suddensoverblowing

Many health-conscious consumers have already cut back on hamburgers, steaks, and deli meats, often by swapping in poultry or seafood. Those protein sources are better than beef, and not just because they’re linked to a lower risk of heart disease, diabetes, and cancer. Chicken and fish are also better for the environment, as their production uses less land and other resources and generates fewer greenhouse gas emissions.

And choosing seafood that’s lower on the food chain — namely, small fish such as herring and sardines and bivalves such as clams and oysters — can amp up those benefits. “It’s much better for your health and the environment when you replace terrestrial food sources — especially red meat — with aquatic food sources,” says Christopher Golden, assistant professor of nutrition and planetary health at the Harvard T.H. Chan School of Public Health. But instead of popular seafood choices such as farmed salmon or canned tuna, consider mackerel or sardines, he suggests.

Why eat small fish?

Anchovies, herring, mackerel, and sardines are all excellent sources of protein, micronutrients like iron, zinc, and vitamin B12, and heart-healthy omega-3 fatty acids, which may help ease inflammation within the body and promote a better balance of blood lipids. And because you often eat the entire fish (including the tiny bones), small fish are also rich in calcium and vitamin D, says Golden. (Mackerel is an exception: cooked mackerel bones are too sharp or tough to eat, although canned mackerel bones are fine to eat).

Small fish are also less likely to contain contaminants such as mercury and polychlorinated biphenyls (PCBs) compared with large species like tuna and swordfish. Those and other large fish feed on smaller fish, which concentrates the toxins.

It's also more environmentally friendly to eat small fish directly instead of using them to make fish meal, which is often fed to farmed salmon, pork, and poultry. Feed for those animals also includes grains that require land, water, pesticides, and energy to produce, just as grain fed to cattle does, Golden points out. The good news is that increasingly, salmon farming has begun using less fish meal, and some companies have created highly nutritious feeds that don’t require fish meal at all.

Small fish in the Mediterranean diet

The traditional Mediterranean diet, widely considered the best diet for heart health, highlights small fish such as fresh sardines and anchovies, says Golden. Canned versions of these species, which are widely available and less expensive than fresh, are a good option. However, most canned anchovies are salt-cured and therefore high in sodium, which can raise blood pressure.

Sardines packed in water or olive oil can be

• served on crackers or crusty, toasted bread with a squeeze of lemon
• prepared like tuna salad for a sandwich filling
• added to a Greek salad
• tossed with pasta, either added to tomato sauce or with lemon, capers, and red pepper flakes.

Golden is particularly fond of pickled herring, which you can often find in jars in supermarkets, or even make yourself; here’s his favorite recipe.

Bivalve benefits

Bivalves are two-shelled aquatic creatures that include clams, oysters, mussels, and scallops. Also known as mollusks, they’re good sources of protein but are quite low in fat, so they aren’t as rich in omega-3’s as small, fatty fish. However, bivalves contain several micronutrients, especially zinc and vitamin B12. Zinc contributes to a healthy immune system, and vitamin B12 helps form red blood cells that carry oxygen and keep nerves throughout the body healthy. While most Americans get enough B12, some may not.

And from a planetary health perspective, bivalves are among the best sources of animal-based protein. “Bivalves can be ‘nature positive’ because they don’t require feed and they filter and clean up water,” says Golden.

Be aware, however, that bivalves can become contaminated from runoff, bacteria, viruses, or chemicals in the water. So be sure to follow FDA advice about buying and preparing seafood safely.

Although we tend to think of coastal cities as the best places to find seafood, it’s available throughout the United States. For less-common varieties, try larger Asian markets, which often carry a wide variety of fish and bivalves, Golden suggests.

Aquatic plant foods

You can even go one step further down the aquatic food chain by eating aquatic plant foods such as seaweed and kelp. If you like sushi, you’ve probably had nori, the flat sheets of seaweed used to make sushi rolls. You can also find seaweed snacks in Asian and many mainstream grocery stores. The truly adventurous may want to try kelp jerky or a kelp burger, both sold online.

