May 26th, 2015

Acetaminophen (Tylenol) Shown to be Ineffective for Back Pain, Knee/Hip Osteoarthritis

Acetaminophen Side EffectsIntroduction

A new detailed analysis of clinical studies on acetaminophen (Tylenol) concluded that this popular drug was ineffective for low back pain and provided no significant clinical relief of hip or knee osteoarthritis (OA) pain, while quadrupling the risk for liver damage. The result from this analysis further calls into question whether this drug should still be on the over-the-counter market.

Background Data:

Acetaminophen is the only remaining member of the class of drugs known as “aniline analgesics” that is still on the market. The rest were discontinued long ago. Acetaminophen only blocks the feelings of pain and reduces fever, it exerts no significant anti-inflammatory action.

Acetaminophen is very hard on the liver and is known to reduce the liver’s store of the important detoxifying aid and antioxidant glutathione. When acetaminophen is combined with alcoholic drinks or other compounds toxic to the liver including other medications, its negative effects on the liver are multiplied. It should definitely not be used in anyone with impaired liver function.

Acetaminophen is often the drug of choice in children to relieve fever. However, use for fever in the first year of life is associated with an increase in the incidence of asthma and other allergic symptoms later in childhood. Asthma appears to be another disease process that is influenced greatly by antioxidant mechanisms. Acetaminophen severely depletes glutathione levels not only in the liver, but presumably other tissues as well, and should definitely not be used in people with asthma.

New Data:

Researchers from the University of Sydney analyzed data from 13 randomized controlled trials that compared the efficacy and safety of acetaminophen with placebo in more than 5,000 patients with low back pain (n = 1825) or hip or knee OA (n = 3541). Primary outcomes were pain (scale of 0 – 100), disability (scale of 0 – 100), and quality of life.

In low back pain, the researchers found very strong evidence that acetaminophen was ineffective in the short term for reducing pain, reducing disability, or improving quality of life. In hip and knee OA, the researchers found the reduction in pain with acetaminophen (−3.7) was far below the −9.0 criterion for minimal clinically significant difference. Similarly, the −2.9 reduction in disability did not meet the criterion for clinical importance. Hence, acetaminophen has no clinical benefit in knee and hip OA.

In regards to the liver damage, it was found that patients who took acetaminophen were 3.8 times more likely to have abnormal liver function tests.

Since acetaminophen provided no benefit in back pain or knee/hip OA and carried with it significant risk for harm, the popular use of acetaminophen in these conditions is questionable.


Most people consider acetaminophen (e.g., Tylenol) as being an extremely safe pain reliever for both children and adults. The reality is that it can be extremely dangerous and causes significant side effects. Each year acetaminophen causes over 100,000 calls to poison control centers; 50,000 emergency room visits, 26,000 hospitalizations, and more than 450 deaths from liver failure. In addition, regular use of acetaminophen is linked to a higher likelihood of asthma, infertility, and hearing loss (especially in men under 50 years of age). The FDA has done a poor job alerting the public to the dangers of acetaminophen. In my opinion, it is a drug that serves no real medical purpose in the 21st century. Bottom line, it is time to pull it from the over-the-counter market.

Machado GC, Maher CG, Ferreira PH, et al. Efficacy and safety of paracetamol for spinal pain and osteoarthritis: systematic review and meta-analysis of randomised placebo controlled trials. BMJ. 2015 Mar 31;350:h1225.

Dr. Michael Murray

May 19th, 2015

Eating a Varied Diet Inversely Linked to Obesity


Most Americans eat a very limited range of foods and consume a very monotonous diet as a result. It seems entirely possible that excessive calorie and food consumption may be some sort of physiological craving gone awry. In other words, perhaps the brain is seeking to help improve nutritional intake, but somehow it is just causing excessive cravings for additional calories in general instead.

Despite this obvious possibility, there is not a lot of research in this area. A new study from researchers at the Harvard School of Public Health and NYU School of Medicine suggests that dietary variety may help prevent obesity. Increasing the intake of a variety of higher quality foods is associated with a lower risk for being overweight.

Background Data:

There are numerous case histories in the medical literature of people having specific food cravings indicating some sort of physiological basis. For example, the eating of dirt or chewing ice cubes is often an indication of iron deficiency. Research done by the U.S. Army showed that when well-nourished men were placed on monotonous diets, it led to increased food craving for foods other than those provided in the monotonous diet. But there is little research into whether individuals self-selecting a very monotonous diet, are more likely to consume more calories than those consuming a more varied diet.

New Data:

To evaluate the role of food variety on body weight, researchers evaluated data from the National Health and Nutrition Examination Survey (NHANES) 2003-2006 of over 7,000 men and non-pregnant, non-lactating women aged ≥20 years old with two 24-hour dietary recalls. Dietary variety was determined by using the US Healthy Food Diversity (HFD) index, which measures dietary variety, dietary quality and proportionality according to the 2010 Dietary Guidelines for Americans. The subjects were dividing into groups 1 through 5 with the higher number reflecting greater dietary variety.

