Weight Bearing Exercise Can Be Dangerous For Neuropathy Patients

Today's post from huffingtonpost.com (see link below) looks at the problems that certain forms of exercise may bring the neuropathy patient who has lost most of the feeling in their feet. These problems are not to be underestimated but it's important to say here that the vast majority of neuropathy patients have some feeling in their feet, despite the numbness that can affect the toes and pads of the foot. These patients are unlikely to step on a nail and not feel something. That said, many people living with neuropathy feel very little and this can certainly lead to serious accidents. When this is the case, load-bearing exercises can be more dangerous than helpful. Nevertheless the article recommends exercise as being essential, as long as this is controlled and the feet are carefully and regularly monitored. The article is aimed at diabetic neuropathy patients but applies to all people living with neuropathy and foot problems.

Type 2 Diabetes and Peripheral Neuropathy: To Walk or Not to Walk?
 
Milt Bedingfield Posted: 05/11/2015 

It is now well known that engaging in light to moderate physical activity on a regular basis is of significant value for most people that have either Type 1 or Type 2 diabetes. In fact the American Diabetes Association recommends that people with diabetes should get a minimum of 150 minutes of light to moderate exercise per week including aerobic and resistance training.

What the ADA says...

It has also been recommended that people with peripheral diabetic neuropathy that have reduced or absent feeling in their feet should not engage in any form of weight bearing exercise activity. The American Diabetes Association recommends that people with diabetes-related peripheral neuropathy should limit the amount of weight-bearing physical activity they perform due to their increased risk of foot ulcers and amputation (1, 2). This is based on the fact that with peripheral neuropathy there is either a decreased ability or total inability in the feet to feel pain or discomfort.

As an example, standing barefoot on hot asphalt maybe in a parking lot in the middle of the summer would be very uncomfortable for someone with normal sensation in their feet, however go unnoticed for someone with peripheral neuropathy. Similarly, the person with peripheral neuropathy may develop a painful nickel-sized blister after walking too far or when wearing new shoes and not even feel it. Without daily inspection of the ankles and feet (which a lot of people do not do) this blister could go unnoticed for days resulting in a potentially infected, slow to heal, or non-healing wound. In the worst case this could lead to an amputation. All of this is the result of losing what is called the protective sensation in the feet.

In the absence of peripheral neuropathy whenever there is insult to the foot or feet such as a blister, a cut or scrape or stepping on a small piece of glass or nail, there would be pain which would cause you to notice the injury and hopefully treat the wound accordingly.

There are also painful stages of neuropathy that can precede lack of sensation which are characterized by frequent but intermittent pain in the feet throughout the day, having pain only in the evening while in bed to constant pain. This stage of neuropathy can result in changing the way you walk, that is your stride length, which part of your feet you strike the ground with first and ultimately what part of your feet support your body weight.

Because of everything I have just mentioned above this leads to the unfortunately recommendation that discourages walking for a great many people with diabetes.

To Walk or Not to Walk?

So where does that leave us? Exercise is arguably the best treatment there is, particularly in controlling Type 2 diabetes, and preventing diabetes related complications, such as peripheral neuropathy, however once you have peripheral neuropathy in your feet you should avoid doing any weight bearing exercise.

I have wrestled with the dilemma for years about how to guide my patients that would benefit immensely from starting to exercise or increasing their exercise however have various stages of neuropathy.

According to the Centers for Disease Control and Prevention, from 2000-2002, approximately 60 percent of lower-extremity amputations in the United States were diabetes-related, with the majority of those amputations being preceded by a foot ulcer (3). Almost all diabetic foot ulcers occur in those people that have lost feeling in their feet due to diabetic peripheral neuropathy (4, 5).

On the other hand poorly controlled blood glucose control contributes greatly to peripheral neuropathy.

Eight-year cardiovascular mortality is 34 percent lower among people with diabetes who walk two hours per week compared with non-walkers (6).

