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Mediterranean diet

Preventing diabetes, cancer and stroke

By David Dunaief, M.D.

Dr. David Dunaief

What better way than a season centered around eating al fresco to kick-start you on the path to preventing chronic diseases? In the past, I have written about the dangers of processed meats in terms of causing chronic diseases, such as cancer, diabetes, heart disease and stroke. These are foods commonly found at barbecues and picnic meals. Therefore, I think it is only fair to talk about healthier alternatives and the evidence-based medicine that supports their benefits.

The Mediterranean-style diet is the key to success. It is composed of thousands of beneficial nutrients that interact with each other in a synergistic way. This particular diet, as I have mentioned in previous articles, includes fish, green leafy vegetables, fruit, nuts and seeds, beans and legumes, whole grains and small amounts of olive oil. We all want to be healthier, but doesn’t healthy mean tasteless? Not necessarily.

At a memorable family barbecue, we had a bevy of choices that were absolutely succulent. These included a three-bean salad, mandarin orange salad with raspberry vinaigrette, ratatouille with eggplant and zucchini, salmon filets baked with mustard and slivered almonds, roasted corn on the cob, roasted vegetable and scallop shish kebobs and a large bowl of melons and berries. I am drooling at the memory of this buffet. Let’s look at the scientific evidence.

Cancer studies

Fruits and vegetables may help prevent pancreatic cancer. This is very important, since by the time there are symptoms, the cancer has spread to other organs and the patient usually has less than 2.7 years to live (1). Five-year survival is only 5 percent (2). In a case control (epidemiological observational) study, cooked vegetables showed a 43 percent reduction and noncitrus fruits showed an even more impressive 59 percent reduction in risk of pancreatic cancer (3). Interestingly, cooked vegetables, not just raw ones, had a substantial effect. 

Garlic plays an important role in reducing the risk of colon cancer. In the IOWA Women’s Health Study, a large prospective (forward-looking) trial involving 41,837 women, there was a 32 percent reduction in risk of colon cancer for the highest intake of garlic compared to the lowest. Vegetables also showed a statistically significant reduction in the disease as well (4). Many of my patients find that fresh garlic provides a wonderful flavor when cooking vegetables.

Diabetes studies — treatment and prevention

Fish plays an important role in reducing the risk of diabetes. In a large prospective study that followed Japanese men for five years, those in the highest quartile of intake of fish and seafood had a substanttial decrease in risk of Type 2 diabetes (5). Smaller fish, such as mackerel and sardines, had a slightly greater effect than large fish and seafood in potentially preventing the disease. Therefore, there is nothing wrong with shrimp on the “barbie” to help protect you from developing diabetes. 

Nuts are beneficial in the treatment of diabetes. In a randomized clinical trial (the gold standard of studies), mixed nuts led to a substantial reduction of hemoglobin A1c, a very important biomarker for sugar levels for the past three months (6). As an added benefit, there was also a significant reduction in LDL, bad cholesterol, which reduced the risk of cardiovascular disease. The nuts used in the study were raw almonds, pistachios, pecans, peanuts, cashews, hazelnuts, walnuts and macadamias. How easy is it to grab a small handful of unsalted raw nuts, about 2 ounces, on a daily basis to help treat diabetes?

Stroke 

Olive oil appears to have a substantial effect in preventing strokes. The Three City study showed that olive oil may have a protective effect against stroke. There was a 41 percent reduction in stroke events in those who used olive oil (7). Study participants, who were followed for a mean of 5.2 years, did not have a history of stroke at the start of the trial. Though these are promising results, I would caution use no more than one tablespoon of olive oil per day, since there are 120 calories in a tablespoon. 

It is not difficult to substitute the valuable Mediterranean-style diet for processed meats or at least add them to the selection. This plant-based diet offers a tremendous number of protective elements in the prevention of many chronic diseases. So this Independence Day and beyond, plan to have on hand some mouth-watering healthy choices.

» A staple of the Mediterranean pantry, beans are a healthy, versatile and super affordable ingredient. Rich in antioxidants, fiber, B vitamins and iron, they are a hearty great alternative to high-fat proteins. Serve guests the following three-bean salad as a side dish at your next summer barbecue or picnic. 

