Obesity and Cancer Archives - Health Tips From The Professor

Best Way To Reduce Risk Of Breast Cancer

September 7, 2021 by Dr. Steve Chaney

What Does The American Cancer Society Say About Reducing Breast Cancer Risk?

Author: Dr. Stephen Chaney

Breast cancer is a scary disease. The American Cancer Society tells us:

281,000 women will be diagnosed with invasive breast cancer in 2021.

43,000 women will die from breast cancer in 2021.

The good news is that both prevention and treatment of breast cancer have gotten much better:

- The 5-year survival rate is 90%.

- The 10-year survival rate is 84%.

- For women over 50 the death rate has decreased by 1%/year between 2013 and 2018 (mainly due to recognition that hormone replacement therapy is a risk factor for breast cancer).

The bad news is:

- The cost of breast cancer treatment can range from $50,000 to over $180,000.

- The side effects of breast cancer treatment can be brutal.

- - For example, there is an effective treatment to prevent breast cancer recurrence for some forms of breast cancer, but many women discontinue the treatment after a few years because of the side effects.

So, wouldn’t it be wonderful if there were some simple changes you could make that would dramatically reduce your risk of developing breast cancer in the first place? There are lots of options for reducing your risk of developing breast cancer, but which one(s) should you choose?

Dr. Strangelove and his friends are only too happy to recommend their favorite potion, food, or diet.

There are long lists of foods you should avoid if you want to reduce your risk of breast cancer.

There are also lists of harmful chemicals in cleaners and other household products that you should avoid.

It can become confusing. It can become overwhelming. It would be easy to just throw up your hands and say, “I give up. I don’t know what to do.”

You may be thinking, “Why doesn’t someone simplify things by identifying the top few lifestyle changes that are most effective for reducing my risk of developing breast cancer?”

It turns out someone has. Today I will share two recent studies that have identified the top 6 strategies for reducing your risk of breast cancer, and I have ranked them from 1 to 6 in order of effectiveness.

What Is The Best Way To Reduce Risk Of Breast Cancer?

The first study (RM Tamimi et al, American Journal of Epidemiology, 184: 884-893, 2016 was designed to identify the major modifiable risk factors for invasive, postmenopausal breast cancer (The term “modifiable risk factors” refers to those risk factors that are under your control.

The study utilized data collected from the Nurses’ Health Study between 1980 and 2010. During that time 8,421 cases of invasive breast cancer were diagnosed in 121,700 postmenopausal women in the study. The study looked at the effect of nonmodifiable and modifiable risk factors on the development of invasive breast cancer in these women.

Nonmodifiable risk factors included current age, age at which menstruation began, height, age of first birth, number of births, weight at age 18, family history of breast cancer, and prior benign breast disease.

Modifiable risk factors included weight change since age 18, alcohol consumption, physical activity level, breastfeeding, and postmenopausal hormone therapy use.

Here were the results from the study:

All the risk factors included in this study accounted for 70% of the risk of developing invasive breast cancer in postmenopausal women.

Modifiable risk factors accounted for 34.6% of the risk of developing invasive breast cancer in postmenopausal women.

When they analyzed the effect of modifiable risk factors on the risk of developing invasive breast cancer separately:

44 pounds of weight gain since age 18 increased the risk by 50%.

Postmenopausal hormone replacement use increased the risk by 35%.

More than one alcoholic beverage/day increased the risk by 32%.

Low physical activity increased the risk by 7%.

Lack of breastfeeding increased the risk by 5%.

What About The Effect Of Diet On Breast Cancer Risk?

You may be wondering, “What about the effect of a healthy diet on my risk developing invasive breast cancer?” Unfortunately, the study I described above completely disregarded the effect of diet on breast cancer risk.

However, the second study (MS Farvid et al, International Journal of Cancer, 144: 1496-1510, 2019) I will discuss today partially addresses this issue. It uses the same database as the first study and looks at the effect of fruit and vegetable consumption on the risk of developing invasive breast cancer.

When this study compared high versus low intake of fresh fruits and vegetable on the risk of developing invasive breast cancer:

Women eating >5.5 servings/day of fruits and vegetables had a 11% lower risk than women consuming ≤2.5 servings/day.

Women consuming >2.5 servings/day of fruit had a 9% lower risk than women consuming ≤0.5 servings/day.

Women consuming >4.5 servings/day of vegetables had a 9% lower risk than women consuming ≤0.5 servings/day.