Feet First Randomized Controlled Trial

The Feet First Randomized Controlled Trial was designed to look at the effect of weight-bearing activity on foot ulcer incidence in people with diabetic peripheral neuropathy. The study, conducted over a 12-month period by Lemaster and colleagues, showed that participants in the Feet First intervention group achieved a modest increase in activity, with no increase in foot lesions, compared with those in the control group. The group also recommended additional research be conducted in this area to investigate the current guidelines and close supervision for patients with diabetes and peripheral neuropathy (7).

Tuttle and colleagues found that people with Type 2 diabetes and peripheral neuropathy experienced no negative consequences when performing moderate-intensity, weight-bearing exercise in their study (2).

Dr. Sheri Colberg reports in her article "Exercising with Peripheral Neuropathy" that recent descriptive studies suggest that patients with a lack of feeling in their feet who participate in daily weight-bearing activity are at decreased risk of foot ulceration compared with those who are less active (8, 9), especially if their daily routine is very similar with little variation from day to day regarding their physical activity (9, 10).

As a result of the above information, I am going to continue evaluating each of my class participants on a case by case basis, however, for those patients with peripheral neuropathy that I believe will be prudent in checking their feet and following the recommended foot care guidelines and stand to gain significant benefit from performing some weight bearing exercise, I will be more likely to recommend it to them.

References:

1. Singh, N., D. G. Armstrong, and B. A. Lipsky: Preventing foot ulcers in patients with diabetes. JAMA 293 (2):217-228, 2005

2. Tuttle, L. J., M. K. Hastings, and M. J. Mueller: A moderate-intensity weight-bearing exercise program for a person with Type 2 diabetes and peripheral neuropathy. Phys Ther 92 (1):133-141, 2012

3. Centers for Disease Control and Prevention. History of foot ulcer among persons with diabetes -- United States, 2000-2002. MMWR. 2003;52:1098-1102. Medline

4. Pham H, Armstrong DG, Harvey C, et al. Screening techniques to identify people at high risk for diabetic foot ulceration: a prospective multicenter trial. Diabetes Care. 2000;23:606-611.

5. Reiber GE, Smith DG, Wallace C, et al. Effect of therapeutic footwear on foot reulceration in patients with diabetes: a randomized controlled trial. JAMA. 2002;287:2552-2558. CrossRefMedline

6. Gregg EW, Gerzoff RB, Caspersen CJ, et al. Relationship of walking to mortality among US adults with diabetes. Arch Intern Med. 2003;163:1440-1447. CrossRefMedline

7. Lemaster, J. W., M. J. Mueller, G. E. Reiber, D. R. Mehr, R. W. Madsen, and V. S. Conn: Effect of weight-bearing activity on foot ulcer incidence in people with diabetic peripheral neuropathy: feet first randomized controlled trial. Phys Ther 88 (11):1385-1398, 2008

8. Richerson, S., and K. Rosendale: Does tai chi improve plantar sensory ability? A pilot study. Diabetes Tech Ther 9(3):276-286, 2007

9. Ko, S. U., S. Stenholm, C. W. Chia, E. M. Simonsick, and L. Ferrucci: Gait pattern alterations in older adults associated with type 2 diabetes in the absence of peripheral neuropathy--results from the Baltimore Longitudinal Study of Aging. Gait Posture 34 (4):548-552, 2011

10. Kanade, R. V., R. W. van Deursen, K. Harding, and P. Price: Walking performance in people with diabetic neuropathy: benefits and threats. Diabetologia 49 (8):1747-1754, 2006

http://www.huffingtonpost.com/milt-bedingfield/post_9394_b_7188266.html

The Dangerous Language Of Medical Research

Today's post from updates.pain-topics.org (see link below) is another excellent article from Dr Leavitt, talking about how drugs are often regulated based on several vague words of conclusion from research papers. 'There is no evidence to suggest...' can let governments and regulatory bodies completely off the hook in their decision making about drugs availability. It means that patients need to be constantly alert and conscious of the fact that their necessary medication may be refused on very shaky grounds. It may require some foot-stamping to get your way; especially if you have done all the research and have taken expert advice which suggests that a particular drug could help you considerably. It's rejection may hang on those six words but in fact all they mean is the opposite of what they say - there may be no evidence to suggest but that equally means there may be no evidence to prohibit. Making an ally of your doctor and taking well-researched and factual arguments to him or her may convince the powers that be that you will in fact, benefit from taking such a drug. 'There is no evidence to suggest...can often be a cop-out which will worsen your condition. This article is well-worth reading.

