Everyone needs vitamin D, but many of us don’t get enough of it. The so-called sunshine vitamin is crucial for building strong bones, reducing inflammation, and supporting immune system function, according to the National Institutes of Health (NIH). But per the Cleveland Clinic, about 35% of Americans are deficient in vitamin D—and a whopping half the globe is low on the nutrient too.

This is a big deal. Not only do our bodies need vitamin D to properly function, but not getting enough of the nutrient can cause symptoms like fatigue, aches and pains, and depression. And in severe cases, vitamin D deficiency may lead to serious health outcomes. Research has linked it with cancer, heart disease, and more, per the NIH.

The metaphorical jury’s still out on why low vitamin D is linked to poorer health outcomes. But here are some of the most serious health conditions associated with vitamin D deficiency.

Cycling was linked to a 19% lower dementia risk and 22% lower Alzheimer’s risk.

Active travel may boost gray matter in memory-related brain regions, like the hippocampus.

Benefits of active travel persist regardless of genetics, especially for Alzheimer’s risk.

Dementia is a condition that disrupts memory, cognitive abilities and the ability to perform daily tasks, and its prevalence continues to rise globally, particularly among older adults. The good news? Staying physically active in middle age may be a powerful way to lower the risk of developing dementia. Research consistently highlights the protective benefits of regular movement, though many adults still fall short of meeting recommended activity levels.

One effective method to boost physical activity is what is referred to as “active travel,” which includes walking or cycling for transportation. In other words, the simple act of skipping the car, bus or train and traveling by foot or bike may have a profound impact on brain health. Active travel not only promotes general health but has also been linked to a decreased risk of conditions like diabetes and, potentially, dementia.

But participating in active travel won’t be a magic bullet to living a dementia-free life. The interplay between lifestyle habits and genetic predisposition to developing dementia adds another layer of complexity. While active travel presents health advantages for most individuals, the extent of those benefits may differ depending on a person’s genetic risk for dementia.

To explore this relationship further, researchers in the U.K. conducted a study to determine how various modes of travel influence dementia risk, including Alzheimer’s disease, alongside changes in brain structure, and their results were published in JAMA Network Open.

How Was This Study Conducted?

To conduct this study, researchers used data from the UK Biobank cohort. These participants came from different regions across England, Scotland and Wales. The study gathered extensive information about their demographics, lifestyles, health conditions and more through surveys and exams.

For this research, some participants were excluded, such as those already diagnosed with dementia at the start or shortly after (within two years), those who couldn’t walk, and those missing travel-related data. The study looked at two groups of dementia cases: those who developed dementia before age 65 (younger-onset dementia) and those diagnosed at 65 or older (later-onset dementia). The researchers ultimately evaluated 479,723 participants with over 13 years of follow-up.

To gather information about travel habits, participants were asked to fill out a questionnaire that included questions about transportation choices that they used. Based on their answers, the researchers grouped travel modes into four categories: nonactive (using cars, motor vehicles or public transport), walking, mixed-walking (a mix of walking and nonactive modes) and cycling and mixed-cycling (cycling combined with other modes).

To identify individuals with dementia, they relied on detailed health records using standardized codes for medical diagnoses.

They also used information from magnetic resonance imaging (MRI) scans of the brain, heart and abdomen. The research also looked at genetic factors related to dementia, focusing on the APOE gene, which is known to play a key role in dementia risk. Specifically, two genetic markers (called single-nucleotide polymorphisms) were used to determine whether a participant had a higher genetic risk. Participants were then grouped based on whether or not they carried the APOE ε4 gene variant.

What Did the Study Find?

Over a follow-up period of about 13 years, researchers found that out of all participants, 1.8% were diagnosed with dementia, including a very small group who developed it at a younger age (0.2%). The study compared different types of travel, like walking, cycling or a mix of the two, with nonactive travel modes like driving. The results showed that people who cycled, or combined cycling with other modes, had a notably lower risk of developing dementia overall, particularly later-life dementia.

