Posted on Sep 26, 2013 by Ruth Loftus
A new study compiled by researchers at London’s Imperial College, indicates a strong correlation between a woman’s weight, her level of physical activity, and her chances of contracting endometrial cancer - which affects the lining of the womb.
The research was published by the World Cancer Research Fund earlier this month. The cancer charity, which claims to be the first to raise awareness about correlations between diet and cancer risk, compiled the first global analysis of this type of cancer since 2007. The research is expected to attract a lot of attention because womb cancer is currently the sixth most common of all cancers in women globally - and it ranks even higher in the UK at fourth place. The new findings state that reducing Body Mass Index and increasing the length of time spent on daily exercise could decrease the chances of women developing this cancer.
The study itself was a Continuous Update Project (CUP), and was compiled using the data and reviews from existing research. A CUP aims to provide a thorough summary of the primary data and relevant literature in order to answer a specific research question. Here, the researchers set out to investigate a total of 159 existing articles about endometrial cancer in order to get a closer understanding of the relationship between this type of cancer and a number of factors including food, nutrition, physical activity and body fat.
The data indicated that reducing the intake of carbohydrate-rich foods reduced the risk of womb cancer because a lower Glycemic Load (the measurement of the amount of carbohydrates per food serving), can protect against endometrial cancer. The report concluded that there was ‘generally consistent evidence from cohort studies (that) Glycaemic load is a probable cause of endometrial cancer’.
The report also indicated that the evidence for the relationship between carbohydrate intake and womb cancer was largely based on findings from developed countries where carbohydrates commonly come in the form of sugars and highly processed foods. In addition, evidence shows that endometrial cancer is more prevalent in high-income countries, with the highest incidences in North America, and Central and Eastern Europe (and the lowest number of cases in Middle and Western Africa). This news received a lot of attention in England recently, which is not surprising considering national statistics released in 2011 indicated that 26% of women in England are obese, and are therefore at high- risk.
The findings also state that increasing physical activity such as cycling or fast walking could have a positive effect. Ideally, to remain healthy, women are expected to do 2 hours and 30 minutes of moderate-intensity aerobic activity per week which should be divided into at least five separate periods. The hormones in fat cells increase the cancer risk, and physical exercise has been proven to keep these hormone levels healthy, thus lowering the risk. The CUP found that if women are active for at least 30 minutes per day (38 minutes ideally), approximately 3,700 cases of endometrial cancer could be prevented annually.
A high proportion of sedentary behaviour- in particular long periods of sitting - was also considered as a risk factor for womb cancer. Although the evidence was limited at this stage, ongoing research into the relationship between the two will continue because long periods of sitting time has been linked to weight gain and and shown to increase the risk of insulin resistance, which is known to have an impact on endometrial cancer.
Perhaps the most surprising point derived from reviewing all the existing worldwide studies into cancer risk related to diet, physical activity and body weight, was the news that drinking coffee might reduce the risk of endometrial cancer. The CUP identified eight studies, all of which indicated a lower womb cancer risk for those with the highest coffee intake. There are a number of scientific theories as to why coffee has this impact: firstly, it is thought that coffee is related to reduced insulin levels, particularly among overweight women; additionally, big coffee consumption has indicated higher levels of adiponectin (a hormone which has proven to be inversely correlated with body fat percentage in adults).
As yet, many medical experts say that this CUP analysis is not enough evidence for them to start recommending patients to more drink coffee to protect against the disease. More research into this area is expected, however, it might only be a matter of time before high caffeine intake is regarded more positively by the medical world.