Blog

Animals renowned for their outstanding night vision include owls, cats, tarsiers (a tiny primate in Southeast Asia) — and even the dung beetle.

But humans? Not so much.

Over time, many people suffer from night blindness, also known as nyctalopia. This condition makes seeing in dim or dark settings difficult because your eyes cannot adjust to changes in brightness or detect light.

What are the dangers for those experiencing night blindness?

Night blindness is especially problematic and dangerous when driving. Your eyes cannot adjust between darkness and the headlights of oncoming vehicles, other cars may appear out of focus, and your depth perception becomes impaired, which makes it difficult to judge distances.

Night blindness also may affect your sight at home by making it hard for your vision to quickly adjust to a dark room after turning off the lights. “This can cause people to bump into furniture or trip and suffer an injury,” says Dr. Isabel Deakins, an optometrist with Harvard-affiliated Massachusetts Eye and Ear.

What happens in the eye to create night blindness?

The ability to see in low-light conditions involves two structures in the eye: the retina and the iris.

The retina, located in the back of the eye, contains two types of light-detecting cells called cones and rods. The cones handle color vision and fine details while the rods manage vision in dim light.

The iris is the colored part of your eye. It contains muscles that widen or narrow the opening of your pupil to adjust how much light can enter your eyes.

If your irises don’t properly react, the pupils can dilate and let in too much light, which causes light sensitivity and makes it hard to see in bright light. Or your pupils may remain too small and not allow in enough light, making it tough to see in low light.

What causes night blindness?

Night blindness is not a disease but a symptom of other conditions. “It’s like having a bruise on your body. Something else causes it,” says Dr. Deakins.

Several conditions can cause night blindness. For instance, medications, such as antidepressants, antihistamines, and antipsychotics, can affect pupil size and how much light enters the eye.

Eye conditions that can cause night blindness include:

• glaucoma, a disease that damages the eye’s optic nerves and blood vessels
• cataracts, cloudy areas in the lens that distort or block the passage of light through the lens
• dry eye syndrome.

However, one issue that raises the risk of night blindness that you can’t control is age. “Our eyes react more slowly to light changes as we age, and vision naturally declines over time,” says Dr. Deakins.  “The number of rods in our eyes diminish, pupils get smaller, and the muscles of the irises weaken.”

What helps if you have night blindness?

If you notice any signs of night blindness, avoid driving and get checked by an eye care specialist like an optometrist or ophthalmologist. An eye exam can determine if your eyeglass prescription needs to be updated.

“Often, a prescription change is enough to reduce glare when driving at night," says Dr. Deakins. “You may even need separate glasses with a stronger eye prescription that you wear only when driving at night.”

Adding an anti-reflective coating to your lens may help to cut down on the glare of the headlights of an oncoming car. However, skip the over-the-counter polarized driving glasses sold at many drug stores. "These may help cut down on glare, but they don't address the causes of night blindness," says Dr. Deakins.

An eye exam also will identify glaucoma or cataracts, which can be treated. Glaucoma treatments include eyedrops, laser treatment, or surgery. Cataracts are corrected with surgery to replace the clouded lens with an artificial one. Your eye care specialist can also help identify dry eye and recommend treatment.

Ask your primary care clinician or a pharmacist if any medications that you take may cause night blindness. If so, it may be possible to adjust the dose or switch to another drug.

Three more ways to make night driving safer

You also can take steps to make night driving safer. For example:

• Wash the lenses of your glasses regularly. And take them to an optician to buff out minor scratches.
• Keep both sides of your front and rear car windshields clean so that you can see as clearly as possible.
• Dim your dashboard lights, which cause glare, and use the night setting on your rearview mirror.

About the Author

Matthew Solan, Executive Editor, Harvard Men's Health Watch

Matthew Solan is the executive editor of Harvard Men’s Health Watch. He previously served as executive editor for UCLA Health’s Healthy Years and as a contributor to Duke Medicine’s Health News and Weill Cornell Medical College’s … See Full Bio View all posts by Matthew Solan

About the Reviewer

Howard E. LeWine, MD, Chief Medical Editor, Harvard Health Publishing; Editorial Advisory Board Member, Harvard Health Publishing

Dr. Howard LeWine is a practicing internist at Brigham and Women’s Hospital in Boston, Chief Medical Editor at Harvard Health Publishing, and editor in chief of Harvard Men’s Health Watch. See Full Bio View all posts by Howard E. LeWine, MD

By midwinter, our urge to hibernate can start to feel constricting instead of cozy. What better antidote to being cooped up indoors than a bracing hike in the crisp air outdoors?

Winter backdrops are stark, serene, and often stunning. With fewer people on the trail, you may spot more creatures out and about. And it’s a prime opportunity to engage with the seasons and our living planet around us, says Dr. Stuart Harris, chief of the Division of Wilderness Medicine at Massachusetts General Hospital. But a multi-mile trek through rough, frosty terrain is far different than warm-weather hiking, requiring consideration of health and safety, he notes. Here’s what to know before you go.

Winter hiking: Safety first

“The challenge of hiking when environmental conditions are a little more demanding requires a very different approach on a winter’s day as opposed to a summer’s day,” Dr. Harris says. “But it gives us a chance to be immersed in the living world around us. It’s our ancient heritage.”

A safety-first attitude is especially important if you’re hiking with others of different ages and abilities — say, with older relatives or small children. It’s crucial to have both the right gear and the right mindset to make it enjoyable and safe for all involved.

Planning and preparation for winter hikes

Prepare well beforehand, especially if you’re mixing participants with vastly different fitness levels. Plan your route carefully, rather than just winging it.

