Roundup: Plant-Based Diets Linked to Disease-Free Aging in Long-Term Study; and More News

Study Finds Plant-Based Diets Linked to Healthier Aging Without Chronic Conditions

A new study provides the latest -- and potentially the strongest -- connection between diet and healthy aging. Published in Nature Medicine, researchers found that a diet rich in plant-based foods, with moderate intake of healthy animal-based foods and minimal consumption of ultra-processed foods, is linked to an increased likelihood of reaching age 70 free of any major chronic diseases, while maintaining cognitive, physical, and mental health.

The research, led by experts from Harvard T.H. Chan School of Public Health, the University of Copenhagen, and the University of Montreal, followed more than 105,000 middle-aged adults over a span of 30 years to investigate the impact of various dietary patterns on overall healthy aging.

Unlike previous studies that have focused on the relationship between diet and specific diseases or mortality rates, this study takes a broader approach, considering how diet affects people’s ability to live independently and enjoy a high quality of life as they age.

"Studies have previously investigated dietary patterns in the context of specific diseases or how long people live. Ours takes a multifaceted view, asking, how does diet impact people’s ability to live independently and enjoy a good quality of life as they age?" said Frank Hu, co-corresponding author and Fredrick J. Stare Professor of Nutrition and Epidemiology at Harvard Chan School, in a news release.

The findings underscore the idea that a healthy diet isn't just about longevity — it’s about thriving as you age. This perspective shift marks a significant leap in the field of aging and nutrition research.

The study analyzed the diets of participants in two major health studies—the Nurses' Health Study and the Health Professionals Follow-Up Study—looking at how adherence to eight distinct dietary patterns affected their health outcomes. The patterns assessed included the Alternative Healthy Eating Index (AHEI), the Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND), the Healthful Plant-Based Diet Index (hPDI), and others.

Each of these diets emphasized plant-based foods like fruits, vegetables, whole grains, nuts, and legumes, while some also allowed moderate consumption of healthy animal-based foods like fish and certain dairy products. The researchers also evaluated the intake of ultra-processed foods, which are typically high in unhealthy fats, sugars, and artificial additives.

The study revealed that all eight dietary patterns were linked to healthy aging, suggesting that there is no one-size-fits-all approach to maintaining health as we age. This highlights the importance of individual dietary preferences and needs, rather than a rigid set of guidelines.

Among the most promising findings was the positive impact of plant-based diets. Those who adhered to the Alternative Healthy Eating Index (AHEI), which prioritizes plant-based foods while minimizing processed meats and sugary beverages, showed a significantly higher likelihood of healthy aging. Participants in the highest quintile of AHEI scores were 86 percent more likely to age healthfully at 70 and 2.2 times more likely to age healthfully at 75 compared to those in the lowest quintile.

"A diet rich in fruits, vegetables, whole grains, nuts, legumes, and healthy fats, while being low in red and processed meats, sugars, and refined grains, was consistently linked to better aging outcomes," said Anne-Julie Tessier, lead author of the study.

The study also highlighted the risks associated with ultra-processed foods. Participants who consumed higher amounts of processed meats, sugary drinks, and diet sodas were less likely to experience healthy aging. The researchers emphasize that limiting the intake of these foods could have significant benefits for long-term health and well-being.

"Since staying active and independent is a priority for both individuals and public health, research on healthy aging is essential," said Marta Guasch-Ferré, co-corresponding author and associate professor at the University of Copenhagen, in a news release. "Our findings suggest that dietary patterns rich in plant-based foods, with moderate inclusion of healthy animal-based foods, may promote overall healthy aging and help shape future dietary guidelines."

While the study does have some limitations—such as its exclusive focus on health professionals—the researchers hope that future studies will expand to include more diverse populations to determine how these findings apply to a broader range of individuals.

Study Examines Potential Drug Treatment That May Delay Alzheimer’s Onset

A new study suggests that an experimental drug can reduce the risk of Alzheimer’s-related dementia in people “destined to develop” the condition in their 30s, 40s, or 50s. Published in The Lancet Neurology, the study marks a potentially major step forward in Alzheimer’s research aimed at delaying the onset of the disease by removing amyloid plaques from the brain before symptoms arise.

The research, led by the Knight Family Dominantly Inherited Alzheimer Network-Trials Unit (DIAN-TU) at Washington University in St. Louis, involved 73 participants with rare genetic mutations that cause the overproduction of amyloid, a protein linked to Alzheimer’s.

