The acceleration of global aging has gradually entered the life of ordinary people with the medical term "Alzheimer's disease", and various types of research are also emerging every year, and even some people shout out the slogan of "cancer is not terrible, dementia is more terrible".
On April 25, The team of Professor Yu Jintai of Huashan Hospital affiliated to Fudan University and the team of Tan Lan, professor of Qingdao Municipal Hospital affiliated to Qingdao University, published a book entitled "Time spent in outdoor light is associated with the risk of dementia: a prospective cohort study of 362094" at BMC Medicine (8.775/Q1). participants" research papers. They conducted a prospective cohort study of 362,094 participants over a nine-year period, revealing for the first time a statistical association between sun exposure and dementia, and suggesting that moderate sun exposure can help prevent "Alzheimer's disease," refreshing our understanding of dementia prevention.
Breztrit said: Where the sun shines, it is where I live.
Basking in the sun is one of the most common forms of health care in our lives. A large number of recent studies have also shown that sun exposure has an important impact on the body's vitamin D (VD) synthesis and absorption, sleep rhythm adjustment and other physiological functions. An important association has been reported between low levels of VD in the body and dementia; while 44% of patients with dementia have circadian rhythm abnormalities. At present, strong light therapy (BLT) has been recognized as a promising non-pharmacological dementia intervention.
However, previous studies have not had direct epidemiological evidence of a pre-existing relationship between sunlight and dementia, and there have been fewer studies of the population involved. In addition, people aged 4-64 in the UK generally believe that sun exposure can supplement with enough VD, so pooling VD in the UK population is not a strictly required dietary vitamin.
In light of this, this paper conducts a large-scale cohort study of the longitudinal correlation between daytime light and dementia-related outcomes in the UK population. In order to provide reasonable light guidance for people living in high latitudes to effectively prevent dementia.
Flow chart of study design
The study recruited around 500,000 men and women aged 37 to 73 years from 2006 to 2010 across the UK. In addition, the statistics take into account factors such as age, sex, education, skin color, use of sun/UV protection, employment status, sleep duration and air pollution, fracture history, vitamin D supplementation, hearing loss, smoking status, alcohol consumption, cardiovascular disease (CVD), total exertional activity (TPA), and body mass index (BMI).
After statistical analysis, the article found that of the 362,094 effective volunteers, 4,149 (1.15%) were diagnosed with dementia during the 9 years of follow-up. This may be analyzed to be associated with low levels of education, never or with little sun protection, unemployment, disturbed sleep schedules, higher PM 2.5 exposure, smoking and drinking, and cardiovascular disease.
Most critically, statistics found that the average time spent outdoors in light was significantly longer than that of volunteers who did not develop dementia.
This caught the researchers' attention, and then the researchers explored the relationship between outdoor light time and dementia.
The correlation between outdoor light time and incident dementia during follow-up
Nonlinear spline model analysis showed a nonlinear association between sunlight exposure (as a continuous variable) and dementia outcomes. A significant increase in the risk of dementia can be observed in either too high or too low sunlight exposure. The segmented nonlinear model analysis showed that the average of 1.5 hours per day, 2 hours a day in summer and 1 hour per day in winter was the most conducive to reducing the risk of dementia. Multifactor cox regression analysis showed that an average of 1.5 hours above or below significantly increased the risk of dementia.
Overall, there is a "J-shaped" curve between sun exposure time and dementia risk. The increase in risk of dementia is significantly accelerated at shorter periods of light, while the increase in risk is relatively slow at longer periods of light.
To further rule out statistical errors, the researchers were able to observe similar results after excluding data from follow-up people under 3 years and more than 10 years. After all the variables were synthesized into the analysis, the results did not change.
In addition, the researchers also found several interesting phenomena:
First, participants over 60 years old showed a more obvious "J-shaped" curve, and the appropriate light time was significantly longer than that of other age group participants (reaching an average of 2 hours per day, 3 hours per day in summer, and 1 hour per day in winter). In participants under the age of 60, light exposure and dementia were not significantly dose-dependent.
Second, women have the lowest risk of dementia, the most appropriate average sunshine time per day is 2 hours, too high or too low will increase the risk of dementia.
Even with regular work and rest, adequate sleep still requires an average of 1.5 hours of light per day to reduce the risk of dementia (2 hours a day in summer and 1 hour per day in winter).
It is well recognized that basking in the sun is good, but the disadvantages are also obvious!
So the article also talks about the disadvantages of sunbathing at the end, including sunburn, skin cancer (melanoma, lip cancer and keratinocytes) and eye diseases (cataracts, ultraviolet keratitis). Therefore, the optimal light time found in this paper is more meaningful.
When the water is full, it overflows, and the monthly profit is lost. China's ancient "moderate" wisdom tells us that what we do end up with a balanced "degree."
The same is true for sunbathing, moderation is good!
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Written by | Ann Piglet
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