Category: Health & Wellness

What Are the Health Risks of Exercising Outside in Winter?

By Nathan Blake |1/4/17
Updated | 10/27/17

Who doesn’t love this time of year? Leaves are changing color, the breeze smells like campfire, and pretty much everything comes in “pumpkin spice” (chicken sausage, anyone?). In just a few months, you’ll be making yet another list of New Year’s resolutions.

Last year, 41% of Americans said they wanted to “live a healthier lifestyle,” while an additional 39% wanted to “lose weight.” And let’s be honest—most of us can sympathize. 40% of U.S. adults are considered obese, a record high.

But gym memberships aren’t getting any cheaper. Rising costs have inspired health buffs to develop fitness routines requiring little or no cost such as bodyweight exercises, yoga, and dancing, or incorporate old standbys like running and cycling.

What most people don’t realize is that the physical cost of cold-weather exercise can mean devastating heart and lung damage. In fact, numerous studies show that heart attack rates tend to spike in colder months, especially December and January.

Those of you who choose to brave the cold this fall and winter should be aware of the potential benefits—and dangers—that lie ahead.

Benefits of Cold Weather Exercise

It’s a myth (more like a half-truth) that chilly weather means greater weight loss. Unless you’re noticeably shivering and expending more energy than usual, your winter workout won’t burn more calories than usual.

That’s not to say athletes should hibernate until spring.

Want to improve your mood? Exercise helps combat the symptoms of seasonal affective disorder, a form of depression affecting 20% of Americans. Additionally, more sunlight exposure increases endorphin levels, putting the “sunny” in “sunny disposition.”

Some research even suggests that 45 minutes of running in cold weather can reduce flu-risk during the winter months by as much as 20-30%.

You may be able to up the intensity of your workouts in the cold, too, since hot weather has been shown to negatively impact physical performance. Factor in the lack of humidity and the invigorating wind chill, and all of a sudden colder climes don’t seem so bad for training.

But as with life in general, moderation is key.

Now for the Dangers (and How to Prevent Them)

Don’t fall into the trap of thinking you’re capable of doing the same activities in winter as you could in summer without a hitch. If you’re in excellent health, you probably won’t experience any major issues exercising outside this winter—barring accidents, of course.

However, if you have a history of heart, lung, or circulation issues, you’re putting yourself at risk for increased discomfort, injury, and even death.

Here’s what you need to be on the lookout for if you want to stay well and fit this winter.

Muscle TearsWhen temperatures drop, our bodies overcompensate to perform tasks that would be easier in milder weather. Our muscles and tendons lose more heat, which causes them to tighten up and become less flexible. This leads to muscle soreness or damage like strains and tears.

What You Can DoTake time to warm-up properly before exercising, but save the stretches for your post-routine cool-down. Ease into your workout with some light cardio instead. Brisk walking, for instance, is great for raising your core temperature and increasing blood and oxygen circulation. Common problem areas include your hamstrings, chest, shoulders, and quadriceps. Show them some extra love!

Asthma: Ever hear of exercise-induced asthma? Coughing, wheezing, chest-tightness, shortness of breath, excessive fatigue. Winter athletes frequently report these symptoms even though they may never experience them in other seasons. Cold, dry air and exercise both aggravate asthma individually. Combined, they’re downright dangerous.

What You Can Do: Cover your mouth with a mask or scarf to warm the air you breathe. If you use an inhaler, use it 15-30 minutes before exercise to open your airways, and carry it on your person at all times. You can also drink extra water, which thins the mucus in your lungs and helps your body move more efficiently.

Heart Attack: Cold temperatures can cause vasoconstriction, or narrowing of your blood vessels. As these passageways constrict, blood pressure rises, which reduces oxygen supply and blood flow to your heart. The result is your heart works harder than it would under normal circumstances. People with heart conditions are inviting additional cardiovascular strain that may result in angina or, potentially, a full blown heart attack.

What You Can DoPeople with a history of high blood pressure and/or heart disease should consult a doctor before starting a new exercise routine. Begin physical activity slowly, and give your body a break every 15-20 minutes. If you begin to feel chest pain, or pain that radiates down your left arm, call 911 immediately or visit the nearest emergency room.

Frostbite: Frostbite occurs when the body’s skin and underlying tissues begin to freeze. As blood flow slows, ice crystals form inside your cells, killing them in the process. People with frostbite will immediately notice numbness and skin discoloration in localized area(s). Left untreated, the resulting skin tissue death can result in gangrene and amputation.

What You Can Do: Limit your exposure to cold, windy, wet weather. Keep an eye out for signs of frostbite like red or pale prickling skin, and stay dry (wet clothes increase heat loss). Dress in layers; aim for clothing that is comfortable, loose, and light; and make sure your outer layer is both windproof and waterproof. If you do notice signs of frostbite, don’t rub or aggravate the frostbitten area. Instead, find shelter as soon as possible, and treat the affected area using either warm—not hot—water or body heat.

Hypothermia: Prolonged exposure to cold weather causes the body to lose heat through the skin and lungs faster than it can be produced. A dramatic drop in body temperature (generally recognized when core temperature falls below 95 degrees Fahrenheit) slows brain function, heart rate, and breathing. Soon, confusion, fatigue, and organ failure set in.