Three-Bean Salad

YIELD: Makes 10 servings

INGREDIENTS:

1 15-ounce can of black beans

1 15-ounce can of red kidney beans

1 15-oounce can of cannellini beans

1 yellow bell pepper, chopped

½ red onion, finely chopped

¼ cup olive oil

2 tablespoons red wine vinegar or to taste

1 clove garlic, minced

1 small bunch cilantro, basil or parsley, chopped

¼ cup dill pickle, diced

¼ cup celery, chopped

Salt and pepper to taste

DIRECTIONS: 

Wash and drain the beans. Transfer to large bowl. Add remaining ingredients, toss well and refrigerate for a few hours before serving.

References:

(1) Nature. 2010;467:1114-1117. (2) Epidemiol Prev Anno 2007;31(Suppl 1). (3) Cancer Causes Control. 2010;21:493-500. (4) Am J Epidemiol. 1994 Jan 1;139(1):1-15. (5) Am J Clin Nutr. 2011 Sep;94(3):884-891. (6) Diabetes Care. 2011 Aug;34(8):1706-1711. (7) Neurology. 2011 Aug 2;77(5):418-425. 

Dr. Dunaief is a speaker, author and local lifestyle medicine physician focusing on the integration of medicine, nutrition, fitness and stress management. 

Different types of exercise have different impacts

By David Dunaief, M.D.

Dr. David Dunaief

Mild cognitive impairment (MCI) is one of the more common disorders that occurs as we age. But age is not the only determinant. There are a number of modifiable risk factors. MCI is feared, not only for its own challenges but also because it may lead to dementia, with Alzheimer’s disease and vascular dementia being the more common forms. Prevalence of MCI may be as high as one-in-five in those over age 70 (1). It is thought that those with MCI may have a 10 percent chance of developing Alzheimer’s disease (2).

Since there are very few medications presently that help prevent cognitive decline, the most compelling questions are: What increases risk and what can we do to minimize the risk of developing cognitive impairment? These are the important questions.

Many chronic diseases and disorders contribute to MCI risk. These include diabetes, heart disease, Parkinson’s disease and strokes. If we can control these maladies, we may reduce the risk of cognitive decline. This involves making lifestyle modifications such as exercise and diet. We know that we can’t stop aging, but we can age gracefully.

Heart disease’s impact

Although we have made great strides, heart disease continues to be prevalent in America. In an observational study, results demonstrated that those suffering from years of heart disease are at a substantial risk of developing MCI (3). The study involved 1,450 participants who were between the ages of 70 and 89 and were not afflicted by cognitive decline at the beginning of the study. Patients with a history of cardiac disease had an almost two times greater risk of developing nonamnestic MCI, compared to those individuals without cardiac disease. Women with cardiac disease were affected even more, with a three times increased risk of cognitive impairment.

Nonamnestic MCI affects executive functioning — decision-making abilities, spatial relations, problem-solving capabilities, judgments and language. It is a more subtle form of impairment that may be more frustrating because of its subtlety. It may lead to vascular dementia and may be a result of clots. This gives us yet another reason to treat and prevent cardiac disease.

Stroke location vs. frequency

Not surprisingly, stroke may have a role in cognitive impairment. Stroke is also referred to as a type of vascular brain injury. But what is surprising is that in a study, results showed that the location of the stroke was more relevant than the frequency or the multitude of strokes (4). If strokes occurred in the cortical and subcortical gray matter regions of the brain, executive functioning and memory were affected, respectively. Thus, the locations of strokes may be better predictors of subsequent cognitive decline than the number of strokes. Clinically silent strokes that were found incidentally by MRI scans had no direct effect on cognition, according to the authors.

Exercise’s effects

Studies have shown that aerobic exercise improves brain function. Stock photo

Exercise may play a significant role in potentially preventing cognitive decline and possibly even improving MCI in patients who have the disorder. Interestingly, different types of exercise have different effects on the brain. Aerobic exercise may stimulate one type of neuronal development, while resistance training or weight lifting another.

In an animal study involving rats, researchers compared aerobic exercise to weight lifting (5). Weight lifting was simulated by attaching weights to the tails of rats while they climbed ladders. Both groups showed improvements in memory tests, however, there was an interesting divergence.

With aerobic exercise, the level of the protein BDNF (brain-derived neurotrophic factor) increased significantly. This is important, because BDNF is involved in neurons and the connections among them, called synapses, related mostly to the hippocampus, or memory center. The rats that “lifted weights” had an increase in another protein, IGF (insulin growth factor), that promotes the development of neurons in a different area of the brain. The authors stressed the most important thing is to exercise, regardless of the type.