Nutrients in seaweed vary quite a bit, depending on species (kelp is one type of brown seaweed; there are also numerous green and red species). But seaweed is low in calories, is a good source of fiber, and also contains iodine, a mineral required to make thyroid hormones. Similar to terrestrial vegetables, seaweeds contain a range of other minerals and vitamins. For now, aquatic plant foods remain fringe products here in the United States, but they may become more mainstream in the future, according to Golden.

About the Author

Julie Corliss, Executive Editor, Harvard Heart Letter

Julie Corliss is the executive editor of the Harvard Heart Letter. Before working at Harvard, she was a medical writer and editor at HealthNews, a consumer newsletter affiliated with The New England Journal of Medicine. She … See Full Bio View all posts by Julie Corliss

About the Reviewer

Howard E. LeWine, MD, Chief Medical Editor, 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

What is a drought?

A drought is a prolonged dry period without rain. In the last few decades, droughts are occurring more frequently worldwide.

With climate change, rising temperatures are making many regions dry within the US and beyond. Here’s how to recognize potential harms if drought has a grip where you live, and actions you can take to stay healthy.

How do droughts affect our world?

The downstream effects of droughts on the planet and our health are complex. One example is water shortages, which can harm crops, livestock, and aquatic life. This compromises food supplies, drives up prices, and worsens food insecurity and malnutrition. Trees, which offer shade during hot weather and help counter climate change, may die during severe droughts. Droughts are making some parts of the world uninhabitable, leading to climate migration.

How can droughts harm health?

There are many ways, big and small, through which dryer conditions harm health.

Droughts play a role in diseases

During droughts, lower water flow leads to stagnation. This can

• increase the concentration of health-harming water pollutants in streams, rivers, and reservoirs
• contribute to harmful algal blooms that can cause skin or gastrointestinal problems
• offer breeding grounds for mosquitoes that carry diseases.

And as water levels drop, the water also becomes warmer. This can foster the growth of pathogens (like some viruses, protozoa, and bacteria). If your drinking water is from a private well, this may be a particular concern for you.

Also, farmers may be more likely to use recycled water for irrigation during droughts. This may lead to more infectious agents like E. coli or Salmonella harbored on crops.

Droughts contribute to poor air quality

The dry conditions during droughts lend themselves to wildfires. That’s an immediate threat to local communities, but also can send harmful wildfire smoke to more distant regions, depending on wind patterns.

Droughts can also lead to dust storms that carry and transport microorganisms, allergens like pollen, and other polluting particulate matter. This can increase the risk of infections, like Valley fever, and worsen respiratory illnesses, such as asthma, chronic obstructive pulmonary disease (COPD), and other lung conditions.

One more challenge is reduced availability of the renewable hydropower energy. Dry periods often coincide with high temperatures. The increased energy demand may require utilities to shift to using more-polluting fossil fuel sources, which further increases the greenhouse gas emissions that cause climate change.

We can all take steps to keep the air we breathe healthier — whether or not drought is contributing to worse air quality where we live.

What can we do to lessen the impact of droughts?

Around the planet, groundwater is stored in natural spaces called aquifers. As overused groundwater aquifers dry up due to drought combined with demands from people and agriculture, more countries face water scarcity. There is growing interest in solutions like treating wastewater for reuse and in desalination of ocean water, though these alternatives come with their own challenges.

To address the drought problem, the US has created the National Integrated Drought Information System (NIDIS) to coordinate research, drought monitoring, and a drought early warning system.

What actions can you take to stay healthy during a drought?

• Stay hydrated. But also stay informed on the quality of your drinking water, especially if you rely on well water. You can contact local water authorities for information on public water quality.
• Check for local advisories on harmful algal blooms before going in the water to swim or allowing pets to swim.
• Follow your local air quality on AirNow.gov, which offers daily information on local air quality. The site also tracks wildfires, and offers guidance on when to minimize your time outdoors and downloadable guides to protect yourself when air quality is unhealthy.
• Be careful about recreational water activities like boating and diving during droughts when the water level may be down.
• Follow Smokey Bear’s advice on how to prevent wildfires.
• If your community is experiencing a drought and water shortage, the Environmental Protection Agency (EPA) provides some tips on home water conservation. But even during water shortages, it is important to not skip hand hygiene and washing fruits and vegetables. And if you are using a rain barrel to conserve water, using a fine mesh screen can help keep away mosquitoes (which only need a teaspoon of water to lay their eggs).