What You Can Do: Layer up, and wear a hat, scarf, and mittens to conserve body heat. Stay dry, being especially mindful of your feet and hands. Avoid alcohol and caffeine, both of which stimulate heat loss. Seek medical attention immediately if you notice any symptoms of hypothermia. In the meantime, remove any wet clothing and wrap yourself warmly in a blanket or other covering. However, do not immerse yourself in hot water. This can lead to shock.

Even though the above scenarios may sound dire, it never hurts to be prepared when it comes to your health. Stay warm this winter, but enjoy the chill. Your body will thank you come spring.

Crohn’s and Colitis — Common but Misunderstood

By Nathan Blake |12/7/16

The first week of December marks the fifth annual Crohn’s and Colitis Awareness Week. These two conditions affect the digestive tracts of nearly 1.6 million Americans each year, although many more remain undiagnosed and deal with persistent pain and discomfort on a daily basis.

If you or a loved one has been diagnosed with either of these conditions, it is important to educate yourself about them in order to best manage the symptoms and reclaim a sense of normalcy.

What are Crohn’s and Colitis?

Crohn’s and colitis are among the most common forms of inflammatory bowel disease (IBD). IBD refers to a family of conditions that causes prolonged inflammation of parts or all of the intestinal tract. IBD and its various forms are known as invisible illnesses, referring to chronic conditions that impair a patient’s day-to-day activities yet show no outward signs.

Crohn’s disease is an inflammatory condition that can affect any part of the digestive tract from mouth to anus. The lining of the digestive tract becomes swollen and develops deep, open sores called ulcers, which can manifest in multiple areas including the esophagus, stomach, small intestine, colon, appendix, and in rare cases the skin and joints. Commonly, there are healthy portions of the intestine between inflamed areas that remain unaffected.

Ulcerative colitis is also an inflammatory disease, although its effects are specific to the superficial tissues of the colon and anus. With ulcerative colitis, ulcers develop on the inner lining on the large intestine. These ulcers may bleed and/or produce pus. Ulcerative colitis generally begins in the rectum and spreads upward to the first part of the colon.

Both diseases often appear gradually and then worsen with time, though many patients report periods of remission during which symptoms disappear for weeks or months. Periods of painful inflammation, on the other hand, are called flare-ups.

Common Symptoms of IBD

Because Crohn’s and colitis affect similar parts of the body, diagnosing these two diseases can be difficult. Their symptoms are often indistinguishable and can vary from person to person. Inflammation of the gastrointestinal tract often leads to the following symptoms, many of which are common for people dealing with Crohn’s or colitis.

• Diarrhea

• Rectal bleeding

• Urgent bowel movements

• Constipation

• Abdominal cramps/pains

• Fatigue

• Unintended weight loss

• Fever

• Night sweats

• Loss of appetite

What Causes Crohn’s and Colitis?

The intestine’s absorptive area spans over 4,300 square feet, making it the single largest surface in the human body, including the skin. Previously, diet and stress levels were implicated as the main determinants of IBD, but today they are seen as aggravating factors and not the actual cause.

While researchers are still unclear as to the exact causes of Crohn’s and colitis, many agree that they likely originate from a combination of factors.

Individual genes: People with a family history of IBD are 10 times more likely to develop the condition than those with no history.

Immune system: It is possible that Crohn’s and colitis appear in response to a viral, bacterial, or fungal infection of the intestinal tract, where the immune system produces an inflammatory response in the intestines to fight off the foreign agent(s). However, people with IBD often have inflammation even when no infection is present, leading researchers to believe that the patient’s immune system may be attacking the body itself. This phenomenon is known as an autoimmune response.

Environmental factors: Clinical and experimental evidence indicates that IBD may be associated with a range of seemingly unrelated environmental influences including cigarette smoking, diet, stress, use of hormones, vitamin D levels, and geographic/social status, among others.

Complications in IBD

Though these two diseases are rarely life-threatening, if left untreated, Crohn’s disease and ulcerative colitis can result in several serious complications deserving of immediate medical attention.

Fistulae: When ulcers extend completely through the intestinal wall, they create fistulae, or abnormal fusions between different parts of the body. The most common site for IBD fistula formation is the tissue surrounding the anus, where the fistula creates a connection between the rectum and the skin. Fistulae can occasionally become infected and form a life-threatening abscess—a localized pocket of pus—if left untreated.

Bleeding: Blood often appears in the stool of people with IBD, caused by inflammation, ulcer formation, and anal fissures. Some even pass blood alone in the absence of stool. Bleeding in the rectum is more common in ulcerative colitis than Crohn’s, but will vary depending on the area(s) affected.

Anemia: People with IBD have difficulties absorbing important nutrients from food, especially iron, which is absorbed in the small intestine (an area commonly affected by IBD). As a result, nearly half of people affected by Crohn’s or colitis do not receive adequate levels of vitamin B12, iron, and folic acid, all of which are necessary for the creation of new red blood cells. Patients with low levels of red blood cells develop anemia, resulting in headache, fatigue, chest pain, and weakness.

