Roundup: Teens Can Lower Risk of Diabetes by Reducing ‘Sitting Time’ by 30 Minutes Daily; and More News

Less Sitting, More Moving: How Small Changes Could Protect Teens from Diabetes

A new study suggests that swapping just 30 minutes of daily sitting time for exercise could significantly lower a teenager's risk of developing type 2 diabetes later on — and the results were stronger than researchers expected.

The study analyzed health data from more than 800 adolescents (average age 13) participating in Project Viva, a long-running study tracking the health of children born in Eastern Massachusetts between 1999 and 2002. Participants wore movement trackers and kept sleep logs for up to 10 days, giving scientists a detailed picture of how teens actually spend their time.

The breakdown was striking: nearly half of each day — about 11.5 hours — was spent sedentary. That includes sitting in class, doing homework, commuting, and evening screen time. Only 2 percent of the day involved moderate-to-vigorous activity like running, swimming, or playing basketball.

Researchers then modeled what would happen if teens shifted just 30 minutes away from sedentary time. The results:

• Replacing sitting with moderate-to-vigorous exercise reduced insulin resistance by nearly 15 percent
• Replacing sitting with sleep reduced insulin resistance by nearly 5 percent
• Swapping sitting for light activity like casual walking showed no significant change

Why Insulin Resistance Matters

Insulin resistance is when the body's cells stop responding well to insulin, the hormone that regulates blood sugar. Over time, this forces the pancreas to work harder, and can eventually lead to Type 2 diabetes — a chronic condition affecting how the body processes sugar. Catching and reversing insulin resistance early, especially in the teen years, is key to long-term health.

Lead researcher Soren Harnois-Leblanc, Ph.D., of Harvard Medical School, called the 15 percent reduction finding notably strong. "Switching from sedentary behaviors to moderate-to-vigorous physical activity or sleep, even if it is only a few minutes per day to start, was beneficial for health," he said.

Simple Steps Parents and Teens Can Take

The American Heart Association recommends practical habits that don't require a gym membership:

• Better sleep: Dim lights before bed, ditch screens at bedtime, and put the phone on "Do Not Disturb"
• Social exercise: Turn time with friends into hikes, pickup games, or active outings
• Start small: Even a few extra minutes of movement each day adds up

The findings are preliminary and have not yet been published in a peer-reviewed journal. But the researchers say the conclusion is clear: for teenagers, less sitting — and more moving or sleeping — could be a powerful defense against diabetes later in life.

Study: Here’s How A Mammogram Could Predict Your Heart Health

Heart disease is a leading cause of illness and death among women, yet it often goes underdiagnosed and undertreated. A new study reveals a promising breakthrough: the routine mammogram that screens women for breast cancer might soon help doctors catch heart disease early, too.

In a study published in the European Heart Journal involving over 120,000 women, researchers wanted to know if artificial intelligence (AI) could analyze standard screening mammograms to identify women at a high risk for major heart events, like heart attacks or strokes.

What Is Breast Arterial Calcification?

The focus of the study was something called breast arterial calcification. Simply put, this is a buildup of calcium in the blood vessels of the breast. It is a common condition and is not related to breast cancer. However, because these vessels are part of the body's cardiovascular system, calcium buildup here can be a strong warning sign of plaque buildup in the heart's arteries.

In the past, measuring this calcium buildup on a mammogram was time-consuming for radiologists. To solve this, the researchers trained an AI tool to automatically find and measure the exact amount of calcification present in the scans. They then tracked the women's health over time to see who developed heart issues.

AI Offers a Powerful New Screening Tool

The results were striking. The AI successfully categorized the calcification into zero, mild, moderate, and severe levels. The study found a clear link between the amount of calcium and a woman's heart risk. Compared to women with zero calcification, those with mild amounts had an elevated risk for heart events. Women with severe calcification faced nearly three times the risk. In fact, every tiny increase in the area of calcium buildup raised the risk of a major heart event by two to three percent.

Most importantly, the AI tool predicted these heart risks better than traditional health questionnaires and standard risk calculators alone.

This research carries exciting implications for women's health. It means doctors can take advantage of a test millions of women already undergo every year. Because the AI analyzes the mammogram image that is already taken, this heart health check requires no extra appointments, no additional costs, and no extra radiation exposure.

By turning routine mammograms into a two-for-one screening tool, healthcare providers gain a powerful new way to assess heart health. It serves as an early warning system, allowing doctors to recommend lifestyle changes or medications to protect their patients long before a heart attack or stroke happens. As AI technology continues to integrate into standard care, women will likely benefit from faster, more comprehensive preventive medicine.

Ultra-processed Foods Linked to Higher Heart Disease Risk, New Study Finds

A growing body of research continues to examine how diet influences heart health, and a new study published in JACC: Advances, a journal of the American College of Cardiology, adds important new evidence—particularly in a diverse U.S. population.

The new study, based on data from the Multiethnic Study of Atherosclerosis (MESA), explored how consumption of ultra-processed foods (UPFs) relates to the risk of atherosclerotic cardiovascular disease (ASCVD).

What are Ultra-processed Foods?
UPFs are industrially manufactured foods that contain little to no whole ingredients. They are often formulated with additives such as preservatives, artificial flavors, colors, and emulsifiers to enhance taste and shelf life. Common examples include sugary drinks, packaged snacks, processed meats, breakfast cereals, and ready-to-eat meals.

Study Design And Population
The researchers followed 6,814 adults aged 45 to 84 years who did not have cardiovascular disease at the start of the study. Participants came from diverse racial and ethnic backgrounds, including White, Black, Hispanic, and Chinese American individuals.

Dietary intake was assessed using a food-frequency questionnaire, and UPF consumption was categorized using the Nova classification system—a widely used method for classifying foods based on processing level.

Key Findings
The study found a clear association between UPF consumption and cardiovascular risk:

• Each additional daily serving of UPFs was linked to a 5.1 percent increase in the risk of ASCVD events.
• Individuals in the highest consumption group had a 66.8 percent higher risk compared to those in the lowest group.
• Importantly, the association was stronger among Black Americans, suggesting potential disparities in how diet impacts health across populations.

ASCVD events in this study included serious outcomes such as heart attack (myocardial infarction), stroke, cardiac arrest, and death from coronary heart disease. The stronger association observed in Black participants may reflect broader structural and environmental factors. These can include differences in food access, targeted marketing of processed foods, and socioeconomic conditions that influence dietary patterns.

Understanding the Mechanisms
While the study was observational (meaning it cannot prove causation), several biological pathways may explain the findings. UPFs are often high in added sugars, sodium, and unhealthy fats, which can contribute to:

• Insulin resistance (reduced ability of the body to regulate blood sugar)
• Dyslipidemia (abnormal cholesterol levels)
• Hypertension (high blood pressure)
• Obesity and inflammation

Additionally, UPFs may disrupt the gut microbiome—the community of bacteria in the digestive system—and interfere with satiety signals, potentially leading to overeating.

Implications for public health

The findings reinforce current dietary recommendations that emphasize whole, minimally processed foods. Eating patterns such as the Mediterranean diet or the DASH (Dietary Approaches to Stop Hypertension) diet—rich in fruits, vegetables, whole grains, legumes, and healthy fats—have consistently been associated with better cardiovascular outcomes.

This study highlights a significant link between ultra-processed food intake and cardiovascular risk in a diverse U.S. population. While more research is needed to fully understand causal pathways, reducing UPF consumption and prioritizing whole foods remains a practical strategy for supporting heart health — particularly in communities disproportionately affected by cardiovascular disease.