Bullish for Bikes

Sponsored by the League of American Bicyclists, May is National Bike Month and is an opportunity to celebrate the many reasons that people choose to ride. For some, bicycles represent their primary means of transportation. Many people ride bikes as

a means to health and fitness. Others yet find pleasure and perspective from a bicycle saddle as they ride along a bike trail. Of the many reasons for bicycling, I find that three in particular stand out---health benefits, economic savings, and environmental advantages.

Health Benefits: The health benefits of regular cycling include:

• Increased cardiorespiratory fitness - The increases in heart and respiratory rate produced by cycling will improve your overall fitness level. While many people choose bicycling as their primary means of exercise, time spent on a bicycle commuting can result in improvement in fitness also. The U.S. Department of Health and Human Services has determined that biking for transportation can count toward the minimum 150 minutes/week of moderate-intensity aerobic activity recommended for physical health.
  
  
• Reduction in heart disease risk - By now, everyone is aware that exercise can reduce the risk of heart attack. Cycling can help strengthen the heart muscles, reduce blood pressure and improve blood fat levels, all of which lower the risk for heart attack. One study found that increasing biking and walking from 4 to 24 minutes a day would reduce cardiovascular disease by 14%.
  
  
• Decreased body fat levels - Cycling raises the metabolic rate and burns body fat. Steady cycling burns about 300 calories per hour. Over the course of a year, a half-hour bike ride every day will burn over 10 pounds of fat. Studies show that school-aged children who bike or walk to school have a lower percentage of body fat and are more likely to remain at a healthy weight than those who are driven or take the bus.
  
  
• Reduction of risk for developing diabetes - Research in Finland found that people who cycled for more than 30 minutes per day had a 40 per cent lower risk of developing diabetes.
  
  
• Improved mental health - Regular exercise, including bicycling, has been shown to reduce stress and depression and improve our sense of well-being. Many people find that cycling serves as an escape to the stresses of everyday life. According to surveys performed by the Transportation Research Board, bike commuters report lower stress and greater feelings of freedom, relaxation, and excitement than car commuters.

Environmental Advantages: Motor vehicles consume the majority of oil used in the U.S. Along with fuel consumption comes the serious problems of carbon dioxide accumulation in the atmosphere and the potential for permanent climate change. It is sobering to realize that for a 10 mile round trip commute in a mid-size care averaging 20 mile per gallon, 1.3 tons of carbon dioxide are released into the environment over the course of a year. The potential for improvements in air quality with widespread bicycling commuting is dramatic. The same can be said of bicycling for exercise instead of the use of fossil fuel powered vehicles.
This not only provides health benefits to the rider but is better for the environment as well. For those concerned about the effects of breathing exhaust while riding a bicycle, a study performed in the Netherlands considered the risks and benefits of bicycling rather than driving for short trips on a daily basis. They estimated that the benefits of increased physical activity from bicycling (3 to 14 months gained) outweigh the effects of increased inhaled air pollution (0.8 to 40 days lost) and increased traffic accidents (5 to 9 days lost).

Economic Savings: With over half of the working population of the U.S. living within 5 miles of their workplace, bicycling becomes a realistic way of getting to work. In fact, it has been reported that from 2000 to 2011, the number of bicycle commuters in the U.S. grew by more than 47 percent. The League of American Bicyclists estimated that in 2012, bicycle commuters in the U.S. saved more than $4.6 billion over their car driving counterparts. Savings for the bicycle commuter comes from a variety of sources including parking fees, fuel costs, car maintenance expenses, and public transportation fares. Businesses benefit also in that cyclists take fewer days off work for illness than non-cyclists. Add to that the savings from treatment of chronic illnesses that bicycling could help prevent, and the economic benefits of bicycling are astonishing.

The Rights and Wrongs of Sunscreen Use

The topic of sunscreen use is rife with  strongly recommends sun avoidance practices including use of sunscreens year round to reduce the risk of developing skin cancer. Here are a few of the common misconceptions regarding the use of sunscreens preventing skin damage from sunburn:

controversy and misconceptions. Some authorities advocate against their use, believing that too little sun exposure will reduce the body's vitamin D levels with the increased risk of osteoporosis and certain cancers (breast, colon, and prostate). The American Academy of Dermatology, on the other hand,

Misconception #1 - The SPF is an indication of sunscreen protection across the entire ultraviolet light spectrum. The sun emits two types of ultraviolet light---UVB, which causes sunburn and can lead to skin cancer, and UVA, which causes wrinkles and deeper skin damage that can also lead to skin cancer. Most people know that SPF stands for sun protection factor. What is less well known is that this is a measure of how well the sunscreen deflects UVB rays only. Sunscreens that pass the Federal Drug Administration's (FDA) broad spectrum test, however, will have demonstrated that they also provide UVA protection that is proportional to their UVB protection.

