Thursday, 9 May 2019

Stool transplants are now standard of care for recurrent C. difficile infection

Each year, nearly a quarter of a million American men learn they have prostate cancer. Most are diagnosed with early-stage cancer that has not spread beyond the prostate gland. Traditional treatments include surgery, radiation therapy, and a “watch and wait” strategy called active surveillance. A new study published online this week in JAMA Internal Medicine indicates that diet may be an important add-on. The study, part of the ongoing Harvard-based Health Professionals Follow-up Study, suggests that eating more foods that deliver healthy vegetable oils can help fight the second leading cause of cancer death in men.

“It’s one of the first studies to look at dietary interventions after men have been diagnosed with prostate cancer,” says Dr. Marc B. Garnick, a prostate cancer specialist at Harvard Medical School and Beth Israel Deaconess Medical Center. “It supports the idea that you can potentially modify the behavior of prostate cancer that is still confined to the prostate gland.”
Healthy fats

The study involved about 4,500 men who were diagnosed with nonmetastatic prostate cancer, which means it had not yet spread beyond the walnut-sized prostate gland. Since 1986, they have been reporting what they usually eat by completing detailed food surveys every four years.

Study participants who ate the largest amount of vegetable fats were less likely to die from prostate cancer—or any other cause—than men who consumed the most animal fats. Most of the vegetable fats consumed by the men came from oils in salad dressings and nuts.

The men who consumed the most vegetable oil lived longer, in part because their cancers were less likely to spread beyond the prostate gland. That suggests, but does not prove, that a diet rich in vegetable oils can slow the progression of the prostate cancer.

Earlier studies have implicated the traditional Western diet, which is relatively high in red meat and other sources of animal fats, with a higher risk for developing prostate cancer in the first place, while eating more vegetable oils and vegetable protein may help prevent it.

“One of the things I tell my patients is not to eat animal fat, or to at least limit its consumption,” Dr. Garnick says. He bases this advice on decades-old data that show a direct relationship between the amounts of animal fat consumed and incidence of prostate and other cancers. It’s never been possible to prove cause and effect between dietary fat and cancer, but this new study lends support to the idea that animal fats may modify the characteristics of prostate cancer.
Switching carbs, too

Although the study focused on oils and fats, it’s important to consider what the men who consumed a lot of vegetable oils were not eating: refined carbohydrates, such as processed white bread, white rice, and desserts.

In the study, men who replaced 10% of their total calories from carbohydrates with calories from vegetable oils were 29% less likely to die from prostate cancer or any other cause over eight years of follow-up.
A generally healthy diet

This one study, of course, can’t prove that a healthful diet fights prostate cancer. For one thing, this type of long-term follow-up study can only show an association between diet and prostate cancer. There were also some differences between the groups. The men who ate the most vegetable oil were healthier to start with. At diagnosis, their blood levels of PSA—a marker for cancer activity—were lower than in the group that ate the most animal fat. Conversely, the men who ate the most animal fats had more unhealthy characteristics. They were more overweight and less physically active, and more of them smoked (7% compared with about 1% in the vegetable-fat group).

Researchers used statistical methods to compensate for these important differences. “Any of these negative influences would independently lead to a worse outcome,” Dr. Garnick says. “Have they accounted for everything? In these studies, you can never be sure.”

So we don’t really know what contributed most to keeping prostate cancer in check—eating more beneficial vegetable oils, eating fewer (or healthier) carbohydrate-rich foods, or eating less meat. It may not matter, since all three are part of a healthful diet.

The JAMA Internal Medicine study, like so many others before it, endorses an overall healthy diet that goes easy on red meat and includes generous amounts of plant foods that deliver healthy mono- and polyunsaturated fatty acids. These come from foods like avocados, walnuts, and soybean, canola, and extra virgin olive oils. That kind of diet has been linked with lower risks of heart disease, cancer, and a host of other chronic conditions.

This week is Men’s Health Week. As we cruise toward Father’s Day, I hope that all men will give themselves the gift of health. One important step in that direction is adopting a diet that may fight prostate cancer and will benefit everything from the head to the feet. “Floaters” and flashes are a common sight for many people. Floater is a catchall term for the specks, threads, or cobweb-like images that occasionally drift across the line of vision. Flashes are sparks or strands of light that flicker across the visual field. Both are usually harmless. But they can be a warning sign of trouble in the eye, especially when they suddenly appear or become more plentiful.