People at the extremes of age — the very old or very young — are most vulnerable to frigid temperatures, and cold-weather hiking can be more taxing on the body. “Winter conditions can be more demanding on the heart than a perfectly-temperatured day,” Harris says. “Be mindful of the physical capabilities of everyone in your group, letting this define where you go. It’s supposed to be fun, not a punishing activity.”

Before setting out:

• Know how far, high, and remote you’re going to go, Dr. Harris advises, and check the forecast for the area where you’ll be hiking, taking wind chill and speed into account. Particularly at higher altitudes, weather can change from hour to hour, so keep abreast of expectations for temperature levels and any precipitation.
• Know if you’ll have access to emergency cell coverage if anything goes wrong.
• Always share plans with someone not on your hike, including expected route and time you’ll return. Fill out trailhead registers so park rangers will also know you’re on the trail in case of emergency.

What to wear for winter hikes

Prepare for extremes of cold, wind, snow, and even rain to avoid frostbite or hypothermia, when body temperature drops dangerously low.

• Dress in layers. Several thin layers of clothing are better than one thick one. Peel off a layer when you’re feeling warm in high sun and add it back when in shadow. Ideally, wear a base layer made from wicking fabric that can draw sweat away from the skin, followed by layers that insulate and protect from wind and moisture. “As they say, there’s no bad weather, just inappropriate clothing,” Dr. Harris says. “Take a day pack or rucksack and throw a couple of extra thermal layers in. I never head out for any hike without some ability to change as the weather changes.”
• Protect head, hands, and feet. Wear a wool hat, a thick pair of gloves or mittens, and two pairs of socks. Bring dry spares. Your boots should be waterproof and have a rugged, grippy sole.
• Wear sunscreen. You can still get a sunburn in winter, especially in places where the sun’s glare reflects off the snow.

Carry essentials to help ensure safety

• Extra food and water. Hiking in the cold takes serious energy, burning many more calories than the same activity done in summer temperatures. Pack nutrient-dense snacks such as trail mix and granola bars, which often combine nuts, dried fruit, and oats to provide needed protein, fat, and calories. It’s also key to stay hydrated to keep your core temperature normal. Bonus points for bringing a warm drink in a thermos to warm your core if you’re chilled.
• First aid kit. Bandages for slips or scrapes on the trail and heat-reflecting blankets to cover someone showing signs of hypothermia are wise. Even in above-freezing temperatures, hypothermia is possible. Watch for signs such as shivering, confusion, exhaustion, or slurring words, and seek immediate help.
• Light source. Time your hike so you’re not on the trail in darkness. But bring a light source in case you get stuck. “A flashlight or headlamp is pretty darn useful if you’re hiking anywhere near the edges of daylight,” Harris says.
• Phone, map, compass, or GPS device plus extra batteries. Don’t rely on your phone for GPS tracking, but fully charge it in case you need to reach someone quickly. “Make sure that you have the technology and skill set to be able to navigate on- or off-trail,” Harris says, “and that you have a means of outside communication, especially if you’re in a large, mixed group.”

About the Author

Maureen Salamon, Executive Editor, Harvard Women's Health Watch

Maureen Salamon is executive editor of Harvard Women’s Health Watch. She began her career as a newspaper reporter and later covered health and medicine for a wide variety of websites, magazines, and hospitals. Her work has … See Full Bio View all posts by Maureen Salamon

News flash: What we eat can play a pivotal role in warding off — or treating — disease and enhancing quality of life. You may already believe this, and certainly mounting evidence supports that idea. But on the cluttered shelf of diets claiming top health benefits, which one ranks as the absolute best?

That’s a trick question. In fact, there is no single best diet. A good diet for me may be different from what’s best for you. And for either of us, there may be several good choices with no clear winner.

How can you choose the right diet for you?

When thinking about what diet might be best for you, ask yourself:

• What goals are most important? A goal might be weight loss, improved health, avoiding disease, or something else.
• How do you define “best”? For some people, best means the diet with the highest number of health benefits. For others, it may focus on one specific health benefit, such as lowering cholesterol. Still other people may prefer a diet that delivers the greatest benefit for the lowest cost. Or a diet that is healthy and also easy to stick with.
• What health problems do you have? One diet may have an advantage over another depending on whether you have cancer, cardiovascular disease, diabetes, or none of these.
• Which foods do you like best? Your tastes, culture, and location may shape your dietary preferences, and powerfully affect how likely you are to stick with a specific diet.

Which diets are high in health benefits?

Two very well studied diets demonstrate clear benefit, including lowering risk for heart disease and stroke and reducing high blood pressure: the Mediterranean diet and the DASH diet.

But the portfolio diet may be as good as or better than these plans, at least for combatting cardiovascular disease that contributes to clogged blood vessels, heart attacks, and stroke. What? You’ve never heard of the portfolio diet? You’re not alone.

What is the portfolio diet?

Just as a financial advisor may recommend having a diverse investment portfolio — not just stocks, not just bonds — the portfolio diet follows suit. This largely plant-based diet focuses on diverse foods and food groups proven to lower harmful blood lipids, including LDL (so-called bad cholesterol) and triglycerides.

If you choose to follow this eating pattern, you simply need to learn which foods have a healthy effect on blood lipids and choose them in place of other foods. For some people, this only requires small tweaks to embrace certain foods while downplaying other choices. Or it may call for a bigger upheaval of longtime eating patterns.

Which foods are encouraged in the portfolio diet?

Below are the basics. Eating more of these foods regularly may help lower levels of harmful blood lipids:

• plant-based proteins such as soy, beans, tofu, peas, nuts, and seeds
• high-fiber foods such as oats, barley, berries, apples, and citrus fruit; other examples include bran, berries, okra, and eggplant
• phytosterols, which are a natural compound in plant-based foods such as whole grains, fruits, vegetables, and nuts (other sources are foods fortified with phytosterols or dietary supplements)
• plant-based oils high in monounsaturated fat such as olive oil, avocado oil, safflower oil, and peanut oil.

