Know the Causes of Breast Cancer to Save You
Interviewer: Gail Edgell

Gail Edgell: We are going to talk about an important topic to women, particularly those over the age of 40: breast cancer. Can you tell us a little bit about that?
Dr. Boham: Yes. As we all know, breast cancer is very common, unfortunately. We know that last year over 200,000 new cases of invasive breast cancer and 60,000 cases of noninvasive breast cancer were diagnosed. We know that a woman’s risk of getting breast cancer increases as she gets older. A woman’s lifetime risk of getting breast cancer is 1 in 8 — we’ve all heard that statistic. We are working hard at detecting breast cancer earlier and getting better treatments for women who have had breast cancer. But today, we are going to really focus on what we can all do to decrease our risk of getting breast cancer and maybe preventing it.

Gail Edgell: What is the first thing that someone can do?

Dr. Boham: We know that estrogen exposure over a lifetime has an influence on the risk of getting breast cancer. We get estrogen from many different places. We get estrogen from our ovaries before we go through menopause. When you have more periods in your lifetime — if you go through menopause later, or if you start having your periods earlier, or if you don’t have any children — your risk of getting breast cancer is higher. Those cycles increase estrogen exposure over your lifetime.

Another place that we get estrogen is from body fat. This is especially important for postmenopausal women — they stop getting estrogen from their ovaries, so their No. 1 source of estrogen is body fat. As a woman’s percentage of body fat increases, her risk of getting breast cancer increases. We think that is because of an enzyme in the body fat called aromatase. That enzyme takes hormones that are made in the body, maybe from the adrenal glands, and converts them into estrogen. The more body fat a woman has, the more estrogen she has in her bloodstream. That has been associated with a significant risk of getting breast cancer.

As I said, that is especially true for postmenopausal women. A recent nurses’ health study showed that if a woman gains 22 pounds after menopause, she increases her risk of getting breast cancer by 18 percent. If a woman gains more than 55 pounds after the age of 18, she increases her risk of getting breast cancer by 45 percent. On the other hand, if a woman loses 22 pounds after menopause, she lowers her risk of getting breast cancer by 57 percent. So if you lose weight after menopause, you can actually decrease your risk of getting breast cancer. The most important thing you can do is maintain or decrease your weight.

Gail Edgell: What else can women do?

Dr. Boham: We know we get estrogen from other places as well, that you can get estrogen from outside the body. That is why there is a lot of concern about our environmental exposure to chemicals and toxins that can mimic estrogen in the body.

A lot of us have heard about the hard plastic (No. 7), which has BPA in it. That plastic can mimic estrogen in the body and increase the risk of breast cancer. Avoiding hard-plastic water bottles, storing food in plastic — these things may be important for decreasing risk. It’s also important to avoid pesticides from the environment. Buy organic and avoid putting any pesticides on lawns or in gardens — they can increase a woman’s risk. They actually can mimic an estrogen in the body and attach to an estrogen receptor. That is where doctors think there is an association with some of these chemicals and a woman’s risk of breast cancer. This is an area where we need to research, research, research. It’s very interesting and probably has a lot to do with why we are getting all sorts of cancers.

Gail Edgell: What else can a woman do?

Dr. Boham: We know that there is another important hormone in the body that has a big influence on our risk of getting all sorts of cancers, especially breast cancer. That hormone is insulin.

Insulin is a hormone that helps the body maintain a good blood-sugar level. If we develop a resistance to our own insulin over the years, we might have higher levels of insulin floating around. Those higher levels of insulin have been strongly associated with an increased risk of breast cancer. If you have heard the term “insulin resistance,” then you know what we are talking about.

Insulin resistance is a process that occurs in the body when it doesn’t respond to insulin as well. This is a pre-diabetic type of situation — blood sugar may be totally normal, but the body has to make a lot more insulin than normal to keep that blood sugar in a normal range. That high level of insulin stimulates us to gain weight, but it also stimulates the growth of other things in the body. Therefore, we know that insulin resistance is tied to many different cancers, especially breast cancer.

There are many things you can do to improve your insulin sensitivity, such as getting more fiber in your diet and preventing a high-blood-sugar response after you eat. Avoiding processed foods and making sure that carbohydrates are complex and full of fiber decreases the amount of insulin that is produced. And you need to make sure you have protein at every meal.

When you exercise, you become more sensitive to your own body’s insulin. There are many studies that show a positive association with lack of exercise and an increased risk of breast cancer. To put it another way, as you exercise more, your risk of breast cancer decreases.

Gail Edgell: Do you think cardiovascular exercises or strength-training exercises .

Dr. Boham: Yes, both are important. A lot of research has shown that cardiovascular exercises are important. But some good research shows that strength-training exercises are also important for decreasing risk. In general, it is recommended that women try to get in three to five hours of good exercise a week to decrease their risk in terms of breast cancer.