Treatment and Management

The goal in treating Crohn’s and colitis is to achieve and maintain remission, and mostly involves drug therapy to reduce the inflammation that causes IBD’s signs and symptoms. Immunosuppressants and anti-inflammatory drugs called aminosalicylates and corticosteroids have proven to be helpful in improving or completely stopping the symptoms of IBD. Biologics are a more recently developed therapy, created out of biological antibodies rather than chemical medications. Biologics also suppress the immune system but offer a distinct advantage in that they target specific proteins in the IBD patient rather than affecting the whole body.

However, there is currently no cure for Crohn’s disease, and ulcerative colitis can only be cured in the most severe cases when the entire large intestine is surgically removed.

Fortunately there are several ways that people with IBD can manage their symptoms. If you or a loved one has been diagnosed with IBD, consider the following strategies in conjunction with a physician’s oversight to help alleviate symptoms of the disease.

Manage stress: Many patients report an intensification of symptoms in times of stress. Consider adopting a meditation, yoga, or acupuncture routine to reduce symptoms, and get plenty of exercise, preferably daily.

Stay hydrated: Inflamed colons do not absorb water and electrolytes properly, resulting in diarrhea, increased bowel movements, and dehydration. Keep yourself hydrated with distilled water in order to combat this increased fluid loss, and monitor your urine to determine whether or not you are drinking enough liquids.

Limit “trigger” foods: Foods that cause flare-ups depend on the individual, but some are more commonly associated with intensified symptoms than others. They include fatty, spicy, and high-fiber foods; alcohol; coffee; carbonated drinks, nuts and seeds; raw fruits and vegetables; and red meat.

Get your vitamins: IBD flare-ups can negatively impact nutrition due to the increased bowel movements, loss in appetite, fatigue, etc. When the small intestine becomes inflamed, the body is unable to absorb nutrients from food. Coupled with a reduced appetite, IBD can easily lead to malnutrition. Patients can avoid malnutrition by eating smaller, well-balanced meals throughout the day. Your doctor may also recommend vitamin supplements as well.

What Does Medical Science Say About Fish Oil Supplements?

By Nathan Blake |11/23/16

A recent survey of over 11,000 consumers revealed that fish oil is currently the second most popular nutritional supplement on the American market today, with annual spending exceeding $1.2 billion for over-the-counter fish oil pills and related supplements.

Fish oil has long been touted for its supposedly positive effects on a variety of bodily functions including lowering blood pressure, triglycerides, and cholesterol levels; preventing heart disease; inhibiting the formation of cancer cells; combatting depression and mood disorders; reversing the effects of macular degeneration; and countless others.

But what does medical science have to say about these claims? Is fish oil the cure-all it’s advertised to be, or would consumers be better off spending their money elsewhere?

Fish Oil’s (Not So) Secret Ingredient

Fish oil capsules contain concentrated amounts of omega-3 polyunsaturated fatty acids. Omega-3 fatty acids are necessary for human health, playing a crucial role in brain health and the regulation of inflammatory responses. There are three main types of omega-3 fatty acids, two of which can be found in fish oil capsules.

Eicosapentaenoic acid (EPA) is absorbed into the body by eating oily, coldwater fish like salmon, menhaden, sardines, mackerel, albacore tuna, halibut, and herring. EPA is also found in edible strains of seaweed as well as human breast milk.

Docosahexaenoic acid (DHA) is an important structural component of the human brain and is essential for its proper functioning. It also plays a primary role in maintaining the health of the eye, cerebral cortex, skin, sperm, and testicles. The human body can produce a small amount of DHA on its own, but like EPA, we get the majority of our DHA from cold-water ocean foods. DHA can also be found in organ meat, poultry, and egg yolks, though in small amounts.

Cardiovascular Health

The positive effects of fish oil on the human cardiovascular system have well been established, but that’s not to say no controversy exists. After evaluating the potential benefits of fish oil supplements for patients with multiple pre-existing cardiovascular disease factors, scientists concluded that DHA and EPA had neither a positive nor a negative effect on cardiovascular health. However, an early meta-analysis of fish oil studies revealed a possible correlation between fish oil supplementation and lower blood pressure. Further, scientific data indicates that fish oil consumption can reduce the risk of coronary heart disease, decrease mild hypertension, and prevent certain cardiac arrhythmias. Other studies show that fish oil capsules can be effective in the prevention of primary and secondary cardiovascular disease. In multiple clinical trials, fish oil supplements have been linked to the suppression of major coronary events. The most conclusive benefit of fish oil supplements seems to be that fish oil capsules are effective in lowering triglycerides in the blood. One study found that a prescription dose of EPA + DHA (2x the normal amount) lowered patients’ triglycerides by 27%.

Mood Disorders

Fish oil is not considered to be an effective replacement for mental health treatments, but when used in conjunction with other therapies, fish oil seems to provide beneficial effects to patients diagnosed with borderline personality disorder, unresponsive depression, and schizophrenia. EPA in particular has been studied for its possible use in regulating mood disorders, and researchers found that EPA-heavy omega-3 supplements appear to be effective against primary depression when used alongside prescription medications and other treatment. There is some evidence, however, that fish oil supplementation does not improve mood when tested against a placebo.

