 5 days.

Bottom Line: Hail to kale: it is today’s new “super-food” that can be prepared in a variety of interesting and delicious ways. Mother’s advice was sound: “Eat your greens.”

Andrew Siegel, M.D.

Author of Promiscuous Eating: Understanding and Ending Our Self-Destructive Relationship with Food: www.promiscuouseating.com

Available on Amazon in Kindle edition

Author of: Male Pelvic Fitness: Optimizing Sexual and Urinary Health, in press and will be available in e-book and paperback formats in the Autumn 2013.

Blog subscription: A new blog is posted every week.   On the lower right margin you can enter your email address to subscribe to the blog and receive notifications of new posts in your inbox.  Please avail yourself of these educational materials and share them with your friends and family.

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Vitamins and Supplements ???

September 21, 2013

Andrew Siegel, MD   Blog #120

The human body needs nutrients and micronutrients—including vitamins and minerals—in balanced amounts in order to ensure optimal functioning. There seems to be a general misconception that with respect to vitamins and supplements, if some are good for you, than more are even better. However, excessive intake may either offer no additional health benefits or may even be harmful to our health. Too much can actually be dangerous—more is less. In light of the following words, caution needs to be applied to excessive intake of vitamins and supplements—less is more.

When I hit the big five-O (50 years old), I began taking a multivitamin and mineral supplement.  The last vitamin I had taken was Chewable Chocks as a kid.  I figured I was on the back nine of life and needed all the help I could get.  Being the value-oriented consumer that I am, I headed over to Costco and picked up One-A-Day Men’s Health Formula that claimed to support prostate health, heart health and healthy blood pressure…all good!  Each tablet contained Vitamins A, C, D, E, K, B1, B2, B3, B6, folic Acid, B12, biotin, calcium, pantothenic acid, iron, magnesium, zinc, selenium, copper, manganese, chromium, potassium and lycopene.  It seemed like a lot of bang for the buck.

I continued taking the vitamins for a year or so, but did not notice any tangible benefit—I did not feel better, was not more energized, stronger, more potent in any way imaginable, did not get less colds, and my annual blood chemistries were unchanged.  I came to the realization that I derived a lot more benefit from my morning caffeine infusion than from the daily vitamin.

Frankly, I had felt pretty good before starting the vitamin and mineral supplement and since I felt absolutely no different after using it, I stopped taking them and have never looked back.  That stated, I eat a very healthy diet with an abundance of vegetables, fruits, legumes, whole grains, and lean sources of protein and am certain that my diet is not deficient in any vitamins or minerals.

At least one in three Americans use multivitamins and mineral supplements on a regular basis.  There is no question that we need micronutrients in sufficient quantities to sustain our health.  A nutritious and well-rounded diet should provide these essential micronutrients.  The exceptions to this are the following: if your diet is poor; if you are pregnant; if you are a child; or if you are ill or have a compromised immune system due to certain medical conditions.  Under such circumstances, supplementation is crucial.  According to Susan Roberts (Tufts University Professor of Nutrition): “Multivitamins can fill in the gaps if you get too little of some vitamins and minerals from your food.”  Specifically, there are five micronutrients that many of us do not get enough of: vitamin D, folic Acid, B12, iron and calcium.

It is best to obtain the necessary daily requirements of micronutrients from one’s diet. Vitamins and minerals that are sourced from a vegetable, fruit, etc. (nature) are advantageous because they contain important enzymes, peptides, and phyto-nutrients that are necessary to the proper/maximal utilization of the vitamins and minerals.  Many studies have concluded that vitamins and minerals derived from diet are far superior to synthetic or formulated vitamin pills.  Bioavailability is the degree of activity or amount of a substance that becomes available for activity in the target organ/tissue.  In short, the bioavailability of the vitamins and minerals within a multivitamin is often significantly less than that of the vitamins and minerals in their natural form.

The other issues aside from bioavailability are that multivitamins vary greatly in quality, some have trivial amounts of some necessary micronutrients, and many have claims that are not clinically proven.  Nobody even knows if the recommended quantities (the RDA or Recommended Dietary Allowances) are accurate or relevant.  Another important point is that the fat-soluble vitamins D, E, A, and K are stored in the body, and excessive quantities can be problematic.  On the other hand, excessive intake of the water-soluble vitamins B and C will result in your vitamin ending up in the urine, with your expensive vitamins enriching the diets of the crocodiles in the lake.