While all fresh fruits and vegetables contributed to this effect:

The most protective fruits were berries and cantaloupe & melons.

The most protective vegetables were yams & sweet potatoes, green leafy vegetables (such as kale, mustard greens, and chard), and cruciferous vegetables (such as Brussels sprouts).

The authors concluded, “Our findings support that higher intake of fruits and vegetables, and specifically cruciferous and yellow/orange vegetables, may reduce the risk of breast cancer, especially those that are more likely to be aggressive tumors.”

Now we are ready to answer your question, “Which lifestyle changes are most effective for reducing your risk of developing breast cancer?” If we combine the two studies and rank order the modifiable risk factors, it would look like this.

#1: Minimize weight gain during your adult years.

#2: Don’t use postmenopausal hormone replacement therapy unless absolutely necessary.

#3: Drink little or no alcohol.

#4: Eat a healthy diet with lots of fresh fruits and vegetables.

#5: Be physically active.

#6: Breastfeed when possible.

What Does The American Cancer Society Say About Reducing The Risk Of Breast Cancer?

The advice of the American Cancer Society is remarkably similar. Here are their recommendations:

Get to and stay at a healthy weight.

After menopause, most of your estrogen comes from fat tissue. Having more fat tissue increases the amount of estrogen your body makes, raising your risk of breast cancer. Also, women who are overweight tend to have higher levels of insulin. Higher insulin levels have also been linked to breast cancer.

If you are already at a healthy weight, stay there. If you are carrying extra pounds, try to lose some. Losing even a small amount of weight can also have other health benefits and is a good place to start.

3) Be physically active and avoid time spent sitting.

Current recommendations are to get at least 150-300 minutes of moderate intensity or 75-150 minutes of vigorous intensity activity each week. Getting to or exceeding 300 minutes is ideal.

In addition, you should limit sedentary behavior such as sitting, lying down, watching TV, and other forms of screen-based entertainment. This is especially important if you spend most of your working day sitting.

3) Follow a healthy eating plan.

A healthy eating pattern includes a variety of vegetables, fiber-rich legumes (beans and peas), fruits in a variety of colors, and whole grains. It is best to avoid or limit red and processed meats, sugar-sweetened beverages, highly processed foods, and refined grain products. This will provide you with key nutrients in amounts that help you get to and stay at a healthy weight.

4) It is best not to drink alcohol.

Research has shown that drinking any alcohol increases the risk of breast cancer. If you choose to drink alcohol, the American Cancer Society recommends that women have no more than 1 alcoholic drink on any given day. A drink is 12 ounces of regular beer, 5 ounces of wine, or 1.5 ounces of hard liquor.

5) Think carefully about using hormone replacement therapy.

Studies show that HRT using a combination of estrogen and progestin increases the risk of breast cancer. This combination can also lead to increased breast density making it harder to find breast cancer on mammogram.

Talk with your doctor about all the options to control your menopause symptoms, including the risks and benefits of each. If you decide to try HRT, it is best to use it at the lowest dose that works for you and for as short a time as possible.

The Bottom Line

Breast cancer is a scary disease. The good news is that detection and treatment of breast cancer has improved over the past decade. The bad news is that treatment is expensive, and the side effects can be brutal.

There are lots of options for reducing your risk of developing breast cancer, but which one(s) should you choose?

Strangelove and his friends are only too happy to recommend their favorite potion, food, or diet.

There are long lists of foods you should avoid if you want to reduce your risk of breast cancer.

There are also lists of harmful chemicals in cleaners and other household products that you should avoid.

It can become confusing. It can become overwhelming. It would be easy to just throw up your hands and say, “I give up. I don’t know what to do.”

You may be thinking, “Why doesn’t someone simplify things by identifying the top few lifestyle changes that are most effective for reducing my risk of developing breast cancer?”

For more details about these studies, my ranking of the top 6 strategies for reducing your risk of breast cancer, and the American Cancer Society recommendations, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

Diet And Cancer Risk

March 31, 2020March 31, 2020 by Dr. Steve Chaney

What Can You Do To Reduce Your Risk Of Cancer?

It seems like everyone has a magic pill, essential oil, food, or diet that prevents cancer. It doesn’t take a genius to figure out that all the claims can’t be true. No wonder you are confused. You want to know:

Which of these claims are true?

What can you do to reduce your risk of cancer?

These aren’t trivial questions.

Cancer is the second leading cause of death in this country, and some experts predict it will surpass heart disease as the leading cause of death in the near future.

