Month: January 2023

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

Howard LeWine, M.D., 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

Hot flashes and sleep or mood changes are well-known, troublesome symptoms that may occur during perimenopause and menopause. Now, one survey suggests nearly 80% of midlife women use cannabis to ease certain symptoms, such as mood issues and trouble sleeping.

Mounting numbers of US states have legalized marijuana for medical or recreational use in recent years. This wave of acceptance runs alongside skepticism in some quarters concerning FDA-approved menopause treatment options, including hormone therapy. But a lack of long-term research data surrounding cannabis use has led one Harvard expert to question how safe it may be, even while acknowledging its likely effectiveness for certain menopause woes.

“More and more patients tell me every year that they’ve tried cannabis or CBD (cannabidiol, an active ingredient in cannabis), particularly for sleep or anxiety,” says Dr. Heather Hirsch, head of the Menopause and Midlife Clinic at Harvard-affiliated Brigham and Women’s Hospital. “Adding to its appeal is that cannabis is now legal in so many places and works acutely for a couple of hours. You don’t need a doctor’s prescription. Socially, it may be easier to justify than using a medication. But why is there a movement toward saying okay to something that has unknown long-term effects, more than something that’s been studied and proven safe?” she asks.

Survey reports on who uses cannabis, why, and how

The new Harvard-led survey, published in the journal Menopause, looked at patterns of cannabis use in 131 women in perimenopause — the often years-long stretch before periods cease — along with 127 women who had passed through menopause. Participants were recruited through online postings on social media sites and an online recruitment platform. Nearly all survey respondents were white and most were middle-class, according to income reporting.

The vast majority (86%) were current cannabis users. Participants were split on whether they used cannabis for medical reasons, recreational purposes, or both. Nearly 79% endorsed it to alleviate menopause-related symptoms. Of those, 67% said cannabis helps with sleep disturbance, while 46% reported it helps improve mood and anxiety.

Perimenopausal women reported worse menopausal symptoms than their postmenopausal peers, as well as greater cannabis use to address their symptoms. More than 84% of participants reported smoking cannabis, while 78% consumed marijuana edibles, and nearly 53% used vaping oils.

One glaring limitation of the analysis is its self-selected group of participants, which lacked diversity and might skew results. But Dr. Hirsch wasn’t surprised by the high proportion reporting regular cannabis use. “I wouldn’t be surprised if those numbers reflect the broader population,” she says.

How might cannabis help menopause symptoms?

It makes sense that midlife women reported cannabis improves anxiety, mood, and sleep, Dr. Hirsch says. The drug likely helps all of these symptoms by “dimming the prefrontal cortex, the decision-making part of our brain.”

For many women, anxiety spikes during perimenopause, she notes. Common stressors during that time, such as aging parents or an emptying nest, add to the effects of dipping hormones. “It’s that feeling of, ‘I can’t turn my brain off.’ It’s really disturbing because they get in bed and can’t fall asleep, so they’re more tired, moody, and cranky the next day,” she explains. Dimming the prefrontal cortex enables people to calm down.

Hot flashes, often cited as the most common menopause symptom, did not improve as much from cannabis use, according to survey respondents. That too makes sense, Dr. Hirsch says, because the hypothalamus — the brain region considered the body’s thermostat — isn’t believed to be significantly affected by the drug.

No research yet on long-term effects

Given a lack of clinical trials objectively testing the effectiveness and safety of cannabis to manage menopause symptoms, more research is clearly needed.

“If people are finding relief from cannabis, great. But is it safe? We think so, but we don’t know,” she says. “There are no studies of middle-aged women using cannabis for 10 years, for as long as menopause symptoms often last. Are there going to be long-term effects on memory? On lung function? We don’t know.”

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

Should a woman consider having her fallopian tubes removed to lower her risk for developing ovarian cancer? Recent recommendations from the Ovarian Cancer Research Alliance (OCRA), endorsed by the Society for Gynecologic Oncology, encourage this strategy, if women are finished having children and would be undergoing gynecologic surgery anyway for other reasons.

Why is this new guidance being offered?

Ovarian cancer claims about 13,000 lives each year, according to the American Cancer Society. The new guidance builds on established advice for women with high-risk genetic mutations or a strong family history of ovarian cancer.

This idea isn’t new for women at average risk for ovarian cancer, either: in 2019, the American College of Obstetricians and Gynecologists (ACOG) floated this strategy in a committee opinion.

A Harvard expert agrees the approach is sound, considering established evidence that many cases of aggressive ovarian cancers arise from cells in the fallopian tubes.