The therapeutic window is the “dose” range between what is effective and the amount that will give adverse effects.  The ideal drug, nutrient, vitamin, supplement, etc., will have a “wide” therapeutic window.  Coumadin is a commonly used drug to prevent blood from clotting.  It has a very “narrow” therapeutic window, meaning that it easily can cause adverse effects.  In the proper dosage, it prevents clotting in someone with atrial fibrillation (heart arrhythmia), venous thrombosis (clots) or in a person with a mechanical cardiac valve.  Too much of a dose and the consequences can be lethal with death by impaired clotting with bleeding.  In fact, this same drug in the form known as Warfarin can be bought in any home supply store and is used as rat poison, causing rodent death by bleeding.  Understanding the concept of therapeutic window is important in terms of gaining insight into the potential adverse effects of overdosing on something that is healthy in the right doses.

Omega-3 fatty acids are widely popular as a means of lowering the risk of cardiovascular disease and cancer.  Omega-3 fatty acids are available either by fish oil supplements or preferably by eating fish that are rich in these fatty acids including salmon, mackerel, etc.  However, a recent report from Dr. Theodore Brasky (Journal of the National Cancer Institute) concluded that men with the highest intake of omega-3 fatty acids had a substantial increased risk of prostate cancer as compared to men with the lowest intake. The bottom line here is that it is difficult—but not impossible—to overdose on omega-3 fatty acids from the natural source (fish), but easy to do so with the supplements, so it is best to exercise moderation.

Other example of the potential benefits vs. risks of vitamin intake:

The SELECT (Selenium and Vitamin E Cancer Prevention Trial) seven-year study, was a study to determine if Vitamin E and selenium conferred a protective benefit regarding prostate cancer.  The study concluded that men who took vitamin E supplements had elevated prostate cancer risk compared to those who took a placebo.

Niacin is a vitamin that is commonly used to decrease cardiovascular risk and works by lowering levels of LDL and raising levels of HDL.  It has been shown that within a certain dose range, niacin decreases cardiovascular risk, but too much can cause severe liver damage as well as other adverse effects.

Magnesium is a mineral that is vital to numerous metabolic functions. In range, it is crucial to bodily functions, but excessive intake can cause cardiac arrhythmias, hypotension, diarrhea, etc.

Vitamin C (ascorbic acid) is an essential micronutrient that can cause the disease scurvy when deficient.   Many people are very fond of taking mega-doses of vitamin C for a variety of reasons, one of which is the notion that they prevent colds.    The problem is that since vitamin C is a water-soluble vitamin, any excess not needed by the body is excreted in the urine.  High levels of vitamin C in the urine are one of the leading causes of kidney stones since the vitamin C is metabolized to oxalate—one  of the ingredients of calcium oxalate stones, which is the most common kind of kidney stone.

The Bottom Line:

One of the keys to good nutrition is achieving balance—finding the happy medium between too little and too much consumption. If you eat a healthy, well-balanced diet that includes fruits, vegetables, lean protein, and whole grains, it is advisable not to waste your resources on multivitamin or mineral supplements. This does not apply to children, pregnant women, those suffering certain illnesses and those with a poor diet.  If you are deficient in D, B12, folic acid, iron or calcium, it is of paramount importance to supplement your diet appropriately.

Andrew Siegel, M.D.

Author of Promiscuous Eating: Understanding and Ending Our Self-Destructive Relationship with Food: www.promiscuouseating.com

Available on Amazon in Kindle edition

Author of: Male Pelvic Fitness: Optimizing Sexual and Urinary Health, in press and will be available in e-book and paperback formats in the Autumn 2013.

Blog subscription: A new blog is posted every week.   On the lower right margin you can enter your email address to subscribe to the blog and receive notifications of new posts in your inbox.  Please avail yourself of these educational materials and share them with your friends and family.