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

Concussion is one of the most common injuries to the brain, affecting about two million children and teens every year. It is a particular kind of injury that happens when a blow to the head or somewhere else on the body makes the brain move back and forth within the skull.

It’s possible to get a concussion after what might seem like a minor injury, like a forceful push from behind, or a collision between two players in a football or soccer game.

What are the signs and symptoms of concussion?

Because the injury may not seem that significant from the outside, it’s important to know the symptoms of a concussion. There are many different possible symptoms, including

• passing out (this could be a sign of a more serious brain injury)
• headache
• dizziness
• changes in vision
• feeling bothered by light or noise
• confusion or feeling disoriented
• memory problems (such as difficulty remembering details of the injury) or difficulty concentrating
• balance or coordination problems
• mood changes.

Some of these are visible to others and some are felt by the person with the concussion. That’s why it’s important to know the signs and to ask all the right questions of a child who has had an injury.

Sometimes the symptoms might not be apparent right away, but show up in the days following the injury. The CDC’s Heads Up website has lots of great information about how to recognize a concussion.

How can further harm to the brain be avoided?

The main reason it’s important to recognize a possible concussion early is that the worst thing you can do after getting a concussion is get another one. The brain is vulnerable after a concussion; if it is injured again, the symptoms can be longer lasting — or even permanent, as in cases of chronic traumatic encephalopathy (CTE), a condition that has been seen in football players and others who have repeated head injuries.

If there is a chance that a child has had a concussion during a sports competition, they must stop playing — and get medical attention. It’s important to get medical attention any time there is concern about a possible concussion, both to be sure there isn’t a more serious brain injury, and to do a good assessment of the symptoms, so that they can be monitored over time. There are some screening questionnaires that are used by doctors that can be used again in the days and weeks after the concussion to see how the child is improving.

What helps children recover after a concussion?

Experts have struggled with figuring out how to protect the brain after a concussion. For a long time, the recommendation was to rest and do very little at all. This meant not doing any exercise, not going to school, not even reading or watching television. As symptoms improved, the restrictions were lifted gradually.

Over time, though, research showed that not only was this much rest not necessary, it was counterproductive. It turns out that getting kids back into their daily lives, and back into being active, is safe and leads to quicker recovery. Experts still recommend rest and then moving gradually back into activities, but the guidelines are no longer as strict as they once were.

One important note: A medical professional should guide decisions to move from rest to light activity, and then gradually from there to moderate and then regular activities based on how the child is doing. This step-by-step process may extend for days, weeks, or longer, depending on what the child needs. Parents, coaches, and schools can help support a child or teen as they return to school and return to activities and sports.

Some children will be able to get back into regular activities quickly. But for others it can take weeks or even months. Schools and sports trainers should work with children to support them in their recovery. Some children develop post-concussive syndromes with headache, fatigue, and other symptoms. This is rare but can be very disabling.

How can parents help prevent concussions?

It's not always possible to prevent concussions, but there are things that parents can do:

• Be sure that children use seat belts and other appropriate restraints in the car.
• Have clear safety rules and supervise children when they are playing, especially if they are riding bikes or climbing in trees or on play structures.
• Since at least half of concussions happen during sports, it’s important that teams and coaches follow safety rules. Coaches should teach techniques and skills to avoid dangerous collisions and other injuries. Talk to your child’s coaches about what they are doing to keep players safe. While helmets can prevent many head injuries, they don’t prevent concussions.

About the Author

Claire McCarthy, MD, Senior Faculty Editor, Harvard Health Publishing

Claire McCarthy, MD, is a primary care pediatrician at Boston Children’s Hospital, and an assistant professor of pediatrics at Harvard Medical School. In addition to being a senior faculty editor for Harvard Health Publishing, Dr. McCarthy … See Full Bio View all posts by Claire McCarthy, MD

If the eyes are the windows to the soul, then consider the tongue a sort of check-engine light for the body. The tongue’s appearance gives doctors an idea about certain aspects of your health, and its color is an important clue.