A floater is a tiny cluster of cells or fleck of protein lodged in the vitreous humor. This clear, stable gel, which looks like raw egg white, supports and fills the rear two-thirds of the eyeball (see “The inside story”). The vitreous provides a pathway for light coming into the eye through the lens. The vitreous connects to the retina, the patch of light-sensitive cells along the back of the eye that captures images and sends them to the brain via the optic nerve.

What you see isn’t actually the floater itself, but the shadow it casts onto the retina. Floaters move as your eyes move. They appear to zoom away when you try to look directly at them, and drift slowly when your eyes stop moving.

The vitreous slowly shrinks with age, causing it to become a bit stringy. The strands cast shadows on the retina, causing floaters. About one-quarter of people have some vitreous shrinkage with floaters by their 60s; that rises to about two-thirds of 80-year-olds. Floaters also appear more often in people who are nearsighted, those who have had cataract surgery or a previous eye injury, and those with diabetes. Although most people tolerate floaters just fine, others feel that floaters affect their vision and disrupt their ability to read.Normal eye

Flashes occur when the vitreous gel bumps, rubs, or tugs against the retina. Like floaters, flashes are generally harmless and require no treatment.
Trouble ahead

Sometimes floaters and flashes signal a condition that can lead to vision loss.

“A new onset of floaters may herald retinal disease,” said Dr. Jeffrey Heier, director of the retina service at Ophthalmic Consultants of Boston and clinical instructor in ophthalmology at Harvard Medical School.

The shrinking vitreous can tug on the retina and pull away from it. This event, called a posterior vitreous detachment, is common, and usually doesn’t threaten vision. In about one in six people, a posterior vitreous detachment causes the retina to tear. Fluid from inside the eye can then seep through the tear and separate the retina from the tissues that nourish it. This separation, called retinal detachment, can lead to permanent vision loss.

Retinal tears and detachments are painless. Key warning signs include:

    a new onset of floaters and flashes of light in the eye
    gradual shading of vision from one side (like a curtain being drawn)
    rapid decline in sharp, central vision. This occurs when the macula — the area of the retina responsible for central vision — detaches.

Laser photocoagulation is usually done in a doctor's office. The ophthalmologist uses a laser to make a series of tiny burns around the retinal tear. This creates a barrier of scar tissue that stops the tear from getting bigger.

Laser photocoagulation is usually done in a doctor’s office. The ophthalmologist uses a laser to make a series of tiny burns around the retinal tear. This creates a barrier of scar tissue that stops the tear from getting bigger.

If you experience any of these warning signs, call your doctor right away. You will need to see an ophthalmologist for an eye exam as soon as possible. If a tear is detected early, treatment can prevent the retina from detaching. Tears can be treated several ways. Pinpoints of laser light can be used to fuse the retina to the back wall of the eye (see “Laser photocoagulation”). Extreme cold, a procedure called cryopexy, does much the same thing.

Cold and laser light can also be paired with the injection of a gas bubble into the eye (pneumatic retinopexy) to repair a detached retina. Two operations, scleral buckling and vitrectomy, can also be used to reattach a retina.
Living with floaters

If your floaters aren’t a sign of retinal damage, they may disappear, become less noticeable, or stay and become irritating. Some clinicians perform and promote laser treatment for benign floaters, but this approach hasn’t been carefully studied in a clinical trial, says Dr. Heier. Floaters can be removed, but for most people the risk to vision from the surgery is greater than the problem posed by the floater. If floaters become a nuisance, Dr. Heier recommends this trick in The Aging Eye, a Special Health Report from Harvard Medical School for which he is a medical editor: move your eyes up and down, or left and right. That can shift the floater and provide temporary relief. My first tick sighting was a mixture of horror and fascination. It happened during my one and only experience with summer camp, on the shores of Alma Lake in north-central Wisconsin. One of my cabin mates discovered a big, fat tick burrowed into the skin of his belly. “Gross!” we chorused, unable to stop looking. Ideas for how to remove the tick swirled fast and furious. The leading contender was to light a match, blow it out, and touch the hot tip to the back end of the tick. As we scurried around looking for matches, cooler heads prevailed and the kid went off to the nurse for a more effective form of tick removal.

Knowing how to remove a tick is a useful skill for anyone who spends time outdoors, or who cares for someone who does. The sooner a tick is removed—correctly—the less likely the critter can deliver microbes that cause Lyme disease or other tick-borne diseases.
Don’t fall for the myths

There are several folk remedies for removing a tick. Touching it with a hot match is a common one. Others include covering it with petroleum jelly or nail polish (in theory to suffocate it), or freezing it off. These are all supposed to make the tick “back out” of the skin on its own. But they often have the opposite effect, forcing the tick to hold tight, burrow deeper, and possibly deposit more of its disease-carrying secretions into the wound, which increases the risk of infection.

