Can Aspirin Help to Prevent Cancer? - the pros and cons

Can Aspirin Help Prevent Cancer? - the pros and cons

Two physicians at Harvard Medical School, Drs. Michelle Holmes and Wendy Chen, recently wrote in the New York Times about the apparent ability of regular aspirin use to prevent death in women with breast cancer.  They called for a randomized trial of aspirin, enrolling 3000 women with stage 2 and 3 breast cancer for five years, which they estimate would cost $10 million.  They have repeatedly tried to raise these funds through federal grants, and have been rejected.  It is possible that the publicity from their article will result in funding from the government, private foundations or private individuals.  The first randomized clinical trial of aspirin is now going on in Britain, funded by a nonprofit group.  They are looking at 4 cancers - colorectal, breast, gastro-esophageal, & prostate - with results expected by 2025.  

Evidence so far:  Many studies in the past 20 years have shown that taking aspirin is associated with the prevention of colon cancer.  A recent study helped to refine the findings - people with high amounts of an enzyme known as 15-PDGH in their gut lining had a 50% lower risk of colon cancer than those with a low level, if they took the equivalent of 2 regular strength aspirins a week.  A regular strength aspirin is 325 mg, and a ‘baby’ aspirin is usually 81 mg.  (2 x 325=650, and 7 X 81=567 - close enough). The test for 15-PDGH is not yet available.  People at high risk for colon cancer - a diet low in vegetables and whole grains, high in red meat and processed meat, inactivity, obesity, smoking, family history of colon cancer - should talk to their doctor about the pros and cons of low dose aspirin.  (People with these habits might also want to make some life-style changes.)

Breast cancer: a Columbia University study published in 2004 showed that women who took aspirin regularly (the 325 mg or 81 mg dose was not distinguished) were 20–30% less likely to develop hormone positive breast cancer.  Aspirin did not decrease the risk of hormone negative breast cancer. The proposed mechanism is that by a series of physiologic steps, aspirin decreases hormone biosynthesis in the body.  The researchers also discussed the anti-inflammatory properties of aspirin, which may reduce cancer risk overall.  NSAIDS such as ibuprofen were also associated with slightly decreased cancer risk, but not as great as aspirin.  Acetaminophen (Tylenol) did not show a protective effect.  Another study, published in 2010 by the authors of the recent NYTimes article, looked at data from The Nurses Health Study in the US.  It found that in women living at least 1 year after a breast cancer diagnosis, aspirin use was associated with a decreased risk of distant recurrence and breast cancer death.

A recent study from the National Cancer Institute showed that daily aspirin use may reduce the risk of ovarian cancer by 20%.  About 20,000 women in the US will be diagnosed with ovarian cancer in 2014, and more than 14,000 will die of this disease, which is hard to diagnose early enough for a cure.  Early symptoms are non-specific, such as abdominal bloating, pelvic or abdominal pain, feeling full quickly, and urinary frequency.    

Many people take aspirin to prevent heart disease, especially if they have already had a heart attack - to prevent another.  Paramedics regularly give aspirin to a heart attack patient on the way to the hospital. Heart attacks and strokes occur when the blood supply to a part of the heart muscle or brain is blocked by ‘plaque’, a buildup of cholesterol, fatty substances, cellular waste products and calcium.  Aspirin helps to prevent blood clotting in the presence of plaque. The dose to take should always be discussed with your health care provider. 

There are side effects of aspirin use, which is why it cannot be recommended to everyone to reduce the risk of cancer or heart disease.  Aspirin can be irritating to the stomach and can cause serious bleeding in the gastrointestinal tract.  It can also cause bleeding in the brain, known as a hemorrhagic stroke. 

Here’s the real message of this column: it looks as though a simple medicine - aspirin - could be very important in the prevention of many common cancers.  However, because of the possible side effects and dangers of aspirin, randomized studies are greatly needed to show its efficacy and safety.  Funding is needed for this, and it will not come from pharmaceutical companies, as aspirin is such a common and inexpensive drug.  The recent publicity about this subject has stirred great interest.  Hopefully there will soon be such studies -with answers coming more quickly than the British study due to be finished in 2025!  

Sadja Greenwood, MD,MPH   back issues on this blog

What's the Connection between Sleep, Exercise and the Immune System?

When we get sick – with an infection, other illness or traumatic event – we want to sleep more.  It’s a natural reaction seen in other animals as well.  Recent research at the University of Pennsylvania showed that sleep helps to facilitate the immune response by increasing resistance to infection and survival after infection.  This research was done on fruit flies – but don’t discount it too quickly.  The genetic pathways found in these insects are preserved in mammals.  The take-home message from this work is that when you get sick – sleep as much as your body tells you to.

Research at the Finnish Institute of Occupational Health showed that healthy young adults restricted to 4 hours of sleep per night for 5 days  showed marked changes in their immune systems, with pro-inflammatory changes and an increase in allergic reactions and asthma.  Sleep deprivation also affects metabolism, leading to obesity, heart disease and diabetes. 

