The traditional East Asian diet is particularly high in isoflavonoids, one type of phyto-oestroghen. Levels of isoflavonoids in the blood have been found to be 7 to 110 times higher in Japanese men with a low incidence of prostate cancer, compared to Finnish men.
However, phyto-oestrogens help is not yet fully understood. Professor Norman Blacklock from Manchester University believes they may exert a “weak oestrogen effect”: there is evidence that phyto-oestrogens may block oestrogen receptor sites, thereby lowing body levels of active oestrogen. If this proves to be so, it is consistent with accumulating evidence that many modern diseases, including breast and prostate cancer, are the result of too much oestrogen.
There is also evidence that a protease inhibitor in soya, Bowman-Birk Inhibitor (BBI), may be another anti-cancer compound. A study at the University of Pennsylvania School of Medicine added BBI to the diet of rats that had previously been fed a substance known to induce colon cancer. None of the rats developed tumours. In another similar study, BBI suppressed the formation of tumours by 71 per cent.
Research is beginning to focus on two isoflavonoids (genistein and daidzein).
Japanese women, who generally have a lower risk of breast cancer than women in other industrialised societies, have been found to have higher levels of these in their bodies.
They may protect against the harmful effects of unopposed oestrogen.
A recent study from Singapore, which monitored a group of women for early signs of breast cancer, found that the more soya a woman ate, the less chance was of having pre-cancer changes in breast cells.
Diet advice
A likely ideal intake for cancer prevention is around 5mg a day of genistein and daidzein, which you can get from a 12oz serving of soya milk or a serving of tofu.
During jet lag, your body clock effectively gets out of sync with the earth. Taking the neurotransmitter melatonin can be very helpful, but it needs to be used cautiously. It cannot be bought over the counter in Britain, but can be bought for your own personal use by mail order from the US or from American websites, as restrictions don’t apply there.
Note that supplementing too much melatonin can have undesirable side effects such as diarrhea, constipation, nausea, dizziness, reduced libido, headaches, depression and nightmares. However, none of this is likely with short-term use.
Supplements
The best way to bring yourself back into balance is to start with 1mg of melatonin for every one-hour time difference, just before your new bed time. Take this the first night, then, halve the dose each subsequent night. So, if you fly from London to Los Angeles, which is eight hours behind, you take 8mg of melatonin on the first night, then halve it to 4mg for the second night, 2mg for the third, then 1mg, then stop.
