Illustration of Earth's orbit around the sun showing the four seasons in the Northern and Southern Hemispheres. Spring occurs when Earth's tilt leans toward the sun in March, with summer in June, fall in September, and winter in December, opposite in the Southern Hemisphere.

  • The sun’s rays are strongest at the equator

  • UV and blue light are immune suppressing

  • Red and Infrared light are immune strengthening

  • In winter there is less light that correlates with more disease and death. This is reverse for summer

  • Cancer and autoimmune disorders are less at the equator

Sunlight Prevents Disease

Line graph showing Type 1 diabetes rates by latitude, with higher rates in higher latitudes and lower rates near the equator. Countries like Sardinia, Italy, and Finland have the highest rates, while Chile, Uruguay, and Argentina are at the lower end.
Graph displaying breast cancer rates by latitude, showing higher rates in the USA and Ice at high latitudes, with lower rates around the equator.
Graph showing decay of influenza virus under simulated sunlight. The x-axis represents time in minutes, and the y-axis shows percent of starting concentration. Two curves: one for total aerosol mass (open circles) and one for infectious virus concentrations (filled circles). The infectious virus decreases rapidly, reaching nearly 0% at around 8 minutes, indicating roughly 100% viral decay at 8 minutes.
Line graph showing the percentage of mortality related to coronavirus each month from July to June, with a peak in January, and declining after.
Line graph titled 'Colorectal Cancer Rates by Latitude' showing incidence rates per 100,000 at various latitudes, ranging from -40 to 70 degrees, with higher rates at higher latitudes. Data source: GrassrootsHealth, chart date 5/9/2019.
Line graph showing the relationship between ultraviolet exposure and breast cancer risk among women over 40. The graph indicates that increased ultraviolet exposure from sunlight reduces breast cancer risk, with a 10% reduction for each 1000 milliwatt per square meter hour increase in sunlight dose. The x-axis measures ultraviolet exposure in milliwatt per square meter hours, and the y-axis represents relative risk, ranging from 0.65 to 1.00. The chart is attributed to Grassroots Health, with a chart date of 5/14/2021, and cites a 2020 study by Li and Ma in Medicine.
Graph depicting lung cancer rates by latitude for men and women, showing higher rates at higher latitudes.
Line graph showing mortality rates from 2005 to 2018, with fluctuations over time.