The 6 Worst Words in Evidence-Based Medicine
Posted by SB. Leavitt, MA, PhD Saturday, December 14, 2013

Writing in the November 2013 edition of the Journal of the American Medical Association, R. Scott Braithwaite, MD, MS, from New York University School of Medicine, comments on a deceptive 6-word phrase often used in evidence-based medicine (EBM) that frequently leads to dangerously false inferences for clinical decision making [Braithwaite 2013]. We further contend that, applied to the interpretation and application of pain research — such as relating to the use of opioids analgesics for chronic pain — those 6 words also can encourage poor quality pain management and inexcusable patient suffering.

What are the offending 6 words? They are quite simply, “There is no evidence to suggest….” Braithwaite proposes that this phrase should be banished from the lexicon of EBM and, while this could be important, we also recognize that it could foster uncertainty and doubt that could be discomforting to many professionals and patients in the pain field.

Untested Hypotheses

Braithwaite provides the following statements as examples of nefarious usage of the phrase:
“There is no evidence to suggest that hospitalizing compared with not hospitalizing patients with acute shortness of breath reduces mortality.”

“There is no evidence to suggest that ambulances compared to taxis to transport people with acute GI bleeds reduces prehospital deaths.”

“There is no evidence to suggest that looking both ways before crossing a street compared to not looking both ways reduces pedestrian fatalities.”

As Braithwaite maintains, all of the statements are absurd as a basis for decision making, yet each statement is technically correct since its underlying hypothesis has not been suitably tested to establish contradictory evidence. This presumes a definition of “evidence” that requires formal hypothesis testing in an adequately powered (eg, large sized) and well-designed (eg, randomized, controlled) research study.

Taking this further, based on a prior review article [Smith and Pell 2003], we would add the following statement: There is no evidence to suggest that jumping from an airplane in flight without a parachute as compared with using a parachute is fatal. As the review authors note (somewhat satirically), while there have been anecdotal accounts of persons without parachutes surviving falls from airplanes, it is extremely difficult to recruit subjects for good-quality randomized controlled trials comparing parachute use with no parachute in such circumstances; so, the statement is technically correct, but unproven and misleading.

Based on his observations, Braithwaite proposes that “there is no evidence to suggest” has become a mantra for EBM practitioners in a wide variety of settings. And, he says, rarely is the statement followed by the clarifying aphorism “absence of evidence is not evidence of absence” [also see Altman and Bland 1995] or discussions of more inclusive definitions of “evidence” for affirming the hypotheses in question.

Seeking Clarity & Precision

Braithwaite proposes that, when an intervention potentially may incur significant harm or require large commitments of resources, deciding not to intervene when “there is no evidence to suggest” the favorability of the intervention can be prudent. “However, deciding to intervene when ‘there is no evidence to suggest’ also may make sense,” he writes, “particularly if the intervention does not involve harm or large resource commitments, and especially if benefit is suggested by subjective experience (eg, the qualitative analogue of the Bayesian prior probability).” 

Side Note
Bayesian theory applied to medical research is regaining popularity — albeit, it is difficult for most people to understand — and it provides a mathematical framework for inference or reasoning using probability estimates. The approach can be particularly helpful in judging the relative validity of hypotheses in the face of sparse or uncertain data. While actual calculations can be complex, to evaluate the probability of a hypothesis being “true” an investigator specifies a prior probability — based on current observation/experience, past research, or scientific principles — which is then updated in the light of new, relevant research data to provide a posterior probability (ie, outcome result). An important feature of a Bayesian approach is that it takes into account what already is known or can be estimated, either quantitatively or qualitatively, about the likelihood of research outcomes being valid; if there is absolutely no (zero) prior probability to support a hypothesis, then research outcomes — whether favorable or unfavorable — are usually unlikely to be valid and reliable. In many respects, this might be viewed as a statistical application of the “Bradford Hill Criteria” for establishing cause-effect relationships [as discussed in Part 11 (here) of our series on “Making Sense of Pain Research].