Not So Sweet on Sugar

September 14, 2013

Andrew Siegel  Blog #119

Nature is ever so clever—look at our human species—brilliantly evolved and adapted not only to survive, but also to thrive on this planet, breathing the air in the atmosphere, drinking the water and eating the bounty from the soils of the fertile earth.

Whenever clever nature provides us with a nutrient that is potentially unhealthy, it protects us by limiting our access to that nutrient.  Take, for example, sugar—also known as sucrose or, alternatively, 50% glucose/50% fructose—clearly unhealthy and a key contributor to the obesity epidemic.  The major sources are sugar cane and sugar beets.  If you ever tried to extract the sugar out of a sugar cane or sugar beet plant you would quickly find that they are fibrous and unyielding. If you want to derive calories from them, it requires great effort and you will likely end up quite frustrated.  It’s not unlike chewing on a stick of bamboo and trying to suck the sugar out—at best we will only get a few calories out of the whole endeavor and probably burn more calories than taken in with the effort.

Because of the collective intelligence of mankind, we are now easily able to remove the protective fiber matrix of the sugar cane or sugar beet and process the sugar into a pure, refined and powdery product.  This enables unrestricted access to the sugar and allows many “naked” calories to be easily consumed in a short time period. That is NOT the way nature intended, but humankind has prevailed over nature. Processing has allowed us to cheat nature by refining sugar, permitting consumption in immoderate and unhealthy amounts, contrary to nature’s design.  However, it is very difficult to beat nature in the long run, and though mankind may have won this battle, we are losing the war, because the consequences of excessive sugar consumption are potentially dire and grave.

Most humans love—if not crave—the taste of sugar. It activates pleasure pathways in our brain that reinforce the desire for its continued consumption and, in some of us, it behaves like addictive substances.  Even if one is extremely disciplined and rarely opens a packet or cube of sugar to sweeten their ice tea, chances are they nonetheless are consuming way too much sugar.  The typical American diet adds 25 or so teaspoons of sugar to our daily consumption.  This includes sugar from sugar cane and sugar beet sources as well as from the highly processed high fructose corn syrup (HFCS).  In one month, this inadvertent cumulative sugar consumption is equivalent to approximately 4 extra days of eating!

Sucrose—a.k.a. table sugar—is a combination of glucose and fructose.   All sugars are not the same.  After consuming glucose, it is absorbed by the small intestine and used as fuel by our cells, aided by the hormone insulin.   Any glucose that does not need to be used for immediate fuel is stored in the form of glycogen in our muscles and liver.   Fructose behaves differently than glucose. Insulin does not have an effect on fructose and after absorption it goes straight to our livers where it is mostly converted to fat.  Fructose does not cause the same amount of satiety as glucose does. Too much fructose leads to increased visceral fat and high blood lipid levels.

Fructose is the predominant sugar in many fruits, hence the term fructose. How do we explain the apparent paradox between fructose being a “bad” sugar, yet fructose being the main sugar in fruit, which is good for us? One difference between the fructose contained within fruit as opposed to that within a bottle of soda is that fruit fructose is natural and not created in a chemistry lab (i.e., high fructose corn syrup).  Additionally, the concentration of fructose in fruit is significantly less than that contained within the soft drink. Furthermore, the fructose in beverages is a source of “empty” calories—essentially liquid candy—as they do not contain health-promoting ingredients present in fruit including fiber, anti-oxidants, vitamins, minerals and other phyto-nutrients. Because of the fiber content of the apple, the sugars are slowly absorbed whereas the “naked” sugars in beverage form are rapidly absorbed, providing a “load” of fructose to the liver.  More than being just empty calories, fructose is a source of poisonous calories that promote obesity—think of fructose as fat.

Let’s do the math comparing an apple to a bottle of soda: An average-sized apple has about 80 calories: this includes 20 grams of sugar consisting of 4 grams of sucrose (equivalent to 2 grams fructose and 2 grams glucose), 5 grams of glucose, and 11 grams of fructose, for a total of 13 grams of fructose.  A 20-ounce bottle of soda has about 240 calories: this includes 60 grams of sugar all from HFCS (55% fructose / 45% glucose) for a total of about 35 grams of fructose. 