See? Some of your favorite foods make the cut. That’s a major strength of this approach: the list of recommended foods is long. So, it’s likely that you’re already eating and enjoying some of the recommended foods.

Which foods are not part of the portfolio diet?

It’s worth highlighting foods that are not on this list, such as

• red meat
• highly processed foods
• refined grains and added sugar, which may contribute to chronic inflammation
• butter, cream, and other dairy products high in saturated fat and cholesterol.

What can the portfolio diet do for you?

Researchers have shown that the portfolio diet can improve blood lipids. But can it also lower the risk of heart attack, stroke, and other cardiovascular problems?

Yes, according to a 2023 study published in Circulation. More than nearly 17,000 people kept careful food diaries for 30 years. Those who most closely followed the portfolio diet, compared with those who followed it the least, were more likely to have favorable lipids and inflammation. They were also 14% less likely to have a heart attack, and 14% less likely to have a stroke.

This was true even after accounting for factors that could affect cardiovascular disease risk, such as taking cholesterol-lowering medications, exercise, smoking, or having diabetes or a family history of cardiovascular disease.

Because this was an observational study, it can’t conclusively prove that the portfolio diet, rather than another factor, was responsible for the observed cardiovascular benefits. And we don’t know how much benefit came from reducing or eliminating certain types of foods, rather than from the specific foods eaten.

Does the portfolio diet help people lose weight or deliver other health advantages?

What about the portfolio diet for weight loss? Although some people lose weight on the portfolio diet, it’s not billed as a weight-loss diet. Understanding its potential benefit for other conditions such as obesity, cognitive decline, diabetes, and cancer awaits further research.

Go beyond diet to boost health

Of course, diet is not the only way to improve cardiovascular health and your overall health. You’ll stay healthier by

• not smoking
• getting regular exercise
• maintaining a healthy blood pressure and weight
• preventing diabetes when possible, or getting good medical care to treat it if necessary
• taking prescribed medications such as cholesterol-lowering drugs.

The bottom line

It’s probably best to move past the idea of there being a single best diet. The overall pattern of your diet and your portion sizes are probably more important. For most people, it’s also a good idea to move away from restrictive diets that are nearly impossible to stick with and toward healthier overall eating patterns. The portfolio diet checks both those boxes.

There’s a lot of overlap between the portfolio diet and other healthy diets. So, no one should be suggesting it’s the best diet ever. But if you’re trying to eat healthier, it’s a great place to start.

About the Author

Robert H. Shmerling, MD, Senior Faculty Editor, Harvard Health Publishing; Editorial Advisory Board Member, Harvard Health Publishing

Dr. Robert H. Shmerling is the former clinical chief of the division of rheumatology at Beth Israel Deaconess Medical Center (BIDMC), and is a current member of the corresponding faculty in medicine at Harvard Medical School. … See Full Bio View all posts by Robert H. Shmerling, MD

Looking for gifts to give or donate this year? Climate-conscious gifts come in many guises. They may directly support our environment, for example, or aim to reduce fossil fuel use and electronic, textile, and food waste. Or they might offer enjoyable, creative ways to connect, reuse, and recycle — and possibly even regift.

“Our purchases and choices impact our climate and planet,” notes Dr. Wynne Armand, a physician and associate director of the Massachusetts General Hospital Center for the Environment and Health. Small steps like these do help, she says, even when the complex issues of climate change leading to health-compromising pollution, extreme weather, and a stressed planet feel so large and overwhelming.

“Unquestionably, we need bold, strong leaders to seek policy changes that address these problems at a systems level. But, as individuals we can make a difference through small steps,” says Dr. Armand. “Our choices help drive cultural and market shifts that hopefully push our neighbors, businesses, and policy leaders in the right direction.”

Four climate-conscious principles for gifting

• Channel the 5 Rs. Refuse, reduce, reuse, repurpose, and only then recycle. Say no to excess. Comic sections from print newspapers or beautiful images from last year’s calendars or magazines make great envelopes and gift wrap. If you’re choosing clothes, consider buying upcycled clothing or at resale shops, as appropriate.
• Beware of greenwashing. Eco-consciousness is big business, and the benefits of what you buy may be questionable. If you have a small lawn that needs infrequent maintenance, says Dr. Armand, keeping a trusty (albeit gas-fueled) mower could be a better choice for the planet than buying an electric mower, when factoring in upstream costs of natural resources and the carbon footprint required to manufacture and ship the new — and toss out the not-so-old. (Alternatively, maybe it’s time to replant that lawn with wildflowers and vegetables?)
• Skip what’s not needed. A new backpack crafted from water bottles? Another sweater to add to a closetful? If there’s no apparent need, think twice about purchases.
• Double down on experiences and connection. Think concert tickets, museum passes, or energetic options like rock-climbing gym passes and outdoor skills classes. “Gifts of experience are great, especially for people who already have all they need. If you buy for two or try a skills swap you also get to enjoy that time together,” says Dr. Armand.

25 climate-conscious gifts

Below are 25 suggestions for climate-conscious giving intended to work with many budgets.

Small but mighty climate-conscious gifts

1. Soft, warm sweaters, thick socks, or puffer vests can help people turn down the heat, saving energy resources and money.

2. Rechargeable batteries reduce materials and packaging waste.

3. An electric kettle, induction hot plate, or toaster oven can help limit indoor pollutants from gas stoves.

4. Perfectly Good Food: A Totally Achievable Zero Waste Approach to Home Cooking aims to pare back food waste and is available online.

5. Shop local artisans and craft fairs rather than buying online.

6. Plants brighten any room and help scrub the air: choose easy-care varieties, such as succulents, colorful coleus, and some herbs.

