Join Integrated GP Dr. Nicole Nelson and fellow integrative medicine GP and Ambassador, Dr. Michelle Woolhouse, on this detailed podcast on breast cancer prevention. In this episode, they explore the multifaceted landscape of modifiable aspects that can significantly impact breast cancer development.
Researchers have outlined a host of modifiable factors, including early pregnancy before the age of 30, breastfeeding support, regular exercise, alcohol consumption, breast density screening, minimizing exposure to endocrine disruptors, and supporting oestrogen processing and excretion. Alcohol consumption, in particular, is dose-dependent and shown to increase breast cancer risk, making zero intake the safest option.
Dietary choices play a pivotal role, with fibre, indole-3-carbinol-rich foods like cruciferous vegetables, vitamin A, iodine, selenium, and gut microbiome health all influencing breast cancer risk. Additionally, understanding and influencing beta-glucuronidase activity, maintaining bowel regularity, and supporting detoxification phases (Phase 1, Phase 2, and Phase 3) are key strategies.
They also explore how adopting a diet aligned with genetic heritage, or the Mediterranean Diet can offer protective benefits.
An interesting and often overlooked aspect, insulin regulation, and how it acts as a tumour growth factor, is covered in detail. Strategies encompass choosing foods with a lower and sustained insulin response, intermittent fasting, selecting sugar alternatives, and closely monitoring sugar levels in food.
Endocrine disruptors, with their wide-ranging negative effects on oestrogen transport and hormone receptors, are discussed in-depth. Functional tests are also outlined such as saliva, serum, and urinary oestrogen metabolites, gut beta-glucuronidase activity, genetic SNPs, and morning spot urine iodine to provide a comprehensive understanding.
Lastly, they explore the significant impact of exercise on reducing mortality risk post-breast cancer and emphasise the importance of prioritising sleep quality as an essential lifestyle aspect.
Covered in this episode
[00:34] Welcoming Dr. Nicole Nelson
[01:53] Actions we can take to reduce risk of breast cancer
[03:48] Is alcohol a risk?
[05:11] Oestrogen detoxification
[07:54] signs and symptoms of impaired oestrogen detoxification
[11:20] Options for genetic testing
[13:10] Diet for prevention
[15:31] Insulin as a tumour growth factor
[19:20] Oestrogen disruptors
[23:13] Avoiding phthalates
[25:45] Looking beyond early detection to functional screening
[27:25] Providing proactive nutritional support
[30:17] Foods sources of nutrients
[34:09] Benefits of exercise in prevention
[35:55] Sleep and effects of caffeine
[38:16] Impacts of stress and trauma
[40:34] Thanking Dr. Nelson and final remarks
- Breast cancer risk can be influenced by modifiable factors such as early pregnancy, breastfeeding, exercise, alcohol consumption, breast density screening, reducing exposure to endocrine disruptors, and supporting oestrogen processing and excretion.
- Alcohol intake is dose-dependent and significantly increases breast cancer risk, with zero intake being the safest option.
- Dietary factors like fibre, foods rich in indole-3-carbinol (cruciferous vegetables), vitamin A, iodine, selenium, gut microbiome health, gut lining integrity, and influencing beta-glucuronidase activity can impact breast cancer risk.
- Supporting detoxification phases with calcium-d-glucarate (Phase 1), DIM, B vitamins, zinc, selenium, milk thistle, and globe artichoke (Phase 2), and maintaining bowel regularity (Phase 3) can be beneficial.
- Adhering to a diet aligned with your genetic heritage or the Mediterranean Diet can be protective. Avoiding inflammatory seed oils is advised.
- Regulating insulin is crucial as it acts as a tumour growth factor. Strategies include choosing low/sustained insulin-response foods, intermittent fasting, selecting sugar alternatives, and reading labels for sugar content.
- Endocrine disruptors have negative effects on oestrogen transport and breakdown, hormone receptors, and sex organ development, particularly during embryogenesis.
- Functional tests like saliva, serum, and urinary oestrogen metabolites, gut beta-glucuronidase activity, genetic SNPs, and morning spot urine iodine can provide insights.
- Exercise significantly reduces mortality risk post-breast cancer, with a 34% reduction in death from breast cancer and a 24% reduction in cancer recurrence.
- Improving sleep quality should be a primary focus, considering factors like caffeine, alcohol, stressors (including trauma), and diet as potential influencers on sleep.