High fructose corn syrup is a gooey, liquefied sweetener that is abundant in processed foods and beverages. The typical American consumes an astonishing 50-100 pounds of HFCS per year! The derivation of HFCS is as follows: Corn is milled to cornstarch, a powdery substance that is then processed into corn syrup.  Corn syrup consists primarily of glucose. Through a complex chemical process, the glucose in the corn syrup is converted to fructose.  HFCS results from the mixing of this fructose back in with glucose in varying percentages to achieve the desired sweetness: 55% fructose/45% glucose ratio of HFCS is used to sweeten soft drinks; 42% fructose/58% glucose ratio of HFCS is used in baked processed foods.  

The processed food industry is quite enamored with HFCS for a number of reasons. First, it is cheaper than sugar because of huge corn subsidies and sugar tariffs.  Second, the liquid syrup lends itself to ready transportation in enormous storage vats within 18-wheelers, similar to how gasoline is hauled.  Third, fructose is incredibly sweet and does not crystallize or turn grainy when cold, as sugar can do.  Fourth, because HFCS is very soluble and retains moisture, it makes for softer and moister processed baked goods.  Fifth, it acts as a preservative that extends the shelf life of processed foods and helps to prevent freezer burn.  Finally, HFCS is a key ingredient in many processed junk foods, which are addictive and promote cravings and continued consumption.

There is a good reason why HFCS is so demonized: while HFCS may help “preserve” processed foods, it does not help “preserve” us!  In fact, a diet high in HFCS will help accelerate our demise. To reiterate an important fact: fructose is metabolized very differently from glucose.  Every cell in our bodies can metabolize glucose, but it is primarily the liver that metabolizes fructose. Fructose does not stimulate insulin release as does glucose, nor does it stimulate leptin (our satiety hormone).  Fructose, more readily than glucose, replenishes liver glycogen, and once the liver is saturated with glycogen, triglycerides (fats) are made and stored. So, too much HFCS and we end up with a fatty liver and body.  The bottom line is that HFCS ingestion pushes our metabolism towards fat production and fat storage, potentially leading to obesity, diabetes, elevated cholesterol, high blood pressure and cardiovascular disease.  HFCS should be thought of as a toxin, in precisely the same way that tobacco is dangerous to our health.  Unfortunately, sugar in the little packets that we use to sweeten our frappuccinos is really no better.

Bottom Line Tips: High fructose corn syrup and sugar are NOT our “friends,” so:

·      Don’t drink too many calories or sugars if possible: minimize sodas, sweetened ice tea, lemonade, fruit juices, sports drinks, etc.  Water or seltzer with lemon, lime or other fruit is so much healthier.  Go for the real fruit instead of the juice.  Easy on the alcohol because it is all carbs. Even milk has sugar in the form of lactose, (consisting of glucose and galactose, about 11-12 grams/cup.

·      Avoid processed yogurts that are laden with excessive amounts of sugar because of the processed fruit on the bottom.  You are much better off adding fresh fruit to plain yogurt.

·      Try to avoid snacking on candy, cookies, energy bars, etc., and instead munch on nuts, fiber-rich fruits and vegetables and whole grains, like popcorn.

·      Eat healthy cereals instead of those that are sugar-laden: steel-cut oats are so much healthier than Fruit Loops.

·      Beware of “alternative” sweeteners—brown sugar, honey, molasses, maple syrup are all more-or-less the same.

·      Read labels carefully since about 75% of packaged foods have sweeteners some that would surprise you, including sauces, salad dressings, breads, etc.

·      Bottom line: use sugar and alternative sweeteners in moderation

Coming soon: Artificial sweeteners

Andrew Siegel, M.D.

Author of Promiscuous Eating: Understanding and Ending Our Self-Destructive Relationship with Food: www.promiscuouseating.com

Available on Amazon in Kindle edition

Author of: Male Pelvic Fitness: Optimizing Sexual and Urinary Health, in press and will be available in e-book and paperback formats in the Autumn 2013.

Blog subscription: A new blog is posted every week.   On the lower right margin you can enter your email address to subscribe to the blog and receive notifications of new posts in your inbox.  Please avail yourself of these educational materials and share them with your friends and family.

