Mediterranean Diet may Reduce Breast Cancer Risk - The PREDIMED Trial

 

A paper by Toledo et al published in JAMAInternal Medicine suggests that women could reduce their breast cancer risk by following a version of the Mediterranean diet that goes heavy on extra virgin olive oil.

The study was conducted within the frame of PREDIMED trial a 1:1:1 randomized, single-blind, controlled field trial from 2003 to 2009, on 4282 women aged 60 to 80 years who were at high cardiovascular disease risk.

Participants were randomly allocated to a Mediterranean diet (MeDiet) that was supplemented with extra-virgin olive oil (EVOO), a Mediterranean diet supplemented with mixed nuts, or a control diet (advice to reduce dietary fat).

After a median follow-up of 4.8 years, they identified 35 confirmed cases of breast cancer.  The observed rates (per 1000 person-years) were 1.1 for the Mediterranean diet with extra-virgin olive oil group, 1.8 for the Mediterranean diet with nuts group, and 2.9 for the control group. The multivariable-adjusted hazard ratios versus the control group were 0.32 (95% CI, 0.13-0.79) for the Mediterranean diet with extra-virgin olive oil group and 0.59 (95% CI, 0.26-1.35) for the Mediterranean diet with nuts group. When both MeDiet groups were merged together, they observed a 51% relative risk reduction (95% CI, 0.25-0.94). When they excluded women who were diagnosed with breast cancer during the first year after enrollment, the results remained unchanged.  The information that was collected in this study was on invasive breast cancers only therefore noninvasive tumors such as DCIS, in situ cancers, were not included or analyzed in this trial.

The data from the PREDIMED trial, suggest a significant inverse association between consumption of a MeDiet supplemented with EVOO and breast cancer incidence. A high consumption of EVOO (≥15% of total energy intake) seems to be instrumental in obtaining this significant protection. A non-significant risk reduction was observed with the MeDiet supplemented with nuts.

In a different trial, the Lyon Diet Heart Study, which was also a randomized trial, a protective effect of a Mediterranean-type diet against overall cancer incidence was observed, supporting the hypothesis of an anticancer effect of the MeDiet.

The low rate of breast cancer among women in the PREDIMED trial should not be surprising. If the MeDiet is actually protective against breast cancer, a low incidence is to be expected in a study with these characteristics, especially when overall adherence to such diet was good already at baseline. 

Several biological mechanisms could explain the anti-carcinogenic properties of EVOO. All types of olive oil provide a high supply of monounsaturated fatty acids, mainly oleic acid, as well as squalene, but EVOO also contains additional biologically active compounds as polyphenols.

These compounds are known to have a likely role in breast cancer prevention due to inhibition of tumor growth and proliferation, migration, and invasiveness of breast cancer cells in both in vitro or in vivo breast cancer models.  Olive oil has been associated with increased apoptosis of cultured breast cancer cells. It has also been reported to reduce intracellular reactive oxygen processes and to prevent oxidative DNA damage in both human breast epithelial cells and human breast cancer cells.

The authors conclude that the findings of their trial suggest a beneficial effect of the Mediterranean diet supplemented with extra-virgin olive oil as a primary prevention of breast cancer.  The authors also state that their findings need to be confirmed with longer-term and larger studies, as breast cancer in addition to being the most prevalent cancer in women worldwide, with 1.7 million new cases diagnosed in 2012 while its incidence is has increased by 20% due to growth and aging of the population.

JAMA Intern Med. published online September 14, 2015.

Physical Activity Promotes Higher Cognition in Older Adults

Burzynska et al from the Lifelong Brain and Cognition Lab at the University of Illinois at Urbana report in an article at PLoS One that by looking at functional and structural MRI data found that higher cardiorespiratory fitness (CRF) and physical activity (PA) in old age were associated with greater brain structural and functional integrity, and higher cognitive functioning.

As we age, the physical make up of our brains changes. This includes changes in neural processing in grey matter, but also in the deterioration of structural connections within, which allow communication between distinct brain regions, so that the brain is able to work as a well-wired interconnected network. 