In another study that complements the previous study, women were found to have improved spatial memory when they exercised — either aerobic or weight lifting (6). Interestingly, verbal memory was improved more by aerobic exercise than by weight lifting. Spatial memory is the ability to recall where items were arranged, and verbal memory is the ability to recall words. The authors suggest that aerobic exercise and weight lifting affect different parts of the brain, which corroborates the animal study findings above.

This was a randomized controlled trial that was six months in duration and involved women, ages 70 to 80, who had MCI at the trial’s start. There were three groups in the study: aerobic, weight lifting and stretching and toning. Those who did stretches or toning alone experienced deterioration in memory skills over the same period.

Here is the catch with exercise: We know exercise is valuable in preventing disorders like cardiovascular disease and cognitive decline, but are Americans doing enough? A Centers for Disease Control and Prevention report claims the majority of the adult population is woefully deficient in exercise: Only about 1 in 5 Americans exercise regularly, both using weights and doing aerobic exercise (7).

Diet’s effects

Several studies show that the Mediterranean diet helps prevent MCI and possibly prevents conversion from MCI to Alzheimer’s (8, 9). In addition, a study showed that high levels of carbohydrates and sugars, when compared to lower levels, increased the risk of cognitive decline by more than three times (5). The authors surmise that carbohydrates have a negative impact on insulin and glucose utilization in the brain.

Cognitive decline is a disorder that should be taken very seriously, and everything that can be done to prevent it should be utilized. Though the number of Americans exercising regularly is woefully deficient, the silver lining is that there is substantial room for improvement. Exercise has potentially positive effects on neuron growth and development. We need more campaigns like the NFL’s Play 60, which entices children to be active at least 60 minutes every day, but we also need to target adults of all ages. Let’s not squander the opportunity to reduce the risk of MCI, a potentially life-altering disorder.

References: (1) Ann Intern Med. 2008;148:427-434. (2) uptodate.com. (3) JAMA Neurol. 2013;70:374-382. (4) JAMA Neurol. 2013;70:488-495. (5) J Alzheimers Dis. 2012;32:329-339. (6) J Aging Res. 2013;2013:861893. (7) Morb Mortal Wkly Rep. 2013;62:326-330. (8) Neurology 2013;80:1684-1692. (9) Arch Neurol. 2009 Feb.;66:216-225.

Dr. Dunaief is a speaker, author and local lifestyle medicine physician focusing on the integration of medicine, nutrition, fitness and stress management. For further information, visit www.medicalcompassmd.com or consult your personal physician.

A recent study showed that patients who are very obese could lose almost two decades of healthy living
Quality of life impacts are considerable

By David Dunaief, M.D.,

Dr. David Dunaief

The media is increasingly focused on covering obesity-related issues. With this in mind, let’s start off with a short quiz to test your knowledge of obesity-related issues. The answers and research are provided below. Regardless of your quiz score, it is important to understand the research.

1. Obesity reduces life span by up to:

A) Not at all

B) 4 years

C) 8 years

D) 10 years

2. Obesity shortens healthy years of life by:

A) 8 years

B) 12 years

C) 15 years

D) 20 years

3. Food cravings can be reduced for the short term by:

A) Counting to 20

B) Tapping your finger against your head

C) Watching TV

D) Texting on your cellphone

4. Obesity can lead to the following complication(s):

A) High blood pressure

B) Diabetes

C) Cancer

D) All of the above

Are you eager to find out the answers? I hope so, because there are some very salient points I am trying to make by providing multiple choice questions. The answers are: 1. D; 2. D; 3. B; 4. D. So how did you do? One of the questions was actually similar to a question on a medical website for doctors, so don’t be too hard on yourself if you did not get them all right. Let’s look at the research.

Mortality and effect on life span

Many of you know that obesity could have an impact on development of other chronic diseases and a decrease in quality of life, but to what extent? A 2013 study indicated that almost as many as one in five deaths in the U.S. is associated with obesity (1).

In a computer modeling study, the results showed that those who are obese may lose up to eight years, almost a decade, of their life span (2). But that is only part of the results. The other, more compelling result is that patients who are very obese, defined as a BMI >35 kg/m², could lose almost two decades of healthy living. According to the researchers, this means you may have diseases such as diabetes and cardiovascular disease. However, even those patients who were obese and those who were overweight also could have reductions in life span, up to 6 years and 3 years, respectively.