Braithwaite further maintains that a fundamental problem with the phrase “there is no evidence to suggest” is that it is “ambiguous while seeming precise.” What does “there is no evidence to suggest” really mean when used to argue against some intervention?

Does it mean that the intervention has been proven to have no benefit? That some evidence does exist, but it is inconclusive or insufficient? That outcomes are somewhat equivocal, with risks exceeding benefits for some patients but not others? Each has a subtly different meaning affecting decision making; whereas, simply stating “there is no evidence to suggest” circumvents the experience or clinical intuition of healthcare providers. Furthermore, as Braithwaite notes, many decisions are particularly sensitive to patient preferences and, when the favorability of an intervention is unclear, “there is no evidence to suggest” may “inhibit shared decision making and may even be corrosive to patient-centered care.”

According to Braithwaite, most practitioners make patient-centered decisions every day without high-quality (eg, randomized controlled trial) evidence as a guide, and those decisions are not always wrong. Furthermore, principles of EBM make it clear that an evidence-based approach was never intended to entirely exclude information derived from clinical experience and intuition — which amounts to a qualitative prior probability in a Bayesian sense.

He recommends that practitioners and researchers make concerted efforts to banish “there is no evidence to suggest” from their professional vocabularies. Instead, they could substitute one of the following 4 phrases, each of which has clearer implications for decision making:
“Scientific evidence is inconclusive, and we don’t know what is best” (corresponding to an uninformative or ambiguous Bayesian prior probability).

“Scientific evidence is inconclusive, but my experience or other knowledge suggests ‘X’” (corresponding to an informative, qualitative Bayesian prior probability supporting ‘X’).

“This has been proven to have no benefit” (if valid evidence indeed exists to confirm this).

“This is a close call, with risks exceeding benefits for some patients but not for others.”

Braithwaite asserts that each of the 4 statements would lead to distinct inferences for decision making and could improve clarity of communication with patients. Finally, he says, “Informed implementation of EBM requires clearly communicating the status of available evidence, rather than ducking behind the shield of 6 dangerous words.”

False Arguments Over Opioids for Chronic Pain

For quite some time, a very outspoken and opinionated group of healthcare professionals in the United States has been arguing against the long-term use of opioids for chronic noncancer pain, based essentially on the premise “there is no evidence to suggest that the benefits of this therapy outweigh its potential risks.” In fact, going further — by relying on similar logic and bolstered by low-quality, invalid, or misinterpreted evidence — they assert that overwhelming risks negate any benefits. The group also went so far as to petition the FDA to make the labeling of all extended-release (ER) and long-acting (LA) prescription opioids more restrictive [first discussed in an UPDATE here]. Even though the petition’s demands were largely rejected by the FDA in updated product-labeling [see UPDATE here], opioid opponents have persisted in their campaign.

Indeed, it is acknowledged that there is virtually no clinical research evidence of good quality examining the efficacy and safety of opioid analgesics prescribed long-term for chronic pain. And, in their labeling-change mandates, the FDA also requires manufacturers to conduct longer duration trials of ER/LA-opioids, including evaluations of serious risks, such as misuse, abuse, addiction, overdose, and death, as well as the risks of developing increasing sensitivity to pain (hyperalgesia).

Meanwhile, the opioid opponents have been using the current lack of evidence as evidence itself to support what might be called argumenta ad ignoratum, or “appeals to ignorance,” as discussed in Part 12 of our “Making Sense of Pain Research” series [here]. In the absence of any high-quality research evidence to the contrary, the opponents have used their own interpretations of data on opioid-related abuse, addiction, deaths, and other risks to arrive at an artificial Bayesian prior probability of harm — and have successfully foisted fallacious inferences on the public.

