Latest news with #HarvardTHChan
Medscape
9 hours ago
- Health
- Medscape
Wildfire Smoke Can Pose Risks Months Later
The particulate matter from wildfire smoke may be difficult to spot — with the eyes — within days, but those dangerous particles continue to post health risks for up to 3 months after exposure, new research suggested. A study published in Epidemiology in late May demonstrated that fine particulate matter in wildfire smoke represents a danger to human health considerably longer than a couple of days as previously thought. Researchers also found that exposure to the particulate matter can occur even after the fires have ended. Because studies have shown that air pollution exposure can trigger heart attack within an hour, the duration of the effects of wildfire particulate matter surfaced by this new research is a key new insight. The study, authored by researchers from the Icahn School of Medicine at Mount Sinai in New York City and Harvard T.H. Chan School of Public Health in Boston, highlighted increased risks for patients with cardiovascular disease (CVD) when exposed to smoke particulate matter, referred to as PM2.5, which by definition is 2.5 microns in diameter. To get an idea of how small the particles in wildfire smoke are, the average human hair is about 70 microns in diameter, meaning a 2.5-micron particle is about 28 times smaller than a human hair. The study showed that this tiny irritant is dangerous to those with ischemic heart disease, arrhythmia, and hypertension, as well as people with a number of cardiorespiratory diseases. Researchers made these conclusions by obtaining hospitalization records for the residents of 15 states between 2006 and 2016 from the State Inpatient Databases as well as daily smoke particulate matter estimates at 10 km2 cells across the contiguous US, and aggregating them using zip codes to match the spatial resolution of the hospital records. The 3-month exposure to smoke particulate matter was associated or marginally associated with increased hospitalization risks for most cardiorespiratory diseases, with hypertension showing the greatest susceptibility. 'Patients with CVD and the general public should be aware that wildfire smoke is a serious health risk, even if the fire is far away from your home. This is because the emissions can remain in the air and travel long distances for weeks or months after a wildfire has ended,' said Yaguang Wei, PhD, assistant professor at the Icahn School of Medicine at Mount Sinai and principal investigator of the study. 'Cardiologists and other healthcare providers should definitely discuss these risks with their patients, not only during wildfires but also in the following weeks, as the risk may persist.' Wei said that ongoing studies show that the particulate matter in wildfire smoke is among the most toxic environmental pollutants and can do systemic damage, which can pose further complications for those battling CVD. Yaguang Wei, PhD 'This is because smoke has smaller particles, which can more easily get into the body, and it has more carbonaceous compounds, which are thought to be especially toxic,' Wei said. 'They can enter the bloodstream and circulate throughout the body, which generates systematic effects. The emissions can remain in the air and travel long distances for weeks or months after a wildfire has ended.' Loren Wold, PhD, a professor at the Ohio State University College of Medicine, Columbus, Ohio, said that this study is crucial, in that it is important to understand the health implications of this particulate matter given the increasing occurrence of wildfires worldwide, and that particulate matter is not very extensively studied. 'People with cardiovascular disease should be especially careful being outside during days when wildfire smoke is present, as exposure to particulate matter from wildfire smoke is especially dangerous for those with cardiovascular disease as it causes an increase in oxidative stress and inflammation, which can further worsen the disease,' Wold, who has been studying particulate matter himself for two decades, said. 'Wildfire smoke can also cause temporarily increased blood pressure and vascular inflammation, as well as changes in heart rate variability, which can further exacerbate cardiovascular disease.' Loren Wold, PhD Particulate matter this small can bypass the nose and throat and enter deep into the lungs, and 'penetrate the linings of blood vessels to gain entry to the circulation,' Wold said. It also contains higher concentrations of organic carbon and black carbon, or soot, and can travel thousands of miles and linger for weeks in the atmosphere, he said. Plus, he said, the scale and unpredictability of exposure to wildfire particulate matter makes the health risks 'especially troublesome.' Shahir Masri, ScD, an associate specialist in air pollution exposure assessment and epidemiology at the Irvine Joe C. Wen School of Population & Public Health, University of California, Irvine, California, said that the notable finding of this study is the duration of the effects posed by the wildfire smoke particulate matter. He pointed out this review paper from 2024 that highlighted its many negative effects, while arguing that the dangerous pollutants that come from wildfires come from other sources, too. 'Many pollutants originate from wildfires, such as carbon monoxide, nitrogen oxides, and polycyclic aromatic hydrocarbons. However, I should mention that these pollutants shouldn't be thought of as exclusively wildfire-related,' he said. Instead, they're common byproducts from the combustion of organic matter, whether it be wildfires or vehicle exhaust, Masri said. 