How lifestyle habits increase breast cancer risk

Poor diet and lack of exercise are associated with cancer development. PHOTO| FILE | NATION

When nutrients, sugars and fats are broken down by the body, advanced glycation end products (AGEs) are formed. When one consumes processed foods that are high in sugar and fat, AGE levels increase. Certain cooking techniques, such as grilling, searing and frying, also increase AGE formation.

Poor diet and lack of exercise are associated with cancer development, but the underlying biology is not well understood.

Advanced glycation end products (AGEs) could offer a biological link that explains how certain lifestyle habits increase cancer risk or lessen the likelihood that an anti-cancer therapy will be effective.

AGEs cause an imbalance between molecules called free radicals and antioxidants, leading to chronic inflammation that can promote the development of a variety of chronic diseases.

As AGEs accumulate in body organs, they cause damage that is associated with diseases such as diabetes, Alzheimer's, cardiovascular disease, arthritis and cancer. However, AGEs have not been studied in depth in the context of cancer.

Researchers report that AGE levels are higher in patients with oestrogen receptor (ER)-positive than ER-negative breast cancer.

PROMOTE CANCER CELL GROWTH

Moreover, addition of AGEs caused breast cancer cells, whose growth had previously been controlled by the drug tamoxifen, to begin to grow again. This suggests that patients with high AGEs may be less likely to respond to tamoxifen treatment.

Elevated AGE levels lead to continual activation of pathways that promote cancer cell growth. A key molecule turned on by those pathways is important in the context of ER-positive and ER-negative breast cancer. This led researchers to explore how AGE might affect cancer cell signalling in ER-positive breast cancer.

They found that AGEs increase the phosphorylation (a process that turns on a biological pathway) of a protein called oestrogen receptor alpha in a breast cancer cell line model. Adding tamoxifen to the cancer cells prevented their growth. However, adding AGEs caused them to grow once again.

The team also found that a defined lifestyle intervention of exercise and dietary counselling lowered systemic levels of AGEs in overweight women with non-metastatic ER-positive breast cancer.

Further research could shed light on how lifestyle interventions can beneficially affect cancer treatments by reducing AGE levels.
The findings were published in the journal Breast Cancer Research and Treatment.