Gail Edgell: Goodness, that is a lot, especially with this age group. They are busy with their own families. Really, they need to be committed and put workouts on their calendars as something they need to do, just as they would with customers. But they’re appointments with themselves.

Dr. Boham: Many times, you are right. Exercise needs to be something that you do every day. It’s just as important as brushing your teeth and taking a shower. Getting in some daily exercise has a huge impact on your health and decreasing your risk.

Gail Edgell: What about alcohol and breast-cancer risk?

Dr. Boham: There is interesting research that has been pretty conclusive. Unfortunately, alcohol intake increases the risk of breast cancer. A lot of us like to relax at the end of the night and have a glass of wine with dinner. And in moderation, that can be OK. But as a woman’s alcohol intake goes up, so does her risk of breast cancer. We see that alcohol can do many different things in the body, and this may be why it is occurring. The depletion of B vitamins from alcohol may be one reason that an increase in alcohol increases a woman’s risk. Some researchers have been looking into whether having one or two glasses of wine a day is OK for women taking B vitamins, but we are not really sure. It may also be that alcohol intake increases insulin or percentage of body fat. But there is a pretty strong relationship between alcohol intake and breast cancer.

In general, we recommend that women have one or less drinks a day, or five or less a week. Just remember that one drink is 5 ounces of wine, 1½ ounces of hard alcohol or 12 ounces of beer. Sometimes this is hard to remember when you pour yourself a glass of wine. But in terms of breast-cancer prevention, you need to try to stay within those guidelines.

Gail Edgell: I know this age group of women starts to have issues with their guts. Does that have any link to cancer risk, especially breast cancer?

Dr. Boham: This is an area that we focus on a lot in functional medicine. We look at how all the different systems in the body interrelate and have an influence on risks for different diseases. I find this area very interesting when you look at the research of the digestive system and risk of breast cancer.

There have been some studies that have looked at how a woman’s risk of breast cancer increases with more antibiotic use over her lifetime. Some of the theories for that are that it influences microbiota. Microbiota are all of the good bacteria that line the digestive tract — the intestines, the stomach, the digestive system. We have about 2 to 3 pounds of good bacteria in each of our bodies. Those are 2 to 3 pounds that we don’t want to get rid of — they are really good bacteria that help the immune system and with digestion. They also help detoxify and eliminate estrogen from the body.

When the body has used up its estrogen, whether it’s an estrogen that has been produced in the body or an estrogen we have taken, it needs to be broken down and gotten rid of through the digestive system, in the stool. We think that if there’s not the right balance of good bacteria in the gut, it may influence how the body gets rid of estrogen and other toxins. It may be that when there’s an imbalance in the digestive flora, the body may reabsorb some of that estrogen, increasing that estrogen level in the body. That is a theory, something that we are really looking into.

Something that I always focus on when I am seeing patients is their digestive systems. Are they having an easy time with eating foods? Are the foods digesting easily? Are they having good bowel movements? For some people, that may mean taking a probiotic, or some of that good bacteria, to help their digestive systems work better.

Gail Edgell: Are there any other things, Dr. Boham, that we can educate women on regarding breast cancer?

Dr. Boham: One really important vitamin that we have not talked about yet is Vitamin D. Women can ask their doctors to check their Vitamin D levels — the test they want their doctors to order is the 25 OH Vitamin D level.We’d like that level around 45 to 60 or 70 nanograms per milliliter. Many, many women are deficient in Vitamin D. Getting enough Vitamin D, either from moderate sun exposure or a supplement, can be really helpful in terms of decreasing the risk of breast cancer.

Gail Edgell: Dr. Ellie Campbell actually lectured on Vitamin D for another audio/article. So listeners and readers can get more information if they are interested.

Dr. Boham: Great. It’s important for women to continue to get to know their breasts. That means not only going for their yearly checkups with their own physicians but doing monthly breast exams themselves. Many women find their own breast cancers. They find them earlier when they are doing monthly breast exams. That is important for women to remember.

Gail Edgell: Can we summarize what our audience should have learned today regarding breast cancer and how they can minimize the risk?

Dr. Boham: The No. 1 thing that you can do is to maintain a healthy weight. If you are overweight, work hard to get that percentage of body fat down to a normal range. You can do that by getting three to five hours of exercise a week; cutting out refined and processed foods; choosing more whole foods; choosing more foods that are higher in fiber; making sure that you have a good protein source at each meal to help balance blood sugar; avoiding toxins from the environment like pesticides and fruits, vegetables, meats and milk that are not organic; avoiding as much plastic as you can; and perhaps taking a probiotic. Lastly, really be conscious of the amount of alcohol that you are consuming. Keep it to less than one drink a day.

Note: This article is an edited transcript of an audio interview. Changes have been made.