7. Protect the natural world: birds, bees, and other insects could use your help. Consider a small bird feeder that attaches to a window, a bee house, gardening tools, or seeds for a pollinator garden of colorful flowers.

8. Donate to national or worldwide climate or environmental organizations, local green spaces, and local conservation groups.

9. Gift green bonds for companies that support renewable energy — do your research, though, because greenwashing can be an issue.

10. Secret gifter-giftee swaps with large groups save sanity and throttle back waste.

Bigger splurges on climate-conscious gifts

11. When appliances reach the end of useful life, consider replacing gas stoves, water heaters, washers, dryers, and similar items with electric versions.

12. Plan a week of nearby tours and events with friends or family instead of flights and faraway travel.

13. Gift clothes and tools to enjoy the natural world: for example, warm, waterproof clothing and hiking boots, cross-country skis or skates, good binoculars for bird-watching.

14. Composters (or a weekly composting service subscription) recycle food scraps and organic waste into soil-enriching “black gold.”

15. Electric bikes may be a boon if they reduce reliance on vehicles using fossil fuels.

16. Help fund energy-efficient heat pumps or renewable solar energy.

17. Substantial donations and sustaining donor gifts to climate-conscious organizations can help in many ways.

No-cost climate-conscious gifts

18. Offer to gather information on big-ticket items in the big splurges section, including state and federal rebates and 0% loans for heat pumps, energy-efficient furnaces, solar panels, and energy-efficient appliances.

19. Teach a skill one-on-one, such as home repair, skating, chess, training for a mud run, knitting, cooking, orienteering, or gardening, or organize skills swaps with friends.

20. Gift the human power needed to replant portions of a lawn with vegetables or pollinator plants, or make a rain garden (note: automatic download) to help divert storm water.

21. Combine a no-cost reminder of the environmental benefits of no-mow May and leave the leaves campaigns with an offer to help peel back these layers come spring.

22. Friends often want to gift one another — costly generosity that can prompt last-minute candle-buying. As an alternative, gather a small group of friends for a clothing, accessories, and candle swap of new, never-took-the-price-tag-off, nearly new, and well-loved items.

23. Offer a DIY nature or bird walk for two. Try the free Pl@ntnet and Merlin apps if you can’t tell a pin oak from a petunia or a robin from a California condor.

24. If you buy for a ton of people, buy in bulk and figure out how to parcel it out in more sustainable packaging.

25. Make dinner, fudge, or another treat with friends — not completely free, but always a great way to gather your community.

About the Author

Francesca Coltrera, Editor, Harvard Health Blog

Francesca Coltrera is editor of the Harvard Health Blog, and associate editor of multimedia content for Harvard Health Publishing. She is an award-winning medical writer and co-author of Living Through Breast Cancer and The Breast Cancer … See Full Bio View all posts by Francesca Coltrera

About the Reviewer

Howard E. LeWine, MD, Chief Medical Editor, Harvard Health Publishing; Editorial Advisory Board Member, Harvard Health Publishing

Dr. Howard LeWine is a practicing internist at Brigham and Women’s Hospital in Boston, Chief Medical Editor at Harvard Health Publishing, and editor in chief of Harvard Men’s Health Watch. See Full Bio View all posts by Howard E. LeWine, MD

I must have seen commercials for Prevagen 50 times: story after story from everyday people who describe improvement in memory once they began taking Prevagen. And perhaps you recall older commercials playing off the idea that many people take supplements that boast of gut, joint, and heart health claims. Those commercials memorably asked, “So why wouldn’t you take something for the most important part of you… your brain? With an ingredient originally found in jellyfish! Healthier brain, better life!”

Never mind that the ingredient from jellyfish (apoaequorin) that was supposed to deliver these benefits has no known role in human memory. Or that many experts believe supplements like this are most likely digested in the stomach and never wind up anywhere near the brain.

Can a supplement actually improve memory? If it doesn’t work, why is the manufacturer allowed to suggest it does? And if apoaequorin is so great, why aren’t jellyfish smarter (as a colleague of mine wonders)?

Mind the gap between graphics and reality

A bar graph in the older ads showed a rise from 5% to 10% to 20% over 90 days in “recall tasks,” though exactly what that meant was never explained. Nor were we told how many people were studied or given any information about effects on memory after 90 days.

One small, company-sponsored study reported improvements in memory after people took apoaequorin. However, the published version demonstrated improvements only in a subset of study participants. And the real-world impact of these changes is uncertain. The study authors recommended additional research to clarify its effectiveness. But I’ve been unable to find any additional, high-quality, independent studies showing the impact of Prevagen or apoaequorin on human memory.

The Prevagen case resolved

The US Federal Trade Commission (FTC) and the New York state attorney general were also unconvinced about the supplement’s benefits. Back in 2017, they charged the supplement maker with false advertising. Fast forward to February 2024, when a New York jury found that many of the supplement’s claims were not supported by reliable evidence, and some (but not all) of the claims were “materially misleading.”

In December 2024, the FTC and New York attorney general won their lawsuit. Now the makers of Prevagen are prohibited from claiming that the supplement can improve brain function or memory.

Supplement claims sound good — so why the disclaimers?

There are many thousands of supplements marketed for hundreds of conditions. But it’s often hard to say if they’re doing much of anything.

For example:

• Glucosamine is often promoted as good for joint health. I have known patients who swore by it. But the best studies suggest this supplement has modest effects, if any.
• When vitamins tout heart-healthy claims, I think of the example of vitamin E, once considered potentially useful to prevent or treat heart disease. Yet, study after study showed no benefit. In fact, it may increase the risk of heart failure.
• As for probiotic supplements, no convincing evidence shows that their use improves digestive health or prevents digestive disease in healthy people.

