Diet And Cancer Risk

What Can You Do To Reduce Your Risk Of Cancer?

Magic WandIt 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

Diet And CancerThis 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?

Questioning ManThese 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.

Whole GrainsFoods 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?

American Cancer SocietyYou 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.

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.”

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.

Colon Cancer Prevention

Why Is Colon Cancer Increasing In Young Adults?

Author: Dr. Stephen Chaney

 

colon cancer intestinesA recent study on colorectal cancer reminds me of that famous Dickens quote: “It was the best of times. It was the worst of times.”

The good news (best of times) is that colorectal cancer rates in the United States have been declining for several decades for adults over 50. The decline is attributed to a healthier lifestyle and better screening.

The bad news (worst of times) is that colorectal cancer rates are increasing at an alarming rate for young adults. We have also learned recently that heart attacks are increasing for young women.

These studies are a wake-up call. We need to be asking:

  • Why are young people in our country dying from diseases that we traditionally associate with older adults?
  • What can we do about it?

How Was The Study Done?

colon cancer studyThis study (RL Siegel et al, Journal of the National Cancer Institute, 109 (8): djw322, 2017 ) was an analysis of data collected between 1974 and 2013 from a registry of cancer diagnoses called the Surveillance, Epidemiology, and End Results (SEER) Program. The data were collected from nine regions of the United States (Atlanta, Connecticut, Detroit, Hawaii, Iowa, New Mexico, Seattle-Puget Sound, San Francisco-Oakland, and Utah).

In this study 490,305 patients 20 years and older developed colorectal cancer between 1974 and 2013. This study divided those colorectal cancer cases into 11 age groups (20-29, 30-39, 40-49, 50-54, 55-59, 60-64, 65-69, 70-74, 75-79, 80-84, and 84+). The study then compared colorectal cancer rates for each age group in 8 five-year time periods (1974-1978, 1979-1983, 1984-1988, 1989-1993, 1994-1998, 1999-2003, 2004-2008, and 2009-2013).

What Did The Study Show?

colon cancer increaseWhen the investigators looked at the change in colon cancer incidence over time in different age groups, the results were quite alarming.

  • For adults age 20-29 colon cancer rates increased by 2.4% per year between the mid-1980s and 2013. While that doesn’t sound like much, 2.4% per year adds up. Colon cancer rates almost doubled between 1985 and 2013 for that age group.
  • For adults age 30-39 colon cancer rates increased by 1% per year over that same time period. That’s a 25% increase between 1985 and 2013.
  • By the mid-1990s colon cancer rates started increasing by 1.3% per year for the 40-49 age group and 0.5% per year for the 50-54 age group.
  • The only good news was that colon cancer rates continued to decrease for adults aged 55 and above.

When the investigators looked at the change in rectal cancer incidence over time in different age groups the results were even more alarming.

  • For adults age 20-29 rectal cancer rates increased by 3.2% per year between 1974 and 2013. That’s an almost 4-fold increase in rectal cancer for that age group.
  • For adults age 30-39 rectal cancer rates increased by 3.2% per year between the mid-1980s and 2013. That’s about a 3-fold increase.
  • By the 1990s rectal cancer rates started increasing by 2.3% per year for the 40-49 age group and the 50-54 age group.
  • Once again, the only good news was that rectal cancer rates continued to decrease for adults aged 55 and above.

 

Why Is Colon Cancer Increasing In Young Adults?

 

whyThis study is a clear wake-up call. If colorectal cancer rates are increasing so dramatically in young adults, it does not bode well for them once they reach their 60s, 70s and beyond. This is an impending health crisis. We need to ask:

  • Why this is happening?
  • What can we do about it?