Alzheimer’s Disease

In a double-blind study spanning 26 weeks, researchers found that neither high nor low doses of fish oil had an observable effect on cognitive performance in patients age 65 and older. A much longer study, however, found that fish oil intake is associated with lower rates of Alzheimer’s disease. That being said, in a study of 174 Alzheimer’s patients, fish oil supplementation was not shown to reduce cognitive decline in patients with mild or moderate Alzheimer’s disease, though some positive effects were shown in a small group of patients with very mild Alzheimer’s. Other trials confirmed these finding that omega-3 supplementation is beneficial only for patients with mild cognitive impairment. While it’s still too early to make firm recommendations regarding the potential benefits of fish oil intake, daily DHA supplementation in excess of 180 mg is associated with a 50% decrease in dementia risk.

Eye Health

Regular consumption of EPA and DHA fatty acids significantly reduces the risk of developing age-related macular degeneration in women. Other findings suggest that increased omega-3 intake via fish oil capsules can prevent age-related macular degeneration in all subjects, sometimes by an estimated 22%. While the precise role of omega-3 fatty acids in eye health is unclear, there is some evidence that suggests DHA supplements can prevent cell damage and eye stroke injury in the retina.

Inflammation

A study of 250 patients with neck or back pain revealed that fish oil supplements are an equally effective but safer treatment for reducing arthritic pain compared to NSAIDs like ibuprofen and aspirin. Some studies suggest that EPA, independent from DHA, is a potential therapeutic treatment for arthritis-related inflammation in mice, and that EPA has a stronger anti-inflammatory effect than DHA. While another study’s findings suggest that fish oil supplements are not as effective in reducing chronic low-grade inflammation in obese men compared to weight reduction, multiple studies seem to suggest that omega-3 fatty acid supplements can decrease inflammation in patients, particularly those diagnosed with rheumatoid arthritis or ulcerative colitis.

Cancer

Some evidence points to the benefit of fish oil’s anti-inflammatory effects on reducing the overall number of cancer cells in the colon. Another investigation found that EPA + DHA are good candidates for primary and secondary breast cancer prevention due to their abilities to reduce inflammation. Strangely enough, one recent study has shown a correlation between elevated levels of omega-3 fatty acids and an increased risk for developing aggressive prostate cancer; men with the highest DHA levels were 2.5x more likely to develop high-risk prostate cancer, though similar studies proved inconclusive. Further, other studies revealed opposite findings, that fish oils are actually helpful in reducing the risk of prostate cancer in healthy individuals, as well as preventing colorectal and breast cancer formation.

The Last Word

Ultimately, the health benefits of fish oil supplements are still unclear. Studies surrounding omega-3 supplements, as we have seen, are conflicting at best, contradictory at worst. That being said, multiple organizations agree that the potential benefits of fish oil capsules outweigh the potential risks for generally healthy people, though more evidence is needed before making a definitive claim.

Continue taking fish oil capsules if they have been prescribed to you by a physician. If you are planning to begin a fish oil regimen, consult with your primary care physician beforehand to make sure you are healthy enough and that they will benefit you. General consumers should be aware that while many of the findings referenced above are interesting, it’s entirely possible you may not be receiving the benefits you’ve been paying for.

Are the Health Risks of Smoking Reversible?

By Mark A. Kelley, MD |09/07/16

As a lung specialist, I am often asked whether the body can recover from many years of smoking.  Based on decades of research, the answer is a resounding “Yes” … but only if you quit smoking – completely.

What Are The Risks of Smoking?

Cigarette smoking kills over 400,000 Americans each year – more than the combined deaths from alcohol, illegal drug use, homicide, suicide, car accidents, and AIDS combined.

Cancer – Before cigarette smoking became widespread in the twentieth century, lung cancer was a rare disease. However, as smoking become popular, lung cancer rose to became a leading cause of death.  Scientific research demonstrated that the toxic chemicals in cigarette smoke are carcinogenic. Smoking is also associated with cancers of the throat and digestive tract.

Heart and Vascular Disease – there is a strong association between smoking and the development of atherosclerosis, the “hardening of the arteries” that causes heart attacks, strokes and aneurysms. These conditions are among the major causes of death in smokers. A heart attack is 2-4 times more likely in a smoker than a non-smoker. Quitting smoking is the single most effective way to reduce the risk of a future heart attack.

Lung Injury and COPD – A person’s first puff from a cigarette invariably causes coughing.   This is the body’s warning sign–inhaled smoke damages the lung. Cigarette smoke irritates the lung’s bronchial tubes, causing mucus production.  The smoke also paralyzes the cells that clear mucus and debris out of the lung. . Over time, cigarette smoke causes mucus plugging, swelling and, sometimes, destruction of the bronchial tubes. This makes the lung more vulnerable to infections. When bronchial tubes are blocked or distorted, it is also much harder to move air in and out of the lung. This condition, called chronic obstructive pulmonary disease (COPD), is a leading cause of death and disability.

Nicotine Addiction – Nicotine is one of the most addictive substances known — often compared to heroin.  Nicotine withdrawal produces symptoms similar to opiates, which is why is it so difficult to quit smoking, Cigarette smoke delivers nicotine immediately to brain areas associated with pleasurable sensations. Nicotine also increases heart rate and blood pressure, and constricts blood vessels. This puts strain on the heart and promotes vascular disease..