Bone Health

September 7, 2013

Bone Health

Andrew Siegel, MD   Blog #118

Our bones are our foundation, the framework that supports the rest of our body.  If our infrastructure is “crumbling,” other organs and tissues that depend on intact structural support can be profoundly affected.  In other words, if our foundation and framework are shoddily constructed, the rest of our structures and functions are likely to be adversely impacted.

“Rickety” is a descriptive adjective meaning shaky, run down, and dilapidated.  It is derived from the disease rickets, a “softening” of the bones due to Vitamin D issues that can lead to fractures and deformities, typically seen in children suffering from malnutrition.  It is important to avoid the development of rickety bones—we do not want to be built of a “house of cards,” as we function best if our bones are “steely.”

A fundamental problem in terms of bone health and vigor is that most people do not consider their bone health early in life.  Unfortunately, it only becomes a matter of concern at a time in which it is getting late in the game to protect against loss of bone strength and fractures. The time to focus on bone health is during childhood when the achievement of bone integrity and strength begins.  This bone formative process continues through adolescence, when the body builds the lion’s share of bone mass, and peaks in our early 20’s. One-quarter of bone mass is obtained within the two-year window of time around puberty; as much bone is gained in this two-year period as is typically lost in the 30-year interval between ages 50-80.

Since children, understandably so, are not likely to consider their bone health, as responsible parents we must educate our kids and be the overseers of their diets, physical activities and sun exposure—all of which can positively contribute to healthy bone development—as well as lead by example. Helping them achieve the goal of bone health during adolescence is an investment in personal health that will pay dividends later in life, helping to prevent bone thinning and the potential for fractures.   It is important to direct our children away from computer games, television and other sedentary activities and motivate them towards the outdoors to participate in a variety of physical activities. It is equally important to encourage them to have a nutritionally sound diet rich in calcium-containing foods including dairy sources such as milk, yogurt and cheese; non-dairy sources including vegetables such as Chinese cabbage, kale, broccoli and spinach; seafood sources such as salmon and sardines; and calcium-fortified sources such as cereals, tofu and fruit juices.  It is equally as important to ensure sufficient vitamin intake.  Vitamin D is necessary in order to absorb and utilize dietary calcium; a brief amount of sunlight exposure on a daily basis is generally sufficient to ensure adequate levels of vitamin D. Children can kill two birds with one stone by participating in athletic activities outside in the sunlight.

In terms of key factors determining bone health, genetics looms large.  In other words, if bone thinning tends to run in your family, you will have a greater likelihood of suffering the same fate.  Like so many of our physical attributes, bone strength and integrity have a strong hereditary basis and there is not a thing that we can do about the genes that we inherit. Additionally, age and gender are important elements.  There is a gradual but insidious loss of bone mass that correlates with the aging process, and the older we are, the greater the likelihood for osteopenia, the medical term for bone loss. Osteoporosis is the medical term applied to severe bone loss with great risk for fractures.  Women are at much higher risk for such bone thinning and wasting processes than men.

Although genetics, age, and gender are factors beyond our control, exercise and intake of bone-building nutrients including calcium and vitamin D are modifiable factors that we have some real influence over. Thin people tend to have greater issues with osteopenia than heavy people.  One of the few advantages of being overweight is that it requires extra anti-gravitational weight-bearing effort to carry around that excess poundage; this exertion against the force of gravity helps to mineralize and fortify bones.

The male and female sex hormones, testosterone and estrogen respectively, play a health role that goes way beyond sexuality.  Both of these hormones promote bone health and mineralization. After menopause, with the precipitous drop in estrogen, there is often an acceleration of bone loss. Men often experience a gradual drop in testosterone levels correlating with the aging process.  A healthy testosterone level is correlated with bone health and low levels of testosterone are linked with osteopenia.   Men who are on medication to purposefully lower testosterone—most typically used for the management of prostate cancer—experience an accelerated loss of bone mass, akin to women at the time of menopause.  Reasons that males experience bone loss at a less accelerated rate than females include the fact that men in general weigh more than women, and thus by virtue of the fact that they have to carry around extra weight, they keep their bones mineralized; additionally, the variable changes in testosterone with aging that men experience are much more minor as opposed to the major precipitous decline in estrogen at menopause in women.

