Human Benefits of Nature

Increasing physical activity and improvement in obesity rates

• Increasing outdoor play in preschoolers decreases BMI. In this study, the more children played outside, the more their BMI decreased over the school year
• Exercising in natural environments has greater physical and mental health benefits than exercising indoors.
• Access to nature lowers rates of obesity and depression.
• Spending more time outside leads to increased physical activity. In this study, Canadian researchers found that, in a nationally-representative sample of 594 children, for each additional hour 5-6 year olds spent outdoors, they had 10 more minutes of moderate to vigorous physical activity.
• Increased outdoor play in preschools leads to decreased risk of obesity. In this study, researchers found that the more children from Head Start programs played outdoors, the more their BMI decreased over the preschool year and the less likely they were to be obese. Sixty minutes was the tipping point for the association between outdoor play time and improvement in BMI. These associations were stronger among children who were obese at the start of the year, less active at home, and living in unsafe neighborhoods.

Decrease in Diabetes

• Higher residential greenness appears to be associated with a lower prevalence of diabetes
• There is a significant association between neighborhood greenness and reduced odds of having type 2 diabetes.
• Neighborhood greenness is associated with improved insulin resistance in adolescents.

Decrease in hypertension (high blood pressure)

• Multiple studies have shown that forest bathing sessions decrease blood pressure. In one study, blood pressure measurements were taken in subjects who participated in a 1 day forest therapy session. The authors found that systolic and diastolic blood pressure significantly decreased during the forest therapy program relative to the value from 3 days before the program, and this decrease was maintained 3 and 5 days after the forest therapy program.
• Children engaging in green exercise have lower blood pressure than when engaging in standard exercise.

Improvements in cardiovascular health

• Increased neighborhood greenness is associated with improved cardiovascular health and decreased risk of stroke.
• Individuals living in areas with the greatest amount of greenspace have a lower risk of cardiovascular disease.

Improved Sleep

• Time outdoors is associated with improved sleep.
• Exposure to neighborhood greenness is also associated with improved sleep quality.

Improved Immunity

• Forest bathing/Shinrin Yoku significantly improved immune function, evidenced by an increase in activity and number of Natural Killer (NK) cells after a 3 day trip ; and decreased stress, shown by lower concentrations of adrenaline in urine. In addition, the increase in NK activity lasted for more than 7 days after the excursion.

Improved Birth Outcomes

• Pregnant women with access to green space close to home had positive associations with birthweight.
• Further distance for a pregnant woman from a park may be associated with an increased risk of preterm birth.

Decreased Myopia (Nearsightedness)

• Children who spend more time outdoors have reduced rates of nearsightedness, or myopia.

Decrease in Asthma

• Children who live in greener neighborhoods have decreased risk of asthma. Researchers followed 49,956 children born in 1998 in New Zealand through age 18 years and found that those who live in greener neighborhoods had a 6% less likely chance of developing asthma.