The simple answer to the first question is that no one knows for sure why colorectal cancer incidence is increasing in young adults. However, here is what experts think might be happening:

  • Obesity is a prime suspect. The increase in colorectal cancer incidence in young adults closely parallels the obesity epidemic, and obesity is associated with an increased risk of colon cancer.
  • Many of today’s most popular diets may just make matters worse. Fad diets promise rapid weight loss, but they may also increase the risk of colorectal cancer.
  • Fad diets often restrict fruits, grains, and/or legumes. Plant based diets containing lots of fruits, vegetables, whole grains, and legumes are associated with a significantly lower risk of colorectal cancer. We have no evidence that we can leave out any component of a plant-based diet and still reduce colorectal cancer risk to the same extent.
  • Fad diets often emphasize red meat as a protein source. The World Health Organization considers red meat as a probable carcinogen. The association between red meat consumption and cancer incidence is stronger for colon cancer than for any other cancer.
  • Fad diets are often high in saturated fats, and saturated fat is associated with an increased risk of colorectal cancer.
  • Finally, fad diets are often low in fiber. Low fiber diets alter our microbiome (gut bacteria), and recent research suggests our microbiome may play an important role in preventing colon cancer.
  • The typical American diet is no better. It is high in red meat and saturated fats. It is low in fruits, vegetables, whole grains, legumes and fiber. Plus, it is high in sugar, sweets, and refined grains. With respect to colorectal cancer risk, it is the worst of all possible worlds.
  • We don’t get enough folic acid, calcium and omega-3s in our diet. Those nutrients are associated with a lower risk of colorectal cancer.
  • We don’t move enough. A sedentary lifestyle is also associated with an increased risk of colorectal cancer.
  • Cigarettes and alcohol are associated with an increased risk of colorectal cancer. However, smoking and alcohol consumption have been declining in recent years, so they do not explain the increase in colorectal cancer we are seeing in young adults.

In summary, the authors of this study concluded: “These results highlight the need for…research to elucidate causes for the…increase in disease risk in young [adults], as well as creative new strategies to curb the obesity epidemic and shift Americans towards healthier eating and more active lifestyles.”

Colon Cancer Prevention

 

colon cancer fruits and vegetablesIf you are a young adult, you are probably wondering what you can do to reduce your risk of colorectal cancer. The good news is that we have a good idea of how to reduce the risk of colon cancer, and it works at any age.

Let’s start with the American Cancer Society recommendations  for decreasing the risk of colorectal cancer. They are (with direct quotes from The American Cancer Society in quotation marks):

  • Get screened for colorectal cancer. The American Cancer Society recommends that screening start at age 45. However, you may want to consult with your doctor about earlier screening if you have a family history of early-onset colon cancer, have blood in your stool, or develop bowel changes that last more than a few weeks.
  • Eat lots of vegetables, fruits, and whole grains. According to the American Cancer Society: “Diets that include lots of vegetables, fruits, and whole grains have been linked with decreased risk of colon or rectal cancers.”
  • Eat less red meat and processed meats. They “have been linked with an increased risk of colorectal cancer.”
  • Get regular exercise. “If you are not physically active, you may have a greater chance of developing colon or rectal cancers.”
  • Watch your weight. “Being overweight increases your risk of getting and dying from colon or rectal cancer.”
  • Don’t smoke. “Long-term smokers are more likely than non-smokers to develop and die from colon or rectal cancer.”
  • Limit alcohol. “Alcohol use has been linked with a higher risk of colorectal cancer.”

 

Other experts recommend:

  • Limit saturated fats. Replace saturated fats with monounsaturated fats and polyunsaturated fats.
  • Get plenty of fiber. That should be no problem if you are consuming a primarily plant-based diet containing lots of fruits, vegetables, whole grains and legumes.
  • Make sure you are getting enough folic acid, calcium, and omega-3s. I recommend supplementation because even healthy diets often fall short of these nutrients.

I would add one final recommendation:

  • Avoid fad diets that take you away from a healthy eating pattern (described above), one that is known to reduce colorectal cancer risk.

 

The Bottom Line

 

A recent study has reported an alarming increase in colorectal cancer incidence in young adults.

  • For adults in the 20-29 age range, colon cancer incidence has increased 2-fold and rectal cancer incidence has increased 4-fold over the last few decades.
  • Colon and rectal cancer incidence have also increased significantly for adults in the 30-39 and 40-49 age groups.
  • The only good news from this study is that colon and rectal cancer incidence is continuing to decline for older adults.

This is a clear wake-up call. If this trend is not reversed, it does not bode well for these adults when they reach their 60s, 70s, 80s, and beyond.