Misconception #2 - The higher the SPF, the better. SPF values displayed on sunscreen labels range from 2 to as high as 50 (or higher). This refers to the product's ability to screen or block out the sun's harmful rays. Theoretically, a sunscreen with SPF 15 will allow you to be in the sun 15 times longer than you could without sunscreen before becoming sunburned. Protection from sunburn, however, does not increase proportionally with an increased SPF number. A SPF of 2 will absorb 50% of ultraviolet radiation, an SPF of 15 absorbs 93% and an SPF of 34 absorbs 97%. No sunscreen can block 100% of the sun's rays.

Misconception #3 - Waterproof sunscreens stay on even when swimming. There is no such thing as "waterproof" sunscreen. The FDA even prohibits manufacturers from labeling sunscreens as "waterproof" because these claims overstate their effectiveness. Sunscreens can be labeled as being "water resistant" if they maintain their SPF rating after 40 to 80 minutes of water exposure. Most sunscreens will not maintain their SPF rating after swimming or sweating heavily for much more than an hour.

Misconception #4 - Sunscreens are so concentrated that a thin coating is all that's necessary. Most people do not use adequate amounts of sunscreen. Studies have shown that people apply only about 25-50% of the amount required to reach the labeled SPF rating.

Misconception #5 - Vitamin A added to sunscreen is important for skin health. It's true that Vitamin A added to sunscreen will help hydrate skin and prevent skin degradation. Data from an FDA cancer study, however, showed that Vitamin A in a synthetic form called retinyl palmitate may also speed the growth of skin tumors.

Recommendations for effective sunscreen use. The ideal sunscreen would completely block all UV rays, remain effective on the skin for several hours, and not cause skin irritation. Unfortunately, the ideal sunscreen does not yet exist. Here are some tips for the more effective use of the sunscreens that are currently available.

• For most people, a sunscreen with a sun protection factor (SPF) of 15-30 will provide adequate protection.
  
• Look for sunscreen that says that it provides "broad spectrum" protection. Broad spectrum protection means that it has both UVA as well as UVB blocking properties.
  
• Perhaps more important than the SPF rating is appropriate application and reapplication of sunscreen. Be sure to apply sunscreen at least 15-30 minutes before exposure to the sun. Follow the guideline from the American Academy of Dermatology--- "one ounce, enough to fill a shot glass", is the amount needed to cover exposed areas of the body. This amount should be adjusted depending on body size and the amount of exposed skin. "Water resistant" sunscreens need to be reapplied every 1 to 2 hours when swimming or sweating heavily.
  
• If you are extremely UV-sensitive, get a sunscreen with an even higher SPF rating. For all intents and purposes, a sunscreen rated 50+ is as high as anyone needs.
  
• For maximum protection against UV rays, use a sunblock rather than sunscreen. These contain physical agents, such as titanium dioxide or zinc oxide keep UV rays from reaching the skin.
  
• One of the best ways to protect your skin from cancer and premature aging is by limiting sun exposure and wearing protective clothing. Avoid sun exposure between 10 AM and 4 PM, the time that UV radiation is at its highest. Remember also that UVA radiation is not significantly lower during morning hours or on overcast days.

If you have any questions about the rights and wrongs of sunscreen use, please log into your account and send us your question. We are here to help.

Iron Deficiency Anemia

Iron is an important building block for red blood cells. When the body lacks adequate amounts of iron, red blood cells become smaller and are produced in inadequate numbers. This results in decreased hemoglobin levels, the protein that transports oxygen in red blood cells. This condition is known as iron deficiency anemia and is the most common reason for having a "low blood count".

What causes iron deficiency anemia? Most people are aware that iron deficiency anemia can occur because of not getting enough iron in the diet. Vegetarians have to be particularly careful to include iron-fortified foods or vegetable sources of iron (beans, tofu, dark green leafy vegetables, etc.), since foods with the highest iron content are primarily animal based (meat, poultry, fish).