While cancer treatments have become much more effective in the past few decades, these treatment successes are often associated with severe side-effects, enormous expense, or both.

That is why I was intrigued by a recent study (FF Zhang et al, JNCI Cancer Spectrum (2019) 3(2): pkz034) on diet and cancer that came from the prestigious Friedman School of Nutrition and Public Policy at Tufts University. This study asked two important questions:

How many newly diagnosed cancer cases could have been prevented by changes in the American diet? This is something the authors referred to as the “preventable cancer burden associated with poor diet”.

Which foods increased or decreased the risk of cancer? This, of course, is the most useful information for you and me.

Diet And Cancer Risk

This study estimated that 80,110 new cancer cases among US adults 20 and older could be primarily attributed to poor diet. While poor diet contributes to many more cancers, the authors of this study felt 80,110 represented the number of cancer cases that were clearly preventable by some simple dietary changes.

While all cancers were affected by diet to some degree, the cancers most affected by poor diet were:

Colon cancer (65% of cases)

Mouth and throat cancer (18% of cases)

Endometrial cancer (4.0% of cases)

Breast cancer (3.8% of cases)

When the diet was broken down into individual food groups:

Low intake of whole grains was associated with the largest number of preventable cancer cases (35% of cases). This was followed by.

Low intake of dairy foods (22% of cases).

High intake of processed meats (18% of cases).

Low intake of vegetables (16% of cases).

Low intake of fruits (10% of cases).

High intake of red meat (7.1% of cases).

High intake of sugar sweetened beverages (4.0% of cases).

Of the diet-associated cancer cases, the scientists who lead the study estimated that 84% of them represented a direct effect of diet on cancer risk. The dietary factors most likely to directly increase the risk of cancer were:

Low intake of whole grains.
Low intake of dairy foods.
High intake of processed meats.

The scientists estimated that 16% of diet-associated cancer cases were “mediated by obesity”. In layman’s terms, this means that diet increased the risk of obesity and obesity increased the risk of cancer. The dietary factors most likely to increase the risk of obesity-mediated cancers were:

High intake of sugar sweetened beverages.
Low intake of fruits.

The authors concluded: “More than 80,000 new cancer cases [per year] are estimated to be associated with suboptimal diet among US adults…Our findings underscore the need for reducing cancer burden in the United States by improving the intake of key food groups and nutrients of Americans.”

What Does This Mean For You?

These findings aren’t novel. Many previous studies have come to the same conclusions. However, many people find these recommendations to be confusing. Should they increase their intake of certain foods? Should they follow some sort of magic diet?

Perhaps we need to get away from the magic food concept. We need to understand that every time we increase one food in our diet, we exclude other foods. We need to step back and look at the overall diet.

Let me break down the recommendations from this study into three categories: foods we should eliminate from our diet, foods we should include in our diet, and foods we should balance in our diet.

Foods we should eliminate from our diet:

Sugar Sweetened Beverages. They provide no nutritional benefit, and the sugar in most beverages rushes into our bloodstream and overwhelms our body’s ability to utilize it in a healthy way. This leads to obesity, diabetes, and a host of other health issues.

- Public enemy number one is sodas. However, this category also includes fruit juices, sweetened teas and energy drinks, and sugary processed foods.

- This category also includes diet sodas. For reasons we don’t completely understand, diet sodas appear to be just as likely to lead to obesity, diabetes, and heart disease as sugar sweetened sodas. I have discussed the proposed explanations of this phenomenon in a recent issue of “Health Tips From the Professor”.

- Sugar, however, is not the enemy. Sugar found naturally in fruits and other whole foods enters the bloodstream slowly and is metabolized in healthy ways by the body. I have discussed this in another issue of “Health Tips From the Professor”. This is what I mean by restoring balance in our diet. Decreasing the sugar intake from sugar sweetened beverages and increasing sugar intake from fruits is associated with a decreased risk of obesity and obesity-related cancers.

Processed Meats. The evidence is overwhelming at this point that processed meats directly increase the risk of cancer.

- If you have trouble completely eliminating processed meats from your diet, my advice is to minimize them and consume them only in the context of an overall healthy diet. Personally, I still consume bacon occasionally as flavoring for a healthy green salad.

