Poverty in childhood linked to higher cancer death risk

A new research suggests that a poor diet and poor living conditions in childhood may influence a person’s risk of developing cancer.

A review of 22 studies found poor diet and growing up in poorer households was linked to several cancers, including bowel and stomach.

The study published in the Journal of Epidemiology and Community Health found that families living in the poorest housing conditions, and where the father had a low status job, had children with a higher lifetime risk of bowel cancer.

There was also a link with stomach cancer, with less well-off families more likely to be exposed to the bacteria Helicobactor pylori, which is a common cause of stomach ulcers and increases the risk of stomach cancer.

Researchers found that poor living conditions as a child were linked to a higher risk of death from cancer overall.

Also, high levels of water hardness in the home may be linked to the development of eczema early in life, according to a new study led by King’s College London, United Kingdom (U.K.).

Eczema affects around a fifth of children globally. Skin barrier impairment and dry skin are thought to be triggers of eczema in early life, partly through genetic predisposition. Environmental factors may also contribute to the breakdown of the skin barrier, including water hardness and chlorine in household water.

Previous studies in the U.K., Spain and Japan have shown associations between domestic water hardness and the risk of eczema in schoolchildren. However, the link between water hardness and eczema has not been studied in early infancy.

The latest study, published in the Journal of Allergy and Clinical Immunology, examined the link between water hardness and chlorine concentrations in household water, damage to the skin’s natural barrier and eczema in infancy.

Researchers recruited 1,300 three-month old infants from families across the U.K. taking part in the EAT study and gathered data on levels of calcium carbonate (that is water hardness) and chlorine in their household water from local water suppliers.

The infants were checked for atopic dermatitis (childhood eczema) and their skin’s barrier function was assessed by measuring transepidermal water loss (TEWL) on the skin of an unaffected forearm. Infants were also screened for mutations in the filaggrin (FLG) gene, which codes for a key skin barrier protein. Mutations in the FLG gene result in an impaired skin barrier, which is thought to allow allergens to penetrate the skin and predispose the body towards an allergic response. Information on the use of a water softener in the home, frequency of bathing and use of moisturizers and bath products was also collected.

Living in a hard water area was associated with an up to 87 per cent increased risk of eczema at three months of age, independent of domestic water chlorine content. The risk tended to be higher in children with mutations in the FLG skin barrier gene, although these latter results were not statistically significant.

Although the study attempted to account for potential confounding factors, such as bathing frequency and the use of soaps and shampoos, skin care and hygiene practices could have already changed by the time of enrolment into the study due to the early emergence of eczema or dry skin. The study also did not have information on children’s exposure to swimming pools, which contain much higher chlorine levels than domestic water and could have an additional detrimental effect on skin barrier function and risk of eczema.

Lead author of the first study and head of Cancer Research UK’s policy research centre, said: “Children who lead healthy lives with strong family and social support will develop healthier behaviours that are likely to reduce their risk of cancer later in life.

“We already knew there was a link between poor living conditions as a child and heart disease. But our research provides more evidence of the link between a child’s surroundings and their risk of developing cancer later in life.”

Dr. Carsten Flohr, lead author from St John’s Institute of Dermatology at King’s College London and Guy’s and St Thomas’ NHS Foundation Trust said: “Our study builds on growing evidence of a link between exposure to hard water and the risk of developing eczema in childhood.”