Vezels
tegen borstkanker.*
Voeding met veel vezels kan het risico voor jonge vrouwen (nog niet in de overgang) op het krijgen van borstkanker met 50% verminderen, aldus een Engelse studie onder 35.000 vrouwen. Onderzoekers vonden echter geen significant effect van een vezelrijk dieet op het risico voor postmenopauzale vrouwen. Eerdere onderzoeken hebben geen duidelijke link gelegd tussen een vezelrijk dieet en een verminderd risico op borstkanker. Maar eerdere studies maakten ook geen onderscheid tussen pre- en postmenopauzale vrouwen. Volgens de onderzoekers zijn er drie mogelijke redenen voor het anti-kanker effect van een vezelrijk dieet:
Vezels hebben een stabiliserend effect op de insuline waarden van het lichaam. (Hoge insuline waarden geven een groter risico op het ontstaan van kanker.
Voedsel
rijk aan vezels
bevat ook vaak andere grotere essentiële voedingstoffen, waaronder belangrijke
antioxidanten.
Wellicht de meest belangrijke reden, voedingsvezels
verlagen de oestrogeenwaarden. Hoge oestrogeenwaarden doen het ontstaan van
borstkanker bevorderen. Dit verklaart wellicht ook het verschil in
uitkomsten tussen pre- en postmenopauzale vrouwen.
Volgens de studie zouden jonge vrouwen tenminste 30 gram vezels per dag moeten eten om het risico op borstkanker te
verminderen.
De studie werd gesponsord door het Wereld Kanker Onderzoek Fonds.
Using Fibre In The Fight
Against Breast Cancer
Wholemeal
bread and wholegrain cereal could be key weapons in the battle against breast
cancer.
New research from the University of Leeds has shown how eating more fibre
particularly cereal fibre reduces the risk of developing breast cancer among
pre-menopausal women.
Researchers at the University's Centre for Epidemiology and Biostatistics have
been tracking the eating habits and health of more than 35,000 women for the
past seven years, and their latest findings are published in the International
Journal of Epidemiology. Their figures suggest that among the pre-menopausal
women, those who have the greatest intake of fibre have cut their risk of breast
cancer in half.
The research is led by Professor Janet Cade, who explained: "Previous
research hasn't shown a convincing link between increased dietary fibre and a
lower risk of breast cancer. But earlier studies didn't draw any distinction
between pre- and post-menopausal women. Our study found no protective effect in
the older group, but significant evidence of a link in the pre-menopausal women."
Of the huge group, 257pre-menopausal women have developed breast cancer during
the study. These were shown to be women who had a greater percentage of energy
derived from protein, and lower intakes of dietary fibre and vitamin C, compared
to the cancer-free women.
The research, which received initial funding from the World Cancer Research Fund,
suggests several possible reasons for this effect:
1. High fibre foods are rich in vitamins, zinc and other micro-nutrients which
have protective anti-oxidant properties;
2. Fibre can smooth out the peaks and troughs in insulin levels in the body.
High levels of insulin may be one possible cause of cancer;
3. There is a known link between breast cancer and the female hormone oestrogen,
and dietary fibre has been demonstrated to regulate oestrogen levels in the
body. This effect would be especially relevant to the pre-menopausal group who
naturally have far higher levels of the hormone.
Said Professor Cade: "Also, we don't yet know at which point in life
dietary habits impact on a woman's susceptibility to breast cancer. The relevant
exposure may be earlier in life, explaining why the protective effect was not
shown in the post-menopausal group."
Whatever the precise cause, or combination of causes, the study does show a
statistically significant effect and supports the message of eating well to stay
healthy. Professor Cade added: "It goes along with the general healthy
eating advice to make sure that you are getting plenty of fibre in your diet
through breakfast cereals, bread, pasta, fruit and vegetables."
(Febr. 2007) (Opm.
Meer over vezels in de voeding.)