Diet and Exercise May Prevent 1/3 of Breast Cancers

By , SparkPeople Blogger
Breast cancer is the most common form of cancer in women. A woman's chance of getting breast cancer is about one in eight. Although genes and heredity are a huge risk factor for developing the disease, new studies are highlighting the large role that lifestyle plays when it comes to breast cancer risk.

Figures from the International Agency on Cancer (part of the World Health Organization), estimate that 25 to 30 percent of breast cancer cases could be avoided if women were thinner and exercised more regularly. In a 2006 British study, obese women were up to 60% more likely to develop any cancer than normal-weight women. So we're starting to see that lifestyle changes (like wearing sunscreen, exercising regularly, quitting smoking and a healthy diet) can have a significant impact on a woman's risk of developing all different types of cancers.

According to the research, "Many breast cancers are fueled by estrogen, a hormone produced in fat tissue. So experts suspect that the fatter a woman is, the more estrogen she's likely to produce, which could in turn fuel breast cancer. Even in slim women, experts believe exercise can help reduce the cancer risk by converting more fat into muscle."

The major risk factors for developing breast cancer are still age, family history and gender. Although these are out of a woman's control, it's important to make as big of an impact as possible on those things you can control- which would be lifestyle habits.

The American Cancer Society recommends 45 to 60 minutes of physical activity at least five days a week to reduce the risk of breast cancer. But the Cancer Society also points out that the risk appears to increase for women who gain weight as adults, but not for women who have been overweight since childhood. So it seems like future research will help further determine the link between lifestyle and cancer risk.

What do you think?

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GEORGE815 9/3/2020
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GABY1948 12/4/2019
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Thanks for a great article! :) Report
Well, fat is fat and muscle is muscle. No turning one into the other, however, I do agree that a healthy lifestyle (diet and exercise) can increase you life expectancy and make it that much more enjoyable. The sooner the test, the better is the best result. Report
Thanks for the information! Report
As there are different types of breast cancer, each seeming to be fueled by different factors, it's almost impossible to generalize about cause and effect. Add in conflicting test results, and one could go crazy trying to reduce one's odds for any disease. I recently read that if you are overweight and have a disease, even if the disease was caused by being overweight (Type II diabetes for instance), the mortality rate is better for overweight people than people who develop the same disease and then lose weight. As this runs current to current conventional thinking among the population at large and the medical profession specifically, no matter how compelling this evidence is (it turns up in almost every study of diet vis a vis disease and mortality), not only is this hypothesis not being tested further, but is being pretty much ignored. So they don't know why this is for sure, they just know that study after study shows this. HOWEVER, the few studies which include exercise and diet (as opposed to just diet) seem to show the more fit you are (no matter how much you weigh), the better your mortality rate. I bring all this up, just to suggest that, developing a healthier lifestyle, with an emphasis on fitness, while no guarantee at all of preventing disease, might increase your odds of surviving one. there is too much compelling evidence about exercise and its direct and immediate effect on certain conditions, not to take heed and get moving. Report
When it says stuff like "converting fat into muscle" which is biologically impossible, it makes me doubt the credibility of the entire article. Report
More body mass = More cells in your body = more of a chance for one of them to mutate into a cancer.

Eat Fruits and veggies, Filter your water, Balance your diet, and exercise. You can drink tea to be safe, but fruits give tons of antioxidants.