What should your tongue look like?

The tongue should have a rounded, symmetrical shape. It’s generally light pink, though it may have a little purple or brown pigmentation in African, Asian, and Mediterranean populations. It can also have a hint of white coating.

“The coating comes from a tough protein called keratin, which helps keep your tongue from being scratched when you eat,” says Dr. Tien Jiang, a prosthodontist in the Department of Oral Health Policy and Epidemiology at the Harvard School of Dental Medicine.

Up close, you might be able to see that your tongue is covered in tiny bumps (papillae) that serve several purposes:

• They sense temperature and touch.
• They contain taste buds that enable you to detect if food is sweet, salty, sour, bitter, or savory.
• They create friction to help you form a little ball of food (bolus) that you can swallow.

Can diet affect tongue color?

Yes. Sometimes diet may be partly to blame for a shift away from your usual tongue tone. That’s because the papillae can absorb the colors and residues of foods and drinks you consume. For example, that blue popsicle or candy you ate as a kid probably turned your tongue an exciting shade of azure. Coffee, tea, and many types of foods, such as curried dishes with lots of yellow turmeric, can also leave their marks.

Discoloration is usually just temporary, however. Drinking plenty of water and maintaining good oral hygiene will wash away food and dyes that cling to the tongue.

A dark or bright tongue, white patches, and other causes for concern

Some tongue colors and appearances are signs of health issues. Check with your doctor if you notice any of the following:

• A brown or black tongue signals a condition called “black hairy tongue.” This occurs when papillae get too long. These tiny bumps don’t usually get much chance to grow because they are shed regularly with all the activity in your mouth. If they do grow, they can trap bacteria and a mix of food colors, leading to the brown or black tinge. Risk factors include taking antibiotics or antihistamines, smoking, dry mouth, drinking excessive amounts of coffee or black tea, or poor oral hygiene.
• Thick white patches or white sores on the tongue probably mean you have an overgrowth of yeast in the mouth (thrush). Thrush can be triggered by conditions such as diabetes or HIV, side effects of antibiotics or cancer treatment, wearing dentures, smoking, dry mouth, or using steroid inhalers. In rare cases, white patches or sores are symptoms of oral cancer.
• If your tongue has painful red or yellow sores, you might be dealing with canker sores (irritated tissues), thrush (which can sometimes appear as red patches), or (in rare cases) oral cancer.
• A bright red tongue can indicate that you have a vitamin B12 deficiency or an infection called scarlet fever — a Streptococcus bacteria infection in the throat (strep throat) accompanied by a red body rash. If you have bright red patches that don’t hurt and seem to migrate from one place on the tongue to another, you might have a harmless, incurable condition called “geographic tongue.”

Should you brush your tongue or use a tongue scraper?

Good oral hygiene requires that you floss your teeth at least once a day and brush them at least twice a day. Take a few seconds to use the brush on your tongue.

“Stick out your tongue and swipe your toothbrush from the back of your tongue to the front: one swipe down the middle, one swipe down the left side, and one swipe down the right side. That helps remove bacteria and debris that collect in papillae,” Dr. Jiang says.

Some people swear by using a tongue scraper to clean the tongue. Dr. Jiang isn’t a fan, but doesn’t have a problem with someone using the tool, which is pulled forward on the tongue in a similar fashion to brushing the tongue. “The data about tongue scraper effectiveness are mixed,” she says. “It just comes down to what you’re willing to do daily to keep your tongue, teeth, mouth, and gums as healthy as possible.”

Worried about your tongue? What to do

If you’re worried about anything wrong with your tongue — especially if you also have a fever, a very sore throat, sores that won’t go away, or other new symptoms — call your primary care doctor or dentist.

Your doctor or dentist can

• assess your condition
• prescribe or suggest treatments to relieve discomfort, such as medicated mouthwashes or warm-water rinses
• urge you to stay hydrated and step up your oral hygiene.

If necessary, your doctor can refer you to a specialist for further evaluation.

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

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