The Brain Can Learn To Decrease Pain

New research led by Raymonde Scheuren from the University of Luxembourg has brought some new insights into the world of pain. It’s generally known that a pain present in one part of the body can be attenuated by painfully stimulating a different part of the body. This is known as diffuse noxious inhibitory control (DNIC) and is thought to take place to allow the body to focus on the new, and potentially more important, threat to the body.

In their experiments, Scheuren et al. caused pain in subjects by electrically stimulating a foot. They then created a second source of pain by placing the opposite hand in a bucket of ice-cold water. As predicted, after the hand was immersed in cold water, the pain from the foot decreased. The interesting part of the experiment was when the insertion of the hand into cold water was repeatedly coupled with a phone ring tone. Afterwards, simply playing the ring tone (without placing a hand in cold water) was enough to decrease foot pain from the electrical stimulation! Conditioning had taken place. Conditioning is a form of learning where the physiological effect of a stimulus (ice-cold water) is reproduced by an unrelated stimulus (phone ring tone) by having the two repeatedly happen simultaneously. The one takes on the effect of the other.

The reverse effect possibly plays a part in chronic pain. Sights, sounds, smells and other sensations that were present during the traumatic incident that caused the injury can unconsciously become triggers for pain long after the injury has healed.

Yoga Can Help Prevent Diabetes (Type 2)

A new study by McDermott et al. was carried out to see if yoga could be effective at preventing type 2 diabetes in those who presented risk factors. The participants were randomly split into 2 groups: the yoga group and a walking group. The participants either had to attend a yoga class or complete monitored walking 3-6 times a week over an 8 week period.

Over the course of the study, there were significant reductions in systolic and diastolic blood pressure, total cholesterol, anxiety, depression, negative affect and perceived stress in both the yoga intervention and walking control groups but the yoga participants had significantly greater reductions in weight, waist circumference and BMI.

This study proves that yoga can reduce weight-related type 2 diabetes risk factors, which is interesting given that previous research has generally not shown yoga to be of benefit in weight control.

Relaxation Response

As mentioned in an earlier post, relaxation has many, many benefits. Through his extensive study of relaxation, Herbert Benson from the Harvard Medical School has put together an 8-step sequence that consistently elicits the relaxation response. The sequence has been proven scientifically and has been used for decades.

Step 1: Pick a focus word, phrase, image or short prayer or focus on your breathing. Choose a word or phrase that is meaningful and emotionally soothing for you. Repeat the word or phrase during your entire exhalation.

Step 2: Find a quiet place away from distractions and sit or lie down comfortably.

Step 3: Close your eyes.

Step 4: Progressively relax all your muscles, moving up from the tip of your toes to the top of your head or vice versa if you prefer.

Step 5: Breath slowly and naturally, silently repeating your chosen word or phrase as you slowly exhale. Alternatively, you can focus on a picture or object or simply pay attention to your breath.

Step 6: Assume a passive attitude. Reserve any judgement regarding how well you are doing or whether it is working. If and when your mind strays to unrelated thoughts, simply think “oh well” and kindly and gently bring your attention back to your word, phrase, object or breath.

Step 7: Continue with this exercise for 12 to 15 minutes.

Step 8: Practice this technique at least once a day, either in the morning to set yourself for the day ahead or at a time that is more convenient or beneficial to you.

“Only that day dawns to which we are awake“

Henry David Thoreau

“Be happy in the moment, that’s enough.

Each moment is all we need, not more.”

Mother Teresa

Vitamin D Deficiency Linked To Chronic Pain

Paul McCabe et al from the University of Manchester analysed data from the European Male Ageing Study and found that men with vitamin D deficiency at the start of the study were more than twice as likely to experience ongoing widespread pain over the next 4 years as those with high levels of vitamin D. It was noted that the men with chronic widespread pain were more likely to be physically active, obese, depressed and to have other health problems. Once these other factors were taken into account the link between vitamin D and pain disappeared.

However, John McBeth et al analysed data from the same study and found that even after adjusting for other health factors, pain remained moderately associated with increased odds of having low vitamin D levels. This is supported by a 5-year longitudinal study published last year by Laura Laslett et al in which vitamin D deficiency was found to predict incidence or worsening of knee pain and hip pain.

