‘Sunlight activates the immune cells by increasing their movement throughout the body.’
The skin, which is the largest organ of the body, has twice the number of T cells circulating in the blood. T cells in the skin fight against the microbes that enter the body.
Sunlight is an excellent source of Vitamin D
, which is known to play a role in boosting immunity
"We all know sunlight provides vitamin D, which is suggested to have an impact on immunity, among other things. But what we found is a completely separate role of sunlight in immunity," said Gerard Ahern, Associate Professor at the Georgetown University in the US.
The scientists found that the role of vitamin D in immunity may be due to the new mechanism.
For the production of vitamin D, ultraviolet (UV) lights are required, but high levels of UV lights are known to cause cancer and melanoma. Low levels of UV lights are safer for the skin and also help boost immunity.
When the sunlight reaches the second layer of the skin, which is called 'dermis,' the T cells move throughout the body, thereby strengthening the immune system.
Role of vitamin D on Immunity
Studies have linked low levels of Vitamin D to increased risk of infections. The positive effects of vitamin D on immunity are due to its important part in the innate antimicrobial response. Immune cells such as B cells, T cells, and monocytes appear to respond to the immunomodulatory effects of vitamin D.
Since vitamin D has beneficial effects on the immune system, it has been supplemented to patients with tuberculosis and autoimmune diseases to boost immunity.
Synthesis of Hydrogen Peroxide
Exposure to sunlight increased the synthesis of hydrogen peroxide, which activated a signaling pathway that increases the movement of T cells. Hydrogen peroxide is a compound which is released by the white blood cells (WBC) when they sense an infection in order to kill and mount an immune response.
"T cells, whether they are helper or killer, need to move to do their work, which is to get to the site of an infection and orchestrate a response. This study shows that sunlight directly activates key immune cells by increasing their movement," said Ahern.
Foods that Boost Immunity
Ways to Boost Immunity
- Citrus fruits, guava, broccoli, bell peppers, and spinach are good sources of vitamin C that play a key role in boosting immunity.
- Almonds, sunflower seeds and hazelnuts contain vitamin E, which is a powerful antioxidant that helps fight infections.
- Brazil nuts, sardines, and mushrooms contain selenium, which has a powerful effect on the immune system.
- Oysters, crab, lean meat and baked beans contain zinc that slows down the immune response and reduces inflammation in the body.
- Quit smoking and avoid alcohol
- Limit caffeine
- Wash your hands frequently
- Cook meats thoroughly
- Control blood pressure
- Maintain healthy weight
- Get adequate sleep
- Exercise regularly
- Thieu X. Phan, Barbara Jaruga, Sandeep C. Pingle, Bidhan C. Bandyopadhyay, Gerard P. Ahern. Intrinsic Photosensitivity Enhances Motility of T Lymphocytes. Scientific Reports, (2016);DOI: 10.1038/srep39479