So when you’re considering supplements, be skeptical of the benefits touted and remember the standard disclaimer stamped on each one: “These statements have not been evaluated by the FDA.”

What are the rules?

Supplement makers are bound by a few basic rules set by the FTC and FDA:

• They can make truthful claims about connections between their supplement and the body’s “structure and function.” For example, a vitamin maker touting calcium in a product can say that calcium is important for bone health — although it’s also true that calcium supplements may offer little or nothing for most people with healthy bones, diets rich in calcium, and no medical condition requiring extra calcium.
• They cannot claim their product treats or prevents a particular disease. That disclaimer, which may seem to contradict marketing promises, must appear on every package. So, commercials suggesting that a supplement can reverse or slow Alzheimer’s disease, or any dementia, may run afoul of the rules on marketing supplements.

The FDA and FTC continue to provide key oversight to the dietary supplement industry. That’s a daunting task given the sheer volume of products on the market.

The bottom line

This country has an enormous appetite for dietary supplements. The supplement industry is now worth an estimated $70 billion or more, with as many as 100,000 products available for purchase.

But there’s a reason dietary supplements carry a disclaimer: “This product is not intended to diagnose, treat, cure, or prevent any disease.” This should remind us all to be wary of claims we see in ads for dietary supplements. Unlike prescription drugs, supplements are not thoroughly tested or evaluated. While dietary supplements might provide benefits in certain cases, it’s vitally important that their makers not make unfounded claims to exploit consumers.

I support the efforts of the FDA and FTC to regulate dietary supplements and their ads. But regardless of how effective their regulations are, it’s best to be skeptical about ads for products that seem too good to be true. There’s a good chance they are.

About the Author

Robert H. Shmerling, MD, Senior Faculty Editor, Harvard Health Publishing; Editorial Advisory Board Member, Harvard Health Publishing

Dr. Robert H. Shmerling is the former clinical chief of the division of rheumatology at Beth Israel Deaconess Medical Center (BIDMC), and is a current member of the corresponding faculty in medicine at Harvard Medical School. … See Full Bio View all posts by Robert H. Shmerling, MD

Metastatic prostate cancer can progress in different ways. In some men the disease advances rapidly, while other men have slower-growing cancer and a better prognosis. Researchers are developing various tools for predicting how fast prostate cancer might progress. Among the most promising are assays that count circulating tumor cells (CTCs) in blood samples.

Prostate cancer spreads by shedding CTCs into the bloodstream, so higher counts in blood generally reflect worse disease. Sometimes referred to as a liquid biopsy, the CTC assay can help doctors decide if patients should get standard or more aggressive treatment. Just one CTC assay is currently on the market for prostate cancer. Called CellSearch, its use is so far limited to men with late-stage metastatic cancer for whom hormonal therapies are no longer effective.

Using CTC data

Hormonal therapies block testosterone, a hormone that drives prostate tumors to grow. Research shows that high CTC counts predict poorer survival and faster disease progression among patients with metastatic prostate cancer who become resistant to this form of treatment. But new research shows CTC counts are also predictive for early-stage metastatic prostate cancer that still responds to hormonal therapy.

Why is that important? Because the earlier doctors can predict a cancer’s trajectory, the better their ability to select patients who could benefit from more powerful (and potentially more aggressive) drug combinations or a clinical trial. Conversely, men who are older or frail might be treated less aggressively if doctors had better insights into their prognosis.

How the study was done

The investigators collected blood samples from 503 newly-diagnosed patients with hormonally-sensitive metastatic prostate cancer who had enrolled in a clinical trial with experimental hormonal therapies. The team collected baseline samples at trial registration, and then another set of samples after the treatments were no longer working. CTC counts were divided in three categories:

• more than 5 CTCs per 7.5 milliliters (mLs) of blood
• between 1 and 4 CTCs per 7.5 mLs of blood
• zero CTCs per 7.5 mLs of blood.

What the research showed

Results showed that men with higher baseline CTC counts fared worse regardless of which cancer drugs they were taking. Median survival for men with 5 or more CTCs per sample was 27.9 months compared to 56.2 months in men with 1 to 4 CTCs. There weren’t enough patient deaths among those with 0 CTCs to calculate a survival rate.

Similarly, higher CTC counts predicted faster onset of resistance to hormonal therapy: 11.3 months for men in the highest CTC category, compared to 20.7 months and 59 months for men with 1 to 4 and zero CTCs respectively. Importantly, higher CTC counts correlated with measures of prostate cancer severity, including PSA levels, numbers of metastases in bone, and other indicators.

Observations and comments

“This research emphasizes the continued emergence of CTCs in helping to determine outcomes and potentially treatment options for men with metastatic prostate cancer,” said Dr. Marc Garnick, the Gorman Brothers Professor of Medicine at Harvard Medical School and Beth Israel Deaconess Medical Center, and editor in chief of the Harvard Medical School Guide to Prostate Diseases.

“Still to be determined is how this type of testing compares with more traditional evaluations of disease advancement, such as x-rays, bone scans, and other types of imaging. Ready access to cancer cells in blood that, in turn, eliminate the need for more invasive biopsy procedures of metastatic deposits will be a welcome addition — especially if future studies show that CTCs inform more precise treatment choices.”

Dr. David Einstein, a medical oncologist specializing in genitourinary cancers at Beth Israel Deaconess Medical Center and assistant professor at Harvard Medical School, agreed with that assessment. “But the Holy Grail is finding predictive biomarkers [like CTCs] that tell you if patients will or will not benefit from particular treatments,” he added. “Answering these types of questions requires randomized clinical trials.”

