A new study has found that eating a large amount of red meat in early adulthood could be associated with an increased risk of breast cancer.

While a second separate newly-published piece of research has found that women with large numbers of moles on their skin may also face a heightened risk of developing the disease.

The first study looked at the eating habits of 89,000 women aged 26 to 43 who were surveyed in 1991.

The scientists then examined the women's medical records over the intervening 20 years and found over 2,800 had developed breast cancer.

Their analysis, published in the British Medical Journal, found a higher intake of red meat was associated with a 22% increased risk of breast cancer.

But substituting one serving of red meat a day with legumes, nuts, poultry and fish reduced the risk by 14%.

However, other experts urged caution, saying the totality of all available evidence indicates red meat consumption has little or no effect on breast cancer risk.

Meanwhile a separate study, published in the journal PLOS One, found women with at least 15 moles on their arm were a third more likely to be diagnosed with breast cancer than those with none.

The authors say the findings require further investigation, to see if there is a need to change clinical screening and treatment.