For instance, using a mix of walking reduced overall dementia risk by 6%, while cycling or combining cycling with other methods lowered the risk by 19%. Even for younger-onset dementia specifically, cycling or mixed-cycling appeared to cut the risk by 40%. On the other hand, walking alone seemed to slightly increase the risk of Alzheimer’s disease by 14%, but cycling or mixed-cycling helped reduce its risk by 22%.

When researchers studied brain scans , they found that cycling and combining cycling with other methods of travel were linked to slight increases in gray matter volume (GMV) in certain parts of the brain, including the hippocampus, which is important for memory. Walking and combining walking with other travel modes, however, were linked to slightly smaller volumes of gray and white matter in some areas. Importantly, these changes don’t suggest a higher risk of dementia but highlight how different activities may affect the brain. Nonactive travel, like driving, didn’t show any significant impact on brain structure in this study.

Interestingly, the researchers found that genetic risk didn’t change the link between travel mode and early-onset dementia or Alzheimer’s disease. However, for all dementia types and late-onset dementia, genetics did play a role. People who didn’t have a specific genetic marker (APOE ε4) seemed to benefit more from cycling, showing lower dementia risks compared to those with the marker.

While these results are interesting and compelling, it is worth noting some limitations to this study. First, because younger-onset dementia is relatively rare, the researchers couldn’t break down the different types of cycling, making it hard to draw a firm conclusion. To improve this, future studies need more participants with younger-onset dementia and longer follow-up periods. Second, they relied on people reporting their own travel habits, which might not always be accurate. Third, the researchers didn’t track how travel habits changed over time, making it challenging to best understand these patterns. Finally, the study group lacked racial and ethnic diversity, as most participants were of European ancestry, so the results may not apply to all groups equally.

How Does This Apply to Real Life?

Understanding how active travel impacts dementia risk can ignite meaningful changes in your daily life, especially if you are focused on supporting your cognitive health. Imagine replacing those quick car rides with a refreshing walk or bike ride! Not only do you help the environment by cutting down on emissions when you do this, but you also take a proactive step toward protecting your brain health. Whether it’s walking to the corner store, cycling to work or enjoying a peaceful stroll in the park, these simple shifts can deliver long-term benefits. The great thing is that incorporating more movement into your routine is achievable for most people and it may also support your brain health to boot.

Not all communities make it easy to bike or walk to work or while running errands. But if you can find time to go for a ride around the neighborhood or lengthen your parking lot walks at the grocery store, those little moments of extra activity could be helpful to your long-term health.

But active travel is just one piece of the bigger picture. Brain health thrives on a combination of regular exercise, a balanced diet, staying socially connected and getting quality sleep. While we can’t control genetic factors, adopting healthy habits like active travel empowers us to take charge of what we can. The key is to tailor these efforts to your environment—whether that’s walking more in pedestrian-friendly cities or cycling in bike-supportive areas. Small, consistent actions add up, and over time, they may help support not only your cognitive health but your overall health as well.

Our Expert Take

This study published in JAMA Network Open suggests that cycling may be linked to a 19% lower risk of developing dementia and a 22% lower risk of Alzheimer’s disease. Researchers found that cycling may increase gray matter volume in the hippocampus, which plays a critical role in memory. Conversely, nonactive modes of travel like driving did not show meaningful effects on brain health. While genetic factors can influence these outcomes, the study suggests that physical activity through active travel offers protective benefits regardless of genetic predispositions, especially for those without high-risk genetic markers.

Whether through cycling, walking or other forms of active travel, making intentional choices about how we move through the world can yield profound health benefits. While active travel is not a one-size-fits-all solution, it can be a practical and rewarding way to support both brain and body. By combining movement with other healthy lifestyle choices, like eating a nutrient-rich diet, getting quality sleep and staying socially connected, you can take meaningful steps toward a healthier future.

Researchers at the Case Western Reserve School of Medicine have found that semaglutide, a popular diabetes and weight-loss drug, may lower the risk of dementia in people with type 2 diabetes (T2D).

Dementia, a condition that slowly makes it harder for people to remember things and think clearly, occurs when brain cells are damaged and their connections stop working properly. This damage, which worsens over time, can be caused by various modifiable factors, including obesity, T2D, cardiovascular diseases, traumatic brain injury and stroke.

