"Free radicals — like the kind formed from sun exposure — damage the membrane of skin cells, potentially allowing damage to the DNA of that cell," says Heller.
This might seem to suggest an appropriate correspondence between the sequence of subjective experiences and the sequence of the underlying events in the brain.
Keys gathered data on heart disease and its potential causes from nearly 13,000 men in Greece, Italy, Croatia, Serbia, Japan, Finland, the Netherlands and the United States.
It is important to note that other factors, such as volcanic particulates or variations in the amount of sunlight received by the Earth, could potentially have affected the climate.