Resources discussed and further reading
Dr. Nicole Nelson
|Dr. Nicole Nelson's website|
|Dr. Nelson's book: Pure Sweetness: Low sugar & keto desserts, gluten free recipes with dairy free options|
Diet and prevention
|Research: Dietary patterns and breast cancer risk, prognosis, and quality of life: A systematic review (Front Nutr. 2022)|
Insulin and breast cancer
|Research: Metabolic Health, Insulin, and Breast Cancer: Why Oncologists Should Care About Insulin (Frontiers in endocrinology, 2020)|
Exercise and breast cancer
|Research: The Benefits of Exercise in Breast Cancer (Arq. Bras. Cardiol, 2022)|
Endocrine disrupting chemicals
|Research: Endocrine disrupting chemicals: exposure, effects on human health, mechanism of action, models for testing and strategies for prevention (Rev Endocr Metab Disord, 2020)|
Oestrogen metabolism and detoxification
|fx Medicine article: Oestrogen Metabolism and the Microbiome|
|fx Medicine article: Organs of detoxifications|
|fx Medicine article: What is Phase III detoxification|
|fx Medicine article: Nutrients for Detoxification|
|fx Medicine monograph: Calcium-d-glucurate|
|fx Medicine infographic: Calcium D-glucarate: breast cancer & oestrogen clearance|
National Breast Cancer Foundation: Learn More and Ways to Support*
* fx Medicine is not affiliated with the National Breast Cancer Foundation, this link is for informational purposes only
fx Medicine acknowledges the traditional custodians of country throughout Australia, where we live and work, and their connection to land, sea, and community. We pay our respects to the elders, past and present, and extend this respect to all Aboriginal and Torres Strait Islander people today.
Breast cancer is the most commonly diagnosed cancer in women, and the incidence is rising. One in eight Australian women will be diagnosed in their lifetime. Most of us listening to the show will know at least one loved one or friend who has been or is going through the condition. But are we doing enough for prevention?
Joining us today is my colleague and friend, Dr. Nicole Nelson. She's an integrative medicine GP working out of the Sunshine Coast, and she's a faculty member of ACNEM, the Australian College of Nutrition and Environmental Medicine, and teaches doctors and health practitioners nutritional and environmental medicine. She's also an author of two ebooks, one on healthy eating called Pure Sweetness, and the other on fasting.
Welcome to fx Medicine, Nicole. Thanks for being with us today.
Nicole: Thank you so much for having me.
Michelle: So, what was really apparent to me as a student of medicine, and I'm sure it was to you in those early days, was that breast cancer risk was often espoused as things you couldn't do much about. There's often talk about the BRCA gene, and family history, and timing of your period and menopause. But there are so many more other really evidence-based modifiable risk factors at play. Tell us about that. What can we do?
Nicole: So, it's very exciting to find out that there are actually some active things that we can do and some things that we can avoid to help prevent breast cancer.
Obviously, we know about those non-modifiable risk factors like your age. So, 3/4 of breast cancers occur in women over 50. You've mentioned the BRCA genes. Family history is only... So, 9 out of 10 women diagnosed with breast cancer have no family history. Obviously, you can plan your pregnancies before age 30, and breastfeeding is also protective for breast cancer. So, that's something you can potentially modify, and making sure women are supported to breastfeed because a lot of times - and not all times - there are some times when a woman just cannot breastfeed. But I think if we had more support available for women, that more women would be able to do that, and that does reduce your risk of breast cancer.
Michelle: Yeah, absolutely.
Nicole: But ones that don't get talked about a lot, things like exercise, alcohol consumption, knowing your breast density, and then other ones that we probably should look into more is reducing our endocrine disruptor exposure, which we can will discuss a bit more. Knowing how to help our body excrete and appropriately process our oestrogen. So, those things are things that we can actually modify.
Michelle: Fantastic. I think we often talk about breast cancer prevention as really early screening. So, it's like it's all about mammograms and picking it up early. We don’t really talk so much about proper prevention, like how do we actually prevent it starting in the first place? So, there are some really good ideas, particularly about alcohol consumption because alcohol is increased so much in women, particularly over the last decade. What do you think?
Nicole: Yes. And the sad thing about the alcohol consumption is there is a dose-dependent correlation, and any alcohol whatsoever is associated with breast cancer. So, there isn't actually a safe level. And I think in the media, we talk about safe levels of alcohol consumption and making sure we don't go over two standard drinks a day and that we have two alcohol-free days. But I think a lot of women would probably change their habits. And it's not that they would never touch alcohol at all. Some would choose that. But a lot of women would reduce their alcohol consumption even more if they knew what a risk factor that was. And it isn't really talked about.