Foods we should include in our diet. I put these in a separate category because Dr. Strangelove and his colleagues have been telling us to eliminate them from our diet, and many Americans are following those recommendations:

Whole grains. We can think of whole grains as the underserving victim of the low-carb craze. The low-carb craze is on the mark when it comes to eliminating added sugars and refined grains from the diet. However, eliminating whole grains from the diet may be doing more harm than good. In fact, this and other studies suggest that whole grains are the most effective foods for reducing cancer risk. Why is that?

- If we assume whole grains are just a good source of fiber and a few vitamins and minerals, it is hard to grasp their importance. We could easily get those nutrients elsewhere.

- However, we are beginning to realize that whole grains play a unique role in supporting certain species of gut bacteria that are very beneficial to our health. In short, whole grains may be essential for a healthy gut.

Dairy Foods. This is another food that has been treated as a villain by Dr. Strangelove and his many colleagues. However, for reasons we don’t completely understand, dairy foods appear to decrease the risk of heart disease and cancer.

Foods we should balance in our diet.

Red Meat. Diets high in red meat are consistently associated with a slight increase in cancer risk. The World Health Organization lists red meat as a probable carcinogen, but that has proven to be controversial.

- Much of the research has centered on why red meat causes cancer. Several mechanisms have been proposed, but none of them have been proven.

- In contrast, very little consideration has been given to what red meat is displacing from the diet. Diets high in red meat are often low in whole grains, fruits and/or vegetables.

- Perhaps instead of eliminating red meat from our diets we should be talking about balancing red meat in our diets by consuming less red meat and more whole grains, fruits, and vegetables.

What Can You Do To Reduce Cancer Risk?

You may have been thinking that 80,110 cases/year represents a small percentage of new cancer cases. That’s because diet is only one component of a holistic cancer prevention strategy. Here is what the American Cancer Society recommends for reducing cancer risk:

Avoid tobacco.

Limit sun exposure.

Achieve and maintain a healthy weight.

Eat a healthy diet, with an emphasis on plant foods (Their recommendations are in line with this study).

Be physically active.

Limit alcohol use.

Get vaccinated against HPV.

Get regular medical checkups.

Doing any of these things will reduce your cancer risk. But the more of these you can incorporate into your lifestyle, the lower your risk.

The Bottom Line

A recent study looked at diet and cancer risk. The authors reported that 80,110 new cancer cases among US adults 20 and older could be primarily attributed to poor diet.

When the diet was broken down into individual food groups:

Low intake of whole grains was associated with the largest number of preventable cancer cases. This was followed in descending order by.

Low intake of dairy foods.

High intake of processed meats.

Low intake of vegetables.

Low intake of fruits.

High intake of red meat.

High intake of sugar sweetened beverages.

For more details, read the article above. For example, I discuss which foods we should eliminate, which foods we should eat more of, and which foods we should balance in our diet. To add a more holistic perspective, I also discuss the American Cancer Society’s recommendations for reducing cancer risk.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

Does Obesity Cause Cancer?

June 14, 2016 by Dr. Steve Chaney

Is The Obesity Epidemic Killing Us?

Author: Dr. Stephen Chaney

Does obesity cause cancer?

You probably already know that we are in the midst of a world-wide obesity epidemic. If not, here are some of the alarming statistics that characterize that epidemic:

The global prevalence of obesity has increased by 27.5% between 1980 and 2013.

35% of the adult population worldwide is now overweight (BMI ≥ 25), including 12% who are classified as obese (BMI ≥30).

According to the NIH the situation is even worse in developed countries like the US where 75.1% of adults are now overweight, including 35.7% who are obese, and 6.3% who are very obese (BMI ≥40).

Unfortunately, overweight and obesity are not benign. You probably already knew that those excess pounds increase your risk of diabetes, heart disease, kidney failure and much more. You probably also knew that those excess pounds increase your risks of certain types of cancer such as colon, rectal, kidney, pancreatic, postmenopausal breast, ovarian and uterine cancer.

It’s been a little more difficult to determine just how much obesity increases cancer risk. However, a recent study suggests that the increased risk could be quite significant. In fact, if this study is correct, obesity may only be second to smoking as a preventable cause of cancer. The truth might just scare you skinny!

Does Obesity Cause Cancer?

The International Agency For Research On Cancer did a worldwide study, (Arnold et al, The Lancet Oncology 16: 36-45, 2015), in which they looked at the effect of BMI on cancer incidence in adults aged 20 years or older. The BMI data was collected in 2002 and was segregated by sex and age groups. Recognizing that cancer takes decades to develop, they then collected data on newly diagnosed cancers in adults 30 and older in the same countries in 2012. They were determined to get closer to answering the question, does obesity cause cancer?