Additionally, they are most likely driven by a personal set of prior probabilities — coming from likeminded peers or individual experiences with select patients — that help guide the calculus of their conclusions. Essentially, they have fabricated their own rendition of Braithwaite’s second statement above to claim, “Scientific evidence is inconclusive, but my experience or other knowledge suggests that opioids are ineffective and unsafe in the treatment of chronic noncancer pain.”

However, using similar evidence deficits and prior probabilities informed merely by empiricism (eg, anecdotal observations), there are other important arguments about opioids for chronic pain that can be stated:
There is no evidence to suggest that opioid-induced hyperalgesia is a frequent clinical occurrence in human subjects administered opioids long-term for any type of pain, or which patients might be most affected.

There is no evidence to suggest that there is an inordinately high incidence rate of de novo, iatrogenic addiction among patients with chronic pain prescribed long-term opioid analgesics.

There is no evidence to suggest that significant numbers of patients with chronic pain do not or cannot benefit from opioid analgesia.

Other, similar, arguments could be expressed that cast doubts on concerns about the efficacy and safety of opioids for chronic pain. But, in all cases, such doubts are motivated by uncertainty — or, an “ambiguous Bayesian prior probability” — and a most objective and unbiased premise could be a variation of Braithwaite’s first statement above; “Until there is good-quality evidence available we cannot reach definitive conclusions.” Meanwhile, using a lack of evidence to argue for or against opioids for chronic pain becomes a cruel game of sorts in which nothing is scientifically established and patients who presently do or prospectively could benefit from such therapy are the losers.

Ubi Dubium, Ibi Intellectum

If we accept Braithwaite’s proposal to eschew the use of “there is no evidence to suggest” as a valid argument against a therapy or intervention, it also raises nagging doubts about the legitimacy of rejecting certain questionable modalities for pain management because they have little if any high-quality evidentiary support. A number of complementary and alternative medicine (CAM) modalities immediately come to mind: eg, homeopathy, reflexology, energy-field therapies (eg, Reiki, etc.), biomagnetic therapy, some variations of acupuncture, and others.

In most cases, high-quality clinical trials are absent and we are left with observational or anecdotal evidence at best. With certain approaches (eg, homeopathy, Reiki, and others), there is no presently-known biological rationale or plausibility to serve as a prior probability of efficacy. Still, there are ample examples of patients with pain being helped by each of the treatments — an informative prior probability — even if the outcomes are primarily due to placebo effects. So, should those CAM approaches be rejected outright as worthless on the basis of “there is no evidence to suggest that they are clinically effective for pain”?

Indeed, many critics have made strong, rational arguments for unequivocally rejecting most CAM approaches on the basis of absent or inadequate supportive evidence and/or the lack of biological plausibility [eg, see Science Based Medicine blog]. Despite those contentions, and in view of Braithwaite’s perspective, it would appear that less absolutist and more definitive statements are needed. And, these must not rely primarily on the absence of evidence as evidence against CAM approaches and any prior probabilities must be taken into account, including those based on limited observational or anecdotal data.

In many cases, prior probability or plausibility may be so low that the respective CAM approach is still deemed ineffective. But, in other instances, this could encourage “suspended disbelief” until further investigation via high-quality research is possible. Many practitioners and patients may be discomforted or irritated by the degree of uncertainty and doubt this tolerates. And, a dilemma may be that, as with the parachute example above, there may never be definitive research to make strictly evidence-based pain management decisions. However, a fundamental theme of these UPDATES, as well as our “Making Sense of Pain Research” educational series has been Ubi Dubium, Ibi Intellectum, or “Where There Is Doubt, There Can Be Understanding” [click to download series PDF].