For more details on what experts think is causing this alarming increase in colorectal cancer among young adults and what young adults can do to protect themselves from colorectal 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

Colon Cancer Prevention and Anti-Inflammatory Diets

How Can You Reduce Colon Cancer Risk?

Author: Dr. Stephen Chaney

 

colon cancer prevention colorectalColorectal cancer is third most common form of cancer in the United States. The American Cancer Society estimates that there will be 140,000 new cases and 50,000 deaths from colorectal cancer in 2018. The death rate has been decreasing due to more aggressive screening, but it is still much too high.

Thus, there is considerable interest in discovering colon cancer prevention we can control. Several studies have suggested that inflammatory diets may be one preventable cause of colon cancer. There are many reasons for suspecting that inflammation may increase colon cancer risk. For example, we know:

  • Inflammation plays an important mechanistic role in cancer development.
  • Obesity causes a chronic state of low-grade inflammation, and obesity increases colon cancer risk.
  • Inflammatory bowel disease increases the risk of colon cancer.
  • Anti-inflammatory medications such as aspirin decrease colon cancer risk.

However, it has been difficult to prove that inflammatory diets increase colon cancer risk. In part, that is because we can’t measure inflammation directly. We must rely on inflammatory markers such as C-reactive protein (CRP), interleukin-6 (IL-6) and tumor necrosis factor (TNF). Unfortunately, these markers correlate with different inflammatory processes in the body and seldom increase or decrease in unison.

The authors of the current study (FK Tabung et al, JAMA Oncology, 4: 366-373, 2018 ) used a dietary scoring system based on all three inflammatory markers to examine the correlation between an inflammatory diet and colon cancer risk.

How Was The Study Done?

colon cancer prevention inflammationThis study made use of data collected from 46,804 men enrolled in the Health Professionals Follow-up Study (conducted between 1986 and 2012) and 74,246 women enrolled in the Nurses’ Health Study (conducted between 1984 and 2012). Lifestyle, medical, and other health-related information were collected every 2 years. A comprehensive dietary questionnaire was administered every 4 years. During the 26-year follow-up period 2699 cases of colon cancer were diagnosed.

The inflammatory potential of the diet was estimated using an index called the empirical dietary inflammation pattern (EDIP) score that the authors had developed in a previous study (FK Tabung et al, Journal of Nutrition, 146: 1560-1570, 2016 ). This index was based on the effects of individual foods on all three markers of inflammation (CRP, IL-6, and TNF). Inflammatory foods had positive EDIP scores (they increased levels of one or more of the inflammatory markers). Anti-inflammatory foods had negative EDIP scores (they decreased levels of one or more inflammatory markers).

Most of the EDIP scores were consistent with previous studies on the inflammatory potential of various foods. For example:

  • Red meats, processed meats, refined grains, sugar-sweetened beverages, and diet beverages all scored as highly inflammatory.
  • One serving of beer or wine, coffee, dark yellow vegetables, and leafy green vegetables all scored as highly anti-inflammatory.

 

Colon Cancer Prevention By Avoiding Inflammatory Diets

colon cancer prevention fireThe subjects enrolled in the study were divided into five groups based on their inflammatory diet (EDIP) scores. When the investigators compared subjects who had the most inflammatory diet with subjects who had the least inflammatory diet:

  • The risk of colon cancer was increased by 44% in men and 22% in women.
  • People who refrain from alcohol consumption received even greater benefit from anti-inflammatory diets. For teetotalers an anti-inflammatory diet decreased colon cancer risk by 62% in men and 33% in women.

The authors concluded: “Findings from this large prospective [that is scientific jargon meaning the study was carried out over a period of many years] study support a role for the inflammatory potential of diet in colorectal cancer development, suggesting inflammation as a potential mechanism linking dietary patterns and colorectal cancer development.”

 

How To Prevent Colon Cancer Or At Lest Reduce The Risk?

 

colon cancer prevention american cancer societyOf course, holistic approaches are always best. Reducing colon cancer risk involves much more than simply consuming an anti-inflammatory diet. To put this study in perspective, let’s look at what the American Cancer Society recommendations about modifiable lifestyle factors that increase your risk of colon cancer. So, consider these when you think about colon cancer prevention.  I call this the 10,000-foot view because they only list the biggest contributors to colon cancer – the ones for which there is the most scientific evidence (I have put their exact comments in quotes):

#1: Being overweight or obese. “If you are overweight or obese your risk of developing and dying from colorectal cancer is higher”.