Both men and women in the group with the greatest degree of dietary variety had a roughly 50% reduced risk for being obese. These results indicate that greater dietary variety is inversely associated with obesity in both sexes, indicating that greater healthful food variety may protect against excess body weight. This study explicitly recognizes the potential benefits of dietary variety in obesity management and provides the foundation to support its ongoing evaluation.


The bottom line is that I am a big proponent of eating a wide variety of health promoting foods. My reasons are that I appreciate the important role that eating a broad range of food components play in promoting human health. In particular, the importance of the long list of phytochemicals in fruits, vegetables, legumes, nuts, seeds, and other plant foods. We need variety in our diet to make sure we are getting the full spectrum of protection. Plus, I also think that a varied diet makes our food choices more interesting and less boring. Eating the same foods and menus over and over is a sure path to food boredom. Dietary variety wakes up the senses.

One of my key dietary axioms is to eat a rainbow assortment of fruits and vegetables. It is has been convincingly shown that a diet rich in fruits and vegetables is your best bet for preventing virtually every chronic disease especially heart disease, cancer, strokes, macular degeneration, and cataracts. By a “rainbow assortment,” I simply mean that by selecting fruits and vegetables in a variety of colors including red, orange, yellow, green, blue, and purple. By eating a wide variety of these colorful foods, you’ll be giving your body the full spectrum of a wide-range of compounds known as phytochemicals – an umbrella term that includes pigments such as carotenes, chlorophyll, and flavonoids; dietary fiber; enzymes; vitamin-like compounds; and other minor dietary constituents. And, according to the study just reviewed, it may help your brain feel more satisfied so that you consume fewer calories helping you to fight off obesity.


Vadiveloo M, Dixon LB, Mijanovich T, Elbel B, Parekh N. Dietary variety is inversely associated with body adiposity among US adults using a novel food diversity index. J Nutr. 2015 Mar;145(3):555-63.

Dr. Michael Murray

May 12th, 2015

Maybe Nuts are Not a High Calorie Food After All

health benefits of almonds & nuts


Nuts and seeds are rich in nutrients and phytochemicals, but they are also high in fat. So, many people avoid nut consumption out of fear that it will counteract their efforts to achieve or maintain their ideal body weight. Large population studies have shown that the people who consumed the most nuts were less obese. A new study from the UK’s Institute of Food Research indicates that although almonds contain more than 50% fat, the fatty acids are not easily digestible or absorbable. Perhaps they are not as calorie dense as we previously thought.

Background Data:

It has been previously shown that nuts produce two key effects that help fight obesity:

  1. They promote satiety, the feeling of appetite satisfaction.
  2. They increase the action of the hormone insulin, thereby improving blood sugar control, appetite regulation, and metabolism.

Nonetheless, it seems counterintuitive to many that such a high calorie food would actually fight obesity. It has been suggested that nuts may not be as high in absorbable calories as previously thought. Researchers have primarily looked at the absorption of almonds as an example. Studies have shown that even after thorough chewing, a high proportion of the fat remains encapsulated in the cells of the chewed almond tissue and is therefore less available for digestion. This effect is easily measured by examining the rise in fats in the blood after consumption of almonds. It is thought that the calorie content of almonds, and perhaps nuts in general, is overestimated by about one-third.

New Data:

The particle size and structure of chewed almonds has a significant impact on nutrient release (bioaccessibility) and digestion. The goals of this new study were to quantify the effects of chewing (mastication) on the bioaccessibility of the fats of almond and examine microstructural characteristics of masticated almonds.

In the study, 17 healthy subjects chewed raw natural almonds (NAs) or roasted almonds (RAs) in 4 separate sessions. After chewing thoroughly, subjects spit out the food bolus so that researchers could measure the particle size using mechanical sieving and laser diffraction. The microstructure of masticated almonds, including the structural integrity of the cell walls, was examined with microscopy. The bioaccessibility of the fat was predicted by using a theoretical model, based on almond particle size and cell dimensions, and then compared with empirically derived data.

Results showed that the bioaccessibility of fat from the almonds masticated by the human volunteers was approximately 8% and 11% for NAs and RAs, respectively. This low percentage of fat bioaccessibility is attributable to the high proportion (35-40%) of large particles (>500 μm) in masticated almonds. Microstructural examination of the almonds by microscopy indicated that most of the fat remained undisturbed in intact cells after mastication.

These results indicate that almonds have a much lower calorie content than previously thought due to 90% of the fat in almond not being absorbed.


This study adds to the growing list of studies highlighting that frequent nut consumption makes sense in improving nutrition and promoting health. In addition to the reduced risk of obesity with nut consumption, numerous large studies have also found that higher nut consumption is also associated with a protective effect against cardiovascular disease and type 2 diabetes.

Key takeaway point – eat a moderate amount of nuts each day. About ¼ of a cup or a small handful is all that you need to see the health benefits. I would still recommend that you keep the portion size moderate and don’t overdo it.


Grundy MM, Grassby T, Mandalari G, et al. Effect of mastication on lipid bioaccessibility of almonds in a randomized human study and its implications for digestion kinetics, metabolizable energy, and postprandial lipemia. Am J Clin Nutr. 2015 Jan;101(1):25-33.

Dr. Michael Murray