In recent years, researchers have observed that variability in the blood oxygenation as determined by the signal obtained in the BOLD sequence from fMRIs is dependent on functional integrity in certain regions of the brain and is linked to younger age and better cognitive performance..

The researchers collected resting-state fMRI and diffusion images as well as well-normed laboratory measures of fluid intelligence, perceptual speed, episodic memory, and vocabulary from 104 healthy participants (60–80 years).  Because some participants did not complete all tasks in the cognitive battery, a final sample of 91 aging non-demented participants was included in their study.

They also measured CRF as oxygen consumption during a maximal exercise test and measured PA in those healthy but low active older adults with an accelerometer that was worn for 7 days. They modeled the relationships between CRF, PA, and brain functional integrity using multivariate partial least squares analysis. 

As an index of functional brain integrity they used moment-to-moment variability in the blood oxygenation level-dependent signal (SD_BOLD), known to be associated with better cognitive functioning. 

The researchers found that older adults who engaged more in light or moderate-to-vigorous physical activities had greater SD_BOLD in brain regions such as precuneus, hippocampus, medial and lateral prefrontal, and temporal cortices that play a role in integrating segregated functional domains in the brain.

Their findings suggest that engaging in higher intensity physical activity may have protective effects on neural processing in aging. Finally, they demonstrated that older adults with greater overall white matter microstructure were those in whom their cardiovascular and respiratory systems were functioning optimally and they engaged in physical activities. They concluded that greater blood oxygenation as determined by SD_BOLD is a promising correlate of functional brain health and may reflect more flexible or adaptive information processing in older adults. 

PLoS One. 2015 Aug 5;10(8):e0134819

Risks associated with non-steroidal anti-inflammatory drugs (NSAIDs)

On July 14, 2015 the Food and Drug Administration issued a warning that plans on asking manufacturers of non-steroidal anti-inflammatory drugs (NSAIDs) to change labels to reflect evidence of increased risk of heart attacks and strokes. 

Most NSAIDs inhibit the activity of cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2), and thereby, the synthesis of prostaglandins and thromboxanes.  It is thought that inhibiting COX-2 leads to the anti-inflammatory, analgesic and antipyretic effects and that those NSAIDs that inhibit COX-1, particularly aspirin, may cause gastrointestinal bleeding and ulcers. 

Non-steroidal anti-inflammatory drugs are widely used all over the world for their analgesic and antipyretic qualities and include Motrin IB, Aleve and Celebrex but not aspirin.  In 2001, NSAIDs accounted for 70 million prescriptions and 30 billion over-the-counter doses annually in the United States.

Experts suggest that the warning reflected new evidence that there was risk even in small amounts and that everyone taking them should use them sparingly and for brief periods. 

The FDA said that the drugs increased the risk of a heart attack and/or stroke soon after patients first started taking them, and that while the risk was higher for people with heart disease, it occurs even for people who had never had heart problems.

A meta-analysis of 280 trials of NSAIDs versus placebo (124 513 participants, 68 342 person-years) and 474 trials of one NSAID versus another NSAID (229 296 participants, 165 456 person-years) was published at Lancet in 2013. 

Major vascular events were increased by about a third by a coxib or diclofenac, chiefly due to an increase in major coronary events.  Ibuprofen also significantly increased major coronary events, but not major vascular events

Compared with placebo, of 1000 patients allocated to a coxib or diclofenac for a year, three more had major vascular events, one of which was fatal. Naproxen did not significantly increase major vascular events. 

Vascular death increased significantly by coxibs and diclofenac, non-significantly by ibuprofen but not by naproxen. The proportional effects on major vascular events were independent of baseline characteristics, including vascular risk. 

Heart failure risk was roughly doubled by all NSAIDs. All NSAID regimens increased upper gastrointestinal complications.

The data from these randomized trials suggest that vascular risks of high-dose diclofenac (Voltaren), and possibly ibuprofen (Advil, Motrin), are comparable to coxibs (Celebrex), whereas high-dose naproxen (Aleve) is associated with less vascular risk than other NSAIDs. 