'Also, even acute, or short-term exposure, to wildfire pollution, is known to exacerbate the symptoms related to underlying health conditions, including cardiovascular disease, as well as asthma, COPD [ chronic obstructive pulmonary disease], and lung cancer, and others mentioned in the new Harvard study.' At-Risk Individuals Should Take Care The take-home from this study is that individuals suffering from CVD, as well as other underlying conditions, should protect themselves against the effects of wildfire smoke particulate matter when it's in the air. That includes both immediate, acute exposure as well as follow-on exposure, which this study shows can linger for up to 3 months after the event. The first key is for impacted individuals to stay aware of when the particulate matter is in the air. The US government provides an air quality tool called Air Now, where users can look up their local air forecast with their zip code or city and state. The meter on this page displays the Air Quality Index (AQI). Government guidelines suggest that if results show that if the AQI is between 101 and 150, those with CVD or other underlying conditions should reduce prolonged or heavy outdoor exertion; if it's over 201, all outdoor exertion should be avoided; and if over 301, all physical activity outdoors should be avoided. Shahir Masri, ScD Wei said that the first thing individuals with CVD should use to protect against the complications from wildfire particulate matter is an air purifier with a high efficiency particulate air filter and noted that these are becoming more inexpensive. Masri agreed that air purifiers are essential to help with indoor air quality and provided some tips on successful use. 'Running an air purifier can be very effective at reducing levels of PM2.5 in the home and workspace by 50% or more. Air purifiers, however, come with different flow rates and (effective) sizes. One must be sure to read the label of the air purifier to understand the size of the room it is capable of cleaning,' Masri said. 'If you only have one air purifier, to ensure the cleanest air I suggest placing it in the room where you sleep or work during the day and closing the doors and windows to that room. This reduces intrusion of dirty outdoor air during a wildfire, for instance, and therefore enables the device to do its job more effectively.' Masking is also an option, Masri said, but only when it's the right mask, worn properly. 'One can also opt to wear an N95 mask or respirator around the face to help reduce particulate matter exposure, but the mask must be secured tightly to the face,' he added. 'Those with facial hair will not achieve the tight seal needed to keep air pollution out of your lungs. Lastly, avoidance of outdoor exercise and other outdoor activities is important during major air pollution events like wildfires.'
Health Line
02-06-2025
- Health
- Health Line
Food Quality May Lower Heart Disease Risk More Than Cutting Carbs, Fat
A new study suggests that food quality matters more than fat or carbs for heart health. A low carb, low fat diet could lack heart-protective nutrients and have too much of certain nutrients associated with heart disease risk. A balanced diet with high quality, unprocessed foods is best for your heart. When it comes to heart health, the quality of the food you eat could matter a lot more than simply cutting carbohydrates or fats. A new study suggests that rather than focusing solely on macronutrient counts, emphasizing whole, minimally processed, and plant-based foods while limiting refined grains, added sugars, and animal products can significantly reduce the risk of coronary heart disease. The study was presented at the American Society for Nutrition's annual meeting, NUTRITION 2025, which was held in Orlando, Florida, from May 31 to June 3. The researchers' findings highlight a shift toward more personalized and nuanced dietary guidance for cardiovascular health. Restricting fat, carbs insufficient for heart health For years, low-carbohydrate (low carb) and low fat diets have dominated nutrition advice as methods to improve health, manage weight, and reduce risks of chronic diseases such as heart disease. However, the scientific community has debated how much these diets truly protect the heart, especially when the quality of foods consumed within these diets varies greatly. Researchers at Harvard T.H. Chan School of Public Health shed light on this important question, concluding that food quality is just as critical, if not more so, than merely restricting carbs or fats. The large-scale study followed nearly 200,000 males and females from three major U.S. cohort studies: the Health Professionals Follow-Up Study, the Nurses' Health Study, and the Nurses' Health Study II. Researchers tracked participants' dietary habits and heart disease outcomes over 25 years. Detailed food frequency questionnaires allowed the team to assign scores based on the healthfulness of the foods consumed within low carb and low fat diets. They found a clear association between low carb and low fat diets that emphasize high quality foods (i.e., whole grains, fruits, vegetables, nuts, and legumes) and a roughly 15% lower risk of developing coronary heart disease. Conversely, diets low in carbs or fat but high in unhealthy foods like refined grains, sugary snacks, processed meats, and animal fats carried a higher risk of heart disease. 