The best way to remove a tick? Here’s what the Centers for Disease Control and Prevention recommend: Use a pair of fine-tipped tweezers to grasp the tick as close to the skin as possible. Then pull it out with a steady motion. Once the tick has been removed, clean the skin with soap and water. Dispose of the tick, which is probably still alive, by placing it in alcohol or flushing it down the toilet.
A tick feeds by way of a two-pronged mouthpart (hypostome) held in place with salivary cement and secured with tiny backward-pointing barbs. To remove the tick, use narrow-tipped tweezers and grasp it as close to the skin as possible; then pull upward slowly and steadily. If the mouthpart remains in the skin, try to remove it. If you can't, check with your clinician. Wash your skin and hands with soap and warm water. Try not to crush or squeeze an attached tick.

A tick feeds by way of a two-pronged mouthpart (hypostome) held in place with salivary cement and secured with tiny backward-pointing barbs. To remove the tick, use narrow-tipped tweezers and grasp it as close to the skin as possible; then pull upward slowly and steadily. If the mouthpart remains in the skin, try to remove it. If you can’t, check with your clinician. Wash your skin and hands with soap and warm water. Try not to crush or squeeze an attached tick.

For most people who are bitten by a tick, removal ends the saga. For others, though, it is just beginning.
Tick-borne diseases

In the United States, the most common tick-borne disease is Lyme disease. It is caused by Borrelia burgdorferi, a bacterium carried to humans by infected blacklegged ticks, also known as deer ticks. Most cases of Lyme disease follow the bite of an immature deer tick, which is about the size of a poppy seed. Adult deer ticks can also transmit Borrelia burgdorferi, but they are larger and more likely to be seen and removed before they’ve had time to infect a person.

Lyme disease continues to spread across the Northeast and upper Midwest, and is now found in most states. The CDC has an interactive map that shows its spread from 2001 to 2011.

Infection with Borrelia burgdorferi often—but not always—causes a rash that looks something like a red bull’s eye soon after the tick bite. Treatment with antibiotics can usually prevent any short- or long-term repercussions. If the infection isn’t treated, problems can develop in other parts of the body, including the joints, heart, and nerves. It can also cause arthritis that persists months or years after the tick bite.

Some people with Lyme disease and some community doctors have argued that Borrelia burgdorferi can somehow evade courses of antibiotics and become a chronic infection that needs long-term antibiotic treatment—even though conventional antibody tests are negative. Chronic Lyme disease has been blamed for causing pain, fatigue, muscle aches, loss of memory and thinking skills, and a host of other problems.

Most Lyme disease experts don’t believe active infection persists after antibiotic treatment and once blood tests are negative for antibodies. They’ve been critical of what they see as unreliable tests for infection and unwarranted, possibly harmful, long-term antibiotic therapy.

A recent front-page article in the Boston Globe highlighted the controversy around Lyme disease and its treatment.

Other tick-borne diseases include:

    babesiosis
    ehrlichiosis
    Rocky Mountain spotted fever
    tularemia
    tickborne relapsing fever

Aim for prevention

The only foolproof method for staying tick free is avoiding areas where they lurk. That means staying out of brush and high grass in and around wooded areas.

If you like to be outdoors and find yourself frequenting those environments, the Connecticut Agricultural Experiment Station has published an excellent comprehensive handbook about tick management. If you don’t have the time to read all 80 pages, here are six tips for protecting yourself from ticks, culled mainly from that handbook.

1. Wear light-colored clothing. Light colors make ticks easier to spot, especially tiny deer tick nymphs.

2. Tuck your pants inside your socks. It may not be a flattering look, but it creates a physical barrier against ticks.

3. Use insect repellent. Most of the chemicals that repel mosquitoes are somewhat effective against ticks, although it may take a heavier concentration of DEET — between 30% and 40% — to really keep them away. Permethrin is a stronger chemical that kills ticks as well as repels them. Products containing permethrin should be sprayed on clothes, not on the skin. Picaridin repels mosquitoes and other insects but not ticks.

4. Stay in the middle of the path (or fairway). Ticks can’t fly or jump, so they can only get on you if you come into contact with the kind of environment they live in: moist, often shady, wooded areas, with leaves, low-lying plants, and shrubs.