There were 3,992 adults between the ages of 20 and 79 evaluated in this study. The data was taken from an NHANES database from 2003 to 2010, which looked at participants who went on to develop diabetes and cardiovascular disease. Though this is not a clinical trial, and there is a need for more study, the results are eye-opening, with the youngest and very obese negatively impacted the most.

Cancer impact

Since it is very difficult to “cure” cancer, although hopefully someday soon we will, it is important to reduce modifiable risk factors. Obesity may be one of these contributing factors, although it is hotly debatable how much of an impact obesity has on cancer development.  The American Society of Clinical Oncologists (ASCO), in a position paper, supported the idea that it is important to treat obesity in the fight against cancer (3). The authors indicate obesity may make the prognosis worse, may hinder the delivery of therapies to treat cancer, and may increase the risk of malignancy.

Also, possibly reinforcing ASCO’s stance, a study suggested that upward of a half-million cases of cancer worldwide were related to being overweight or obese, with the overwhelming concentration in North American and Europe (4).

Possible solutions

A potential counterweight to both the reductions in life quality and life expectancy may be the Mediterranean diet. In a published analysis of the Nurses’ Health Study, results show that the Mediterranean diet helped slow shortening of the telomeres (5). Repeat sequences of DNA found at the end of chromosomes, telomeres, shorten with age; the shorter the telomere, the shorter life expectancy.

Thus, the Mediterranean diet may decrease occurrence of chronic diseases, increase life span and decrease premature mortality — hence, the opposite effect of obesity. In fact, it may help treat obesity, though this was not mentioned in the study. Interestingly, the effects of the Mediterranean diet were on a dose-response curve. The greater the adherence to the diet, rated on a scale of 0 to 9, the better the effect. Those who had an increase in adherence by three points saw a corresponding decrease in telomere aging by 4.5 years. There were 4,676 middle-aged women involved in this analysis. The researchers believe that the anti-inflammatory and antioxidant effects could be responsible for the diet’s effects.

According to an accompanying editorial, no individual component of the diet was identified as having beneficial effects by itself, so it may be the diet as a whole that is important (6).

Short-term solutions

There are easy-to-use distraction tactics that involve physical and mental techniques to reduce food cravings. These include tapping your foot on the floor, staring at a blank wall and, yes, alternating tapping your index finger against your forehead and your ear (7). The forehead and ear tapping was most effective, although probably most embarrassing in public. Among mental techniques, seeing pictures of foods that were unhealthy and focusing on their long-term detriments to health had the most impact (8). All of these short-term distractors were done for 30 seconds at a time. The results showed that in obese patients they indeed decreased food cravings.

Exercise impact

I have written about exercise and that it does not lead to fat percentage loss in adults. Well, before you write off exercise for fat loss, it seems that adolescents may benefit from exercise. In a randomized controlled trial, the gold standard of studies, results show that those in the resistance training group alone and those in a combined resistance and aerobic training group had significantly greater percentages of fat loss compared to a control group (9).

However, the aerobic group alone did not show a significant change in fat percent versus the control. There were 304 study participants, ages 14 to 18, followed for a six-month duration, and results were measured with MRI. The reason that resistance training was effective in reducing fat percentage may have to do with an increase in muscle mass rather than a decrease in actual fat. Still, exercise is important. It doesn’t matter if it decreases the fat percentage; it is still getting you to the goal.

Obesity can have devastating effects, from potentially inducing cancer or worsening it, to shortening life expectancy and substantially decreasing quality of life. Fortunately, there may be ways to help treat obesity with specific lifestyle modifications. The Mediterranean diet as a whole may be an effective step toward decreasing the burden of obesity and reducing its complications. Kids, teenagers specifically, should be encouraged to “Play 60,” as the NFL has encouraged, but also to do some resistance training. As we mentioned, there are simple techniques that may help reduce short-term food cravings.

References: (1) Am J Public Health. 2013;103:1895-1901. (2) The Lancet Diabetes & Endocrinology, online Dec. 5, 2014. (3) J Clin Oncol. 2014;32(31):3568-3574. (4) The Lancet Oncology. online Nov. 26, 2014. (5) BMJ. online Dec. 2, 2014. (6) BMJ 2014;349:g6843. (7) Obesity Week 2014 abstract T-2658-P. (8) Obesity Week 2014 abstract T-3023-OR. (9) JAMA Pediatr. 2014;168(11):1006-1014.