According to the National Institutes of Health, more than 6 million people in the United States are diagnosed with dementia, and it causes more than 100,000 deaths each year. Encouragingly, research indicates that 45% of dementia cases could be prevented by addressing modifiable risk factors.

The study, published on June 24 in the Journal of Alzheimer’s Disease, suggests T2D patients taking semaglutide had a significantly lower risk of developing dementia compared to other antidiabetic medications. These results were more profound in women and older adults.

Semaglutide, a glucagon-like peptide receptor (GLP-1R) molecule that decreases hunger and helps regulate blood sugar in T2D, is also the active component in the diabetes and weight-loss drugs Wegovy and Ozempic. Semaglutide has shown a broad range of benefits, including reductions in cardiovascular diseases.

The research team — led by biomedical informatics professor Rong Xu — analyzed three years of electronic records of nearly 1.7 million T2D patients nationally. The researchers used a statistical approach that mimics a randomized clinical trial.

They found patients prescribed semaglutide had a significantly lower risk for Alzheimer’s disease-related dementia, compared to those who had taken any of seven other anti-diabetic medications, including other types of GLP-1R-targeting medications.

“There is no cure or effective treatment for dementia, so this new study provides real-world evidence for its potential impact on preventing or slowing dementia development among at-high risk population,” said Xu, who also directs the School of Medicine’s Center for AI in Drug Discovery and is a member of the Cancer Genomics Epigenomics Program at the Case Comprehensive Cancer Center.

Although their findings potentially support the idea that semaglutide could prevent dementia, the study’s limitations restrict the researchers from making firm causal conclusions, she said.

“Our results indicate that research into semaglutide’s use for dementia prevention will need to be further investigated through randomized clinical trials” Xu said.

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A new study published in the journal Neurology has found that drinking alcohol, even in relatively moderate amounts, significantly increases the risk of dementia and other serious health conditions.

The research, conducted in Brazil, analysed data from autopsies of 1781 people, shedding light on the long-term effects of alcohol on brain health.

Subjects were grouped into four categories: those who never drank, moderate drinkers (who consumed up to seven standard drinks per week), heavy drinkers (who had eight or more standard drinks per week), and former heavy drinkers who had not drunk for at least three months but had a history of heavy drinking.

In the study, a standard drink was defined as 14 grams of alcohol, roughly equivalent to a 350ml glass of beer or 147ml of wine, according to Psychology Today.

While drinking habits were reported by relatives, which may not always be entirely accurate, the overall findings still proved the link between drinking and cognitive decline.

Drinking a moderate amount of alcohol has been shown to increase the risk of dementia. Picture: iStock

Alcohol linked to dementia

Interestingly, the amount of alcohol that can impair brain function is lower than many people might expect.

The study defines “heavy” drinking as eight or more drinks per week, but this is a level many would consider moderate. It would be the same as having a beer or a glass of wine each week night, plus two on the weekend.

But the results showed that those who consumed up to seven or more than eight drinks per week faced a higher risk of brain injuries associated with memory loss and dementia.

Up to seven or more than eight drinks was linked to cognitive decline, memory loss and dementia. Picture: iStock

Heavy drinkers in the study had a 133 per cent higher risk of developing hyaline arteriolosclerosis, a condition involving the thickening and hardening of arteries.

This process restricts blood flow to the brain and can result in tiny, often unnoticed strokes that damage memory and increase the risk of dementia.

Former heavy drinkers, even after abstaining for three months or more, were still 89 per cent more likely to develop this condition compared to those who never drank.

Meanwhile, moderate drinkers faced a 60 per cent increased risk, proving that even lower levels of alcohol consumption were harmful.

Even former heavy drinkers were at risk of serious health issues. Picture: iStock

Other health impacts

Beyond artery damage, heavy drinkers and former heavy drinkers were also more likely to develop neurofibrillary tangles, which are protein formations in the brain strongly associated with dementia and Alzheimer’s disease.