These mutations “all but guarantee” that individuals will develop Alzheimer’s disease by middle age, states a news release on the study’s findings from Washington University. For a subgroup of 22 participants who started treatment early, the results were striking. After an average of eight years of treatment, the risk of developing Alzheimer’s symptoms was reduced by half—dropping from nearly 100 percent to about 50 percent.

“Everyone in this study was destined to develop Alzheimer’s disease and some of them haven’t yet,” said senior author Randall J. Bateman, M.D., the Charles F. and Joanne Knight Distinguished Professor of Neurology at WashU Medicine, in a prepared statement. “We don’t yet know how long they will remain symptom-free — maybe a few years or maybe decades. In order to give them the best opportunity to stay cognitively normal, we have continued treatment with another anti-amyloid antibody in hopes they will never develop symptoms at all. What we do know is that it’s possible at least to delay the onset of the symptoms of Alzheimer’s disease and give people more years of healthy life.”

The study reinforces the "amyloid hypothesis" of Alzheimer’s disease, which suggests that amyloid plaques in the brain contribute to the development of dementia. By removing these plaques, the drug may prevent or delay the cognitive decline associated with Alzheimer’s.

The findings are part of a larger, international effort to test treatments that might prevent Alzheimer’s in people genetically predisposed to the disease. The DIAN-TU study is part of the Knight Family DIAN-TU-001 trial, the world’s first Alzheimer’s prevention trial, which began in 2012. Participants who received the treatment the longest, averaging eight years, showed the most significant reduction in risk.

However, the study also highlights some challenges. The drug used, gantenerumab, was discontinued in 2022 for another phase of trials because it failed to meet the primary goal of slowing clinical decline in those already showing symptoms. Yet, this latest analysis of participants who received the drug for several years before symptom onset provides critical evidence that earlier intervention is key.

Though the drug’s effects are still being evaluated, particularly for those who started treatment later, the study’s results are encouraging. The longer participants go without symptoms, the more significant the effect may become.

Babies Can Form Memories Earlier Than Previously Thought, Researchers Find

We all know that babies go through a huge amount of learning during their first few years of life. But, as adults, we typically can’t recall specific events from our earliest years.

This phenomenon, known as “infantile amnesia,” has long puzzled scientists. For years, researchers believed that babies couldn’t retain memories because the hippocampus—the part of the brain responsible for storing memories—wasn’t fully developed in infancy. However, a new study from Yale University challenges this belief, providing evidence that babies can form memories much earlier than previously thought.

Yale researchers showed infants images of new faces, objects, and scenes. Afterward, they tested whether the babies could recognize those images later. The researchers measured the activity in the infants’ hippocampus as they looked at the images. The results were clear: when an infant’s hippocampus showed more activity the first time they saw an image, they were more likely to recognize that image later.

This suggests that even at a young age, babies are able to encode memories in their brains, challenging the assumption that the hippocampus isn’t ready to store memories until much later in life.

The study, published in Science, has important implications on the ongoing research of memory formation in early childhood. While it’s long been accepted that memories during the first few years of life are inaccessible, the findings suggest that memory encoding begins much earlier than previously thought.

Nick Turk-Browne, a psychology professor at Yale and senior author of the study, explained in a news release:  "The hallmark of episodic memory is that you can describe it to others. But that’s difficult when dealing with pre-verbal infants."

The key finding here is that babies, especially those older than 12 months, do indeed show signs of episodic memory, the kind of memory that involves recalling specific events or experiences.

In this research, the team used functional magnetic resonance imaging (fMRI) to observe the infants' brain activity. The more active the hippocampus was when an infant first saw an image, the longer the infant gazed at that image when it appeared again later. This suggests a direct link between hippocampal activity and the strength of the memory.

While this study sheds light on how infants form memories, it raises new questions about what happens to those memories as children grow. Researchers are now exploring whether these early memories persist or fade over time. Do babies hold onto these early experiences, or are they lost to the effects of growing up and developing new cognitive abilities?

This research also adds to a previous finding by the Yale team that infants as young as three months old are capable of a different type of memory known as "statistical learning." This type of learning is about recognizing patterns in events – such as understanding that most restaurants have menus or noticing the typical steps in a dining experience -- which is different from recalling specific events, such as a particular birthday party.