Sunday, April 28, 2019

Diabetes drug showing promise for prostate cancer treatment

There are many reasons to keep your blood sugar under control: protecting your arteries and nerves are two of them. Here’s another biggie: preventing dementia, the loss of memory and thinking skills that afflicts millions of older Americans.

A study published today in the New England Journal of Medicine shows that even in people without diabetes, above normal blood sugar is associated with an increased risk of developing dementia. This finding goes beyond previously seen links between diabetes and dementia. “It establishes for the first time, convincingly, that there is a link between dementia and elevated blood sugars in the non-diabetic range,” says study author Dr. David Nathan, a Harvard Medical School professor and the director of the Diabetes Center and Clinical Research Center at Massachusetts General Hospital.

Dr. Nathan teamed up with researchers across the country to look at blood sugar levels in more than 2,000 older adults—the average age was 76—taking part in the Adult Changes in Thought study. The vast majority of the study participants did not have diabetes. What the researchers found is that any incremental increase in blood sugar was associated with an increased risk of dementia—the higher the blood sugar, the higher the risk.

Why? There are only theories. “The speculation is that elevated blood sugar levels are causing more vascular disease, but it may be other metabolic issues. For example, people with elevated blood sugar often have insulin resistance which may be the link that affects our brain cells,” says Dr. Nathan.

The study does not prove that high blood sugar causes dementia, only that there is an association between the two. For that reason, don’t start trying to lower your blood sugar simply to preserve your thinking skills, cautions Dr. Nathan. There’s no evidence that strategy will work, although he says it should be studied.

But it is worth keeping an eye on your blood sugar to try to avoid developing type 2 diabetes. This disease is at epidemic proportions. Almost 26 million Americans—one in 12—have diabetes. High blood sugar is hallmark of this disease. Normal blood sugar is under 100 milligrams per deciliter of blood mg/dL after an eight-hour fast. You have diabetes if your blood sugar is 126 mg/dL or higher after a fast. People with a blood sugar reading of above 100 but below 126 have what’s called prediabetes. Nearly 80 million Americans are in that camp.

Excess blood sugar is a problem because it can lead to a variety of health problems including heart, eye, kidney, and nerve disease.
Taming blood sugar

What if your blood sugar is above normal? There’s good news in that department: You can lower your blood sugar by exercising and, if needed, losing weight. Shifting to a healthier diet with more vegetables, fruits, and whole grains and cutting back on highly refined grains can also help.

Try to get 150 minutes per week of moderate intensity activity, such as brisk walking. If that’s daunting, know that even a little activity can make a big difference in lowering blood sugar levels. Short but frequent walking breaks—as brief as a minute and forty seconds every half hour—can lower blood sugar. So can taking a walk after a meal.

And it doesn’t always have to be official “exercise.” Try taking the stairs more often, parking farther away from the store, and getting up and moving if you’ve been sitting too long. “It’s common sense,” says Dr. Nathan. “The more active you are and the less sedentary, the more likely it is that your muscles can uptake glucose, and the insulin you make will be more effective.”

Also helpful is cutting back your intake of highly refined carbohydrates, especially foods with added sugars such as sucrose, high fructose corn syrup, and also molasses, cane sugar, corn sweetener, raw sugar, syrup, honey or fruit juice concentrates. The American Heart Association recommends no more than 100 calories from sugar or six teaspoons of sugar per day for women, and 150 calories or nine teaspoons of sugar per day for men. If you’re in the prediabetic or diabetic range, you’ll want to work with a dietitian to determine your exact needs.

Making these changes is an investment, to be sure. But the payoff—better physical and mental health—is definitely worth it. Not that long ago, celebrating an 80th birthday was an uncommon event. I remember watching the 1950s TV show “You Bet Your Life” with Groucho Marx. On one of his shows, Groucho had an 81-year-old male contestant. The man received resounding applause just for being alive. Today, the average life expectancy in many developed countries is 80-plus years, and more people than ever are living beyond age 100.