Michelle: No, no. It's almost like it's talked about at ‘safe levels for me.’ And, of course, women get involved with it. But women, particularly, have a strong sensitivity to alcohol and the negative ramifications of that from cancer perspective and other issues as well.
Michelle: So, let's break it down a little bit more. You mentioned oestrogen detoxification, which has so many different parts, obviously, from how much we produce, to how it gets detoxified in the liver and the gut. So, what's going on? Let's talk a little bit more detail and drill down into oestrogen detoxification. And how does a woman know, or how do we pick that up if they've got problems with oestrogen detox?
Nicole: Well, sadly, in Orthodox medicine, it isn't really discussed or tested. But in the scientific literature, they've actually found that there can be many factors affecting how we detox oestrogen, and whether we do it in a safe way and whether we produce toxic metabolites of oestrogen that can predispose to cancer, but also other issues like endometriosis. So, it's in the scientific literature, but it hasn't reached clinical practice.
And some of the things that affect oestrogen metabolism are our diet. So, there's a lot of different foods, our fibres, foods that have certain compounds, one of them being indole-3-carbinol, which is found in cruciferous vegetables, so broccoli, cauliflower, cabbage. So, there's certain vegetables that can change the way we detox oestrogen.
Obviously, our diet affects our gut microbiota. So, the bacteria in our gut is affected by our diet. And our gut bacteria play a big role in how oestrogen is detoxified. So, the healthier our gut is, the more safely we will be able to excrete and eliminate excess oestrogen that the body is trying to get rid of. Conversely, if our gut isn't healthy, we may end up accidentally re-absorbing oestrogen that the body's trying to get rid of via some beta-glucuronidase activity in the gut.
So, beta-glucuronidase is involved in whether or not we excrete or don't excrete oestrogen. And some women have higher levels of this enzyme, beta-glucuronidase, which means that the oestrogen that's trying to be excreted gets cleaved off and gets re-absorbed, so anything we can do to affect that system.
The other thing is just good excretion, so making sure a woman's bowels are going really well each day, but also making sure that other elimination mechanisms like through our sweat. So, that involves things like exercise and sauna, but also good hydration so that we can metabolise through our kidney. And then the other huge thing is reducing and looking at how we excrete endocrine disrupters.
Michelle: Yeah, I'm going to get on to that. Hold that thought for a sec. But I just wanted to also break it down from a practitioner's perspective. Obviously, we know about PMT and problems with perimenopause and those things, but when people have got issues with oestrogen detoxification, they can show that up in so many different ways. In your clinical practice, what are the most common things that you see when somebody's having problems with that detoxification of oestrogen?
Nicole: Yes, so that really, you see it with a lot of hormonal issues. So, you'll see a woman having breast tenderness, women who are predisposed to premenstrual tension. Premenstrual dysphoric disorder, that can be - it isn't always - but it can be a sign of a woman who's oestrogen-dominant, women who have signs or diagnosis of endometriosis. So, they're probably the most common things. And probably the thing that affects women the most is when it's disturbing the menstrual cycle, so when they've got terrible pain associated with that, or when it's affecting mood. So, probably, the most common thing is when women have their mood and irritability affected.
Michelle: And so the liver detoxification capacity, like Phase 1 and Phase 2, very important for oestrogen detoxification as well. Let's talk a little bit about that because that can sometimes be a really big issue for some women perhaps maybe Gilbert's syndrome, or other kinds of factors that impact the ability of that oestrogen detoxification.
Nicole: Yes. So, when we're looking at Phase 1, obviously, things like Calcium D-glucarate have been shown to be helpful. And that can be taken orally. With Phase 2 detoxification, we can take agents like DIM. But there are also nutraceuticals that affect that because, obviously, we've got to look at also our methylation and how well our body is detoxifying in general, so anything thing that we can do to support the liver so that... We know of various agents. There's things like milk thistle, one, globe artichoke for bile flow. But often a lot of nutraceuticals are needed in that for liver support and supporting those enzymes in detoxification. So, making sure we've optimised B vitamins, making sure zinc is optimised, and then antioxidants and liver support. Things like selenium are also important.
So if we're looking specifically at what are our big things for Phase 1 and Phase 3, it will be Calcium D-glucarate. Phase 2 would be DIM. And then Phase 3 is keeping your bowels moving. And so the most important thing, we can look at all these nutraceuticals and look at agents to try and help, but none of that is going to work unless we've got really good, regular, healthy bowel motions.
