islamabad - New research finds evidence of a link between use of certain hair products, such as dyes and relaxers, and raised risk of breast cancer in women.
In their study report, the researchers explain that there is conflicting evidence on whether use of hair products, some of which contain cancer-causing chemicals, or carcinogens, can raise the risk of breast cancer in women.
Some of the evidence comes from animal testing, and some of it comes from studies in defined human populations. However, research in human populations has tended to focus on hair dyes, with mixed results.
The researchers investigated links between raised risk of breast cancer and use of hair products, with particular focus on the use of hair dyes, use of products for relaxing or straightening hair, and use of creams containing cholesterol or placenta for deep conditioning of hair.
When they analysed the data, the researchers found some significant links between raised risk for breast cancer and use of hair dyes and chemical relaxers, or straighteners, and that the patterns of risk differed between white women and black women.
For example, for black women, they found that use of dark shades of hair dye was linked to an overall higher risk of breast cancer, and an even higher risk of estrogen positive breast cancer.
For white women, the analysis found that use of relaxers, or straighteners, either alone or together with hair dyes, was linked to raised risk of breast cancer.
Among white women, there was also a raised risk of estrogen positive breast cancer with use of dark hair dyes and raised risk of estrogen negative breast cancer with use of relaxers.
The authors conclude that these findings support the idea of a relationship between use of certain hair products and a raised risk of breast cancer. They suggest: “Further examination of hair products as important exposures contributing to breast cancer carcinogenesis are necessary.”
Meanwhile, a new study, however, finds that the treatment could be more harmful than helpful if cardiac stem cells are involved.
Researchers found that using patients’ own cardiac stem cells to repair damaged heart tissue may not only be ineffective, but that the stem cells may also develop inflammatory properties that cause further heart damage.
Prof. Leor and colleagues came to their findings by isolating stem cells derived from the cardiac tissue of mice that had left ventricular dysfunction caused by a heart attack.
The team then injected the stem cells back into the hearts of the mice and assessed how they affected heart remodeling and function, compared with a saline solution.
Instead of repairing the rodents’ damaged heart tissue, the researchers found that the transplanted stem cells developed inflammatory properties, which may increase heart damage.
“We found that, contrary to popular belief, tissue stem cells derived from sick hearts do not contribute to heart healing after injury,” explains Prof Leor.
“Furthermore, we found that these cells are affected by the inflammatory environment and develop inflammatory properties. The affected stem cells may even exacerbate damage to the already diseased heart muscle.”
An increasing number of end-stage heart failure patients are turning to stem cell therapy as a “last resort,” but the researchers believe that the treatment should be approached with caution.
“[...] our findings suggest that stem cells, like any drug, can have adverse effects. We concluded that stem cells used in cardiac therapy should be drawn from healthy donors or be better genetically engineered for the patient.”
While the findings may come as a blow for many heart failure patients, the study did uncover some information that could help to improve autologous stem cell therapy.
By studying stem cells derived from the heart tissue of mouse models and humans with heart disease, the team was able to identify the gene that causes the stem cells to develop inflammatory properties.
Furthermore, the researchers found that deleting this gene, called TLR4, can shift the stem cells back to a reparative state, a discovery that the team believes could be used to transform autologous stem cell therapy for patients with heart failure.
“Our findings determine the potential negative effects of inflammation on stem cell function as they’re currently used,” says Prof. Leor. “The use of autologous stem cells from patients with heart disease should be modified.”