Dr. Dunaief is a speaker, author and local lifestyle medicine physician focusing on the integration of medicine, nutrition, fitness and stress management. For further information, visit www.medicalcompassmd.com or consult your personal physician.

Mediterranean Diet
Can we overcome our genes?

By David Dunaief, M.D.

Dr. David Dunaief

We have made great strides in the fight against heart disease, yet it remains the number one cause of death in the United States. Approximately one-third of Americans over the age of 35 will die of heart disease (1). I hope this statistic has captured your attention, because it should. What is causing or contributing to such high numbers of heart disease deaths: genetics, environment or both? Many of us have the propensity toward heart disease. Can we alter this course, or is it our destiny?

A 2013 study, involving the Paleo-type diet and other ancient diets, suggests that there is a significant genetic component to cardiovascular disease, while another study looking at the Mediterranean-type diet implies that we may be able to reduce risk factors greatly. Most of the risk factors for heart disease, such as high blood pressure, high cholesterol, sedentary lifestyle, diabetes, smoking and obesity are modifiable (2). Let’s look at the evidence.

Genetic components

In a study published online in The Lancet, researchers used computed tomography scans to look at 137 mummies from ancient times across the world, including Egypt, Peru, the Aleutian Islands and Southwestern America (3). The cultures were diverse, including hunter-gatherers (consumers of a Paleo-type diet), farmer-gatherers and solely farmers. Their diets were not vegetarian but rather involved significant amounts of animal protein: fish and/or cattle.

Researchers found that one-third of these mummies had atherosclerosis (plaques in the arteries), which is a precursor to heart disease. The ratio should sound familiar. It seems to coordinate with modern times.

Interestingly, but not surprisingly, the average age of death was 43. The authors concluded that atherosclerosis could be part of the aging process in humans. In other words, it may be a result of our genes. Being human, we all have a genetic propensity toward atherosclerosis and heart disease — some more than others — but many of us can reduce our risk factors significantly.

I am not saying that the Paleo-type diet specifically is not beneficial compared to the standard American diet. Rather, that we do not know it based on this study, which was not meant to provide the validity of the Paleo-type diet, but whether atherosclerosis is part of the normal aging process. However, other studies demonstrate that we can reduce our chances of getting heart disease with lifestyle changes, potentially by following a Mediterranean-type diet with an emphasis on a plant-rich approach.

Mediterranean-type diet

A study about the Mediterranean-type diet and its potential positive impact on cardiovascular disease risk was published in the New England Journal of Medicine (4). Here, two variations on the Mediterranean-type diet were compared to a low-fat diet. People were randomly assigned to three different groups. The two Mediterranean-type diet groups both showed about a 30 percent reduction in the risk of cardiovascular disease, with end points including heart attacks, strokes and mortality, compared to the low-fat diet. This improvement in risk profile occurred even though there was no significant weight loss.

The Mediterranean-type diets both consisted of significant amounts of fruits, vegetables, nuts, beans, fish, olive oil and potentially wine. I call them “the Mediterranean diet with opulence,” because both groups consuming this diet had either significant amount of nuts or olive oil and/or wine. If the participants in the Mediterranean diet groups drank wine, they were encouraged to drink at least one glass a day.

The study included three groups: a Mediterranean diet supplemented with mixed nuts (almonds, hazelnuts or walnuts), a Mediterranean diet supplemented with extra virgin olive oil (at least four tablespoons a day) and a low-fat control diet. The patient population included over 7,000 participants in Spain at high risk for cardiovascular disease. The high-risk population included those with high blood pressure (80 percent of the population), diabetes and those who were overweight and/or were smokers.

The strength of this study, beyond its high-risk population and its large size, was that it was a randomized clinical trial, the gold standard of trials. However, there was a significant flaw, and the results need to be tempered. The group assigned to the low-fat diet was not, in fact, able to maintain this diet throughout the study. Therefore, it really became a comparison between variations on the Mediterranean diet and the standard American diet.

What do the leaders in the field of cardiovascular disease and integrative medicine think of the Mediterranean diet study? Interestingly there are two diametrically opposed opinions, split by field. You may be surprised by which group liked it and which did not. Cardiologists hailed the study as a great achievement. They included Henry Black, M.D., who specializes in high blood pressure, and Eric Topol, M.D. They emphasized that now there is a large RCT measuring clinical outcomes, such as heart attacks, stroke and death.

