Friday, April 25, 2008

Cancer survivors have low levels of physical activity and high levels of obesity

You are less active after undergoing treatment for cancer. Who knew? Who would have DREAMT that those nasty cancer treatments would slow you down? It must have been very disappointing to them that only one in five of cancer survivors was obese, though. And they have the hide to makes policy recommendations on the basis of this crap!

A new study reports that many cancer survivors are inactive and obese, which may negatively affect the control of their disease. The findings, which come from a study of cancer survivors in Canada, show that a cancer diagnosis does not appear to prompt significant behavior change and that interventions to increase physical activity and promote better eating habits among cancer survivors are warranted. The study is published in the June 1, 2008 issue of CANCER, a peer-reviewed journal of the American Cancer Society.

Obesity and physical inactivity are known to be detrimental to health, and in cancer patients, studies have linked these factors to negative outcomes including disease recurrence, cancer-specific death and reduced quality of life. However, few studies have looked at the prevalence of physical activity and obesity in populations of cancer survivors.

To determine this prevalence and compare it to individuals without a history of cancer, Kerry S. Courneya, Ph.D. of the University of Alberta in Edmonton analyzed data from the 2005 Canadian Community Health Survey consisting of computer-assisted interviews of more than 114,000 adults. Survey participants reported their cancer history, height and body weight (to calculate body mass index), and participation in various leisure time activities.

The study revealed that fewer than 22 percent of Canadian cancer survivors were physically active, with the lowest rates reported by male and female colorectal cancer survivors, female melanoma survivors and breast cancer survivors. Also, nearly one in five (18 percent) of cancer survivors was obese, and one in three (34 percent) was overweight with little variation among the cancer survivor groups. The authors concluded that Canadian cancer survivors have low levels of physical activity and a high prevalence of obesity that are comparable to the general population.

However, some differences were found between cancer survivors and those without a history of cancer. Prostate cancer survivors were more likely to be active and less likely to be obese than men without a history of cancer, and male skin cancer survivors were more likely to be active than their disease-free counterparts. Also, obese breast cancer survivors were less likely to be active compared with obese women without a history of cancer. "This finding is cause for concern because physical activity may be particularly important for obese breast cancer survivors," the authors note. Studies suggest that obese breast cancer survivors may particularly benefit from higher physical activity levels in terms of preventing disease recurrence and improving quality of life.

In light of their findings, the authors recommend that lifestyle interventions be implemented to increase physical activity and promote a health body weight among cancer survivors.


Mother's diet can influence baby's sex

This sounds pretty crazy. It is a gene on the Y chromosome contributed by the MALE that determines sex. I suppose the woman could do some sort of spontaneous selective abortion, though. Note: It is entirely possible that diet-type is a proxy for something else (such as social class) rather than itself being the causative agent for what do seem to be some rather interesting differences. So if you decide to eat up big on the basis of these findings, you could well be wasting your time

Oysters may excite the libido, but there is nothing like a hearty breakfast laced with sugar to boost a woman's chances of conceiving a son, according to a new study. Likewise, a low-energy diet that skimps on calories, minerals and nutrients is more likely to yield a female of the human species, says the study, published in Proceedings of the Royal Society B: Biological Sciences, Britain's de facto academy of sciences.

Fiona Mathews of the University of Exeter in Britain and colleagues wanted to find out if a woman's diet had an impact on the sex of her offspring. So they asked 740 first-time mothers who did not know if their unborn fetuses were male or female to provide detailed records of eating habits before and after they became pregnant. The women were split into three groups according to the number calories they consumed per day around the time of conception.

Fifty-six per cent of the women in the group with the highest energy intake had sons, compared to 45 percent in the least-well fed cohort. Beside racking up a higher calorie count, the group who produced more males were also more likely to have eaten a wider range of nutrients, including potassium, calcium and vitamins C, E and B12. The odds of an XY, or male outcome to a pregnancy also went up sharply "for women who consumed at least one bowl of breakfast cereal daily compared with those who ate less than or equal to one bowl of week", the study reported.

These surprising findings were consistent with a very gradual shift in favour of girls over the last four decades in the sex ratio of newborns, according to the researchers. Previous research had shown - despite the rising epidemic in obesity - a reduction in the average energy uptake in advanced economies. The number of adults who skipped breakfast had also increased substantially.

"This research may help to explain why in developed countries, where many young women choose low calorie diets, the proportion of boys is falling,'' Ms Mathews said. The study's findings could point to a "natural mechanism'' for sex selection. The link between a rich diet and male children might have an evolutionary explanation. For most species, the number of offspring a male can father exceeds the number a female can give birth to, but only if conditions are favourable.

Poor quality male specimens may fail to breed at all, whereas females reproduce more consistently. "If a mother has plentiful resources, then it can make sense to invest in producing a son because he is likely to produce more grandchildren than would a daughter,'' thus contributing to the survival of the species, Mathews said. "However, in leaner times having a daughter is a safer bet.''

While the mechanism is not yet understood, it is known from in vitro fertilisation research that higher levels of glucose, or sugar, encourage the growth and development of male embryos while inhibiting female embryos.


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