While inadequate intake is a common cause, there are a number of other reasons for the development of iron deficiency anemia. Women with heavy periods or gynecological conditions associated with excessive bleeding may develop iron deficiency anemia because the iron in red blood cells, which is usually recycled, is lost from the body. Likewise slow and sometimes unnoticed blood loss (such as that from a stomach ulcer, colon polyp, or colon cancer) can result in iron deficiency anemia.

Two increasingly common causes of iron deficiency anemia develop because of the inability to absorb iron from the intestine. Celiac disease, an autoimmune disease that damages the small intestine interferes with absorption of iron from food. Likewise, people who have undergone gastric bypass may also lose the ability to absorb iron due to decreased gastric acid secretion and from bypassing the first portion of the small intestine (duodenum).

Pregnant women are at risk of developing iron deficiency anemia because of an increased blood volume during pregnancy, as well as the demands of the growing fetus for iron. Infants who drink cow's milk in the first year of life are at risk for iron deficiency anemia because cow's milk does not have enough of the iron infants need to grow and develop.

What are the symptoms of iron deficiency anemia? Initially in the course of iron deficiency anemia, people may have no symptoms at all. As the anemia worsens and significant reduction in oxygen carrying capacity of the red blood cells develops, symptoms may include pale skin, fatigue, lightheadedness, glossitis (tongue inflammation), and cold intolerance. In severe cases, iron deficiency anemia may lead to a rapid or irregular heartbeat, shortness of breath, and fainting. Pregnant women with iron deficiency anemia may experience premature delivery with low birth weight babies. In infants and children, severe iron deficiency can lead to delayed growth and development. Some of the signs and symptoms of iron-deficiency anemia are related to the condition's underlying cause. For example, a sign of intestinal bleeding is bright red blood in the stools or black, tarry-looking stools.

How is iron deficiency anemia diagnosed? The typical blood tests used to diagnose iron deficiency anemia are:

• Hematocrit, a test that measures the percentage of the blood volume that is made up of red blood cells. Normal results vary, but in general, a male has between 40 and 50% of their blood volume as red blood cells and women between 36 and 44%. Levels below this indicate that someone is anemic, although it does not specify the cause.
  
• Hemoglobin is a protein in red blood cells that carries oxygen. A reduced hemoglobin level occurs in most types of anemia.
  
• Red blood cell indices are part of a complete blood count (CBC), along with hemoglobin and hematocrit. This test looks at the size and the hemoglobin content of red blood cells. In iron deficiency anemia, red blood cells are smaller and paler in color than normal.
  
• Serum Iron/Ferritin measure the amount of iron in the blood and the amount of a stored form of iron in the body, respectively.

How is iron deficiency anemia treated? The treatment of iron deficiency anemia hinges on the underlying cause. When blood loss is responsible, the source for the bleeding should be addressed. This could necessitate medical treatment for a bleeding ulcer or surgery in the case of bleeding fibroid tumor or colon cancer. Avoidance of sources of gluten (when, rye, barley) with subsequence easing of the inflammation in the small intestine will allow someone with celiac disease to absorb iron normally.

Even if the cause of the iron deficiency is identified and treated, it is usually necessary to increase dietary sources of iron and to take iron supplements until iron stores are restored. The best iron sources include meat, poultry, fish, legumes (lima beans, peas, pinto beans, etc.), dried fruits such as apricots, prunes and raisins, iron-enriched pastas, grains, rice, and cereals, and green vegetables (spinach, broccoli, kale, etc.). Medicinal iron used in treating patients with iron deficiency is higher than the amount found in most daily multivitamin supplements. Most people with iron deficiency will need 150-200 mg per day of elemental iron per day. There are many forms of iron supplements which contain different amounts of elemental iron: 1 gram of ferrous gluconate = 120 mg elemental iron (12% iron); 1 gram of ferrous sulfate = 200 mg elemental iron (20% iron); 1 gram of ferrous fumarate = 330 mg elemental iron (33% iron). The effectiveness and side effects are similar for these different forms when used in equal doses of elemental iron. Vitamin C (ascorbic acid) improves iron absorption, and some doctors recommend that you take 250 mg of vitamin C with iron tablets. Possible side effects of iron tablets include abdominal discomfort, nausea, vomiting, diarrhea, constipation, and dark stools. In the case of a severe iron deficiency anemia, particularly when the inability to absorb oral iron is responsible, administration of iron through the vein may be necessary.