(Mercola)—COVID-19 lockdowns accelerated brain aging in adolescents, according to a recent study.¹ The pandemic drastically changed daily routines, leaving many young people struggling with their mental and physical health. You might have noticed how isolation affected teens, especially girls, more than boys. Increased feelings of anxiety and depression became common as social interactions dwindled.²

As the lockdowns wore on, physical fitness levels among young adults began to decline sharply. Reduced opportunities for exercise and more time spent sedentary led to significant drops in both aerobic and anaerobic fitness.³ This decline isn’t just about physical health; it’s closely tied to mental well-being as well.

We’re only now beginning to see the many ways COVID-19 lockdowns impacted adolescent brain development and physical fitness; the full effects likely won’t be apparent for years or decades to come.

The Impact of Lockdowns on Adolescent Brain Development

Adolescence is a critical period for brain maturation, where emotional and social development take center stage. During this time, your brain undergoes significant changes, including synaptic pruning and myelination, which are essential for cognitive and emotional growth. However, the COVID-19 lockdowns disrupted these typical developmental trajectories, particularly in girls.⁴

Researchers used MRI scans to compare brain structures before and after the lockdowns, revealing that young girls experienced more rapid cortical thinning than boys did. Cortical thinning is a natural part of brain development during adolescence, where your brain’s outer layer, the cortex, becomes thinner as it matures.

This process is essential for improving cognitive functions like thinking, memory and emotional regulation. However, the study showed that the lockdowns caused this thinning to happen much faster than usual, especially in female adolescents. Girls experienced a mean brain age acceleration of 4.2 years compared to 1.4 years in boys.

The acceleration in brain maturation is linked to increased stress caused by the pandemic restrictions. Prolonged social isolation and the disruption of daily routines led to higher levels of stress hormones like cortisol. These hormones affect brain development, leading to the accelerated thinning observed in the study.

Moreover, the faster brain maturation in females is concerning because it’s associated with a higher risk of developing mental health issues such as anxiety and depression. The rapid changes in brain structure may interfere with the normal development of emotional and social skills, making adolescents more vulnerable to neuropsychiatric disorders.

The study highlights the critical need for ongoing support and monitoring of adolescents who experienced the lockdowns. Providing mental health resources and promoting healthy lifestyles may help mitigate the negative impacts of accelerated brain aging, but early intervention is essential to address the long-term consequences on young minds.

Autobiographical Memories Impact Mental Health in Lockdown

Another study found that as lockdowns continued, children’s memories of that time became less detailed and more negative over time. Initially, kids could recall specific events and feelings from the lockdown, but as months passed, their memories lost some of that detail and leaned more toward negative emotions.⁵

Psychological well-being among children and adolescents also took a hit during the lockdowns, with girls showing the most significant decline. While all young people experienced increased anxiety and depression, female adolescents were particularly hard-hit, reporting the lowest levels of happiness and the highest levels of depressive symptoms.⁶

The content of these memories played a crucial role in mental health outcomes. Memories that were filled with negative emotions and detailed factual information about COVID-19 and the restrictions predicted poorer psychological well-being over time. Not surprisingly, kids who focused more on the negative aspects and the hard facts about the pandemic struggled more with their mental health.⁷

Overall, the findings suggest that the way children and adolescents remember and narrate their experiences during challenging times significantly influences their mental health. Negative memory narratives lead to worse psychological outcomes, highlighting the need for supportive interventions that help young people process their experiences in healthier ways.⁸

Long-Term Impact of COVID-19 Lockdowns on Physical Fitness in Young Adults

COVID-19 lockdowns also had a significant long-term impact on the physical fitness of young adults.⁹ Researchers conducted a comprehensive analysis involving over 5,300 university freshmen, comparing their physical fitness levels before and after the pandemic lockdowns. Again, not surprisingly, the lockdowns led to notable declines in both aerobic and anaerobic fitness compared to previous years.

The study showed that anaerobic fitness, which is essential for short bursts of intense activity like sprinting, decreased by an average of 0.84 points. More strikingly, aerobic fitness, crucial for sustained activities such as running or cycling, dropped by 2.25 points in males and a more substantial 4.28 points in females. This indicates that young adults became significantly less capable of performing endurance-based activities post-lockdown.

