Month: August 2022

We can feel groggy when our sleep schedule is thrown off even just a little. So what happens when shift work requires people to regularly stay awake through the night and sleep during the day — and how can they protect their health and well-being?

What is shift work disorder?

Mounting evidence, including several new studies, paints a worrisome picture of the potential health fallout of nontraditional shift work schedules that affect 15% to 30% of workers in the US and Europe, including factory and warehouse workers, police officers, nurses, and other first responders.

So-called shift work disorder mainly strikes people who work the overnight or early morning shift, or who rotate their shifts, says Eric Zhou, an assistant professor in the Division of Sleep Medicine at Harvard Medical School. It is characterized by significant problems falling and staying asleep, or sleeping when desired. That’s because shift work disrupts the body’s normal alignment with the 24-hour sleep-wake cycle called the circadian rhythm.

“People who work 9-to-5 shifts are typically awake when the sun is up, which is aligned with their body’s internal circadian clock. But for shift workers, their work hours and sleep hours are misaligned with the natural cues to be awake or asleep,” Zhou says. “They’re working against the universe’s natural inclinations — not just their body’s.”

What’s the connection between shift work and health?

A 2022 research review in the Journal of Clinical Sleep Medicine links shift work to higher risks for serious health problems, such as heart attack and diabetes. This research suggests adverse effects can include metabolic syndrome (a cluster of conditions that raises the risks for heart disease, diabetes, and stroke), accidents, and certain types of cancer.

“The research is consistent and powerful,” Zhou says. “Working and sleeping during hours misaligned with natural light for extended periods of time is not likely to be healthy for you.”

How do new studies on shift work boost our understanding?

New research continues to add to and strengthen earlier findings, teasing out specific health effects that could stem from shift work.

• Shift workers on rotating schedules eat more erratically and frequently than day workers, snack more at night, and consume fewer healthier foods with potentially more calories, a study published online in Advances in Nutrition suggests. This analysis reviewed 31 prior studies involving more than 18,000 participants, comparing workers’ average food intake over 24 hours.
• Disrupting the circadian rhythm through shift work appears to increase the odds of colorectal cancer, a malignancy with strong ties to lifestyle factors, according to a 2023 review of multiple studies published online in the Journal of Investigative Medicine. Contributors to this higher risk may include exposure to artificial light at night, along with complex genetic and hormonal interactions, study authors said.

“Cancer understandably scares people, and the World Health Organization recognizes that shift work is a probable carcinogen,” Zhou says. “The combination of chronically insufficient and poor-quality sleep is likely to get under the skin. That said, we don’t fully understand how this happens.”

How can you protect your sleep — and your health?

If you work overnight or early morning shifts, how can you ensure you sleep more soundly and restfully? Zhou offers these evidence-based tips.

Time your exposure to bright and dim light. Graveyard shift workers whose work schedule runs from midnight through 8 a.m., for example, should reduce their light exposure as much as possible after leaving work if they intend to go right to sleep once they return home. “These measures could take the form of wearing blue light–blocking glasses or using blackout shades in your bedroom,” he says.

Make enough time for sleep on days off. “This is often harder than it sounds, because you’ll want to see your family and friends during nonwork hours,” Zhou says. “You need to truly protect your opportunity for sleep.”

Maintain a consistent shift work schedule. “Also, try to minimize the consecutive number of days you spend working challenging shifts,” he says.

Talk to your employer. Perhaps your boss can schedule you for fewer overnight shifts. “You can also ask your doctor to make a case for you to be moved off these shifts or have more flexibility,” Zhou says.

Look for practical solutions that allow you to get more restful sleep. “People engaged in shift work usually have responsibilities to their job as well as their family members, who often operate under a more typical 9-to-5 schedule,” he notes. “The goal is to preserve as strong a circadian rhythm as possible under the abnormal schedule shift work requires.”

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

Lifestyle changes like regular exercise, a healthy diet, and sufficient sleep are cornerstones of self-care for people with type 2 diabetes.

But what about mind-body practices? Can they also help people manage or even treat type 2 diabetes? An analysis of multiple studies, published in the Journal of Integrative and Complementary Medicine, suggests they might.

Which mindfulness practices did the study look at?

Researchers analyzed 28 studies that explored the effect of mind-body practices on people with type 2 diabetes. Those participating in the studies did not need insulin to control their diabetes, or have certain health conditions such as heart or kidney disease. The mind-body activities used in the research were:

• yoga
• qigong, a slow-moving martial art similar to tai chi
• mindfulness-based stress reduction, a training program designed to help people manage stress and anxiety
• meditation
• guided imagery, visualizing positive images to relax the mind.

How often and over what time period people engaged in the activities varied, ranging from daily to several times a week, and from four weeks to six months.

What did the study find about people with diabetes who practiced mindfulness?

Those who participated in any of the mind-body activities for any length of time lowered their levels of hemoglobin A1C, a key marker for diabetes. On average, A1C levels dropped by 0.84%. This is similar to the effect of taking metformin (Glucophage), a first-line medication for treating type 2 diabetes, according to the researchers.

A1C levels are determined by a blood test that shows a person’s average blood sugar levels over the past two to three months. Levels below 5.7% are deemed normal, levels from 5.7% to less than 6.5% are considered prediabetes, and levels 6.5% and higher are in the diabetes range.