Is there a limit to how long a human can live? Equally important, if it is well above 100, would you want to live that long? In a just-released survey, the Pew Research Center asked more than 2,000 adults if they would take medical treatments that would slow the aging process and let them live to age 120. More than half (56%) said they would not, but 65% thought that other people would want to live that long.

Among those polled, 69% said the ideal length of life was between 79 and 100 years; 14% said 78 years or under, while 8% said 101 year or older. There was optimism, however, about advances that could extend life. A majority (69%) said they thought there will be cures for most forms of cancer by 2050. Overall, those polled said they believed medical advances that prolong life are generally good (63%) rather than interfering with the natural cycle of life (32%).
Take action now to increase your “healthspan”

The Pew survey did not ask why most adults would not want life extending treatment. Previous work has identified what people fear about getting too old. These include:

    loss of independence
    running out of money
    inability to manage their own activities of daily living
    not being able to live at home
    having constant pain
    reliance on others to care for them
    isolation or loneliness
    fear of falling or hurting themselves

These fears are the realities virtually all of us have seen in older family members and friends. But there are ways to minimize the problems that come with age. The strategies aren’t sexy, nor do they rely on medical breakthroughs.

Avoid tobacco. If you are a smoker, it is never too late to quit. Your body reaps health benefits from the day you stop.

Eat a healthy diet with plenty of fruits and vegetables, especially the brightly colored ones. Get the nutrients you need. With a balanced diet and 10 to 15 minutes of daily sunshine (for the vitamin D), you should be able to get all you need. For pennies a day, a generic multiple vitamin can add some insurance.

Stay physically active. Schedule time every day for at least 30 minutes of dedicated exercise.

Don’t over eat and keep your body weight in check.

Socialize. Maintain contacts with family and friends throughout your life.

Think positive. Most centenarians have a positive attitude and easily shed stress.

Challenge your mind. Learn new skills, try new hobbies, volunteer, and do other things to keep mentally sharp.

Don’t overuse alcohol. While a drink per day may actually help your health, more is not better. When I first began to see patients with tattoos, I marveled at the novelty and variety of this “skin art.” But now that tattooing has become more common—an estimated 1 in 4 Americans between the ages of 18 and 50 has one—reports of skin cancer “hiding” in a tattoo takes on added significance.

Writing in JAMA Dermatology, three German clinicians describe the case of a young man who wanted to remove large, multicolored tattoos on his arms and chest. Before beginning laser removal therapy, his doctors noticed a suspicious-looking mole inside the tattoo on his right arm and recommended that it be removed. He declined, and began having laser therapy to remove the tattoos. Seven years and 47 laser sessions later, the doctors told the man they wouldn’t continue treatment unless the mole was removed. It turned out to be cancerous—stage II melanoma.

This wasn’t the first time doctors have discovered a melanoma inside a tattoo. The German clinicians found reports of 16 other cases in English-language journals. It’s possible that this is the tip of the iceberg.
Detecting melanoma

Melanoma is a form of cancer that begins in melanocytes—cells that make a pigment called melanin. Melanin is the pigment most responsible for skin color, and for tanning. Each year, more than 75,000 Americans are diagnosed with melanoma, and more than 9,000 die from it. Early diagnosis can identify this type of skin cancer while it is curable, meaning while it is confined to the mole or top layer of skin and before it has spread (metastasized) to deeper tissues or to other parts of the body.

The first sign of melanoma is often a change in an existing mole. (It can also appear as a new mole.)  It’s especially important to have a mole checked if it has one or more of the “ABCDE” features:

    Asymmetry. One side of the mole looks different from the other.
    Border irregularity. An edge of the mole is ragged or uneven.
    Color variations. There is an uneven mixture of brown, black, tan, or red.
    Diameter. The mole is bigger than quarter of an inch (6 millimeters)
    Evolution. The mole evolves, or changes over time. This could be a change in size or shape.

The National Library of Medicine has helpful pictures of melanoma.
Moles and tattoos

Tattoos may make it difficult to evaluate moles. Tattoo ink can hide suspicious changes in moles. Ink can also seep into underlying tissues and mimic the spread of metastatic melanoma.