About the Author

Charlie Schmidt, Editor, Harvard Medical School Annual Report on Prostate Diseases

Charlie Schmidt is an award-winning freelance science writer based in Portland, Maine. In addition to writing for Harvard Health Publishing, Charlie has written for Science magazine, the Journal of the National Cancer Institute, Environmental Health Perspectives, … See Full Bio View all posts by Charlie Schmidt

About the Reviewer

Marc B. Garnick, MD, Editor in Chief, Harvard Medical School Annual Report on Prostate Diseases; Editorial Advisory Board Member, Harvard Health Publishing

Dr. Marc B. Garnick is an internationally renowned expert in medical oncology and urologic cancer. A clinical professor of medicine at Harvard Medical School, he also maintains an active clinical practice at Beth Israel Deaconess Medical … See Full Bio View all posts by Marc B. Garnick, MD

As wildfires become more frequent due to climate change and drier conditions, more of us and more of our communities are at risk for harm. Here is information to help you prepare and protect yourself and your family.

How does wildfire smoke affect air quality?

Wildfire smoke contributes greatly to poor air quality. Just like fossil fuel pollution from burning coal, oil, and gas, wildfires create hazardous gases and tiny particles of varying sizes (known as particulate matter, or PM10, PM2.5, PM0.1) that are harmful to breathe. Wildfire smoke also contains other toxins that come from burning buildings and chemical storage.

The smoke can travel to distant regions, carried by weather patterns and jet streams.

How does wildfire smoke affect our health?

The small particles in wildfire smoke are the most worrisome to our health. When we breathe them in, these particles can travel deep into the lungs and sometimes into the bloodstream.

The health effects of wildfire smoke include eye irritation, coughing, wheezing, and difficulty breathing. The smoke may also increase risk for respiratory infections like COVID-19. Other possible serious health effects include heart failure, heart attacks, and strokes.

Who needs to be especially careful?

Those most at risk from wildfire smoke include children, older adults, outdoor workers, and anyone who is pregnant or who has heart or lung conditions.

If you have a chronic health condition, talk to your doctor about how the smoke might affect you. Find out what symptoms should prompt medical attention or adjustment of your medications. This is especially important if you have lung problems or heart problems.

What can you do to prepare for wildfire emergencies?

If you live in an area threatened by wildfires, or where heat and dry conditions make them more likely to occur:

• Create an evacuation plan for your family before a wildfire occurs.
• Make sure that you have several days on hand of medications, water, and food that doesn't need to be cooked. This will help if you need to leave suddenly due to a wildfire or another natural disaster.
• Regularly check this fire and smoke map, which shows current wildfire conditions and has links to state advisories.
• Follow alerts from local officials if you are in the region of an active fire.

What steps can you take to lower health risks during poor air quality days?

These six tips can help you stay healthy during wildfire smoke advisories and at other times when air quality is poor:

• Stay aware of air quality. AirNow.gov shares real-time air quality risk category for your area accompanied by activity guidance. When recommended, stay indoors, close doors, windows, and any outdoor air intake vents.
• Consider buying an air purifier. This is also important even when there are no regional wildfires if you live in a building that is in poor condition. See my prior post for tips about pollution and air purifiers. The EPA recommends avoiding air cleaners that generate ozone, which is also a pollutant.
• Understand your HVAC system if you have one. The quality and cleanliness of your filters counts, so choose high-efficiency filters if possible, and replace these as needed. It's also important to know if your system has outdoor air intake vents.
• Avoid creating indoor pollution. That means no smoking, no vacuuming, and no burning of products like candles or incense. Avoid frying foods or using gas stoves, especially if your stove is not well ventilated.
• Make a "clean room." Choose a room with fewer doors and windows. Run an air purifier that is the appropriate size for this room, especially if you are not using central AC to keep cool.
• Minimize outdoor time and wear a mask outside. Again, ensuring that you have several days of medications and food that doesn't need to be cooked will help. If you must go outdoors, minimize time and level of activity. A well-fitted N95 or KN95 mask or P100 respirator can help keep you from breathing in small particles floating in smoky air (note: automatic PDF download).

About the Author

Wynne Armand, MD, Contributor

Dr. Wynne Armand is a physician at Massachusetts General Hospital (MGH), where she provides primary care; an assistant professor in medicine at Harvard Medical School; and associate director of the MGH Center for the Environment and … See Full Bio View all posts by Wynne Armand, MD

The holiday season is one of the hardest times of the year to resist salty, fatty, sugary foods. Who doesn’t want to enjoy the special dishes and treats that evoke memories and meaning — especially during the pandemic? Physical distancing and canceled gatherings may make you feel that indulging is a way to pull some joy out of the season.

But stay strong. While it’s okay to have an occasional bite or two of marbled roast beef, buttery mashed potatoes, or chocolate pie, gorging on them frequently can lead to weight gain, and increased blood pressure, blood sugar, and “bad” LDL cholesterol.

Instead, skip the butter, cream, sugar, and salt, and flavor your foods with herbs and spices.

The bounty of nature’s flavor-makers go beyond enticing tastes, scents, and colors. Many herbs and spices contain antioxidants, flavonoids, and other beneficial compounds that may help control blood sugar, mood, and inflammation.

Amp up holiday foods with herbs and spices

Try flavoring your foods with some of the herbs and spices in the list below. Play food chemist and experiment with combinations you haven’t tried before. The more herbs and spices you use, the greater the flavor and health rewards. And that’s a gift you can enjoy all year through.

Allspice: Use in breads, desserts, and cereals; pairs well with savory dishes, such as soups, sauces, grains, and vegetables.

Basil: Slice into salads, appetizers, and side dishes; enjoy in pesto over pasta and in sandwiches.

Cardamom: Good in breads and baked goods, and in Indian dishes, such as curry.

Cilantro: Use to season Mexican, Southwestern, Thai, and Indian foods.

Cinnamon: Stir into fruit compotes, baked desserts, and breads, as well as Middle Eastern savory dishes.