How can mind-body practices help control blood sugar?

Their ability to reduce stress may play a big part. “Yoga and other mindfulness practices elicit a relaxation response — the opposite of the stress response,” says Dr. Shalu Ramchandani, a health coach and internist at the Harvard-affiliated Benson-Henry Institute for Mind Body Medicine at Massachusetts General Hospital. “A relaxation response can lower levels of the stress hormone cortisol. This improves insulin resistance and keeps blood sugar levels in check, thus lowering A1C levels.”

A relaxation response can help people with diabetes in other ways, such as by improving blood flow and lowering blood pressure, which protects against heart attacks and strokes.

What else should you know about this study?

The results of studies like this suggest a link between various mind-body practices and lower A1C levels, but do not offer firm proof of it. Levels of participation varied widely. But because all mindfulness practices studied had a modest positive effect, the researchers suggested that these types of activities could become part of diabetes therapy along with standard lifestyle treatments.

Could mind-body practices protect people against developing type 2 diabetes, especially for those at high risk? While this study wasn’t designed to look at this, Dr. Ramchandani again points to the long-range benefits of the relaxation response.

“Reducing and managing stress leads to improved moods, and greater self-awareness and self-regulation,” she says. “This can lead to more mindful eating, such as fighting cravings for unhealthy foods, adhering to a good diet, and committing to regular exercise, all of which can help reduce one’s risk for type 2 diabetes.”

Trying mind-body practices

There are many ways to adopt mind-body practices that can create relaxation responses. Here are some suggestions from Dr. Ramchandani:

• Do a daily 10-minute or longer meditation using an app like Insight Timer, Calm, or Headspace.
• Attend a gentle yoga, qigong, or tai chi class at a local yoga studio or community center.
• Try videos and exercises to help reduce stress and initiate relaxation responses.
• Practice slow controlled breathing. Lie on your back with one or both of your hands on your abdomen. Inhale slowly and deeply, drawing air into the lowest part of your lungs so your hand rises. Your belly should expand and rise as you inhale, then contract and lower as you exhale. Repeat for several minutes.

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

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

Infertility is a remarkably common problem. It affects up to one in five people in the US who are trying to become pregnant, and 186 million people worldwide. A thorough medical evaluation can spot key contributing issues in many cases — whether in a woman, a man, or both partners — that might respond to treatment, or call for assisted reproductive tools like in vitro fertilization (IVF).

But in a substantial number of cases, no cause is found for infertility. Could inflammation be to blame for some of those cases, as recent research suggests? And if so, will an anti-inflammatory diet or lifestyle boost fertility?

Exploring the connection between inflammation and infertility

Chronic inflammation has been linked to many health conditions, such as cardiovascular disease, stroke, and cancer.

While its importance in infertility is far from clear, some evidence supports a connection:

• The risk of infertility is higher in conditions marked by inflammation, including infection, endometriosis, and polycystic ovary syndrome.
• Bodywide (systemic) inflammation may affect the uterus, cervix, and placenta, thus impairing fertility.
• Women with infertility who had IVF and followed an anti-inflammatory diet tended to have higher rates of successful pregnancy than women who did not follow the diet.

Could an anti-inflammatory diet improve fertility?

It’s a real possibility. Decades ago, researchers observed that women following a prescribed fertility diet ovulated more regularly and were more likely to get pregnant. Now a 2022 review of multiple studies in Nutrients suggests that following an anti-inflammatory diet holds promise for people experiencing infertility. The research was done years apart, but the diets in these two studies share many elements.

The 2022 review found that an anti-inflammatory diet may help

• improve pregnancy rates (though exactly how is uncertain)
• increase success rates of assisted reproductive measures, such as IVF
• improve sperm quality in men.

The authors add that improving diet might even reduce the need for invasive, prolonged, and costly fertility treatments. However, the quality of studies and consistency of findings varied, so more high-quality research is needed to support this.

Will adopting an anti-inflammatory lifestyle improve fertility?

While recent research is intriguing, there’s not enough evidence to show that an anti-inflammation action plan will improve fertility. A plant-based diet such as the Mediterranean diet, and other measures considered part of an anti-inflammatory lifestyle, improve heart health and have many other benefits.

It’s not clear if this is directly due to reducing inflammation. But this approach comes with little to no risk. And abundant convincing evidence suggests it can improve health and even fight disease.

What is an anti-inflammatory lifestyle?

Health experts have not agreed on a single definition. Here are some common recommendations:

• Adopt a diet that encourages plant-based foods, whole grains, and healthy fats like olive oil while discouraging red meat, highly processed food, and saturated fats.
• Stop smoking or vaping.
• Lose excess weight.
• Be physically active.
• Get enough sleep.
• Treat inflammatory conditions, such as rheumatoid arthritis or allergies.
• Avoid excessive alcohol consumption.
• Control stress.

Anti-inflammatory medicines may help in certain situations — for example, treatments for autoimmune disease. However, they are not warranted for everyone. And for people trying to conceive, it’s far from clear that any potential benefit would exceed the risk of side effects for parent and child.

The bottom line

It’s possible that inflammation plays an important and underappreciated role in infertility and that an anti-inflammatory diet or lifestyle could help. But we need more evidence to confirm this. Until we know more, taking measures to improve your overall health and possibly reduce chronic inflammation makes sense.

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