Wednesday, October 01, 2008

ARE TALLER PEOPLE HEALTHIER? And the role of calorie restriction

The study below found that taller people are healthier but seem not to realize that this is a fairly common finding. They attribute their findings to nutrition -- arguing that food shortage stunts growth -- which it does. So they say that the tall women in their Korean sample are healthier because they were better nourished while growing up.

I should take the time to look up the studies but the height/health correlation has also been found in Western countries where there are little or no food shortages so I think a genetic explanation is more likely to be the real explanation for their findings. Calorie restriction in fact seems generally to lead to LONGER life so using it to explain SHORTER life is drawing a long bow

Adult Height and the Risk of Mortality in South Korean Women

By Yun-Mi Song and Joohon Sung

To evaluate the association between adult height as a surrogate marker of childhood circumstances and the risk of mortality, 344,519 South Korean women aged 40-64 years categorized into six height groups were prospectively followed for mortality between 1994 and 2004. In Cox proportional hazards regression with adjustment for behavioral and biologic risk factors, there was an inverse association between height and total mortality; mortality risk decreased 7% for each 5-cm increment in height. The association did not materially change after adjustment for behavioral factors and adulthood socioeconomic factors or after full adjustment for all available covariates. When height-associated risks of death from specific causes were evaluated in a fully adjusted analysis, a 5-cm increment in height was associated with lower risks of death from respiratory diseases, stroke, diabetes mellitus, and external causes (hazard ratios were 0.84 (95% confidence interval (CI): 0.74, 0.96), 0.84 (95% CI: 0.80, 0.88), 0.87 (95% CI: 0.80, 0.96), and 0.88 (95% CI: 0.83, 0.94), respectively) and with a higher risk of death from cancer (hazard ratio = 1.05, 95% CI: 1.02, 1.09). Given that adult height reflects early-life conditions, the independent associations between height and mortality from all causes and specific causes support the view that early-life circumstances significantly influence health outcomes in adulthood.

American Journal of Epidemiology 2008 168(5):497-505

Social class dictates cancer risk

Some cancers are more common in the rich and some are more common in the poor. Rather good evidence that there are tradeoffs whatever you do. Reducing one risk may expose you to another, different, risk

Cervical and lung cancer are more common in poor people while rates of breast cancer and melanoma are higher in the wealthy. A detailed analysis of the incidence of these four different kinds of cancer, carried out on more than 300,000 English cancer patients and published today in the open access journal BMC Cancer, describes the effects of socioeconomic group, region and age.

Lorraine Shack at the North West Cancer Intelligence Service and a team of researchers working on behalf of the United Kingdom Association of Cancer Registries used information from all eight English cancer registries from 1998 to 2003. They compared the rates of these four cancers with variations in deprivation. The data were further categorised by the person's age.

As Shack describes, "We looked at all invasive cases of lung cancer, cervical cancer, malignant melanoma of the skin and female breast cancer. The deprivation statistics were based on average levels of socioeconomic status in the patient's local area."

Malignant melanoma and breast cancer were most common in more affluent groups. According to the authors, the variations in breast cancer rates may be because "Women from affluent socioeconomic groups are more likely to have their first child at a later age, have fewer children in their lifetime and take hormone replacement therapy. Each of these factors is associated with a slightly higher incidence of breast cancer."

The higher incidence of melanoma in the more wealthy groups may be partially explained by holidays abroad and the resulting exposure to UV. However, the authors highlight that sun bed use may have an impact across all socioeconomic groups, particularly in the young, "It is difficult to estimate sun bed use as most salons are private and poorly regulated. However, anecdotal evidence suggests that sun bed use is increasing in England, particularly for teenagers and young adults. Sun parlours tend to be clustered in areas of deprivation."

The study also found that the highest rates of lung and cervical cancer occurred in the most deprived groups. The higher incidence of lung cancer in the deprived groups is squarely blamed on smoking, "Smoking is strongly associated with socioeconomic status and over 80% of lung cancer cases can be estimated to be attributable to smoking."

Worryingly, the authors found the greatest difference in lung cancer rates between socioeconomic groups in people under the age of 65, possibly suggesting that the more deprived groups continue to smoke while the wealthier groups have quit smoking.

The study provides further evidence of the link between wealth and cancer risk. Research such as this has a crucial role to play in tailoring government screening programmes, and other preventative measures, to local needs.


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