There seems to be a link between a deficiency of vitamin D and pain but could supplementation with vitamin D help to decrease pain? Between 2008 and 2010, Shreuder et al conducted a study in Holland and they did indeed find a small positive benefit (less pain and better function) after taking a high dose of vitamin D for 6 weeks.

What could the mechanism behind vitamin D and pain be? Tague et al found that vitamin D deficiency in rats can lead to a hyperinnervation of skeletal muscle which is likely to contribute to muscle hypersensitivity and pain.

Vitamin D is naturally present in a few dietary sources such as fish oils, mushrooms, eggs and liver. Other than supplements, sunlight exposure is the best source of vitamin D for most of people.

Glucosamine Promotes Longevity

In life, sometimes a new use is found for an existing product and this new use turns out to be way better than the original use for which the product was designed. Examples of this are:

• Propecia: now used to promote hair growth in balding men but originally sold to treat prostate enlargement
• Viagra: now used to treat male erectile dysfunction but originally sold to treat hypertension and angina
• Play-Doh: now sold as molding clay for children but originally marketed as a wallpaper cleaner
• WD-40: now used as a mechanical lubricant but originally invented to protect nuclear missiles

Last week I read an article in Medical News Today that made me think glucosamine could be next on the list. Glucosamine has been used for years to treat joint pain and stiffness but Ristow and colleagues have explored a different use and published their findings in the April issue of Nature Communications. They fed glucosamine to roundworms and found that they lived about 5% longer than the control group. Encouraged by the results they then fed glucosamine to ageing mice. The mice were 100 weeks of age which is equal to around 65 years in human age. Amazingly, the lifespan of the mice on glucosamine was increased by 10% compared to the controls on a normal diet. This is equivalent to 8 extra years of human lifespan! The researchers found that glucosamine offered protection from diabetes by improving glucose metabolism.

How could this relate to humans? Well, a study by White and colleagues published a couple of years ago in European Journal of Epidemiology may answer that question. Over 77,000 people aged 50-76 years were followed for mortality for about 5 years. Glucosamine was linked to a significant decreased risk of death from cancer and a large risk reduction for death from respiratory diseases. Glucosamine and chondroitin use was associated with a decreased risk of total mortality.

There are no known side effects of glucosamine supplementation. If I wasn’t already taking glucosamine, I’d be heading straight for the shops!

“To be patient is simply to be completely open to each moment,

accepting it in its fullness,

knowing that,

like the butterfly,

things can only unfold in their own time.“

Jon Kabat-Zinn

Achilles Tendon Repair Improved By Embedding Stem Cells Into Sutures

New research published in Foot & Ankle International by Dr Samuel Adams Jr and colleagues has shown promising results with Achilles tendon repairs. They cut the Achilles tendon of rats and then performed 3 types of surgical repair:

• repair with suture only (SO)
• repair with suture plus injection of stem cells at the repair site (SI)
• repair with suture loaded with stem cells (SCS)

The Achilles tendons were analysed and tested for strength at 14 days and 28 days post surgery. The SI and the SCS groups had significantly higher ultimate failure strength than the SO group. Strength was maintained at 28 days in the SCS group but not in the SI group. Cellular analysis in the SCS group was significantly better than in the two other groups.

The findings suggest that, following surgery, the use of stem cells can enhance the healing of Achilles tendons and embedding stem cells directly into sutures offers even more benefit than injecting stem cells.

Yoga Improves Health In Breast Cancer Patients Undergoing Radiotherapy

A study published in this month’s Journal of Clinical Oncology by Lorenzo Cohen and colleagues from the University of Texas MD Anderson Cancer Center has proven that yoga can complement the medical treatment of cancer. Women undergoing radiotherapy for breast cancer were split into 3 groups:

• yoga (including asanas, breathing exercises, meditation and relaxation techniques) group
• stretching (specific to condition) group
• control group

The yoga and stretching groups practised 3 times a week for an hour during the 6 week duration of radiotherapy. Data was collected before, at the end and 1, 3 and 6 months after treatment.

Compared to the two other groups, the yoga group showed statistically significant improvements in subjective measures of physical functioning, ability to engage in daily activities, general health perceptions and in the ability to find meaning in the illness experience. The changes were maintained over time. Additionally, measures of cortisol in saliva revealed better stress hormone regulation in the yoga group.