'Healthy versions of these diets — those rich in plant-based foods and whole grains — were linked to better heart health outcomes and improved metabolic function. In contrast, low-carb and low-fat diets emphasizing unhealthy foods were associated with a higher risk of heart disease,' Lead study author Zhiyuan Wu, PhD, a postdoctoral research fellow in the Department of Nutrition at Harvard, explained in a press release. This suggests that simply cutting carbs or fats without considering the source and quality of these macronutrients can be counterproductive. To deepen their understanding, the research team also measured blood metabolites — a wide range of biological markers related to metabolism — in a subset of over 10,000 participants. This allowed them to observe how different diet qualities influenced metabolic regulation and lipid profiles in the body. The findings showed that healthy and unhealthy versions of low carb and low-fat diets distinctly affected plasma lipid species and other metabolites, which are important indicators of cardiovascular health. Interestingly, the study differentiated between various types of low carb and low fat diets. For example, 'animal-based' low carb diets, which tend to be higher in saturated fats and proteins from animal products, were linked to increased heart disease risk. On the other hand, 'vegetable-based' or plant-focused low carb diets showed more favorable outcomes. Similarly, unhealthy low fat diets that rely heavily on refined carbohydrates and added sugars also increased risk, whereas healthy low fat diets emphasizing whole foods lowered it. Food quality matters more than macronutrient intake Yaa Boakye, a registered dietitian nutritionist, personal trainer, and nutrition consultant, said it's helpful to think of food quality like a grading rubric for your body. Boakye wasn't involved in the study. 'Imagine asking a student to write a book report without providing the grading rubric; they may complete the assignment, but without clear direction, their work might miss the mark,' she told Healthline. Boakye noted that food quality is akin to the rubric in that your body uses it to interpret what you eat. 'It is not enough to check off a box labeled 'low carb' or 'low fat' — we need to examine what is actually in the food: fiber content, added sugars, sodium, micronutrients, and anti-inflammatory or proinflammatory compounds,' she explained, adding that carbohydrates, fats, and proteins are only broad categories. 'A carbohydrate could be a refined white roll or a fiber-rich lentil; a fat could be processed trans fat or cold-pressed olive oil,' she said. 'Food quality helps us zoom in on these differences.' Boakye added that when individuals simply follow a low fat or low carb diet without considering these nuances, they tend to overlook important nutrients that have consequences for heart health. 'High sodium levels, added sugars, lack of fiber, and insufficient antioxidants are all red flags that often go unnoticed,' she said, adding that you could be meeting your macro targets but still consuming a diet conducive to hypertension, poor cholesterol profiles, or systemic inflammation. 'A 'low fat' diet lacking magnesium, potassium, and omega-3s could backfire, while a 'low carb' plan omitting prebiotic-rich plants or colorful fruits might hinder gut health and indirectly stress the cardiovascular system,' she added. How to eat a heart-healthy diet Registered dietitian Ayanna Smart, author of The Dementia Dietitian blog, said a balanced diet with high quality food is the key to steady blood sugar, optimal blood pressure, a healthy weight, and improved cholesterol levels — all of which can support a strong heart. Smart wasn't involved in the study. She advised following the plate model, which involves filling one-half of your plate with vegetables and fruit, one-quarter with lean proteins (including meat, fish, beans, or lower-fat cheese), and one-quarter with whole grains. 'Making this your plate automatically reduces the amount of carbohydrate you eat and reduces the fat that you're eating because it removes a lot of excess fats that can enter someone's diet through eating higher fat foods,' she told Healthline. Smart further noted that vegetables and fruit contain fiber, which helps keep you full so you're less tempted to snack between meals. They also contain vital nutrients like vitamins, minerals, and antioxidants, which help protect your heart and blood vessels. According to Smart, whole grains also contain fiber and B vitamins. 'All this fiber helps better control blood sugar,' she said. 'Poorly controlled blood sugar contributes to heart disease by damaging blood vessels, so better blood sugar control reduces heart disease risk.' Smart added that eating lean proteins like lean meats, beans, and legumes helps keep your saturated fat intake low. Additionally, eating nuts can provide healthy polyunsaturated and monounsaturated fats that aid in keeping the 'bad' low-density lipoprotein (LDL) cholesterol in check. She added that a diet filled with high quality foods will naturally include fewer highly processed foods, which reduces your intake of sodium, saturated fat, and excess calories. 'Reducing the amount of highly processed foods you eat helps to protect your cardiovascular health by helping to control blood pressure and reduce your risk of developing atherosclerosis (hardening of the arteries) and helps to prevent excess weight gain,' Smart concluded.