A conclusive answer could come from a large randomized trial, called Precision, that is comparing the rate of heart problems among patients with high cardiovascular risk for ibuprofen (Motrin IB), naproxen (Aleve) and celecoxib (Celebrex).

Patients who use over-the-counter medications, which have the lowest doses, should be aware that they probably increase their risk of a cardiovascular event by about 10 percent. Low-dose prescription medications were likely to increase the risk by about 20 percent and higher-level dose prescription medications by about 50 percent with significant variability in each estimate. 

One in Two Americans will develop Cancer in their Lifetime

According to the American Cancer Society the lifetime risk of developing or dying from cancer refers to the chance a person has, over the course of his lifetime, of being diagnosed with or dying from disease. These risk estimates, like annual incidence and mortality data, provide another measure of how widespread cancer is in the United States.

The information is from the US National Cancer Institute’s Surveillance Epidemiology and End Results (SEER) Database, and is based on incidence and mortality data for the United States from 2009 through 2011.

The risk is expressed both in terms of a percentage and as odds. For example, the risk that a man will develop bladder cancer during his lifetime is 3.83%. This means he has about 1 chance in 26 of developing bladder cancer (100/3.83 = 26.1). Put another way, 1 out of every 26 men in the United States will develop bladder cancer during his lifetime.

The risk for women of developing cancer at any site is 37.8% while their risk of dying due to cancer is 19.6%.  This means 1 in 3 women will develop cancer in their life while 1 in 5 will die from the disease.

The risk for females for developing breast cancer, the most common cancer in women, is 12.3%.   This means 1 in 8 women will develop the disease while the risk of dying form cancer is 2.7%, which means 1 in 37 will die from the disease.

The risk for men of developing cancer at any site is 43.3% while the risk of dying due to cancer is 22.6%.  This means 1 in 2 men will develop cancer in their life while 1 in 4 will die from the disease.

The risk for men to develop prostate cancer, the most common cancer in men, is 15%.   This means 1 in 7 men will develop the disease while the risk of dying is 2.6%, which means 1 in 38 will die from the disease.

According to a study published in the British Journal of Cancer, the odds of developing cancer over the course of one’s life in the UK has increased from 38.5% for men born in 1930 to 53.5% for men born in 1960. For women it increased from 36.7 to 47.5%.

Therefore according to the data for the United States and United Kingdom over half of people who are currently adults under the age of 65 years will be diagnosed with cancer at some point in their lifetime.

Cancer Mortality Declining in United States

Cancer constitutes an enormous burden on societies as the occurrence of cancer is increasing because of aging of the population, as well as the prevalence of risk factors such as smoking, increase in weight, decrease in physical activities.

Each year, the American Cancer Society estimates the numbers of new cancer cases and deaths that will occur in the United States in the current year and compiles the most recent data on cancer incidence, mortality, and survival. 

A total of 1,665,540 new cancer cases and 585,720 cancer deaths are projected to occur in the United States in 2014. During the most recent 5 years for which there are data (2006-2010), delay-adjusted cancer incidence rates declined slightly in men (by 0.6% per year) and were stable in women, while cancer death rates decreased by 1.8% per year in men and by 1.4% per year in women. The combined cancer death rate (deaths per 100,000 population) has been continuously declining for 2 decades, from a peak of 215 in 1991 to 169 in 2011. This 20% decline translates to the avoidance of approximately 1,340,400 cancer deaths (952,700 among men and 387,700 among women) during this time period. The magnitude of the decline in cancer death rates from 1991 to 2011 varies substantially by age, race, and sex, ranging from no decline among white women aged 80 years and older to a 55% decline among black men aged 40 years to 49 years.  

While cancer deaths declined in every state, Southern states posted the smallest decreases (15 percent) while Northeastern states had the biggest reductions (25 to 30 percent) according to the data, published in CA: A Cancer Journal for Clinicians.

The American Cancer Society’s Cancer Statistics 2015 reports that prostate, breast, lung and colorectal tumors account for half of all cancers in the U.S. Progress has been made in reducing the incidence of prostate, lung and colon cancers, while breast cancer rates have leveled off in recent years.