On the other hand, the integrative medicine physicians, Caldwell Esselstyn, M.D., and Dean Ornish, M.D., both of whom stress a plant-rich diet that may be significantly more nutrient dense than the Mediterranean diet in the study, expressed disappointment with the results. They feel that heart disease and its risk factors can be reversed, not just reduced. Both clinicians have published small, well-designed studies showing significant benefits from plant-based diets (5, 6). Ornish actually showed a reversal of atherosclerosis in one of his studies (7).

So which group of physicians is correct about the Mediterranean diet? Each opinion has its merits. The cardiologists’ enthusiasm is warranted, because a Mediterranean diet, even one of “opulence,” will appeal to more participants, who will then realize the benefits. However, those who follow a more strict diet, with greater amounts of nutrient-dense foods, will potentially see a reversal in heart disease, minimizing risk — and not just reducing it.

Thus, even with a genetic proclivity toward cardiovascular disease, we can very much alter our destinies. The degree depends on the willingness of the participants. Potentially, we can have an impact that ranges from reduction to reversal.

References: (1) Circulation. 2008;117(4):e25. (2) www.uptodate.com. (3) The Lancet. 2013;Mar 11. (4) N Engl J Med. Online 2013;Feb 25. (5) J Fam Pract. 1995;41(6):560-568. (6) Am J Cardiol. 2011;108:498-507. (7) JAMA. 1998 Dec 16;280(23):2001-2007.

Dr. Dunaief is a speaker, author and local lifestyle medicine physician focusing on the integration of medicine, nutrition, fitness and stress management. For further information, visit www.medicalcompassmd.com or consult your personal physician.

A diet rich in fruits, vegetables, beans, nuts and oily fish may prevent breast cancer. Stock photo

By David Dunaief, M.D.

NFL players are wearing pink shoes and other sportswear this month, making a fashion statement to highlight Breast Cancer Awareness Month. This awareness is critical since annual invasive breast cancer incidence in the U.S. is 246,000 new cases, with approximately 40,000 patients dying from this disease each year (1). The good news is that from 1997 to 2008 there was a trend toward decreased incidence by 1.8 percent (2).

We can all agree that screening has merit. The commercials during NFL games tout that women in their 30s and early 40s have discovered breast cancer with a mammogram, usually after a lump was detected. Does this mean we should be screening earlier? Screening guidelines are based on the general population that is considered “healthy,” meaning no lumps were found, nor is there a personal or family history of breast cancer.

All guidelines hinge on the belief that mammograms are important, but at what age? Here is where divergence occurs; experts can’t agree on age and frequency. The U.S. Preventive Services Task Force recommends mammograms starting at 50 years old, after which time they should be done every other year (3). The American College of Obstetricians and Gynecologists recommends mammograms start at 40 years old and be done annually (4). Your decision should be based on a discussion with your physician.

The best way to treat breast cancer — and just as important as screening — is prevention, whether it is primary, preventing the disease from occurring, or secondary, preventing recurrence. We are always looking for ways to minimize risk. What are some potential ways of doing this? These may include lifestyle modifications, such as diet, exercise, obesity treatment and normalizing cholesterol levels. Additionally, although results are mixed, it seems that bisphosphonates do not reduce the risk of breast cancer nor its recurrence. Let’s look at the evidence.

Bisphosphonates

Bisphosphonates include Fosamax (alendronate), Zometa (zoledronic acid) and Boniva (ibandronate) used to treat osteoporosis. Do they have a role in breast cancer prevention? It depends on the population, and it depends on study quality.

In a meta-analysis involving two randomized controlled trials, results showed there was no benefit from the use of bisphosphonates in reducing breast cancer risk (5). The population used in this study involved postmenopausal women who had osteoporosis, but who did not have a personal history of breast cancer. In other words, the bisphosphonates were being used for primary prevention.

The study was prompted by previous studies that have shown antitumor effects with this class of drugs. This analysis involved over 14,000 women ranging in age from 55 to 89. The two trials were FIT and HORIZON-PFT, with durations of 3.8 and 2.8 years, respectively. The FIT study involved alendronate and the HORIZON-PFT study involved zoledronic acid, with these drugs compared to placebo. The researchers concluded that the data were not evident for the use of bisphosphonates in primary prevention of invasive breast cancer.