Clove: Good in baked goods and breads, but also pairs with vegetable and bean dishes.

Cumin: Accents Mexican, Indian, and Middle Eastern dishes, as well as stews and chili.

Dill weed: Include in potato dishes, salads, eggs, appetizers, and dips.

Garlic: Add to soups, pastas, marinades, dressings, grains, and vegetables.

Ginger: Great in Asian and Indian sauces, stews, and stir-fries, as well as beverages and baked goods.

Marjoram: Add to stews, soups, potatoes, beans, grains, salads, and sauces.

Mint: Flavors savory dishes, beverages, salads, marinades, and fruits.

Nutmeg: Stir into fruits, baked goods, and vegetable dishes.

Oregano: Delicious in Italian and Mediterranean dishes; it suits tomato, pasta, grain dishes, and salads.

Parsley: Enjoy in soups, pasta dishes, salads, and sauces.

Pepper (black, white, red): Seasons soups, stews, vegetable dishes, grains, pastas, beans, sauces, and salads.

Rosemary: Try it in vegetables, salads, vinaigrettes, and pasta dishes.

Sage: Enhances grains, breads, dressings, soups, and pastas.

Tarragon: Add to sauces, marinades, salads, and bean dishes.

Thyme: Excellent in soups, tomato dishes, salads, and vegetables.

Turmeric: Essential in Indian foods; pairs well with soups, beans, and vegetables.

About the Author

Heidi Godman, Executive Editor, Harvard Health Letter

Heidi Godman is the executive editor of the Harvard Health Letter. Before coming to the Health Letter, she was an award-winning television news anchor and medical reporter for 25 years. Heidi was named a journalism fellow … See Full Bio View all posts by Heidi Godman

About the Reviewer

Howard E. LeWine, MD, Chief Medical Editor, Harvard Health Publishing; Editorial Advisory Board Member, Harvard Health Publishing

Dr. Howard LeWine is a practicing internist at Brigham and Women’s Hospital in Boston, Chief Medical Editor at Harvard Health Publishing, and editor in chief of Harvard Men’s Health Watch. See Full Bio View all posts by Howard E. LeWine, MD

Medications can provide a host of health benefits. They may prevent or eliminate a disease. They might improve your quality of life and even help you live longer. But the medicines we take also have potential side effects. While listed side effects don’t always occur, it’s always possible.

And though that’s unfortunate, it also makes sense: while fighting the good fight against infection, cancer, or other health issues, medicines can also affect normal, healthy parts of the body. That can lead to bothersome symptoms and, sometimes, deadly consequences.

What are the most common and annoying side effects?

If you think you’re experiencing a medication side effect, you can check the National Library of Medicine database for the medicines you take to learn about their side effects.

Among the most common side effects caused by medicines are:

• nausea, constipation, diarrhea
• dry mouth
• drowsiness
• rash
• headache.

While the nature and severity of drug side effects vary widely, some are more bothersome than others. For example, sexual side effects can be especially distressing (and are likely underreported). And forgetfulness or trouble concentrating (often called “brain fog”) can have a serious impact on daily functioning, employment, and quality of life.

Which medication side effects are dangerous?

Though most side effects from medicines are more bothersome than dangerous, there are exceptions. Here are four serious drug side effects that require immediate medical attention.

• Anaphylaxis. This is a sudden allergic reaction affecting many parts of the body, including rash; swelling of the lips, tongue, or throat; and trouble breathing.
• Stevens-Johnson Syndrome (SJS) and toxic epidermal necrolysis (TEN). These two related allergic conditions are marked by severe, widespread rash, skin peeling, and fever. The main difference between them is that skin damage is more severe in TEN. Complications can be life-threatening, such as kidney and lung injury, or skin detachment similar to experiencing a serious burn.
• Drug reaction with eosinophilia and systemic symptoms (DRESS). This rare reaction to medications causes abnormal blood counts, rash, enlarged lymph nodes, and liver injury. Other organs, including the kidneys, lungs, and heart, may be harmed.

What about drug interactions?

Some medicines may cause no side effects until you start taking a second one. That’s because drugs can interact — that is, one drug alters the effects of another drug.

For example, if you take a blood thinner, also taking an anti-inflammatory medicine like ibuprofen or naproxen can suddenly increase your risk of bleeding.

There are thousands of known drug interactions. Medication prescribers, pharmacists, and computerized prescription ordering systems routinely check for them in advance so they can be avoided.

Are medication side effects ever a good thing?

Yes, indeed. In fact, some drugs developed to treat one condition have been approved for something entirely different because of what might be called positive side effects.

That’s how a blood pressure medicine (minoxidil) became a blockbuster treatment for hair loss (Rogaine and other brands). Another medicine (sildenafil), also developed for high blood pressure, was found to trigger erections in men. This lead to its approval as Viagra. There are many other examples of the good side of side effects.

When should you contact your health care provider?

If you suspect you’re experiencing a medication side effect, let your health care provider know. They can help you make the choice that’s best for you.

For serious or dangerous side effects like the examples noted above, it’s important to stop the drug and seek treatment right away. Let the FDA know as well. The FDA welcomes voluntary reporting of serious side effects so they can learn more about a drug’s impact on users, and take steps to improve its safety if necessary. Improvements might include new medication labeling, or even a recall.

For less serious side effects your first inclination might also be to stop the drug. But that’s not always the best choice. While stopping the drug may eliminate the side effect, you’ll also lose the drug’s benefit.