If You Quit Smoking, Health Risks Fall Dramatically. 

Cancer – Smoking cessation for 10 years cuts the risk of lung cancer in half.  The reason is that the lung is no longer exposed to the carcinogens in cigarette smoke. With continued abstinence from smoking, the risk continues to decline. Similar results have been seen with laryngeal and other forms of cancer.

Heart and Vascular Disease – For someone with known coronary artery disease (CAD), smoking cession reduces the risk of a future cardiac event by 50%. For someone without CAD, quitting smoking for one year reduces the risk of CAD by 50%. If abstinence continues for 15 years, the risk of future heart events is almost the same as a lifetime non-smoker. The same is true for the risk of stroke.

COPD – Smokers expose their lungs to the constant irritation of cigarette smoke, and have a faster decline in lung function than non-smokers.   This decline occurs slowly and is not noticeable until the lung function is so low that it affects everyday activity. At that point, smoking cessation will reduce lung irritation but the chronically diseased lung cannot repair years of damage. The best strategy is to stop smoking before significant damage has occurred. The good news is smoking cessation can halt the rapid decline in lung function before more damage occurs.

Nicotine Addiction – Most smokers want to quit smoking but nicotine withdrawal is a major obstacle. As the old saying goes, “if it were easy, everyone would do it”. Most smokers who try to quit fail multiple times. However, the encouraging statistic is that millions of Americans have kicked the habit. The best results come from planned programs to break the nicotine addiction and eliminate lifestyle habits associated with smoking. (see references below)

In summary, smoking has life-threatening health care risks. Once a person stops smoking, these risks decline significantly over time. While kicking the habit is challenging, the health benefits are enormous. It is never too late to quit.

For more information about smoking and health risks, see the Centers for Disease Control (CDC) and the American Lung Association.

The Sun — America’s Leading Cause of Cancer

By Mark A. Kelley, MD |08/23/16

Skin cancer is the most common cancer in the United States. Here are some facts:

•Over 3 million Americans are treated for skin cancer every year.

One in five Americans will develop skin cancer during their lifetime.

•Skin cancer is preventable and easy to detect.

•When caught early, this cancer is usually curable.

Skin cancer is caused by sunlight damage to the skin. The only way to prevent it is to stay out of the sun, or block the sun’s rays.

People with fair skin are more vulnerable to skin cancer. Those with dark complexions have some natural protection since their skin filters out some of the sun’s rays. Nonetheless, people of color can still get skin cancer.

The sun’s ultraviolet rays can damage the DNA of skin cells. These cells may grow abnormally and eventually become cancerous. This transformation may evolve slowly over many years or may occur earlier in life, particularly if sunlight exposure has been intense.

Sunlight can also lead to another problem–premature wrinkling of the skin.  Sun worshipers believe that a tan is healthy. In reality, a suntan is a sign of the skin injury. If it continues, the damage can destroy the foundations of the skin, and make it look like leather. Tanning also triples the likelihood of developing the most dangerous form of skin cancer, melanoma.

A melanoma starts as a pigmented skin lesion. Early detection and removal can cure this malignancy. However, if untreated, melanoma can spread to other parts of the body and cause death.

The other types of skin cancer are less aggressive and spread slowly to the surrounding tissue. The most common are basal cell and squamous cell carcinoma. These cancers are rarely fatal and in early stages, are easy to remove.  If ignored, they can invade deeply and widely, making surgical removal challenging.

To prevent skin cancer, protect your skin from sunlight:

1. Limit your exposure to the sun. The sun’s rays are most intense between 10 am and 4 pm.

2. If you must go out in the sun, block the sun’s rays with “cover-up” garments and/or with sunblock.

3. Use sunblock that has sun protection factor ratings (SPF) of 15 or more.   An SPF of 15 means that it would take you 15 times longer to get sunburn with the sunblock, compared to none at all.

4. Follow the directions for applying and reapplying the sunblock product. Sunblock can lose its effectiveness after a few hours. It can also be removed by perspiration or swimming.

5. Avoid indoor tanning salons. Research has shown that those using tanning beds have an alarming increase in skin cancer including the most deadly form, melanoma. Click here for more information.

Screening for Skin Cancer

The benefits of routine skin cancer screening are controversial. However, most experts agree that anyone with a suspicious skin lesion or with a history of skin cancer should seek medical advice. Click here for details.

More information on skin cancer can be found at the National Institutes of Health and the Skin Cancer Foundation.

Summer Heat — A Dangerous Health Risk

By Mark A. Kelley, MD |08/15/16

Weather cross the U.S. has been unusually extreme this summer. Most regions have experienced high temperatures, often accompanied by high humidity. Summer heat can be a serious health hazard. This is why weather forecasters issue “heat alerts”, warning people to stay in cool environments.

Historically, heat waves have caused many deaths, especially among the elderly. Heat-related illness has also claimed the lives of younger victims, such as athletes and military trainees. These tragedies are preventable.

Our bodies are vulnerable to heat or cold. Major organs, blood flow and biochemical mechanisms only work within a narrow range of internal body temperature.