What are some natural ways to get enough sleep?  If you work at home and can’t sleep well at night, try a nap during the day – any time from 10 to 30 minutes may revive your day.  Regulate your 24 hour (circadian) rhythms by exposing yourself to bright light n the morning – sunlight or a ‘happylight’ during foggy days or the winter.  Before bedtime, wear blue-blocking glasses for an hour, while you read, compute, play music or watch television.  When you block the short blue wavelengths of the light spectrum with these orange colored glasses, you prevent the suppression of your natural melatonin. Melatonin is a hormone produced by the brain’s  pineal gland, located behind your eyes.  Melatonin outflow promotes good sleep. As an anti-oxidant, it has many salutary effects on the body, which we have suppressed with the artificial light of light bulbs, televisions, tablets et al.  Go to the website LowBlueLight.com to read about the benefits of normal melatonin release - by wearing the glasses for an hour or more before bedtime.  You can get a pair that will fit over your regular glasses and allow you to read, compute, or watch TV.  You can also take 1-3 mg of melatonin as a sleeping pill - start with the lowest dose.  This is safer than prescription sleeping pills such as Ambien or Valium.

Exercising  is another way to induce melatonin release and help sleep.   Morning exercise may be the most effective in increasing melatonin secretion in the evening, but exercise at any time of day can work for many people.  Here’s another benefit of exercise – a recent study from UCLA showed that maintaining muscle mass through resistance exercise (or plain hard work such as lifting, or farming) is more important than BMI (body mass index) in determining the risk of death from any cause.  So – turn your compost, get out those weights, take a Pilates class or do pushups to increase your muscle mass.

I will be away for a few weeks; my column will resume on Monday, May 26^th. Keep eating those colorful vegetables and fruits, a brassica vegetable every day, herbs, olive oil, pre and probiotic foods, and nosh on nuts.  Get some blueblocking glasses for evening use, and thereby improve your sleep. They are widely available on the Internet; I think the ones at LowBlueLight are the best – but more expensive. If you are sleep deprived at night, remember that taking a daytime nap does not mean you are lazy  - just look at your dog or cat..  Write me a comment and I’ll reply. 

Sadja  Greenwood, MD – back issues on this blog

Regulate your Blood Sugar with the Right Plant Foods

Dietary compounds known as flavones and anthocyanins, found in many herbs and vegetables, can help to regulate blood sugar and lower inflammation.  Recent research from the University of East Anglia and King’s College London looked at nearly 2000 women who were twins, and compared their dietary histories with their blood levels of glucose, insulin and inflammatory markers.  The research focused on flavones, found in herbs and vegetables such as parsley, thyme and celery, and anthocyanins, found in berries, red and purple grapes, wine, and other red or blue-colored fruits and vegetables.

Findings were that those who ate the most foods with flavones and anthocyanins had lower insulin resistance.  This means that their cells were able to respond to insulin and take in blood glucose in a normal way.  People with high insulin resistance have elevated levels of insulin in their blood, and may experience weight gain, increased blood pressure, high triglycerides, low HDL (good cholesterol), and other health problems. Diabetes is a frequent result. 

The study also found that those who ate the most anthocyanins were least likely to suffer from chronic inflammation.  Inflammation – as seen by redness, swelling, and pain, is a normal and necessary part of the body’s reaction to injury.    As healing occurs, the inflammatory response goes away.  However, chronic inflammation is a risk factor for many illnesses and should be identified and reduced.  It can be caused by chronic infections, gum disease, and obesity, especially abdominal obesity.  The usual antidote has been to eat less, follow a Mediterranean type of diet, and move more.  This new study indicates which foods may be especially helpful.  Anthocyanins are concentrated in foods that are red, purple or blue, but are found in most plants, in leaves, stems, roots, flowers and fruits.  The highest amounts are found in blueberries, cranberries, blackberries, black currants, cherries, eggplant peels, black rice, dark colored grapes, red cabbage, red-fleshed peaches, beets, and blood oranges. 

The researchers also cited dark chocolate and red wine as compounds with anthocyanins, and cautioned that moderation is the key, because of the potential for too much sugar (chocolate) and addiction/inebriation (wine).  Here’s a no sugar chocolate recipe:  mash a ripe banana, add unsweetened cocoa powder and some peanut butter to taste. Stir it up with a fork, and share it with a pal for dessert.  Put it on a whole grain cracker for crunch, or add chopped nuts. 

This is an exciting study because it is one of the first large-scale human studies to look at how flavones and anthocyanins can reduce chronic inflammation and also affect insulin resistance, blood glucose regulation and the risk of diabetes.  A study of twins is especially valuable, as it eliminates or modifies the role of genetics.

The take home message of this article is – go for dark colors in your food choices.  Also go for the flavones in celery, parsley, thyme and other herbs.  You can find these foods year-round at natural food stores and many markets.  Try growing purple potatoes – I can’t stop them in my garden.   Thyme and parsley are also easy to grow in our climate.

Sadja Greenwood, MD, MPH   back issues on this blog