Michelle: So, it really comes down to the basics when we're really talking about prevention because I think sometimes women are like, "I've got this either breast cancer gene or family history of breast cancer," which doesn't necessarily, as you said, associate with an increased risk, per se. Like, we know in the literature it's... In clinical practice or in real-life medicine, it doesn't necessarily work that way, but some people are really concerned about their risk of breast cancer. And so these simple things can be so important.
So, with genetics, we talk about the BRCA gene, which is not as common as people actually recognise. And a lot of women go down gene pathways to find out their risk. Do you do any testing for genes? And how does this work in particular relationship with breast cancer?
Nicole: Yes, so what I tend to do with my patients, is if there is a family history of breast cancer... Often it has been done, but occasionally you will get a woman whose mother may have passed away before this technology was available, or another family member may have passed away before the technology is available. So, I'll often refer to a genetic counsellor to discuss that with them because, obviously, there's that risk, the trauma of finding out that you have this potential increased risk of breast cancer. So, for some women, it's like, "Great, that's going to change my life. Now, I know that I need to work on these risk factors. I need to get more serious about exercise. I need to get more serious about my alcohol consumption," and other things that we know that contribute to a healthy lifestyle.
But for those women that do want to know, it's about one in eight breast cancers that do have any genetic predisposition. But, yeah, I would refer to a genetic counsellor to talk more about that and find out about that risk. And the implication with that, is that particularly with the BRCA genes and some of the other genes, there are associations with other cancers, for example, ovarian cancers. So, in a woman who comes up as a high-risk with those genes, there then is the possibility of whether they would do prophylactic surgery, so bilateral mastectomy or oophorectomy, removing the ovaries and removing that breast tissue to try and reduce the risk.
Michelle: Yeah, it's a really complex scenario.
So, our audiences listening to this is all over diet and the importance of diet for prevention and disease modification. But the dietary advice for breast cancer prevention is really unclear in the literature. So, we know epidemiologically, some breast cancer incidence is vastly different across the world. And certainly, in the Western world, we're seeing a significant rise.
Tell us why there's so much confusion about this. And is there any patterns we can ascertain from these epidemiological or observational studies in terms of helping practitioners really drill down and define what is the best diet from a prevention perspective?
Nicole: It is really tricky. And what's made it quite confusing is there's...and we have this debate in natural medicine at the moment over being more vegan versus the carnivore keto movement that's higher in protein. And what's made it confusing is that one of the lowest incidences of breast cancer in the world is actually in Mongolia, which appears to have a really high meat and dairy product diet.
Michelle: It's so confusing.
Nicole: So, that's quite confounding. That goes against some of the other studies that we've seen that talk about more vegetables in preventing breast cancer. There is talk about dietary fat being an issue. And I think at the end of the day, one of the things we need to look at is your genetic history. So, a lot of people, for example, if they're of a certain Asian country, for example, China, and then we move them into a more Western diet, people seem to do better following their genetic diet that they've traditionally followed or that is in their family. So, that's one thing to consider about going back to what is in your genetic history and the more diet that's indigenous to the country that you've come from.
The other thing we know, in general, is that more the Mediterranean diet is fairly healthy, where we're focusing on polyphenols and good oils, avoiding those toxic inflammatory seed oils. So, we don't have specific incidences with breast cancer, but we know that seed oils, for example, canola, sunflower, that they are inflammatory, and we know that inflammation and cancer go together.
And the other thing is, the big thing that I think is the most overruling, so whether you're a vegan, or whether you're an omnivore and you're following a Mediterranean diet, or whether you're doing keto or carnivore, the big thing is that insulin is a tumour growth factor. So, one thing that every group...
Michelle: I was just going to mention that.
Nicole: ...agrees on is that we need to lower our sugar and keep our refined carbohydrates low. And so many types of cancer have extra insulin receptors, making them respond more than normal to insulin's ability to promote growth. And so one thing we can agree on is that we need to keep that to a minimum. And that's another thing that just isn't talked about. And unfortunately, when people turn up for cancer treatment, it's those foods that we have that incredible research on with insulin and glucose stimulating and really firing up cancer growth. It's those foods that people are fed while they're receiving treatment.
Michelle: Metabolic health is a really interesting point. And I think the more that I research into, I guess, that as an umbrella form for patients makes it a lot easier to actually shape the dietary advice. So, it becomes less about the types of food, actually about how your body is responding to that. And given the particular role of insulin in cancer proliferation what can we advise our patients regarding to lowering that key driver of insulin?