NETTELYNNH: "it is a myth that bra wearing has any association with breast cancer. The study you refer to was done by anthropologist and was not conducted according to the well-established standards for scientific population-based research. It did not attempt to account for and control other well-accepted risk factors in comparing bra wearing and non-wearing women."
The Singer study is not the only such study. Human beings cannot be put in cages, fed identical diets and compelled to wear bras identically made to identically fit each individual. The best that can be done is to study existing populations. Some of the women identified as "without breast cancer" may have already had undetected cancer.
They would have to be followed for decades to see what happens to them.
Bras vary in design, tightness, insulation characteristics (elevated heat is suspected of being contributory to breast cancer). It is not the bra itself that is believed to directly cause cancer. It is the buildup of toxins (irritants) in the breasts, and that buildup may be caused by the tightness of the bra. Toxins are strongly associated with cancer in the rest of the body. Why would the breasts be an exception?
It is generally accepted that tobacco smoking causes lung and other cancer. Yet whatever mechanism brings about lung cancer is not precisely known. The tobacco-cancer connection is a statistical association. Not every smoker develops lung or any cancer. Not everyone who develops lung cancer is a smoker, or even lives and works around smokers.
Not nearly all bra-wearing women develop breast cancer, and some women who never wore a bra in their lives develop breast cancer. The breast cancer rate among women who do not wear bras is about the same as the breast cancer rate among men, among whom almost none wear bras, but many of whom have breasts as large or larger than many women.
Are you willing to wait 40+ years to see if there is a provable connection between bra wearing and breast cancer (never mind fibrocystitis of the breasts, also connected with bra wearing)? It took that long to establish the connection between tobacco smoking and lung cancer, and it still hasn't been proven. Report
Genes are a huge part of what health issues one will experience or not experience. However, I believe, a healthy, active lifestytle can improve the quality of your life and you will handle better what you are dealt. Report
I agree with SUNSET09...what could it hurt? If anything, it will definitely help us to live healthier, longer lives. I have a history of breast cancer, I'm considered high risk because both my mother and sister had it. My sister had it at age 30, so I have been having my annual mammograms since I turned 30. But so far, I have had a clean bill of health and prayerfully, I intend to keep it that way! Report
I lost my favorite aunt 18 months ago to complications from breast cancer - chemo destroyed her heart - and she was always healthy and active. I am a wellness coach so I always recommend healthy eating and an active lifestyle. Unfortunately for my aunt, that wasn't enough. Sometimes it isn't. That's why yearly mammograms after age 40 and monthly self-exams are also so important. It would be nice if eating right and exercising were always the answer. Report
Another good point why we need to do exercises and have healthy diet!

Several of my relatives have died of various type of cancers, including breast cancer. I didn't meet them personally but if you look at my other relatives, most of us are happy-eating people and not quite consistant with exercises. And worse, we have long history of diseases, sickness. I wish I can break that "tradition" and influence them as well. Fortunately, I have my support groups - in and out websites :D Report
Trudy you have to click the spark points button under the article to earn points for reading... you can also get points when you submit a comment... Report
I read two articles every time I come to this site,the only way to get my points is to leave a message. Am I doing something wrong? Report
What could it hurt; even if it weren't true!? I realize that when you work out, you can't helpb ut eat right and eating right and working out gives way to a longer, healthy life. Sometimes, before someone succumbs to their incurable diseases, it could be something else. Report
the basicprinciples of healthy life style, heatlhy diet, exercise, etc, are contributory here Report
@ Vixen 2188, it is a myth that bra wearing has any association with breast cancer. The study you refer to was done by anthropologist and was not conducted according to the well-established standards for scientific population-based research. It did not attempt to account for and control other well-accepted risk factors in comparing bra wearing and non-wearing women. The American Cancer Society has a great description at
Ponderous!!! Lots of variables.. Report
I had a hard time reading this blog. My sister-in-law just turned 50 and is in the middle of chemo and radiation treatments for breast cancer. She is also a mere 18 months older than me, but unlike me has been a healthy weight throughout her life and fairly active. OTOH her mother died from cancer when she was 3 and mine is still alive and 80 years old. So I'd say that while there's a lot to increasing once's odds by being a healthy weight and exercising, I think the genetic component is grossly underestimated in this article. Report
The article is important in that it stresses the role of diet and exercise in overall health. The most recent findings from a European study seem to think that eating fruits and vegetables plays a smaller role in prevention of cancer than previously thought.
As a breast cancer survivor myself (5 years) I think articles such as this put too much "blame" on those who have dealt with breast cancer. If the causes of breast cancer were weight, or exercise or diet, than none of the thin, normal weight healthy eaters would not get breast cancer. We know this is not the case. Or, why don't all overweight women with poor diets get it? Fewer than 5% of breast cancers are caused by any know genetic factor. And all breast cancers are not "fueled" by estrogen, so the premise that fat somehow promotes the cancer is not true for all types.
I think what this means is that we still have so much to learn about the causes and prevention of breast cancers. While getting fit and eating well are great for your health and lots of other reasons, I think we need to be careful when pointing to poor health as the cause of breast cancers.
If you are really interested in helping find the real causes, please participate in the activities where money will go to research to find the causes, such as those offered by Komen or the American Cancer Society. (There are many others as well) Also, if you have not done so, please join the Army of Women. This is for women with or without cancer. Many of the research studies are available online, so you don't have to live in a certain place to participate. The organization recruits women to be involved in studies to find the causes of Breast Cancer. It is founded by Dr. Susan Love, a reputable Breast Cancer Research advocate. The website is of
The best quote I have found about the explanation of why some women get it and other don't is this. "Genetics loads the gun, but environment pulls the trigger". With this in mind, I would reiterate the fact that research is important to find all the causes of cancer, both genetic and environmental. I am looking forward to the day that my daughters can be vaccinated to prevent it. Report
It really pains me to think that I might have avoided my recent bout of breast cancer. Although my sister also had it about 10 years ago (and she is really thin), perhaps if I had looked after myself regarding my weight I might have avoided it. Believe me when I say that I would have loved to have missed the chemo and radiation and the chemo burn in my wrist if I had know this a few years earlier. I would like to think that I would have taken my health in hand much sooner. Report
Breastfeeding your babies is one of the BEST ways to avoid getting Breast Cancer as it releases old cells and helps new cells to grow. I see the picture at the top of the article and the girl in the Gray top appears to be pregnant. I know that breastfeeding is a key issue. Since bottle-feeding was introduced by the formula companies after WW2, the BC rate has increased.

