Eight of the ten counties in the San Francisco Bay Area have higher rates of leukemia than the state average. Napa County has the highest rate in California, with 1 in 6,000 people diagnosed each year. A possible cause for the higher rates is the region's high protein diets, which are linked to increased secretion of IGF-1 and a higher risk of developing leukemia. Meat consumption in the Bay Area is estimated to be above the national average based on USDA and NASS statistics. High protein diets have been shown to promote abnormal cell growth associated with cancer.