Health Line
21-05-2025
- Health
- Health Line
High Quality Carbohydrates Linked to Healthy Aging, Longevity in Women
A new study builds on evidence supporting the effects of complex carbohydrate consumption on long-term health and longevity. The findings show that women who reported higher intakes of complex carbohydrates and dietary fiber had up to a 37% greater chance of living longer, healthier lives. Other factors for long-term health should be considered aside from diet, such as getting enough exercise and quality sleep. Dietary fiber and high quality carbohydrate intake during midlife were linked to healthy aging outcomes in women later in life. Researchers from the Jean Mayer USDA Human Nutrition Research Center on Aging (HNRCA) at Tufts University and Harvard T.H. Chan School of Public Health examined total carbohydrate intake in more than 47,000 females ages 70–93 from the Nurses' Health Study, the largest investigation into risk factors for major chronic diseases in women. Healthy aging was defined as healthy cognitive and physical function, good mental health, and the absence of 11 chronic conditions. A total of 3,706 participants met these criteria. Self-reported food-frequency questionnaires were collected every four years between 1984 and 2016. Researchers examined intakes of total carbohydrates, including refined carbohydrates, high quality or unrefined carbohydrates (i.e., whole grains, fruits, vegetables, legumes), and dietary fiber. Dietary glycemic index (GI) and glycemic load (GL) were calculated based on the questionnaires. The analysis showed that consumption of high quality complex carbohydrates and dietary fiber during midlife was linked to a 6–37% greater chance of healthy aging and improved physical and mental health. By contrast, refined carbohydrates (i.e., added sugars and refined grains) and starchy vegetables were linked to a 13% lower chance of healthy aging. The results were published on May 16 in JAMA Network Open. 'We've all heard that different carbohydrates can affect health differently, whether for weight, energy, or blood sugar levels. But rather than just look at the immediate effects of these macronutrients, we wanted to understand what they might mean for good health 30 years later,' Andres Ardisson Korat, a scientist at the HNRCA and lead author of the study, said in a news release. 'Our findings suggest that carbohydrate quality may be an important factor in healthy aging.' Healthy carbs improve physical, cognitive function The study builds on evidence supporting healthy, high quality carbohydrate consumption for long-term health. 'Our results are consistent with other evidence linking consumption of fruits and vegetables, whole grains, and legumes with lower risks of chronic diseases, and now we see the association with physical and cognitive function outcomes,' senior author Qi Sun, associate professor in the departments of nutrition and epidemiology at Harvard Chan School, said in a news release. Mir Ali, MD, board certified general surgeon, bariatric surgeon, and medical director of MemorialCare Surgical Weight Loss Center at Orange Coast Medical Center in Fountain Valley, CA, agreed the findings align with general nutrition recommendations about the benefits of complex carbohydrates. Ali wasn't involved in the study. 'Foods that have high quality or complex carbohydrates have relatively low glycemic index and glycemic load, and in this study were found to have a favorable impact on long-term physical, mental, and cognitive health,' Ali told Healthline. 'Foods high in simple and refined sugars lead to insulin spikes that, over time, can cause insulin resistance, weight gain, and chronic inflammation; all these factors increase the risk for diabetes, cardiovascular disease, decreased cognition, and even cancer,' he noted. Sheryl Ross, MD, board certified OB-GYN and Women's Health Expert at Providence Saint John's Health Center in Santa Monica, CA, echoed Ali's remarks. Ross was likewise not involved in the study. 'Refined carbohydrates are associated with an increased risk of chronic diseases,' Ross said. 'There is no surprise with this study's conclusion showing high quality carbohydrates promoting healthy aging and less chronic medical conditions. The specific details of our diet have never been more front and center on how we can support our longevity and live our best lives,' she told Healthline. Why are complex carbohydrates so healthy? Carbohydrate quality matters when it comes to healthy aging. Complex carbohydrates are rich in fiber and promote satiety, which can help with weight management. 'The powerful combination of dietary fiber and high quality carbohydrates [is] the perfect duo for healthy aging and longevity,' Ross said. Complex carbs also contain other important nutrients, such as vitamins and minerals. 'While dietary fiber is a standout component of high quality carbohydrates, these foods also deliver a spectrum of nutrients that play a critical role in supporting long-term health and longevity,' said Michelle Routhenstein, a registered dietitian at Entirely Nourished specializing in heart disease. Routhenstein wasn't involved in the new research. '[Many] high quality carbohydrates contain B vitamins such as folate, B6, and thiamine, which contribute to healthy methylation and help regulate homocysteine levels — key for vascular health and proper blood clotting,' she told Healthline. 