Our bones demand physical activity in order to stay well mineralized.   When our bodies are kept in a sedentary state—for example when one’s arm is in a cast because of a fracture, or when one is immobilized by a severe injury and is at bed rest—there is a rapid demineralization and thinning of our bones.  Spinal cord injured patients who are paralyzed undergo a very rapid demineralization. Astronauts who spend time in zero gravity experience a remarkably fast demineralization and run the risk not only of thinning bones—as does anybody with rapid demineralization— but also of developing kidney stones that result from the calcium mobilized from the bones.

In general, the more active the individual, the greater the bone mineral density (BMD) and the less risk for fracture.  Most any physical exercise is healthy for our bones, but there are certain exercises that are better to achieve the endpoint of achieving bone mineralization and vigor. BMD is greater in sprinters, ball sport athletes and gymnasts than in endurance sports athletes including walkers, runners, swimmers and cyclists.  Bone mineralization is promoted by stresses placed upon the bones, rest periods, and variety, as opposed to repetitive, monotonous movements.  Aerobic ball sports activities provide highly effective variable stresses on our bones that work against gravity and provide periods of rest; these include tennis, squash, football, soccer, basketball, hockey, field hockey, lacrosse, dancing, and gymnastics.   Additionally, weight training and any activity that uses resistance equipment can be a highly effective means of promoting bone mineralization.  Training that necessitates straining, versatile movements, and a high peak force is more effective in terms of bone mineralization than training with a large number of low-force repetitions. It seems that just as ones body requires a variety of different and variable nutrients to maintain its health, so ones bones require a variety of different exercises, movements, and stresses to maintain their health

Runners and swimmers have the lowest bone densities among athletes. Some studies have even shown that participants in endurance and non-weight-bearing sports have bones that are less robust and at a greater risk of fracture than the population of sedentary and inactive people.  In terms of increasing bone mineral density, when running, swimming, and cycling, it is best to shake it up and do interval training at variable speeds, intensities, and durations and not maintain a monotonous motion, since repetitive unvarying stress can actually demineralize bone and is thus not a productive means of increasing bone fortitude.

Bone mineralization is a dynamic process as opposed to a static process.  In other words, our bones are not fixed in composition like the framing and foundation of our homes.  Our bones are constantly being remodeled, restructured and refashioned in accordance with the building blocks available and in an adaptive response to biomechanical forces including gravity and musculo-skeletal stresses.

The concept of  “energy availability” is important in terms of understanding bone building versus bone destruction.  Energy availability is defined as the amount of energy taken in while exercising minus the amount expended, divided by lean body mass (consisting of bone and muscle).  Energy availability is the net amount of energy available to support all the body’s functions including new bone formation, a process that requires energy.  Low energy availability will occur if there is insufficient intake of calories, excessive burning of calories, or a combination of both.  Endurance athletes—including long-distance runners and cyclists—can burn so many calories that there is not sufficient energy remaining to fuel the dynamic process of maintaining bone health.  When there is low energy availability, the consequence can be stress fractures, fractures due to repeated stresses on a weight-bearing bone.

Bottom Line: Bone health has its critical beginnings in childhood, then continues (at a slower pace) into adulthood.  Key factors contributing to maximal bone health are proper nutrition, varied and continued physical activity, vitamin intake, and exposure to sunlight.  It is never too early to address—and take the necessary measures—to ensure the life-long health of the body’s vital skeletal framework

Reference:  “To Ensure Bone Health, Start Early,” article in New York Times by Jane E Brody, August 5, 2013

Andrew Siegel, M.D.

Author of Promiscuous Eating: Understanding and Ending Our Self-Destructive Relationship with Food: www.promiscuouseating.com

Available on Amazon in Kindle edition

Author of: Male Pelvic Fitness: Optimizing Sexual and Urinary Health, in press and will be available in e-book and paperback formats in the Autumn 2013.

Blog subscription: A new blog is posted every week.   On the lower right margin you can enter your email address to subscribe to the blog and receive notifications of new posts in your inbox.  Please avail yourself of these educational materials and share them with your friends and family.