REFERENCES:
> Altman DG, Bland JM. Absence of evidence is not evidence of absence. BMJ. 1995;311(7003):485 [access here].
> Braithwaite RS. EBM’s Six Dangerous Words. JAMA. 2013;310(20):2149-2150 [access by subscription here].
> Smith GC, Pell JP. Parachute use to prevent death and major trauma related to gravitational challenge: systematic review of randomised controlled trials. BMJ. 2003;327(7429):1459-1461 [abstract here]

http://updates.pain-topics.org/2013/12/the-6-worst-words-in-evidence-based.html

Doctors And Patients Alike Can Be Guilty Of Dangerous Assumptions

Today's short post from kevinmd.com (see link below) is a timely reminder that the relationship between doctor and patient is always a fragile one, influenced by suppositions and assumptions, on both sides. With a disease like neuropathy, where the boundaries are vague and diagnoses and treatments less than 100% reliable, it's vital that there's mutual give and take. Far too often doctors send nerve damage patients home with the cliched; 'You'll have to learn to live with it', leading to frustration and anger and unresolved medical issues. In that case, the doctor is wrong and deserves to be called on his/her bedside manner. However, patients are equally guilty when they self-diagnose, or demand certain treatments, or come to the surgery without a coherent story. The point is that there's room for a little humility and 'counting to ten' on both sides. This article illustrates that perfectly and is a lesson for both doctor and patient. In the case of neuropathy, there's often no right and no wrong but the middle ground must be found in order to provide the best possible treatment for the patient. That demands a preparedness for the long haul...on both sides, with patience and respect as prerequisites on the side. Well worth a read.

You think the patient is difficult? Maybe it’s you.
Jordan Grumet, MD | Physician | April 28, 2017

I have come to believe that humility is an essential component of wisdom. Never have I found this truer than in the practice of medicine. In fact, for almost every atrocious professional error in judgment I have made, I can pinpoint the exact moment where I stopped being humble.

Yet time and time again, humility quickly disappears when dealing with the difficult patient. In fact, the label “difficult” assumes the problem lies within the patient and not the technique being utilized by the care provider. Already, blame is turned outward and personal responsibility abandoned.

A few years ago, when I was in a group practice, one of the senior partners had a particularly needy patient that somehow showed up on all our schedules from time to time. Her aged joints carried her into the exam room to in a particularly hobbled rhythm. She paused before each sentence, her voice barely above a whisper.

Her litany of issues was long and nonsensical. And this was always the precise moment when humility left the room. We all became convinced that her complaints were psychosomatic. And we were right. It still amazes me at how cavalier I can be when I think a solution is either simple or nonphysiologic.

It was only after several visits that the need for a thorough exam became apparent. I tapped my feet and waited outside the door for what seemed like an eternity as she undressed and climbed into the gown. My stethoscope stumbled over the heart as if its mighty muscle had not thumped hundreds of thousands of beats. I auscultated the lungs absentmindedly untouched by the unmeasurable volumes that glanced the porous surface.

My hands fumbled over the fibrosed joints that absorbed the shock of a child’s prance, a young athlete’s stride and,now, an ancient shuffle.

My conceit, however, unshakable as it was, was shattered by the faded serial number tattooed on her forearm.

And my humility, once again, was restored to a respectable level.

Jordan Grumet is an internal medicine physician who blogs at In My Humble Opinion. Watch his talk at dotMED 2013, Caring 2.0: Social Media and the Rise Of The Empathic Physician. He is the author of Five Moments: Short Works of Fiction and I Am Your Doctor: and This Is My Humble Opinion.

http://www.kevinmd.com/blog/2017/04/think-patient-difficult-maybe.html

CLIMATE EMERGING DISEASES DANGEROUS CONNECTIONS FOUND

Climate change may affect human health directly or indirectly. In addition to increased threats of storms, flooding, droughts, and heat waves, other health risks are being identified. In particular, new diseases are appearing, caused by infectious agents (viruses, bacteria, parasites) heretofore unknown or that are changing, especially under the effect of changes in the climate (change of host, vector, pathogenicity, or strain). These are so-called "emerging" or "re-emerging" infectious diseases, such as leishmaniasis, West Nile fever, etc. According to the WHO, these diseases are causing one third of deaths around the world, and developing countries are on the front line.

