From BBC News:
Historically women from this ethnic group have had a lower risk of the disease than white British women, the University of Sheffield team said.
But they found breast cancer incidence had risen in recent years for South Asian women.”
I wonder if these are largely British-born women of South Asian descent? These women, unlike their immigrant parents, will not have been born into a world where the amount of sunlight is of any use, regardless of whether they dress highly conservatively.
“Between 2000-2004, South Asian women were found to have a 45% cent lower rate of breast cancer compared with white women.
But by the 2005-2009 period, rates of breast cancer among South Asian women had increased significantly and had risen to be 8% higher than white women, whose rates had not changed significantly.
… “The exact causes behind this change are not clear cut, they could relate to increases in screening uptake among these groups of women, which have in the past been shown to be lower than in other groups.”
Large South Asian – and black – migration to the UK started around the 1950s/1960s (on British appeal to former Empire-ruled regions to fill jobs); many of them will have had children who are about 50-60yrs old now, a fairly untypical age range for breast cancer to arise. We’re probably seeing a growing cohort effect. And it’s not improbable that childhood sun exposure could have a lasting cancer-protective effect even if there is deficiency later in life.