'High quality carbohydrates contain potassium, which supports blood sugar regulation, fluid balance, and healthy blood pressure. [They] are also rich in phytonutrients, including carotenoids and flavonoids, which help combat inflammation and oxidative stress — two processes strongly linked to aging and chronic disease,' she continued. Routhenstein noted that complex carbohydrates also stimulate the production of butyrate in the gut, which may promote gut health and reduce arterial stiffness to support heart health. Ross added that high quality carbohydrates include other important nutrients like magnesium and omega-3 fatty acids, which help promote longevity. They also help regulate blood sugar. 'Carbohydrates from whole grains, fruits, vegetables, and legumes have a low dietary glycemic index (GI) and low glycemic load (GL), which have better health consequences as it relates to chronic medical conditions. Low GI and GL create more stability in blood glucose and insulin levels, which support having more energy, better mental clarity, and cognitive functioning, and less inflammation,' Ross said. Routhenstein shared a few sources of high quality carbohydrates: non-starchy vegetables (i.e., broccoli and spinach) fruits (i.e., berries, apples, and oranges) legumes (i.e., lentils, chickpeas, and black beans) whole grains (i.e., quinoa, oats, brown rice, and whole wheat bread) Not all carbs are 'created equal' Ross explained that refined carbohydrates, such as white bread, white pasta, white rice, or foods with added sugars, are higher on the glycemic index (GI) and glycemic load (GL) scales. High GI and GL may cause blood glucose and insulin levels to spike and raise the risk of chronic health conditions, such as: obesity cardiovascular disease type 2 diabetes mood disorders cognitive decline increased inflammation 'Not all carbs are created equally,' Ross said. On the flipside, however, not all carbs are bad for you, either. 'In an era where carbohydrates are often vilified and ultra-low-carb or ketogenic diets are widely promoted, it's critical to reframe the conversation around nutrient adequacy,' Routhenstein said. 'Many people are navigating significant nutrient deficiencies, and this research reinforces the importance of including high quality carbohydrate sources that nourish and protect the body,' she noted. More research on complex carbs and longevity needed The authors of the new study note a key limitation in their findings, since the study population comprised mainly white health professionals. Further research is needed to determine whether these findings translate to other populations. Author Ardisson Korat said that additional research is needed to understand the effects of dietary fiber and high quality carbs on healthy aging. 'Studies are starting to find an association between food choices in midlife and quality of life in later years. The more we can understand about healthy aging, the more science can help people live healthier for longer,' Ardisson Korat said. Ali suggested the positive health outcomes could be linked to increased fiber intake to improve glucose control, but agreed other potential mechanisms warrant further investigation. Additionally, the effects of complex carbohydrate intake and longevity in men should be considered, but similar health benefits may be seen in men nonetheless. 'Although this study focused specifically on women, the mechanisms by which high quality carbohydrates support health, such as reducing inflammation, enhancing gut health, regulating blood sugar, and lowering cardiovascular risk, are biologically relevant to both women and men,' Routhenstein said. What else can women do to support long-term health? The findings of the study align closely with a heart-healthy, nutrient-dense diet, Routhenstein said. Yet supporting health and longevity goes beyond balancing macronutrient intake, she noted, especially for women. A long-term balanced diet should also emphasize adequate intake of lean proteins and heart-healthy fats, which maintain metabolic function and hormonal balance. 'During the menopause transition — a time when body composition, blood pressure, and cholesterol levels often shift — there's a tendency to resort to restrictive, low calorie diets,' Routhenstein said. 'I frequently see how these approaches can backfire, particularly when they compromise heart health, bone health, and muscle mass. Instead, we should focus on responding to the body's evolving nutrient needs.' Physical activity is, of course, another pillar of long-term health. Most experts recommend a combination of heart-pumping aerobic exercise and strength and agility training to maintain heart health, muscle mass, and flexibility, and to prevent falls and fractures. Current recommendations for physical activity for adults include a minimum of 150 minutes of moderate-intensity exercise per week and two days of strength training. Routhenstein said adults should also prioritize quality sleep, which is crucial for immune function, cognitive health, and hormonal balance, and foster strong social connections to support well-being. 'Together, these lifestyle choices create a whole-person approach and a sustainable path to aging gracefully,' Routhenstein said.
