As healthy lifestyles go, the one I am following is hard to beat. Here is the lowdown: although I am eating all I want to at the moment, I am losing weight. Even better, research shows I am unlikely to put it back on again. My blood pressure is down and likely to stay that way, and despite a demanding schedule with four young children I feel a lot less stressed than usual.
And there is more. Without having to forgo any of the pleasures of life, I am managing to cut the risk of contracting both breast and ovarian cancer. My chances of a hip fracture in later life are lower than they were, and I am less likely to die of rheumatoid arthritis.
Even more astonishing, this health regime is not costing me anything: in fact, it is saving me several hundred pounds a year. Because all I am doing right now is breastfeeding my three-month-old baby, just as I breastfed her three older sisters.
Like most breastfeeding mothers, I was keen to breastfeed because it seemed more natural, and I knew it would give them a healthy start. But what I had not realised until recently was how much of a health boost I would be getting into the bargain.
Most campaigns aimed at encouraging women to breastfeed stress how good it is for the baby - but comb through the research papers on how it benefits mothers, and you begin to wonder whether we don't come out of it even better than the children. After all, everyone knows someone who was bottlefed and ended up with a first from Oxbridge - despite all that research that shows how breastfeeding boosts childrens' brain power - and there is no doubt that infant formula, if you do end up using it, is now better than it has ever been.
Breast cancer rates, on the other hand, are soaring - and while we are all worried as hell about them, most of us feel there is very little we can do to protect ourselves beyond checking for lumps. But according to a 1994 US study involving 14,000 women, the rate of breast cancer is 22% lower among pre-menopausal women who breastfed than among those who had not. The authors estimated that if all women with children breastfed for between four and 12 months, breast cancer rates could be reduced by 11% - and if all women with children breastfed for a total of 24 months, the incidence of the disease could be slashed by 25%.
Earlier this year a study by leading epidemiologist Sir Richard Doll concluded that a woman cuts her risk of breast cancer by 4% for every year that she breastfeeds. Another epidemiologist, Dr Stephen Duffy of Cancer Research UK, says that figure could be even higher. "It's certainly true that breastfeeding has a real protective benefit. We've known about it for decades, but it used to be thought that it was artificial because the real benefit was from being pregnant and giving birth, rather than from breastfeeding as such. Now we know that's wrong - there is a benefit from having a baby, but there's another benefit from breastfeeding as well."
The benefit is thought to be hormonally-based, says Duffy. "We know that breast cancer is linked with exposure in the breast to ovarian oestrogens, so it's likely that the protection breastfeeding offers comes about because the menstrual cycle is usually suppressed for longer in women who breastfeed, and so oestrogen levels are reduced for that time."
More could be made of the protective aspects of breastfeeding. "Breast cancer is mostly linked with things you've little or no control over - when you first started to menstruate, your family history, when you had your first child - but here is something many women do have some control over, whether or not they breastfeed. Given that, I do think it's surprising that so little has been made of this evidence, because it does seem very convincing."
Duffy believes breastfeeding offers greater protection against breast cancer than against other cancers, but there is evidence that ovarian cancer could be held at bay too. In 1993 a study sponsored by the world health organisation showed a 20%-25% decrease in the risk of ovarian cancer for women who lactated for at least two months per pregnancy. The same year another piece of research, which looked at 311 women over 65 with hip fractures, concluded that those who had had children but hadn't breastfed had twice the risk of a break than women who had never had children and those who had breastfed. Two years later, a Norwegian study found a link between breastfeeding and a reduction in risk of dying from rheumatoid arthritis, although it is generally acknowledged that more work is needed on this.
Just as positive, for many women, is the fact that breastfeeding helps them return to their pre-pregnancy weight - and what's more, to stay there. Some studies have shown that women who are feeding their babies themselves are losing weight faster as early as one month after the birth. Others suggest this weight loss speeds up after three months for a mother who is continued to breastfeed. Not altogether surprising, in fact, when you bear in mind that feeding a baby uses up an extra 500 calories a day.
Psychologically there is an upside too: oxytocin, the hormone released at every breastfeed, is a natural sedative which, while it might mean you drop off over a daytime feed, has the distinct advantage of helping you fall back to sleep in the middle of the night if roused by a hungry baby.
Best news of all, though, comes in a new study from Okayama University in Japan which seems to suggest that oxytocin actually makes breastfeeding mums brainier. Professor Hideki Matsui found that brains awash with oxytocin had a heightened state of activity that lasted three times longer than brains without the hormone, and that both mental ability and short-term memory are better as a result.
The big question is, would knowing all of this encourage breastfeeding in some women who might otherwise choose not to? Should campaigns like this week's Breastfeeding Awareness Week make more of these studies?
Dr Mike Woolridge, senior lecturer in infant feeding at the mother and infant research unit at Leeds University, believes they could, and that the information should be made more widely available. "One of the anxieties about campaigns about breastfeeding is no one wants to overplay the guilt for women who, for whatever reason, have not breastfed," he says. "But the way I see it, there's a finite number of women out there whose experience is behind them, and an infinite number whose chance of breastfeeding is still ahead. We should be sensitive to women's concerns, but we shouldn't lose sight of the fact that there are a lot of potential mothers to inform. And of course there's a cost implication - the savings to the health service - not to mention the improvement to women's quality of life."
Melanie Every of the Royal College of Midwives is more cautious. "I do think these studies are worth talking about, and I think knowing the health benefits could sway some women into deciding to breastfeed. But in this country there's still a big cultural discomfort about breastfeeding, and I feel that's a bigger stumbling block to increasing our figures, which are still too low.
"On the other hand, there are a lot of women out there who worry about the effect of pregnancy and birth on their figures, and I think knowing how much breastfeeding helps you get back into shape would be welcome news to many of them."