With gyms, parks and sports facilities closed, many young adults found themselves spending more time sitting or engaging in less physically demanding activities like video games or desk work.

Curiously, females experienced greater declines in aerobic fitness compared to their male counterparts. This gender disparity suggests that lockdown measures may have disproportionately affected girls in maintaining their cardiovascular endurance. Possible reasons include differences in how males and females engaged in physical activities during the lockdown or varying access to exercise resources and support systems.

The decline in physical fitness may lead to long-term health issues such as obesity, cardiovascular diseases and metabolic disorders. The study underscores the urgent need to promote physical activity among young adults, especially in the aftermath of lockdowns or similar restrictions. Encouraging regular exercise and reducing sedentary time are essential steps in preventing these negative health outcomes and ensuring that fitness levels recover post-pandemic.

Furthermore, the research highlights that addressing fitness declines is important for supporting the overall health of young adults. Promoting accessible and enjoyable forms of exercise may help mitigate the long-term consequences of the pandemic on youth fitness and well-being.

Lockdowns Led to Vitamin D Deficiency, Worse Birth Outcomes in Pregnant Women

In related news, a team of Spanish researchers looked into the effects of strict lockdown on the prevalence of vitamin D deficiency in pregnant women, noting, “In Spain, a strict lockdown (SL) was declared, with the population being confined at home, therefore influencing their exposition to sunlight.”¹⁰

For this study, vitamin D deficiency (VDD) was defined as a vitamin D level below 20 ng/mL, and vitamin D insufficiency as a level between 20 and 30 ng/mL. This is notable, since it represents an extremely low level of vitamin D. While sufficiency begins around 40 ng/mL (100 nmol/L in European measurements), the target range for optimal health is 60 to 80 ng/mL (150 to 200 nmol/L).

If higher levels were used to define vitamin D deficiency in the study, even more women would have been deemed deficient. Still, even using 20 ng/mL as the deficiency cutoff, 55.5% of pregnant women in the region were vitamin D deficient. Among those on strict lockdown (SL), the prevalence was 77.8%.¹¹

While the study stopped short of examining the pregnancy outcomes of lockdown-driven vitamin D deficiency, past research has linked VDD with adverse effects in pregnancy, including pre-eclampsia, gestational diabetes, preterm birth and caesarean delivery.¹²

COVID-19 lockdown was also associated with an increased risk of gestational diabetes, with risk increasing the longer the lockdown continued,¹³ as well as an increased risk of preterm birth.¹⁴

Other studies also suggest that lockdowns negatively affected pregnant women in other ways. For example, in a study comparing women who experienced a Level I lockdown in China during the pandemic with women who did not, the lockdown group had shorter gestational length and a higher risk of preterm birth.¹⁵

Brain Development and Fitness Are Suffering After Pandemic Lockdowns

To conclude, the COVID-19 pandemic had a profound impact on adolescent brain development and physical fitness, particularly in young girls. These effects, coupled with increased stress and prolonged social isolation, have heightened the risk of mental health challenges, including anxiety and depression.

Physical fitness has also taken a significant hit, with both aerobic and anaerobic capacities declining, especially among young women. The shift toward sedentary lifestyles and reduced opportunities for physical activity has had lasting effects on health and well-being, with implications for long-term health outcomes.

To mitigate these impacts, it’s essential to promote regular physical activity, provide mental health support and encourage healthy lifestyle habits. By understanding the unique challenges faced by adolescents during the pandemic, we can develop targeted interventions to support their recovery and ensure a healthier future for our youth.

Early intervention, consistent support and fostering resilience are crucial steps toward helping adolescents navigate these challenging times and safeguarding their mental and physical health.

• ^1, 4 PNAS September 9, 2024, 121(38)
• ^{2, 5, 6, 7, 8} Child Development August 14, 2024
• ^3, 9 Scientific Reports September 18, 2023, volume 13, Article number: 15430 (2023)
• ¹⁰ Nutrients 2023, 15(8), 1972
• ¹¹ Nutrients 2023, 15(8), 1972, Discussion
• ¹² Nutrients 2023, 15(8), 1972, Introduction
• ¹³ Front Endocrinol (Lausanne). 2022; 13: 824245
• ¹⁴ Front Med (Lausanne). 2021; 8: 705943
• ¹⁵ BMC Pregnancy Childbirth. 2021; 21: 795