The human body can make some adjustments to outside temperature change. When it is cold, blood flow shifts away from our limbs to internal organs to preserve heat.  This is why our hands and feet feel cold.

In hot weather, our bodies do the opposite. We cool off by shifting more blood flow to our skin while producing sweat. When sweat evaporates, it acts like a natural sprinkler system and pulls heat away from the skin. . The extra blood flow to the skin speeds up the cooling process by moving “hot blood” from inside the body to the cooler surface of the skin.

This works well except when the environment is unusually hot and humid.

In that situation, sweat does not evaporate because of the high humidity. This blocks the body’s best method to eliminate body heat, and can lead to high internal body temperatures.

There are two stages of heat-related illness … and both have warning signs.

In the first stage called “heat exhaustion” the patient sweats profusely with cold clammy skin and may feel faint or nauseous. If this continues, the result can be dehydration and failure to sweat. Without any sweat, body temperature can climb quickly.

This can lead to the second and most dangerous stage, called “heat stroke”. The victim becomes confused and may have seizures or trouble walking. If left untreated, heat stroke can result in major organ failure and death. Heat stroke is an emergency that requires immediate medical treatment.

These serious conditions can be prevented. The concept is simple–-avoid environments that raise body heat and keep well hydrated. Here are some tips:

1. Avoid the high heat and humidity by staying out of the sun and seeking cool, well-ventilated, preferably air-conditioned spaces. This will keep your body heat down.

2. Avoid vigorous outdoor exercise in extreme heat. Exercise in these conditions is risky. It quickly raises body heat while the hot, humid air prevents cooling and promotes dehydration. If you must exercise outdoors, choose times early or late in the day when the temperature is lower. This is the strategy used by high performance athletes.

3. Take special precautions if you are elderly or live in an apartment. The elderly are particularly sensitive to extreme heat. During heat waves, apartments and other closed dwellings can become dangerously hot if they do not have fans or air conditioning. In these situations, it is wise to seek temporary shelter in a cooler place, either with friends or relatives or in cooling shelters provided by municipalities.

4. Drink lots of fluids whether or not you are thirsty. Staying hydrated helps your body cope with the heat.

With these sensible approaches, you can safely ride out the heat wave and look forward to cooler days.

For excellent recommendations on prevention, recognition and treatment of heat exhaustion and heat stroke, see the Centers for Disease Control website.

For more detailed information about the hot weather and health, see E-medicine.

How to Fight Zika — Lessons from the Panama Canal

By Mark A. Kelley, MD |08/08/16

The Zika virus continues to capture headlines. Zika virus has been found in Puerto Rico and now in a Miami Florida neighborhood.

Is this the beginning of a major epidemic? Not likely – if we follow the lessons of the Panama Canal.

I recently visited Panama and its famous canal that links the Atlantic and Pacific Oceans. The canal was built between 1880 and 1914 at the cost of many lives. Over 30,000 workers perished, most of them dying from tropical diseases. The most deadly were malaria and yellow fever. The latter could kill some victims within a week.

The tropical disease epidemic in Panama was stopped without the use of any vaccines or drugs. The key was understanding how mosquitoes spread these diseases to humans. Female mosquitoes need blood nourishment to lay their eggs. Infected mosquitoes can transmit the diseases to humans when they sample human blood. Eliminating mosquitoes prevents the disease.

Zika virus, known for almost seventy years, belongs to a group of tropical viruses transmitted by mosquitoes. Among them are yellow fever and dengue fever.
Until recently Zika was not considered a major public health problem because it rarely caused problems in humans.

Now Zika has changed and become dangerous. When the virus is transmitted from an infected woman to her fetus, the infant may be born with major birth defects, particularly of the brain. At the moment we have no drugs or vaccines to fight Zika.

This sounds like the Panama problem in the early 1900s. What stopped the epidemic back then?

The answer came from understanding the aegypti mosquito, the major carrier of these viruses. Each mosquito lives only 2-4 weeks. The female lays hundreds of eggs that hatch immediately upon contact with water. In dry conditions, these eggs can survive for 12 months. The resulting larvae emerge as adult mosquitoes in about ten days.

Aegypti mosquitoes have several important characteristics.

1. They stay close to human dwellings and need very little water for their eggs. These bugs prefer to be close to their victims and hide in and near dwellings –not in the jungle. They love stagnant water to lay their eggs. Human dwellings, with flowerpots and gardens, sinks and toilets, are perfect. During the Panama Canal construction, mosquitoes were happily breeding in the inkwell of the chief physician!

2. The typical female travels no more than a quarter mile during its lifetime. The only way for Zika virus to leave the neighborhood is by “hitching a ride” with a human. In the Miami outbreak, the “neighborhood” where Zika was found is about 10 blocks wide and 20 blocks long. An infected human who leaves this “Zika zone” may bitten by a mosquito in a new location that is “Zika-free”. If that local mosquito becomes infected, it can pass Zika to victims in the new neighborhood.

3. They like to bite humans during the day. This makes prevention more challenging for those who leave their home during daytime.