“We’ve known for a long time that many hereditary cases of ovarian cancer likely originate in lesions in the fallopian tubes,” says Dr. Katharine Esselen, a gynecologic oncologist at Beth Israel Deaconess Medical Center. “Although we group all of these cancers together and call them ovarian cancer, a lot actually start in the fallopian tubes.”

Can ovarian cancer be detected early through symptoms or screening?

No — which helps fuel these recommendations.

Ovarian cancer is notoriously difficult to detect. Symptoms tend to be vague and could be related to many other health problems. Signs include bloating, pelvic pain or discomfort, changes in bowel or bladder habits, feeling full earlier when eating, fatigue, unusual discharge or bleeding, and pain during sex.

Disappointing results from a large 2021 study in the United Kingdom reported in The Lancet show that lowering the risks of a late-stage diagnosis isn’t easy. The trial tracked more than 200,000 women for an average of 16 years. It found that screening average-risk women with ultrasound and a CA-125 blood test doesn’t reduce deaths from the disease. By itself, the CA-125 blood test isn’t considered reliable for screening because it’s not accurate or sensitive enough to detect ovarian cancer.

Only 10% to 20% of patients are diagnosed at early stages of ovarian cancer, before a tumor spreads, Dr. Esselen notes. “There’s never been a combination of screenings that has reliably identified the majority of these cancers early, when they’re more treatable,” she says.

What does it mean to be at higher risk for ovarian cancer?

Family history is the top risk factor for the disease, which is diagnosed in nearly 20,000 American women annually. A woman is considered at higher risk of ovarian cancer if her mother, sister, grandmother, aunt, or daughter has had the disease.

Additionally, inherited mutations in the BRCA1 or BRCA2 gene raise risk considerably, according to the National Cancer Institute. (These mutations are more common among certain groups, including people of Ashkenazi Jewish heritage.) While about 1.2% of women overall will develop ovarian cancer in their lifetime, up to 17% of those with a BRCA2 mutation and up to 44% with a BRCA1 mutation will do so by ages 70 to 80.

How much can surgery lower the odds of ovarian cancer?

It’s not clear that all women — even those not scheduled for surgery — should undergo removal of their fallopian tubes to reduce this risk once they finish having children, Dr. Esselen says. This surgery can’t totally eliminate the possibility of ovarian cancer — and surgery carries its own risks. She recommends discussing options with your doctor depending on your level of risk for this disease:

For those at average risk for ovarian cancer: Available data seem to support the idea of removing the fallopian tubes. Studies of women who underwent tubal ligation (“tying the tubes”) or removal to avoid future pregnancies indicate their future risks of ovarian cancer dropped by 25% to 65% compared to their peers. And if a woman is already undergoing gynecologic surgery, such as a hysterectomy, the potential benefits likely outweigh the risks.

Before menopause, removing the fallopian tubes while leaving the ovaries in place is preferable to removing both. That’s because estrogen produced by the ovaries can help protect against health problems such as cardiovascular disease and osteoporosis. Leaving the ovaries also prevents suddenly experiencing symptoms of menopause.

“The fallopian tubes don’t produce any hormones and aren’t really needed for anything other than transporting the egg,” she says. “So there’s little downside to removing them at the time of another gynecologic procedure if a woman is no longer interested in fertility.”

For those at high risk for ovarian cancer: “In a world where we don’t have good screening tools for ovarian cancer, it makes sense to do something as dramatic as surgery to remove both ovaries and fallopian tubes when a woman is known to be at higher risk because of a strong family history or a BRCA gene mutations,” Dr. Esselen says.

Currently, preliminary evidence suggests it may be safe to proactively remove the fallopian tubes while delaying removal of the ovaries to closer to the time of menopause to avoid an early menopause. However, it’s unclear how much this procedure lowers the odds of developing ovarian cancer.

“Generally, the findings so far have focused on the safety of the surgery itself and women’s quality of life,” Dr. Esselen says. “Long-term data in high-risk women takes a great number of years to accumulate. We need this data to know whether removing the fallopian tubes alone is equally effective in preventing ovarian cancer as removing the tubes and ovaries.”

Discussing your options is key

Ultimately, Dr. Esselen says that she advocates OCRA’s new recommendations. “For anyone who’s completed childbearing, if I’m doing surgery that wouldn’t necessarily include routinely removing their fallopian tubes, I’m offering it,” she says. “A woman and her doctor should always discuss this at the time she’s having gynecologic surgery.”

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