Here are some options your health care provider may suggest:

• Wait. If the side effect is minor, you could decide to put up with it to see if it goes away on its own as your body adjusts to the medication. If time doesn’t help, you may need to decide with your doctor whether the benefits of the medicine outweigh the side effects.
• Reduce. Your health care provider may suggest reducing the dose or how often you take the drug, which may improve or eliminate the side effects.
• Stop. You and your health care provider could decide to stop the medicine and consider a different treatment option, or reconsider whether treatment is still necessary.
• Add. Sometimes it’s reasonable to take a second drug to treat the first drug’s side effects. This option is not ideal. Taking a second drug to treat side effects from the first drug adds yet another medicine to your list. And that second drug could cause its own side effects, or even prompt the need to repeat this sequence with more medications. But sometimes adding another medication is a good option. For example, it’s reasonable to take an over-the-counter medicine (such as acetaminophen or ibuprofen) to treat a mild drug side effect (such as headache). Or if a medicine that causes a significant side effect is actually working well for a serious health condition, then adding a second medicine might make sense.

The bottom line

Drug developers may someday discover the perfect medicine, one that provides major health benefits without any risk of side effects. Until that happens, though, there are many ways to handle drug side effects. The challenge is figuring out which one is best for you.

About the Author

Robert H. Shmerling, MD, Senior Faculty Editor, Harvard Health Publishing; Editorial Advisory Board Member, Harvard Health Publishing

Dr. Robert H. Shmerling is the former clinical chief of the division of rheumatology at Beth Israel Deaconess Medical Center (BIDMC), and is a current member of the corresponding faculty in medicine at Harvard Medical School. … See Full Bio View all posts by Robert H. Shmerling, MD

Roughly one in six men will be diagnosed with prostate cancer at some point in their lives, but these cancers usually aren’t life-threatening. Most newly diagnosed men have Grade Group 1 (GG1) prostate cancer, which can linger for years without causing significant harms.

Prostate cancer is categorized according to how far it has spread and how aggressive it looks under the microscope. Pure GG1 prostate cancer is the least risky form of the disease. It occurs frequently with age, will not metastasize to other parts of the body, and it doesn’t require any immediate treatment.

So, should we even call it cancer? Many experts say no.

Dr. Matthew Cooperberg, who chairs the department of urology at the University of California, San Francisco, says men wouldn’t suffer as much anxiety — and would be less inclined to pursue unneeded therapies — if their doctors stopped referring to low-grade changes in the prostate as cancer. He recently co-chaired a symposium where experts from around the world gathered to discuss the pros and cons of giving GG1 cancer another name.

Treatment discrepancies

GG1 cancer is typically revealed by PSA screening. The goal with screening is to find more aggressive prostate cancer while it’s still curable, yet these efforts often detect GG1 cancer incidentally. Attendees at the symposium agreed that GG1 disease should be managed with active surveillance. With this standard practice, doctors monitor the disease with periodic PSA checks, biopsies, and imaging, and treat the disease only if it shows signs of progression.

But even as medical groups work to promote active surveillance, 40% of men with low-risk prostate cancer in the United States are treated immediately. According to Dr. Cooperberg, that’s in part because the word “cancer” has such a strong emotional impact. “It resonates with people as something that spreads and kills,” he says. “No matter how much we try to get the message out there that GG1 cancer is not an immediate concern, there’s a lot of anxiety associated with a ‘C-word’ diagnosis.”

A consequence is widespread overtreatment, with tens of thousands of men needlessly suffering side effects from surgery or radiation every year. A cancer diagnosis has other harmful consequences: studies reveal negative effects on relationships and employment as well as “someone’s ability to get life insurance,” Dr. Cooperberg says. “It can affect health insurance rates.”

Debate about renaming

Experts at the symposium proposed that GG1 cancer could be referred to instead as acinar neoplasm, which is an abnormal but nonlethal growth in tissue. Skeptics expressed a concern that patients might not stick with active surveillance if they aren’t told they have cancer. But should men be scared into complying with appropriate monitoring? Dr. Cooperberg argues that patients with pure GG1 “should not be burdened with a cancer diagnosis that has zero capacity to harm them.”

Dr. Cooperberg does caution that since biopsies can potentially miss higher-grade cancer elsewhere in the prostate, monitoring the condition with active surveillance is crucial. Moreover, men with a strong family history of cancer, or genetic mutations such as BRCA1 and BRCA2 that put them at a higher risk of aggressive disease, should be followed more closely, he says.

Dr. Marc Garnick, the Gorman Brothers Professor of Medicine at Harvard Medical School and Beth Israel Deaconess Medical Center, and editor in chief of the Harvard Medical School Guide to Prostate Diseases, agrees. Dr. Garnick emphasized that a name change for GG1 cancer needs to consider a wide spectrum of additional testing. “This decision can’t simply be based on pathology,” he says. “Biopsies only sample a miniscule portion of the prostate gland. Genetic and genomic tests can help us identify some low-risk cancers that might behave in a more aggressive fashion down the road.”

Meanwhile, support for a name change is gaining momentum. “Younger pathologists and urologists are especially likely to think this is a good idea,” Dr. Cooperberg says. “I think the name change is just a matter of time — in my view, we’ll get there eventually.”

About the Author

Charlie Schmidt, Editor, Harvard Medical School Annual Report on Prostate Diseases

Charlie Schmidt is an award-winning freelance science writer based in Portland, Maine. In addition to writing for Harvard Health Publishing, Charlie has written for Science magazine, the Journal of the National Cancer Institute, Environmental Health Perspectives, … See Full Bio View all posts by Charlie Schmidt

About the Reviewer

Marc B. Garnick, MD, Editor in Chief, Harvard Medical School Annual Report on Prostate Diseases; Editorial Advisory Board Member, Harvard Health Publishing

Dr. Marc B. Garnick is an internationally renowned expert in medical oncology and urologic cancer. A clinical professor of medicine at Harvard Medical School, he also maintains an active clinical practice at Beth Israel Deaconess Medical … See Full Bio View all posts by Marc B. Garnick, MD