What stopped the Panama Canal epidemic a century ago? Public officials declared war on these mosquitoes with an aggressive action plan:

• Every house and neighborhood was inspected regularly to eliminate standing water and stop mosquitoes from breeding. All water containers were cleaned weekly to kill any eggs or larvae.

• Irrigation ditches and swampy areas near homes were drained.

• To prevent spread, yellow fever patients were kept in isolation from mosquitoes.

• Workers and the general public covered up with long sleeves and pants to reduce the chance of mosquito bites.

The plan worked. In less than one year, the yellow fever epidemic ended. .

Today, we have many more tools to fight this virus – window screens, air conditioning, municipal sanitation, and effective insect repellant. Also many regions in the U.S. either are too dry or too cool for the aegypti mosquito to thrive.

We still have much to learn about Zika. One surprise is that Zika can be transmitted by sexual contact. This makes things more complicated and prevention recommendations are still evolving. Hopefully, a Zika vaccine may eventually emerge, as happened with yellow fever.

Meanwhile, the lessons of the Panama Canal still hold true:

• Eliminate standing water near humans.

• Prevent mosquito bites by staying inside screened dwellings. When outside, wear clothing that covers the skin and use insect repellent.

These measures are effective. During a five-day visit to Panama City, none of my family and friends was bitten by a mosquito. In fact we never saw one.

For the most accurate and up-to-date information about Zika, check the Centers for Disease Control website. There you will find details about prevention, transmission, and Zika in Florida and other locations.

What is Precision Medicine?

By Mark A. Kelley, MD |08/01/16

In his State of Union address this year, President Obama announced a federally funded program called ”Precision Medicine”. This $215M project is designed to improve disease treatment and prevention by studying the variability in genes, the environment, and lifestyle for each person. A “cohort” of one million volunteers from different parts of the nation will followed over a number of years.

This project resembles the famous Framingham Heart Study, which began almost 70 years ago. That study has provided major insights into the causes of heart disease by following patients over many decades.

In this era, we have many more tools to improve our understanding of how diseases evolve over time. We can track massive amounts of information about patients and analyze their genes. We also have new electronic communication and monitoring tools. The hope is that we can find better ways of prevention, detection and cure of diseases. Already, medical research is facing some important challenges. Here are several examples.

Inherited disease is more complicated that we thought. Medical science has achieved major breakthroughs in understanding how the human genome behaves. Genes control most of the processes in our bodies and slight changes in those genes can cause problems. Some inherited genes have been known for decades – such as sickle cell disease and cystic fibrosis. However, the system is much more complex than ever imaged. Only recently have we begun to understand how inherited genes cause disease.

Genes can control our response to prescribed drugs. Some drugs, such as those for conditions like hypertension and blood clots do not work the same for everyone. Many patients may need higher (or lower doses) and for some, the drug does not work at all. Research suggests that these variances may be due to different genes that control the way the drug interacts with our bodies. How do we know which drugs are best for each person? Should we test everyone for genes that control response to prescribed drugs?

Genes can become abnormal and trigger disease. Curing cancer is at the core of the Precision Medicine project. All cancer is from the uncontrolled growth of cells. In many cancers, genes that control cell growth no longer work normally and the result is a tumor. We do not understand how or why this happens. In some cases, genetic analysis of the patient’s tumor reveals which genes are defective and therapy can be developed to block the effects of these abnormal genes. The influence of genes on human disease is the hottest area of medical research. Precision Medicine will help us understand much more about these processes.

How are diseases related to the environment, including social factors? We know much about toxins and other environmental risks but we need to learn more. The influence of social factors on health is not well understood. Poverty, education, and life style can affect health but the details are lacking. For example, is poverty a risk factor for hypertension when you exclude all other factors except poverty itself?

Fortunately, we have the tools to improve our understanding of these issues. Studying the human gene has become very sophisticated and less expensive. With this technology, we may learn how and when genetic testing is useful in a large population. Supercomputers can analyze enormous volumes of information about patients over many years. This may reveal important clues on disease patterns and risks for individual patients.

We in the United States are a very diverse population and each of us is uniquely different. With Precision Medicine, we may better understand how to provide the best care for every individual.

For more information about Precision Medicine, go to the National Institutes of Health website or the White House webpage.

If you are interested in enrolling in the project, contact the NIH Precision Medicine participation website.

Is Genetically Modified Food Safe?

By Mark A. Kelley, MD |07/25/16

Genetically Modified (GM) Food is a major breakthrough, but, like many discoveries, it has created controversy.

All living things, whether plants or animals, face many challenges to their survival: climate, predators, competition for food etc. Genes that give an organism a survival advantage are passed on to future generations.

There are many examples. Some plants develop their own natural insect repellent. Birds and fish have different colors to attract mates or to hide from predators. Bacteria develop resistance to antibiotics.

Science has now developed laboratory techniques to insert new genes into the DNA of some plants and animals. The goal is to make the food supply more productive. Plants can be changed to be more resistant to drought, heat, and insects. Farm animals can be bred to grow with less feed, water etc.

These biologically engineered animals are termed “Genetically Modified Organisms” or GMOs. You may see foods labeled as “GM” (or GMO) -free”. That means that the plant or animal has not been genetically modified by laboratory techniques.