Laser removal therapy is also problematic when moles are present. Lasers break up pigment inside the tattoo. But it can also break up pigment inside a suspicious mole, making assessment of the mole difficult. One report suggests that laser therapy may delay the diagnosis of melanoma and there is even some concern – unproven so far – that repeated laser surgeries may promote transformation of benign moles to melanoma .

Here are two key take-home lessons from the JAMA Dermatology report:

    If you are considering getting a tattoo, either make sure it will be applied to skin that is free or moles or birthmarks, or have your doctor check any moles in the to-be-tattooed area beforehand.
    If you are planning to have a tattoo removed, check for moles within the tattoo. If you see any, ask your doctor or dermatologist to check them out before starting laser therapy. The omega-3 fats in fish have been linked to all sorts of health benefits, including protection against prostate cancer. But for the second time in two years, researchers have found a link between high levels of omega-3 fats in the blood and prostate cancer.

The latest report comes from researchers at the Fred Hutchinson Cancer Center in Seattle. Their case-control study compared blood samples from 834 men diagnosed with prostate cancer with samples from 1,393 men who didn’t have the disease. The blood samples had been collected as part of the SELECT trial designed to find out if taking selenium or vitamin E could prevent men from developing prostate cancer. (Selenium had no effect and vitamin E was associated with an increase in risk.)

The researchers tested the samples for their omega-3 content. Men whose blood samples were in the top 25% of omega-3 fat content were 43% more likely to have been diagnosed with prostate cancer than men whose blood samples were in the lowest 25% of omega-3 content. The finding were published online in the Journal of the National Cancer Institute.

The results didn’t differ much when the three different types of omega-3 fats found in fish and fish oil—eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and docosapentaenoic acid (DPA)—were analyzed separately.

A similar study published two years in the American Journal of Epidemiology used blood samples from a different prostate prevention study. The results of that study didn’t show any correlation between omega-fat levels in the blood and low-risk prostate cancer.

But there was a catch, because men with the highest DHA levels were found to be 2.5 times more likely to have developed high-risk prostate cancer than men with the lowest levels.
Doubt cast on omega-3s and heart disease protection

Recent research has also dented the reputation that omega-3 fats have for protecting folks against heart disease.

In May of this year, Italian researchers reported in the New England Journal of Medicine that omega-3 fatty acid supplements did nothing to reduce heart attacks, strokes, or deaths from heart disease in people with risk factors for heart disease.

Late last year, a Harvard study published in JAMA found that fish oil supplements immediately before and after surgery didn’t prevent postoperative atrial fibrillation among cardiac surgery patients.

And a few months before that study, Greek researchers weighed in with a meta-analysis that came to the conclusion that fish oil supplements are useless if you’re looking for protection from heart disease–related death, heart attacks, or stroke.


Could it be fish oil and not fish that’s to blame?

Omega-3s have anti-inflammatory effects, and that’s part of the reason they have been seen as dietary good guys and possibly having an anticancer effect. Why they might have a dark side that increases prostate cancer risk is anybody’s guess.

One important point to keep in mind, though, is that there may be a difference between eating fish and taking fish-oil supplements. Over and over again, nutrition research has shown that diets full of food and drink that supply vitamins, minerals, and healthful fats are correlated with good health, whereas studies of supplements that try to isolate what are believed to be the healthful constituents of the food have consistently been disappointing.

Just to be clear: this latest study correlated blood levels of omega-3 fats to prostate cancer. It wasn’t able to prove that omega-3 fats cause prostate cancer, nor did it go into how those blood levels came about and whether men with high blood levels were big fish eaters, took fish-oil supplements, or both.

We like what our colleague, Dr. Howard Lewine, chief medical editor for Internet publishing for Harvard Health Publishing, wrote about the Fred Hutchinson research:

Despite this one study, you should still consider eating fish and other seafood as a healthy strategy. If we could absolutely, positively say that the benefits of eating seafood comes entirely from omega-3 fats, then downing fish oil pills would be an alternative to eating fish. But it’s more than likely that you need the entire orchestra of fish fats, vitamins, minerals, and supporting molecules, rather than the lone notes of EPA and DHA.

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