5. Think sunny. Ticks don’t do well in dry, open areas. Lawn furniture and playground equipment should be set back from the edge of wooded, shady areas. If you’re picnicking, pick a patch of well-tended lawn or some open ground.

6. Inspect yourself and your children (and your pets), especially the legs and groin. Ticks usually get picked up on the lower legs and then climb upward in search of a meal. The odds of contracting Lyme or other tick-borne disease are minimized if a tick is removed soon after it’s attached, and there’s no risk if it’s still crawling around. The shower is a good place to conduct a tick check. Feel for any new bumps on soaped-up skin. When you think of the Mediterranean these days, the region’s azure waters, rich history, and lively cultures may not come to mind. Instead, you may first think of the Mediterranean diet. This heart- and brain-healthy diet includes olive oil, fruits, vegetables, nuts and fish; occasional red meat; and a moderate amount of cheese and wine. Most doctors and nutrition experts I interview for the Harvard Health Letter tell me that the evidence points to a Mediterranean diet as the very best for our health. But there’s another diet that appears to be equally good: a vegetarian diet.

A study published this week in JAMA Internal Medicine found that people who ate a vegetarian diet were 12% less likely to have died over the course of the five-year study than nonvegetarians. The researchers, from Loma Linda University in California, noted that the benefits of a vegetarian diet were especially good for men, who had a significant reduction in heart disease. Keep in mind that the study couldn’t prove that a vegetarian diet caused good health—it’s possible that it was something else that vegetarians did and nonvegetarians didn’t do that made the difference.

The fact that vegetarian diets are good for you isn’t new. They have long been linked to reduced risk for hypertension, metabolic syndrome, type 2 diabetes, and heart disease. This one underscores the idea that meat consumption influences long-term health. “A diet with meat in it raises the risk of heart disease and cancer, when compared with a vegetarian diet,” says cardiologist Dr. Deepak Bhatt, a Harvard Medical School professor. Red meat and processed meats appear to be the worst offenders as far as boosting the risk of cardiovascular disease or cancer.

Dr. Bhatt told me that he is a vegetarian—meaning that he doesn’t eat meat—and he personally feels that a vegetarian diet is the way to go for environmental and ethical reasons. He also feels it’s a healthy way to eat.
A personal decision

Should you consider forgetting the Mediterranean diet and becoming a vegetarian instead? There isn’t much high-quality data from comparing different types of healthy diets against each other. There is good evidence that following either a Mediterranean diet or a vegetarian diet—which share many common features—can lower cardiovascular risk. “The bottom line is that either type of diet is healthier than the typical American diet,” says Dr. Bhatt. So it’s really a matter of personal choice.

It’s also a matter of determining what kind of vegetarian you want to be. A vegetarian diet can take a number of forms. A vegan diet excludes all animal products (no meat, poultry, fish, eggs, dairy or gelatin). Other more liberal interpretations include a pesco-vegetarian diet, which includes seafood; a lacto-ovo-vegetarian diet, which includes dairy and egg products; a lacto-vegetarian diet, which includes dairy products; and an ovo-vegetarian diet, which includes eggs.

With all of that variety, you’ll need to assess your eating style and determine which fits in best with your lifestyle and personal beliefs.

It’s also important to consider your nutritional needs, warns Dr. Bhatt. Vegetarian diets that include only raw fruits and vegetables can lead to nutrient deficiencies. Without meat or dairy, you may run the risk of not getting enough protein, calcium or vitamin B12. You can get all the protein you need from plant sources, such as peas, beans, lentils, chickpeas, seeds, nuts, soy products, and whole grains such as wheat, oats, barley, and brown rice. You can get calcium from plant sources, such as bok choy, broccoli, Chinese cabbage, collards, and kale. And you can get vitamin B12 from soy and rice drinks, and fortified breakfast cereals.

It’s also important to remember that even with a vegetarian diet, calories still matter and consuming too many—even if they are meat-free—is bad for health.

Becoming a vegetarian will require you to pay more attention to your nutrition, which is a good thing. But it’s also a bit of work, so don’t hesitate to get some advice from your doctor or a dietitian before proceeding. If you want to go with a Mediterranean diet, that’s a good thing, too, and probably easier for many people. Again, it’s a personal choice.

Future research on vegetarian, Mediterranean, and other beneficial diets should examine what is it about these diets that makes them good for us. As Dr. Robert Baron, professor of medicine at the University of California, San Francisco wrote in an editorial accompanying the Loma Linda study, “Our debates about the superiority of one diet over another have not served the public well. It is time to acknowledge the common features of diets associated with good clinical outcomes.”

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