Nicole: Yes, so one of the most powerful things is diet. So, being really mindful that every time we eat, so even if we're eating as healthy as we can, we do stimulate insulin. So, trying to choose foods that give a lower and more sustained insulin response rather than spiking and causing high insulin. And so it can be the types of foods you eat, but also intermittent fasting can play a role in this.
So, there's a lot of research coming out now about the role of having small eating windows like six to eight hours where you eat in a six to eight-hour window and fast for the remaining amount of time, which, despite what type of food you eat in that window, does seem to actually help reduce your insulin response.
And I think it's just learning. Like, I don't think we need to deprive ourselves. And that's why I wrote the Keto and Low Sugar Cookbook because I think there are sugar alternatives and ways to reduce sugar that we can still have treats and enjoy it. But unfortunately, it's taken a lot of time for that to start to show up commercially and to be seen in cafes and things.
So, I think we need to change our culture and realise that sugar is meant to be just a sometimes food treat. Unfortunately, it's just being put into commercial foods in such high amounts that people don't actually realise how much they're eating. So, I think more education...
Michelle: It's so massive.
Nicole: ...around that is needed to be able to choose. And I was horrified myself when I first started looking into this about 15, 20 years ago when I actually looked at what I was eating because I thought I was a low-sugar person. And once I started looking at labels, all the savoury foods that I loved, especially I love a lot of Thai and Chinese foods, and the amount of sugar that was in the savoury foods was quite horrific.
Michelle: Like Lo Mein.
Nicole: And I had no idea that I was having such a high-sugar diet.
Michelle: It may be reason why Mongolia was so significantly deficient as well. They're nomads. And I think it's the highest country in the world that don't live in a city-based environment, so they're less sedentary, etc.
You mentioned also oestrogen disruptors. So, over the last, what, 50 years or whatever, it's just year upon year just more and more exposure to these really toxic oestrogen-disrupting chemicals that affect not just human health, but animal health and the health of the soil. And they're at ubiquitous levels. So, very few people can avoid them completely from takeaway coffee cups, to petrol receipts, to wrapping food in Glad wrap, all of that stuff.
Let's break this down because I know you're particularly passionate about oestrogen-disrupting chemicals and how we can best teach patients about this, I guess, without freaking them out really.
Nicole: Yes. And it is that balance of... Sometimes, you'll hear people say, "Everything causes cancer, so I can't do anything." But I actually do believe that there are some things that we can do to reduce that risk. And the problem with endocrine disrupters is that they affect the transport and breakdown of oestrogen. They act on receptors to bind or block at the receptor level. They affect our endocrine and sex organ development in the womb. And the first 10 days of embryogenesis is the most sensitive time that endocrine disruptors can have their effect. And what can happen is those first 10 days of that embryo developing can actually decide your risk of breast cancer, of endometriosis, of prostate cancer for men. And so I think this is something that's been ignored and the people just aren't aware of, so probably the most passionate time. The people that I love educating the most about this are people who are planning on a pregnancy.
Nicole: But in terms of things we can do with some of those things you mentioned, so, unfortunately, a lot of these endocrine disruptors have been allowed into commercial products. And one of the most common ones is actually aluminium, which is in deodorant. It's also in al foil. But it's also used a lot in industry. And you can't avoid aluminium. Even if you avoided all the known sources, you would still have aluminium in your body because it is used throughout industry.
And once we get these heavy metals in our body, it's actually very hard to get rid of them. So, someone might have a high aluminium, who has been avoiding aluminium for many years. So buying a natural deodorant that doesn't have aluminium, being careful with coffee pods. So, coffee pods with aluminium, not only are we heating up plastic because the pods are made out of plastic, but we're heating up that aluminium foil that seals it. We can move to stainless steel coffee pods instead, or we can just make our own coffee with beans.
Michelle: Might pick that up.
Nicole: Being careful of what you put on your feet. Your feet is one of the areas of your body that absorbs the most. And so making sure you're not bathing your feet in plastic, so trying to wear cotton socks if you can, having leather liners. When you get into your car, when it's been a hot day and you get into your car, the plastics in your car that are released just from the car heating up, it's a very toxic place. So, if you can just spend a couple of minutes just winding the windows down and airing it out.
And the other thing that our building biologist colleagues would say is making sure your home has adequate ventilation because all of this fake furniture that we have now, just so much plastic used in carpets and in our furniture and on all the glues and things that are used in the home. If we can ventilate our home really well, that's important as well.