FYI, breast cancer is fueled by estrogen, which is produced in the body from SOY products.
Anyone concerned or fighting cancer should GOOGLE Gerson Therapy. It works. Report
Once again, moderation seems to carry the day. I really think some of the comments right below mine sum things up nicely. Report
It's distressing to think I could have been spared the trauma of breast loss & chemo had I maintained a healthy weight & exercised earlier. But, this gives me hope that I may be able to avoid problems in my remaining breast & elsewhere by my healthier lifestyle now. I will keep up with my breast self exams - I found the earlier lump myself, & will stay vigilant. Also do yearly mammogram, since I'm an obvious risk. & 7 years cancer free now, want to stay that way! Be pro-active for your health! Report
Good to know, but, really, it boils down to (1) do what you can for lifestyle (2) do the diagnostics in a systematic manner and (3) get on with living what your life hands out. I'm sure quality of life is not improved by too much worry over cancer or other imponderables. It's kind of like the old serenity prayer--for the serenity to accept what you cannot change, the courage to change what you can--and the WISDOM to know the difference. We do not control all the variables. Report
Firstly, you cannot "convert fat into muscle." It's impossible. Other than that, I think the article highlights what we already know - diet and exercise are crucial to a healthy lifestyle. Report
Firstly, you cannot "convert fat into muscle." It's impossible. Other than that, I think the article highlights what we already know - diet and exercise are crucial to a healthy lifestyle. Report
Family history is a small piece of the risk for breast cancer. A very small percentage of breast cancer is familial. PLEASE don't let the fact that you don't have a family history lull you into complacency. I have a niece that was diagnosed at the age of 23 and we had no family history. If she had listened to her doctor and "watched it" she would have a very different prognosis than she does now. We are training right now to walk a half marathon to celebrate her 5 years cancer free!! Report
I think that we don't know all that we should concerning this subject but I do believe that staying within normal range with your weight and getting adequate exercise is good for one. Report
Hooray for the estrogen+ survivors...for the rest of us, the triple negatives (who are much more likely black than white), I'd like to see more triple neg research Report
Breast cancer is a multifaceted disease. If they knew what caused it, there would be a cure. Whenever anyone says it is do to being overweight, I always say remember Linda McCartney, the skinny vegetarian who died of it. Living a healthy lifestyle is important but it does not prevent all diseases. Report
I think they are looking at the genetic risk as the chance you will get if you have the gene, vs the overall percentage of cases that are "genetic".
I'm glad to be motivated to take care of myself. Report
"Genes and heredity are a HUGE risk factor"? According to the National Institutes of Health and the College of Physicians of Canada, heredity accounts for only 5-10% of breast cancer diagnoses (those associated with the BRCA 1, 2, and 3 genes).

While they state that "The remaining (familial) 10% to 15% is due to some other factor involving the family, such as an environmental factor, chance, or an undiscovered gene mutation", this is NOT the same thing as saying 25% of breast cancers are genetic, and the comment about it being a "HUGE" risk factor is quite misleading.