What are the advantages of GM foods?
With climate change and expansion of the world population, many experts feel that we will need more efficient ways to grow food. Extremes of weather, and shortages of fertile land and water could all contribute to a food shortage. If we can genetically modify plants and animals to adapt to these challenges, the food supply may still thrive.

What are the risks of GM foods? So far, GM foods have proven very safe. One reason is that they must undergo safety tests before they can be introduced into the food chain. The food must be proven safe for human consumption and the plants and animals must not disrupt the environment. One common concern, especially for plants, is whether the new version can cause allergic reactions.

Can the new genes in the plant or animals be transmitted to humans? Eating a food product does not transmit genes. Every food has billions of genes that have no biologic way to mingle with our own genes. However, to artificially change a plant of animal gene, viruses are used to transmit the new DNA. . Some have argued that such viruses might linger in the food and infect humans. This theory has not been proven after decades of research. However, even if that were true, viruses have produced natural genetic changes in plants and animals for millions of years.. So far, humans have suffered so ill effects.

What are the dangers to the environment?
The GM organism could be so successful that it alters the natural balances in the environment. The organism may crowd out competitors or breed with them. We have seen this happen naturally when animals or plants from other continents have reached the US. With no competitors in their new land , these foreign organisms can spread rapidly. Examples include the zebra mussel in the Great Lakes and the Japanese beetle – found in almost every state. So far, no significant “outbreak” has happened with GM organisms.

Based on current information, these are the “take-home” messages about GM food:

• GM technology has improved food production, making food more affordable and available. With increasing pressure on the food supply, it is likely that more GM food will be developed.

• Most countries, including the US, regulate these products carefully, as they do other sources of food.

• The safety record of these GM foods has remained excellent , but the experience has only been over a few decades. Careful surveillance should continue.

• Before GMOs, we made serious mistakes in our food supply. Examples include applying harmful pesticides, and feeding animals growth-enhancing antibiotics that cause the life-threatening infections in food.

• The lesson is that we should always pay close attention to the safety of our food supply. GMOs are no exception. They have many benefits and minimal, if any risks to our health. Whether GMOs will threaten other organisms and the environment remains unknown.

You can learn more about GMOs from the Scientific American and the World Health Organization.

Preventing vs. Detecting Disease — What is the Difference?

By Mark A. Kelley, MD |07/11/16

For decades, the public has been educated that prevention is the best way to reduce the risk of disease.

From time to time, news articles describe how some tests or procedures may not be effective in preventing medical conditions. This can be confusing because the reports may not explain the difference between preventing a disease versus detecting it.

Prevention reduces the chance of ever getting a disease. Examples include public measures like clean water; vaccines against smallpox and polio; and lifestyle habits like not smoking. All these significantly reduce the risk of disease.

Detection of disease is a different strategy. If the patient already has the disease or condition, early detection may improve outcome, For example, early detection is particularly important in treating infections. The correct antibiotic, given early, has a much better chance of eliminating the infection before it can spread. In another example, early detection of high blood pressure or high cholesterol can lead to treatment that reduces the risk of heart attacks and stroke.

Some of the recent controversies have been about the early detection of cancer. This is an evolving strategy. Most cancers start as small tumors and cause no symptoms until they grow large or spread. In theory, finding and eliminating these early tumors could result in higher cure rates.

For the most common cancers, this strategy has been effective … but with some uncertainties.

“Early Detection” Success

Cervical Cancer: The Pap smear of the cervix has detected early, curable cancer in thousands of women. Early detection has transformed cervical cancer from an incurable disease to one with a very high cure rate.

Colon cancer: This slow-growing tumor, if detected early, is also highly curable. The detection tools are testing for blood in the stool or looking for tumors inside the colon periodically with a flexible scope.

Skin Cancer: There are multiple forms of skin cancer but in nearly every circumstance, early detection improves cure. The “test” is easy: examination of the skin by a trained expert and when necessary, skin biopsies to determine diagnosis.

“Early Detection” Success – Some Controversy

Breast Cancer: Mammography and related breast imaging technologies are excellent for detecting early breast cancer and this early detection saves lives. However, experts can disagree on the age a woman should begin this testing, or how often it should be performed. These decisions may depend on the woman’s risk for breast cancer based on family history and other factors.

Lung Cancer: Until recently, there was no early detection test for this common tumor. Recent research has suggested that periodic CT scans of the lung can detect early, curable cancer in current or former smokers. However, some experts think this recommendation is preliminary until more results are known.

“Early Detection” – More Controversy

Prostate Cancer: This malignancy grows slowly and is common in elderly men. A blood test called the PSA, when abnormal, suggests prostate cancer but the diagnosis must be confirmed with biopsies. Even if the biopsies confirm the diagnosis, it is often unclear when or how to treat prostate cancer since it is usually not very aggressive. This has made policy-makers wary of recommending the PSA since, so far, the test has not improved the cure rate. However many men and their physicians still monitor PSA levels.

Prevention and detection of disease are important to discuss with your doctor. As medical science gains new insights, some new recommendations may evolve.

However, one recommendation will never change: pay attention to your health and take the steps that can keep you healthy.

For more information about cancer screening tests, visit the website Choosing Wisely.

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