In a previous meta-analysis of two observational studies from the Women’s Health Initiative, results showed that bisphosphonates did indeed reduce the risk of invasive breast cancer in patients by as much as 32 percent (6). These results were statistically significant. However, there was an increase in risk of ductal carcinoma in situ (precancer cases) that was not explainable. These studies included over 150,000 patients with no breast cancer history. The patient type was similar to that used in the more current trial mentioned above. According to the authors, this suggested that bisphosphonates may have an antitumor effect. But not so fast!

The disparity in the above two bisphosphonate studies has to do with trial type. Randomized controlled trials are better designed than observational trials. Therefore, it is more likely that bisphosphonates do not work in reducing breast cancer risk in patients without a history of breast cancer or, in other words, in primary prevention.

In a third study, a meta-analysis (group of 36 post-hoc analyses — after trials were previously concluded) using bisphosphonates, results showed that zoledronic acid significantly reduced mortality risk, by as much as 17 percent, in those patients with early breast cancer (7). This benefit was seen in postmenopausal women but not in premenopausal women. The difference between this study and the previous study was the population. This was a trial for secondary prevention, where patients had a personal history of cancer.

However, in a RCT, the results showed that those with early breast cancer did not benefit overall from zoledronic acid in conjunction with standard treatments for this disease (8). The moral of the story: RCTs are needed to confirm results, and they don’t always coincide with other studies.

Exercise

We know exercise is important in diseases and breast cancer is no exception. In an observational trial, exercise reduced breast cancer risk in postmenopausal women significantly (9). These women exercised moderately; they walked four hours a week. The researchers stressed that it is never too late to exercise, since the effect was seen over four years. If they exercised previously, but not recently, for instance, five to nine years ago, no benefit was seen.

To make matters worse, only about one-third of women get the recommended level of exercise every week: 30 minutes for five days a week. Once diagnosed with breast cancer, women tend to exercise less, not more. The NFL, which does an admirable job of highlighting Breast Cancer Awareness Month, should go a step further and focus on the importance of exercise to prevent breast cancer or its recurrence, much as it has done to help motivate kids to exercise with it Play 60 campaign.

Soy intake

Contrary to popular belief, soy may be beneficial in reducing breast cancer risk. In a meta-analysis (a group of eight observational studies), those who consumed more soy saw a significant reduction in breast cancer compared to those who consumed less (10). There was a dose-response curve among three groups: high intake of >20 mg per day, moderate intake of 10 mg and low intake of <5 mg.

Those in the highest group had a 29 percent reduced risk, and those in the moderate group had a 12 percent reduced risk, when compared to those who consumed the least. Why have we not seen this in U.S. trials? The level of soy used in U.S. trials is a fraction of what is used in Asian trials. The benefit from soy is thought to come from isoflavones, plant-rich nutrients.

Western vs. Mediterranean diets

A Mediterranean diet may decrease the risk of breast cancer significantly.
A Mediterranean diet may decrease the risk of breast cancer significantly.

In an observational study, results showed that, while the Western diet increases breast cancer risk by 46 percent, the Spanish Mediterranean diet has the inverse effect, decreasing risk by 44 percent (11). The effect of the Mediterranean diet was even more powerful in triple-negative tumors, which tend to be difficult to treat. The authors concluded that diets rich in fruits, vegetables, beans, nuts and oily fish were potentially beneficial.

Hooray for Breast Cancer Awareness Month stressing the importance of mammographies and breast self-exams. However, we need to give significantly more attention to prevention of breast cancer and its recurrence. Through potentially more soy intake, as well as a Mediterranean diet and modest exercise, we may be able to accelerate the trend toward a lower breast cancer incidence.

References: (1) breastcancer.org. (2) J Natl Cancer Inst. 2011;103:714-736. (3) Ann Intern Med. 2009;151:716-726. (4) Obstet Gynecol. 2011;118:372-382. (5) JAMA Inter Med online. 2014 Aug. 11. (6) J Clin Oncol. 2010;28:3582-3590. (7) 2013 SABCS: Abstract S4-07. (8) Lancet Oncol. 2014;15:997-1006. (9) Cancer Epidemiol Biomarkers Prev online. 2014 Aug. 11. (10) Br J Cancer. 2008;98:9-14. (11) Br J Cancer. 2014;111:1454-1462.

Dr. Dunaief is a speaker, author and local lifestyle medicine physician focusing on the integration of medicine, nutrition, fitness and stress management. For further information, visit www.medicalcompassmd.com or consult your personal physician.

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