#2: Physical inactivity. “If you are not physically active, you have a greater chance of developing colon cancer.”

#3: Certain types of diets.

  • “A diet that’s high in red meats (such as beef, pork, lamb, or liver) and processed meats (like bacon, sausage, hot dogs and some luncheon meats) raises your colorectal cancer risk.” My comment: The evidence is stronger for red meats and processed meats than for any other foods. Processed meats are listed as likely carcinogens and red meats are listed as probable carcinogens by the International Agency For Research On Cancer (IARC), an agency of the WHO.
  • “Cooking meats at very high temperatures (frying, broiling, or grilling) creates chemicals that may raise your cancer risk.”

#4: Smoking. “People who have smoked for a long time are more likely than non-smokers to develop and die from colorectal cancer.”

#5: Heavy alcohol use. “Colorectal cancer has been linked to moderate to heavy alcohol use. Limiting alcohol use to no more than 2 drinks a day for men and 1 drink a day for women could have many health benefits, including a lower risk of many kinds of cancer. “

#6: Early detection. In case you have not heard, the American Cancer Society just released new guidelines recommending that screening for colon cancer begin at age 45.

If you want to take a closer look at the diet – colon cancer connection, you might be interested in the recommendations of Harvard’s Men’s Health Watch newsletter.

 

What Does This Mean For You?

colon cancer prevention inflammatory dietsIf you are confused about the conflicting information about which foods affect colon cancer risk, start with the American Cancer Society recommendations. Avoid red meats and processed meats as much as possible and don’t cook your meats at high temperatures. I realize this is not popular advice at the time of year when everyone is firing up their grills for summer cookouts, but these recommendations will go a long way towards colon cancer prevention. Don’t shoot the messenger. I’m just conveying information based on the best scientific evidence we have to date.

For best results follow the recommendations of the Harvard Men’s Health Watch newsletter to also avoid fried foods, sugary beverages and refined carbohydrates and add anti-inflammatory foods such as fresh fruits & vegetables, nuts, olive oil, and fatty fish.

With Harvard’s recommendations in mind, let me extend an olive branch to all of you red meat lovers. An ounce or two of red meat in a green salad or a stir fry with lots of fresh, colorful vegetables is much less likely to increase your risk of cancer than a steak or burger with fries. You will find more information on this topic in my book “Slaying The Food Myths.”

 

The Bottom Line:

A major study has just been published looking at the correlation between an inflammatory diet and colon cancer risk. When the investigators compared subjects who had the most inflammatory diet with subjects who had the least inflammatory diet:

  • The risk of colon cancer was increased by 44% in men and 22% in women.
  • People who refrain from alcohol consumption received even greater benefit from anti-inflammatory diets. For teetotalers an anti-inflammatory diet decreased colon cancer risk by 62% in men and 33% in women.

The authors concluded: “Findings from this large study support a role for the inflammatory potential of diet in colorectal cancer development, suggesting inflammation as a potential mechanism linking dietary patterns and colorectal cancer development.”

If you are confused about the conflicting information about which foods are inflammatory and anti-inflammatory, start with the American Cancer Society recommendations. Avoid red meats and processed meats as much as possible and don’t cook your meats at high temperatures. I realize this is not popular advice at the time of year that everyone is firing up their grills for summer cookouts, but these recommendations will go a long way towards colon cancer prevention.

For best results follow the recommendations of the Harvard Men’s Health Watch newsletter to also avoid inflammatory foods such as fried foods, sugary beverages and refined grains and add anti-inflammatory foods such as fresh fruits & vegetables, nuts, olive oil, and fatty fish.

With Harvard’s recommendations in mind, let me extend an olive branch to all of you red meat lovers. An ounce or two of red meats in a green salad or a stir fry with lots of fresh, colorful fruits and vegetables is much less likely to increase your risk of cancer than a steak or burger with fries. You will find more information on this topic in my book “Slaying The Food Myths.”

For more details on the American Cancer Society and Harvard recommendations and colon cancer prevention, 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.

Do NOT follow this link or you will be banned from the site!