By comparing BMIs in 2002 with the incidence of newly diagnosed cancers 10 years later they were able to calculate the effect of excess body weight (BMI ≥25) on cancer incidence. The results were startling:

They estimated that 481,000 new cases of cancer in 2012 in adults over 30 were attributable to excess weight.

That represents 3.6% of all new cancer cases, which makes overweight second only to smoking as a preventable cause of cancer.

Uterine cancer, postmenopausal breast cancer, and colon cancer accounted for 63.6% of all cancers caused by overweight. Other cancers affected by excess weight were rectal cancer, pancreatic cancer, kidney cancer, gallbladder cancer, and ovarian cancer.

The effect of excess weight on cancer risk was almost 3-fold greater for women (5.4% of new cancer cases) than for men (1.9% of new cancer cases).

In North America 111,000 new cases of cancer in 2012 for adults over 30 were attributable to excess weight. That represents 3.5% of all new cancers in men and 9.4% of all new cancers in women.

A quarter (about 118,000) of the worldwide cancer cases related to high BMI in 2012 could be attributed to the increase in BMI that has occurred since 1982.

The authors concluded “These findings emphasize the need for a global effort to abate the increasing numbers of people with high BMI. Assuming that the association between the high BMI and cancer is causal, the continuation of current patterns of population weight gain will lead to continuing increases in the future burden of cancer.”

What Does This Study Mean For You?

We have to stop kidding ourselves. That excess flab isn’t harmless. It is killing us, and cancer is a particularly gruesome way to go. It’s time to get serious about weight loss. Here are my top 5 tips for lasting weight loss.

Eat healthy low calorie meals and snacks with plenty of protein so that you maintain muscle mass while you are losing fat.
Avoid the fad diets. You don’t need to restrict carbohydrates or fats. You just need to focus on fresh fruits and vegetables, healthy proteins and modest amounts of healthy fats and healthy carbohydrates.
Find an exercise program you like and stick with it every day.
Focus on true lifestyle change rather than short term diets. A good strategy is to make one healthy change at a time rather than trying to do everything at once.
Change how you think about food, think about exercise, and think about your ability to make the kinds of changes that will lead to permanent weight loss. Don’t think of yourself as a fat person who is trying to lose weight. Think of yourself as a skinny person who happens to have a few extra pounds that are on their way out.

Of course, getting to a healthier weight isn’t the only change you want to make if you are trying to reduce your risk of cancer. Here are my top 7 lifestyle change suggestions (besides weight loss) for reducing cancer risk.

If you smoke, stop. No ifs, ands, or buts. Smoking is still the #1 cause of cancer.
Eat a healthy diet (including supplements to fill the gaps).
Eat plenty of fresh fruits and vegetables, especially those that are good sources of cancer-fighting antioxidants, carotenoids, flavonoids, and polyphenols.
Eat fish and fish oil supplements to make sure that you get plenty of omega-3 fatty acids.
Minimize saturated fats and avoid trans fats. Substitute olive oil for vegetable oils whenever possible.
If you drink alcohol, drink it in moderation.
Avoid sun exposure as much as possible, and use sunscreen when outdoors.
Eat healthy proteins.
Minimize consumption of red meats and processed meats.
Use chicken, fish and vegetable proteins whenever possible.
Soy protein is particularly helpful for reducing the risk of breast cancer. (Yes, those scary blogs about soy and breast cancer are wrong. For accurate information, just go to https://chaneyhealth.com/healthtips and type soy in the search box).
Get plenty of exercise.
Get regular check-ups.

So, does obesity cause cancer? I think you now know the answer.

The Bottom Line

A recent study has shown:

481,000 new cases of cancer worldwide each year are attributable to excess weight.

That represents 3.6% of all new cancer cases, which makes overweight second only to smoking as a preventable cause of cancer.

Uterine cancer, postmenopausal breast cancer, and colon cancer accounted for 63.6% of all cancers caused by overweight.

The effect of excess weight on cancer risk was almost 3-fold greater for women (5.4% of new cancer cases) than for men (1.9% of new cancer cases).

In North America 111,000 new cases of cancer for adults over 30 are attributable to excess weight. That represents 3.5% of all new cancers in men and 9.4% of all new cancers in women.

That excess flab isn’t harmless. It is killing us, and cancer is a particularly gruesome way to go. For my top 5 tips for lasting weight loss and my top 7 tips for reducing your risk of cancer, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.