Recent times have seen breast cancer making its way up the political agenda, and awareness of this condition and the coffers of breast-cancer charities have both been augmented through fundraising activities such as sponsored moonlit walks and the sale of pink ribbons and wristbands. On a recent trip to the US, I discovered special-edition packs of pink M&Ms for sale, a proportion of the profits from which are to be donated to a leading breast-cancer foundation. On the surface, this looks like a sweet enough way to raise money for an important and deserving medical cause.
The selling of chocolate to help fund efforts to combat breast cancer reminded me, however, of recent research linking the eating of sweet foods with this very disease. This research, published in the Annals of Oncology, involved assessing the diets of more than 5,000 women for their intake of sweet foods, such as cakes, biscuits, sugar and chocolate. This study found that, compared with women with relatively low levels of consumption of sweet foods, those with the highest intake had a 19 per cent increased risk of breast cancer. The authors of this study concluded that they had found a direct association between breast-cancer risk and a high consumption of sweet fare.
Some scientists believe that the link between sugary foods and increased cancer risk has something to do with the rapid speed with which such foods tend to release their sugar into the bloodstream. The consumption of these foods, termed high glycaemic index (GI) foods, generally stimulates the secretion of substantial quantities of the chief blood-sugar lowering hormone insulin. The consumption of high-GI foods also seems to affect the activity of a related compound known as insulin-like growth factor (IGF), which is believed to have cancer-promoting properties.
The activity of IGF is to some degree modulated by other related substances known as 'IGF binding proteins' (IGFBPs). In a study published earlier this year in The American Journal of Clinical Nutrition, the consumption of a high-GI meal, compared to slower sugar-releasing food, was found to lead to changes in the levels of two types of IGFBP. It has been suggested that such changes promote the activity of IGF, and in so doing raise cancer risk. Interestingly, the consumption of high-GI foods has previously been linked with an enhanced risk of other cancers, too, including those of the ovary, pancreas and colon. With this in mind, I wonder whether the selling of confectionery to raise money to combat cancer is a good idea after all.
Nutrition news
Osteoarthritis is a common debilitating condition that is characterised by degeneration in the cartilage tissue of one or more joints. While such degeneration may be mechanical in nature, it has been suggested that it may also relate to the activity of damaging substances known as 'free radicals'. Free radicals can be quenched in the body by compounds known as 'antioxidants', which include nutrients such as the mineral selenium. In a recent study, scientists in the US assessed the relationship between osteoarthritis and body selenium levels in 940 individuals. The participants were divided into three groups according to body selenium levels. Individuals with the highest selenium levels were found to have a 40 per cent lower risk of osteoarthritis of the knee compared to those with the lowest selenium status. Low selenium levels were associated not only with an increased risk of osteoarthritis, but more severe disease, too. This study, presented at the annual meeting of the American College of Rheumatology, suggests that higher selenium intakes may help to protect against osteoarthritis. Maintain a good intake of selenium by eating a few Brazil nuts each day or supplementing with about 200mcg of this mineral daily.
Dear John
I suffer from pernicious anaemia, and need to have regular B12 injections. Will this condition affect my ability to absorb either folic acid or vitamin B6?
Name withheld
The absorption of vitamin B12 depends to a large degree on the presence of a substance called intrinsic factor, which facilitates the nutrient's transfer through the gut wall and into the body. Conventional wisdom dictates that individuals with pernicious anaemia have insufficient amounts of intrinsic factor to enable them to absorb adequate amounts of vitamin B12 from their diets. Such individuals are usually advised to have B12 injections.
It is very unlikely that your relative lack of intrinsic factor will result in problems with your ability to absorb vitamin B6 and folic acid, as these nutrients do not require intrinsic factor for their absorption. Also, while it is assumed that individuals with pernicious anaemia require B12 injections to maintain B12 levels in the body, there is evidence that they can maintain B12 levels through oral supplementation of 1,000 mcg (1mg) of B12 per day.
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