Michelle: Yeah, they always talk about indoor air pollution being more toxic than external air pollution. But that message hasn't really been driven home.
Nicole: Yes, so absolutely. Phthalates are found in plastics but also found in carpets and furniture. And what we find is that because they're known to be carcinogens, and they've actually done studies in animals, induced tumours by providing phthalates in the studies, and the incidence of mammary tumours in rodents when also their offspring were challenged with other carcinogens. So, it can be that you are exposed to a phthalate in childhood and then later in life another carcinogen has a bigger effect because you were exposed to a phthalate earlier in life. So, it can prime you for other carcinogens.
And so the important thing is to, one, know how to avoid these things. So, we talked about plastics. Also, cosmetics. We have to be careful with what we put on our skin. So, that's why people say don't put anything on your skin that you wouldn't eat. But what we need to do is not just avoid them, but know what we can do to detox these things out of our body. And some of the nutraceutical companies have come up with some really good supports for detoxification. So, you can actually, from some of the nutraceutical companies, buy nutrient agents that try to help you detoxify.
But in terms of what we can do, sauna is huge. So, they've done studies with sauna where they looked at blood, sweat, and urine levels of some of these endocrine disruptors, including phthalates. And what they found was that some of these things only came out through sweat in a sauna. And so that's really interesting. So, some of them weren't showing up detoxifying in the urine and didn't necessarily show up in the blood samples but came out in sweat.
So, obviously exercise because it helps with lymphatic drainage. So, anything we can do that helps the lymphatic system, anything we can do to sweat. But sweating with saunas sweats you in a way by just exercising or living in a hot climate, it does it in a different way and seems to get rid of these chemicals in a different way.
Michelle: Wow, such a fantastic advice that we can give to patients, because they're pleasant. Saunas are pleasant and a really nice way to relax as well.
But I wanted to drill down into... We know one of the key strategies in mainstream medicine is for early detection using breast imaging. But a lot of my patients come and they've got significant breast density. And that is now recognised an independent risk factor for breast cancer, one, I guess we can't inherently do much about. But what is the clinical advice that we can give to women to further highlight, I guess, the preventative necessity if breast density becomes a problem in those early detection/screening/mammogram situations?
Nicole: So, about 2/3 of women in their 40s have dense breast tissue, and up to 1/3 of these women will retain that into menopause. And the problem with that is that it is an independent risk factor in itself, as you mentioned, for breast cancer, and it makes it harder to read a mammogram. And so what's starting to happen in the U.S. is it's become mandatory for women to be notified of what classification they have with in terms of breast density, and they are to be notified if they have dense breasts. This is starting to happen. So, some of the radiology centres in Australia are starting to report that.
And so what I do, if I get a mammogram back, even if it's normal, obviously, we'll call the patient back in, but we won't alarm that they've got anything wrong on their mammograms, but we'll have a discussion around the things that we've talked about today, that they've got this independent risk factor for breast cancer and the kinds of things that they can try and do, and also have some discussions around imaging.
Michelle: Yeah, excellent. And I also wanted to look beyond early detection, because I think in medicine as we know, we think about prevention as early screening, which really isn't prevention at all. What can we do in terms of nutritional support that is more proactive in many ways that individuals can do to support their breast health?
Nicole: So, ideally, we would have certain nutrients tested, so our immune nutrients, vitamin A, vitamin C, vitamin D, iron, iodine, and zinc. And there's others like selenium that are important. So, we'd make sure, in an ideal world, that we had adequate levels. There is some low-level evidence around vitamin A decreasing the risk of breast cancer, also ovarian and cervical cancer. It is low level, but still, that's something, for me, that I'd want to make sure that I have adequate vitamin A.
The other thing is trying to make sure that we avoid those endocrine disruptors in our foods, so trying to have food as organic as we can. I also discuss those certain nutrients like calcium D-glucarate and DIM that we can potentially use to help modify the way oestrogen is detoxified. And, ideally, we would have our Cytochrome P450 enzymes and polymorphisms that affect oestrogen metabolism tested. But it’s still emerging science and still in the realm of Orthodox medicine is considered a bit Star Trek.
We can also have our saliva, serum, and urinary oestrogen metabolites tested to see what's happening there. Again, that's been done in laboratories, if we do have access to that. But, again, it's considered emerging. So, it'd be great if there was more research around that and that was more accessible to women. It's also very expensive to get some of that testing done. But it's a cost that some women, if they knew it was available, would be willing to have. And a lot of your listeners are actually already prescribing these kinds of tests to try and help determine what metabolites a woman might be, and whether she's pushing her oestrogen down a toxic pathway and looking at where they can intervene with these medicines. But it hasn't become mainstream, which is unfortunate.