Heavy drinkers were 41 per cent more likely to have these tangles, while former heavy drinkers were 31 per cent more likely.

Even after stopping drinking, former drinkers remain at a higher risk of dementia, which is a harsh reminder that the effects of alcohol can linger long after the last drink.

In saying that, it’s never too late to begin to make healthier lifestyle choices and re-evaluate your alcohol consumption.

Australian implications

Interestingly, the National Health and Medical Research Council (NHMRC) Australian Alcohol Guidelines recommend that adults should drink no more than 10 standard drinks per week to reduce the risk of harm from alcohol-related disease or injury.

This is particularly worrying because this new research found increased dementia risks even at levels of drinking well below the current NHMRC guideline.

What’s even more concerning is that one in four Australian adults exceed this guideline, with men more likely to do so than women.

Among young adults aged 18 to 24, more than one in three go over the recommended limit.

Originally published as New study reveals dementia risk linked to surprisingly low alcohol intake

Would you believe me if I told you that staying single or ending your marriage could lower your odds of getting dementia? A new study led by researchers at Florida State University somewhat shockingly suggests that unmarried people are less likely to develop dementia.

If you think you’ve heard the opposite, you are correct. A 2019 study from America found that unmarried people had “significantly higher odds of developing dementia over the study period than their married counterparts”.

Indeed, married people are generally thought to have better health. Studies have shown that they are at reduced risk of having heart disease and stroke and they tend to live longer. So why did the new study come up with this surprising finding? Let’s take a closer look.

The researchers analysed data from more than 24,000 Americans without dementia at the start of the study. Participants were tracked for up to 18 years. Crucially, the team compared dementia rates across marital groups: married, divorced, widowed and never-married.

At first, it looked as though all three unmarried groups had a reduced risk of dementia compared with the married group. But, after accounting for other factors that could influence the results such as smoking and depression, only divorced and never-married people had a lower risk of dementia.

Differences were also seen depending on the type of dementia. For example, being unmarried was consistently linked with a lower risk of Alzheimer’s disease, the most common form of dementia. But it was not shown for vascular dementia – a rarer form of the condition.

The researchers also found that divorced or never-married people were less likely to progress from mild cognitive impairment to dementia and that people who became widowed during the study had a lower risk of dementia.

Possible explanations

One reason for the unexpected results? Married people might be diagnosed earlier because they have spouses who notice memory problems and push for a doctor’s visit. This could make dementia look more common in married people – even if it’s not.

This is called ascertainment bias — when data is skewed because of who gets diagnosed or noticed more easily. However, the evidence of this was not strong. All participants had annual visits from a doctor, who could be thought of as a proxy partner who would spot early signs of dementia in the participant.

Perhaps it was the case that the sample of people used, from the National Alzheimer’s Coordinating Center (NACC) study, was not representative of the wider population. Specifically, the sample showed low levels of ethnic and income diversity. Also, nearly 64% of the participants were married. This may affect how these unexpected findings translate to the wider world. They could just have been unique to NACC participants.

However, it is more likely that these findings highlight just how complex the effects of marital disruptions, transitions and choices on brain health really are. Being married is by no means an established protective factor for dementia, with an earlier meta-analysis (a study of studies) showing mixed results.

The new study from Florida State University uses one of the biggest samples to date to examine this issue, and carries a good deal of weight. It highlights that assumptions based on previous research that widowhood and divorce are very stressful life events that can trigger Alzheimer’s disease or that unmarried people are socially isolated and therefore may be at higher risk of dementia, may not always be correct.

Relationship dynamics are by no means straightforward. As mentioned in the paper, such dynamics may “provide a more nuanced understanding than a simple binary effect”. Factors such as marriage quality, levels of satisfaction after divorce, cultural considerations, or the sociability of single people compared with coupled ones may help explain these seemingly contradictory results.

This study challenges the idea that marriage is automatically good for brain health. Instead, it suggests the effect of relationships on dementia is far more complex. What matters might not be your relationship status but how supported, connected and fulfilled you feel.

This article is republished from The Conversation under a Creative Commons license. Read the original article.