New Study Confirms Oestrogen And Breast Cancer Link

Increased weight means increased oestrogen, so a new report shows that losing weight will boost your chances of beating breast cancer, but what about the protective role of bioidentical progesterone?


US researchers predict that even small amounts of weight loss and moderate exercise can improve survival odds of cancer patients by more than 20 per cent

An article in the Daily Mail on 6 June, 2016 confirmed what bioidentical doctors have been saying for years – that excess oestrogen (oestrogen dominance) is linked to increased cancer risk and can also reduce survival rates from the disease.

They failed to mention the protective role of bioidentical progesterone, but focused on the report’s effects of diet on breast cancer.

Excess fat means excess oestrogen, particularly at menopause, when women start producing oestrogen in their fat cells instead of their ovaries but applies to any women who is overweight. Excess fat encourages circulation of the hormones oestrogen, insulin and leptin, which fuel tumour growth.

So losing weight can improve your odds of not just beating cancer, but surviving for longer.

The new study

A team from Harvard Medical School announced the launch of the world’s biggest trial into the effects of diet on breast cancer at the American Society for Clinical Oncology conference in Chicago in June 2016.

The team will study 13,200 women with breast cancer over two years, of whom half will be told to eat no more than 1,500 calories a day and exercise for half an hour, five times a week.They will be urged to lose 10 per cent of their body weight, an average of just over a stone. The findings – expected in five years’ time – will be eagerly awaited by cancer experts around the world, as they could prompt a major overhaul in treatment guidelines for all types of tumours.

The US researchers predict that losing 10 per cent of weight increases survival chances over a five year period by between 20 and 23 per cent.

But early results from a series of other studies unveiled at the conference have already found that weight loss and exercise may hugely impact survival odds and I have already reported on the benefits of exercise for cancer prevention (see Helpful information below), as have many others so it is not exactly news. 

Two fold strategy to beat cancer

This isn’t rocket science, but common sense, but for the first time a major trial is looking at more natural ways of reducing breast cancer risk. Losing weight and taking moderate exercise are the simplest ways to improve your health generally, but it seems that in terms of breast cancer risk and survival it could prove to make a major difference.

Research by Yale University showed that woman who lost just 6 per cent of their body weight – an average of three-quarters of a stone – had far lower levels of hormones such as oestrogen which trigger tumours. The team recorded similar findings for women with ovarian cancer who did just 30 minutes of brisk walking a day or other forms of moderate exercise.

Patients should be urged to lose weight as soon as they were diagnosed said Dr Jennifer Legible, Leader of the Harvard trial saying .. ‘It’s the next best pill to treatment and it’s free and has no side effects.’

And by the way, oestrogen dominance does not just affect women but is now acknowledged as a factor in prostate cancer as other studies have also shown the benefits of weight loss for men with prostate cancer.

The ‘missing’ hormone in breast cancer treatment and prevention

Given that it is only small, but significant, lifestyle changes that are going to make this difference it is a pity the research is not extending into the role that bioidentical progesterone has to play in cancer protection. In its role of opposing excess oestrogen this was first outlined by the late John Lee, MD and his colleague Ray Peat, the author of a number of cutting-edge publications that look at aging, nutrition, and hormones from a biochemical perspective.

Currently, women who have had surgery to remove breast cancer are prescribed drugs known as aromatase inhibitors for five years to prevent tumours coming back. But the two main aromatase inhibitors – letrozole and anastrozole – can cause side effects in about half of patients, including hot flushes, sleep problems and osteoporosis. 

However bioidentical natural progesterone has no side effects and is used by many women worldwide who have had breast cancer or treatment, or with a family history of the condition. As it is out of balance oestrogen (oestrogen dominance) that is linked to breast cancer, surely it makes sense to use its natural balancer, progesterone, to help the body protect itself and help women without the side effects linked to the prescribed drugs?

Dame Dr Shirley Bond – a private GP who has been prescribing bioidentical hormones for many years – has recommended using progesterone alongside Tamoxifen to offset the side effects of the drug and combining progesterone with a good weight loss and exercise programme is a natural recipe to protect women in a very simple, practical way.

Dr Tony Coope, who is also an experienced practitioner in the use of bioidentical hormones, goes further and asks why given what we know about the oestrogen-opposing functions of bioidentical progesterone, are we not having a close look at whether progesterone could take the place in this situation of both Tamoxifen and the aromatase inhibitors. This would give protection against the cancer promoting effects of oestrogen, with little or no side effects, and considerably less strain on the NHS budget.

Helpful information:

Many women with a history of breast cancer risk and/or treatment have been using bioidentical progesterone to safely help with their menopausal symptoms so although a good diet and exercise are important, it is also crucial to oppose the excess oestrogen that is behind many hormonal cancers such as breast, uterine and ovarian.