The other thing is looking at your gut beta-glucuronidase activity. And there are some labs that are actually looking at that and doing gut testing and actually reporting on whether that's something that you need to improve on in your gut in order to metabolise and safely excrete oestrogen out of your bowel.
So, there's a lot we can do, but it's still considered emerging. But I think it's important for women who would like to have those things done to be informed about those alternative tests that can be done.
Michelle: You mentioned iodine, and you mentioned vitamin A and vitamin D as really key players from a nutritional perspective. I know, in particular, vitamin D deficiencies are a major issue across the board, and as is vitamin A. In fact, I think the Australian Bureau of Statistics a couple of years back mentioned that about 90% of people are not reaching their vitamin A on a daily basis. Obviously, we can get it from beta-carotene as well, but pure vitamin A is in short supply. So, tell us what foods should we be aiming for, and how do we best get these nutrients up to optimal levels?
Nicole: So, the interesting thing about vitamin A is that we do, as you said, get most of our sources of vitamin A through beta-carotene being converted into active vitamin A. But about 40% of women in the studies show that they may have a gene polymorphism that stops the conversion of beta-carotene into vitamin A. And there are various factors that can interfere with that, including our gut health. So, probably the purest source is a non-vegan source, which is liver. And in this modern world, we've gotten out of the habit of having offal, whereas in the olden days, there was no waste and organs were eaten as well and vitamin A is found in ready supply in the liver.
But in terms of beta-carotene sources, it's really interesting because, in the media, people talk about carrots. But carrots actually aren't the highest. So, if you were trying to get the best source of beta-carotene, it's actually sweet potato. So, sweet potato, followed by pumpkin, and I think carrot is actually further down the list. So, with that, because it is a fat-soluble vitamin, when you're having your beta-carotene sources, provided you can actually convert that into active vitamin A, it’s a good idea to have some fat with it. So, eating avocado or having some olive oil with your sweet potato can actually help the absorption and conversion.
Michelle: Oh, it sounds delicious. Nice.
Nicole: And then moving on to iodine, our best sources are seaweed, so anything from the sea basically. So, seaweed is a great source. And what I do is I have a salt that I actually mix seaweed into and I try to make that my source that I will use for iodine. And so just always thinking, 'How can I add that into meals?’
It's interesting, in Japan, that have a very high seafood and seaweed intake, due to the higher iodine and selenium found in their diet, they actually, traditionally, have a much lower breast and prostate cancer incidence. So, there does seem to be some association. We know that breast tissue has a lot of iodine receptors. It's always been said with breastfeeding in a lot of ancient cultures that if a woman is having trouble lactating, that she should have some fish or have some seaweed. And so it's been known traditionally that these sources of iodine actually are needed, for example, to breastfeed.
Michelle: Yeah, interesting.
Nicole: So, the breasts have a rich source of iodine. And so making sure that we have adequate iodine in the diet is really important.
And the other thing is that it can be tested. So, we have to be careful. The spot urine iodine testing can vary. And so it's important to make sure that we do that test properly, that we avoid seafood and iodine three days before the test, that we appropriately fast before that, and make that a morning spot urine iodine. But that's one of the measures that has been looked at to look at population iodine levels. And that's something that we can do to actually test for iodine.
Michelle: And what about...? Obviously, stress is very ubiquitous, but also sedentary issues are a big problem, as is sleep. So, they're the more emotional and lifestyle factors. What should we be telling patients about that in terms of prevention from a breast cancer point of view?
Nicole: Yes. So, it's really interesting with exercise. There was actually a meta-analysis done in 2010 that looked at women who had been through a breast cancer diagnosis. And it was found that women who were previously, before their diagnosis, were exercising regularly had much better outcomes post-breast cancer. So, when they were looking at the survival outcomes in breast cancer, they found that women who were regularly exercising after diagnosis had a 34% lower risk of breast cancer death. They also had a 41% lower risk of death from any cause and had a 24% lower risk of breast cancer recurrence than inactive women.
And there's been various studies looking at, well, how much should we be doing? What does that look like? And any amount of exercise, even just an hour a week, has been shown to be helpful. But the consensus seems to be about 30 minutes of moderate exercise most days. And so that means that you're actually a bit out of breath. You're struggling to have a conversation. So, it's not just going for a gentle walk. You actually have to get your heart rate up and be a little bit out of breath.