The dramatic reduction in mortality due to cancer since 1991 is attributed to falling smoking rates, better cancer prevention, detection and treatments.  Further reductions can be obtained in the future by applying existing cancer prevention and treatments across the population at large.

Two out of three Americans with invasive cancer are living more than five years

Α report by Henley et al from the Centers for Disease Control and Prevention published in Morbidity and Mortality Weekly Report indicates that “two out of three Americans with invasive cancer are living five years or more after diagnosis.”

     

Because of improvements in early detection and treatment of cancer, the proportion of persons with cancer who survive more than 5 years after diagnosis has increased. The authors analyzed data from U.S. Cancer Statistics (USCS) for 2011. 

In 2011, a total of 1,532,066 invasive cancers were diagnosed and reported to central cancer registries in the United, including 786,102 among males and 745,964 among females. The age-adjusted annual incidence for all cancers was 451 per 100,000 population: 508 per 100,000 in males and 410 per 100,000 in females. Among persons aged <20 years, 14,754 cancer cases were diagnosed in 2011. By age group, rates per 100,000 population in 2011 were 18 among persons aged <20 years, 154 among those aged 20–49 years, 816 among those aged 50–64 years, 1,840 among those aged 65–74 years, and 2,223 among those aged ≥75 years.

By cancer site, rates were highest for cancers of the prostate (128 per 100,000 men), female breast (122 per 100,000 women), lung and bronchus (61 per 100,000 persons), and colon and rectum (40 per 100,000 persons). These four sites accounted for half of cancers diagnosed in 2011, including 209,292 prostate cancers, 220,097 female breast cancers, 207,339 lung and bronchus cancers, and 135,260 colon and rectum cancers. In 2011, the cervical cancer incidence rate was 7.5 per 100,000 women, representing 12,109 reported cancers.

By state in 2011, all-sites cancer incidence rates ranged from 374 to 509 per 100,000 persons. State site-specific cancer incidence rates ranged from 79 to 195 per 100,000 men for prostate cancer, 106 to 153 per 100,000 women for female breast cancer, 29 to 93 per 100,000 persons for lung cancer, 33 to 49 per 100,000 persons for colorectal cancer, and 4.5 to 13.7 per 100,000 women for cervical cancer. Healthy People 2020 targets were reached in 37 states for incidence of colorectal cancer and in 28 states for incidence of cervical cancer. Compared with the states and DC, cancer incidence rates in Puerto Rico in 2011 were lower for all-sites cancer (339 per 100,000 persons), lung cancer (17 per 100,000 persons), and breast cancer (93 per 100,000 women), but higher for prostate cancer (150 per 100,000 men), colorectal cancer (43 per 100,000 persons), and cervical cancer (13.5 per 100,000 women).

Among persons with cancer diagnosed during 2003–2010, the 5-year relative survival rate was 65%. This percentage was similar for males and females. The 5-year relative survival was highest among those diagnosed with cancer before age 45 years (81%) and decreased with increasing age. Among the most common cancer sites, 5-year relative survival was highest for prostate cancer (97%) and breast cancer (88%), intermediate for colorectal cancer (63%), and lowest for lung cancer (18%). The 5-year relative survival after any cancer diagnosis was lower for black persons (60%) than for white persons (65%) and for each cancer site.

Medical News Monthly: Top Three Posts

Over the past year I have written and uploaded 11 posts about diseases, conditions, that been reported on by news outlets across the globe.  The three most visited posts were the following:

1. Ebola outbreak
http://medicalnewsmonthly.blogspot.gr/2014/08/ebola-outbreak.html

2. Mediterranean diet
http://medicalnewsmonthly.blogspot.gr/2014/07/the-mediterranean-diet.html

3. Obesity
http://medicalnewsmonthly.blogspot.gr/2014/09/obesity.html

Most of the visitors were from United States, Greece, and France in that order.  I would like to thank all my visitors and promise to continue reporting on new medical developments, epidemics or maladies that affect a large percentage of humans such as obesity.