I *do* think we've far more to worry about from our environment and behaviours when it comes to developing different kinds of cancers, but articles like this, with rather misleading statements straight out of the box? I think I'll get my information (confirmation) elsewhere. Report
Bottom line: one can reduce ones risk but still A LOT of cases occur in people leading healthy lifestyles. The story doesn't end there though. If you get breast cancer anyway, you will bounce back better from the stresses of breast cancer treatment (esp. from surgery and toxic meds) if you start in shape and strong and with good nutrition.
Even doing everything "right", this disease can strike. That's been driven home for me by the fact that i have THREE friends who have battled this disease- and they are the fittest, leanest and non-stressed out of all my friends. Go figure. So careful not to extrapolate from this article that breast cancer is a lifestyle disease!
I am walking the Avon Walk this year in their honor.
And REMEMBER, the leading killer for women is heart disease- so go for the healthy lifestyle!!!!!!!!!
You can be thin and active but still have too much stress which kills your immune system. It's all about having a strong immunity so your body can fight the cancer cells that (everyone) has. So do away with stress if you can, reduce use of chemicals that mimic estrogen in the body, exercise, and eat your fruit and veggies. Cover all your bases. Also take supplements ( cruciferous veggies) take calcium-d-glucarate to lower estrogen in the body. Antioxidants. Report
Well it's good that I have irregularly high testosterone levels then. Report
Yes, I was just thinking of Martina and also Olivia Newton John, people always active, slim, trim, and so forth. And Paul McCartney's wife, who was a almost life long just don't know for sure really, no matter what researchers say, they don't follow people around 24 hours a day for years and years either. Report
It seem there is no down side to being healthy,why did I wait so long. Report
I agree with TOCONNER, comment #2.
I was diagnosed with breast cancer at the age of 39 in 2003; I was fairly active and had a job in which I was on my feet and moving all day. I never smoked, and very rarely drank. I believe a lot of mine was genetic; my mom's mother died from breast cancer when she was in her 40's, when my mother was 12 years old, and there has been other kinds of cancer on both sides of the family.

I was about 25 pounds overweight when I joined Spark; it was a few months after my chemo was finished in 2004; I put on most of that extra weight because of medication that I was on, and being too fatigued to work on my fitness or care about what I was eating.

My cancer returned in 2007, in the form of bone mets; and now it's starting to spread again; I am getting ready to go through chemo a second time starting next week. I intend to keep up with my healthy eating and exercising as much as I am able, to give my body a better chance against the chemo side effects.

That being said, I still believe that living as healthy as possible, by diet and exercise, can really do a lot to improve quality of life, but I don't think it can prevent certain types of cancer.

And living a healthy lifestyle can also help a lot to prevent heart disease and diabetes. Report
As a breast cancer survivor, I can vouch for this! My doctor told me straight out I needed to lose some weight, because the chance of the breast cancer coming back is much higher with me being overweight. Now it is true that genes and heredity has a big part to do with it too-cancer of all kinds run rampant in my family: both parents, both grandparents on both sides, and numerous aunts and uncles all have had some kind of cancer, and some with more than one.

Whichever 'reason' it is, it still helps to live a healthy, active life! Report
"...reduce the cancer risk by converting more fat into muscle?" Fat cannot be converted into muscle. One can reduce the amount of fat and increase muscle mass. Perhaps, that's what this inaccurate and unscientific statement meant... Report
Another reason to pursue a healthy lifestyle. Report
I agree with you TOCONNER. My mom had a breast cancer with mastectomy 21 years ago. She has always lived an active lifestyle and was never overweight. I think genetics has a lot to do with it. Report
I stopped wearing a bra to prevent my breast cancer!

* Women who wore their bras 24 hours per day had a 3 out of 4 chance of developing breast cancer (in their study, n=2056 for the cancer group and n=2674 for the standard group).

* Women who wore bras more than 12 hour per day but not to bed had a 1 out of 7 risk.

* Women who wore their bras less than 12 hours per day had a 1 out of 152 risk.

* Women who wore bras rarely or never had a 1 out of 168 chance of getting breast cancer. The overall difference between 24 hour wearing and not at all was a 125-fold difference. Report
I would be interested in what the findings show for a woman who doesn't have a genetic predisposition and has already gone through menopause. Report
I believe genetics play a huge roll in Breast Cancer and other illnesses. I know that in my family weight was not the issue on either side of my family for those who had Breast Cancer.
I also realize that not only weight but being fit can help to ward off a lot of illnesses. We have to take care of ourselves physically, mentally and emotionally to help us overcome so many illnesses.
I worked in a hospital with Cancer patients and those who had a positive outlook and family support where more likely to go into remission and live a longer fuller life. Report
I send out an email each month to my co-workers to check their breast and also if this is the month for their annual mammogram to get it scheduled. I think the best we can do is prevent and be aware. Report