Michelle: Yeah, great. It's such good advice. It's across the board obviously. We know exercise decreases all-cause mortality, but there seems to be something particular about breast cancer. So, that's fantastic.
And what about sleep? Because I know the women that I speak to in clinic, I don't know, 50% of them just got poor sleep. It's almost ubiquitous, and they even forget to tell you about it. So, what role does sleep play in breast cancer prevention?
Nicole: You've hit the nail on the head there being one of the most important things because when we look at inflammation, which is the driver of all disease, but particularly cancer as well, if we don't get enough sleep, we are more likely to be inflamed and also have neuroinflammation, which really affects our ability to be able to look after ourselves. So, that's probably one of the first things I screen with my patients and one of the first things I address. And interestingly, exercise helps with sleep quality.
Michelle: Yeah, of course.
Nicole: But there are some things that people don't realise. For example, one of the biggest things is caffeine. So, people have this idea that caffeine is safe and that having one cup of coffee or two cups, as long as I have it early in the morning, won't affect my sleep. But, again, looking at our gene polymorphisms and individual variations in how we metabolise caffeine, for some people, a morning coffee can be enough to stop them from sleeping or impair their sleep at night. We talked about alcohol consumption. Any alcohol, even just one drink, does reduce your deep quality sleep and affects your sleep quality. So, again, going back to that with breast cancer.
But just back on to caffeine, it also reduces adenosine. So, caffeine blocks adenosine. We talk about melatonin, but adenosine is one of our relaxation neurotransmitters that actually increases over the day and it's actually really important for helping us sleep. And if you're sensitive or you've got reduced adenosine due to stressors in your life or you're sensitive to caffeine, you could be actually reducing one of your major relaxation neurotransmitters, and just that one cup a day can make a big difference.
So, it's those common things that have snuck into our everyday life that if we can just make some changes, which I know it's not easy, it's telling people to try going without caffeine, try going without alcohol. It's not easy, but it can have a huge impact.
Michelle: Absolutely. And you mentioned lifestyle and emotional factors across the board are really important not only for our everyday health and how we feel in the moment but also for long-term prevention. And there's a particular combination of emotional stress and breast cancer. Tell us about the research that shows that there is a strong link between emotional stress and breast cancer, and what do we do about that?
Nicole: Yeah, well, it's just really interesting. They've done some studies, for example, in mothers of autistic children, and they've found that there's actually an increased risk of breast cancer in this population. And when we look at it, this can be various factors, including genetic factors and how we metabolise toxins, but also the emotional stress of having a child with high needs. So, it's hard to pick out what is the exact mechanism, and it's probably multiple mechanisms.
But the other thing that people who work in the emotional space with cancer have found, particularly in breast cancer that there is a frightening correlation with intimate relationship difficulty in either a dominant relationship, for example, your spouse or your boss, but also trauma such as losing a child.
Michelle: Yeah. And so looking at those stress factors, and stress management, and emotional stress, and even just being open to the discussion around it, because I think people in those particular environments can either normalise their situation and minimise it, or they actually don't recognise that the situation that they're in is actually impacting their health long term.
Nicole: Absolutely. And that's where another screening thing I'll do with patients when they come in is look at that, look at traumas, look at ongoing stressors. And we've got some amazing techniques that have been used now in the fields, for example, with EMDR, which is a form of trauma release, but there's other types of trauma release. There's also some evidence that's been done through Bond University around tapping, emotional tapping. So, there's a lot of things that we can try and do to support women, even if they've got ongoing... They can't get rid of certain stressors, but to help them release that trauma in an ongoing way.
Michelle: Yeah, absolutely. Dr. Nicole, thank you so much for being with us today to discuss breast cancer prevention. It's such an important issue. And I think we need to look as a community beyond just that simple early detection and really feel much more empowered, particularly about the evidence-based opportunities we have to support the women of our community long-term, especially considering this toxic load and ubiquitous environmental exposure that we're all experiencing. I really want to thank you for coming on the show today.
Nicole: Thank you for having me. And I really hope that there's been something there that women can feel empowered and that clinicians can feel empowered to educate their patients about to make a change.
Michelle: Thank you, everyone, for listening today. Don't forget that you can find all the show notes, transcripts, and other resources from today's episode on the fx Medicine website. I'm Dr. Michelle Woolhouse, and thanks for joining us. We'll see you next time.