A difficult relationship to establish

Several parameters may be behind this increased spread of pathogens and their hosts (vectors, reservoirs, etc.). Climate change modifies temperature and humidity conditions in natural environments, and therefore alters the transmission dynamics for the infectious agents. It also affects the range, abundance, behaviour, biological cycles, and life history traits of the microbes or related host species, changing balances between pathogens, vectors, and reservoirs. However, these effects remain poorly explained, in particular because they require an understanding of the long-term spatial or temporal changes to the phenomena. Therefore, it is difficult to establish a direct link between climate change and the overall evolution of infectious pathologies.

Decreased rainfall rhymes with epidemic

Providing some clarification on this question for the first time, a study by IRD researchers and their partners has shown the relationship over a 40-year period between climate change and epidemics of a disease emerging in Latin America: Buruli ulcer. Rising surface temperatures in the Pacific Ocean tend to increase the frequency of El Niño events, which especially affect Central and South America approximately every five to seven years, causing waves of droughts. The research team compared changes in rainfall in the region with changes in the number of cases of Buruli ulcer recorded in French Guyana since 1969 and observed the statistical correlations.

In fact, the decrease in rainfall and runoff led to an increase in areas of residual stagnant water, where the bacteria responsible, Mycobacterium ulcerans, proliferates. The greater access to swampy habitats that results from this facilitates frequentation by humans (fishing, hunting, etc.) and thus intensifies human exposure to the microorganism living in this type of aquatic environment. This result, published inEmerging Microbes and Infections -- Nature, was made possible through long-term time series data.

In light of the rainfall conditions in recent years, the researchers fear a potential new outbreak of Buruli ulcer in the region. Beyond an improvement in forecasting the risk of an epidemic, this study highlights the need to consider a set of parameters and their interactions. Contrary to the accepted idea, less rainfall does not mean a certain decrease in the prevalence of infectious diseases, as shown by this example. Similarly, the expected warming of the atmosphere could provide temperature conditions unsuitable to the development cycle of some pathogenic agents, such as for malaria in Africa.

HERBAL MEDICINES COULD CONTAIN DANGEROUS LEVELS OF TOXIC MOLDS

Herbal medicines such as licorice, Indian rennet and opium poppy, are at risk of contamination with toxic mold, according to a new study published in Fungal Biology. The authors of the study, from the University of Peshawar, Pakistan say it's time for regulators to control mold contamination.

An estimated 64% of people use medicinal plants to treat illnesses and relieve pain. The herbal medicine market is worth $60 billion globally, and growing fast. Despite the increasing popularity of herbal medicine, the sale of medicinal plants is mostly unregulated.

The new study analyzes toxic mold found on common medicinal plants in the Khyber Pakhtunkhwa province of Pakistan, where the majority of people use herbal medicine. They found that around 43% of the plants were naturally contaminated with toxins, produced by molds that could be harmful to human health. 30% of the samples contained aflatoxins, which are carcinogenic and linked to liver cancer, and around 26% were contaminated with ochratoxin A, which is toxic to the liver and kidneys, and can suppress the immune system..

"It's common to use medicinal plants in our country and to buy from local markets and shops," said Ms. Samina Ashiq, one of the authors of the study from the University of Peshawar. "There's a common misconception that just because they're natural, the plants are safe. We knew from experience that this wasn't the case, but we wanted to really test it and quantify the contamination."

Ms. Ashiq and the team analyzed 30 samples of plants known for their medicinal properties, including licorice, Indian rennet and opium poppy. They found that 90% of the samples were contaminated with mold, and the levels exceeded permissible limits in 70% of the samples.

They then grew the molds to find out if they produced toxins that could be harmful to human health. 19% of the molds produced aflatoxins, and 12% produced ochratoxin A. Overall, 31% of the molds growing on the plants they tested produced harmful toxins.

"These results are a clear indicator that we need more stringent regulation in place," continued Ashiq. "There is a real public health concern due to the lack of effective surveillance of the quality, safety and efficacy of these medicinal plants. It's time for regulators to step in and set limits to protect people who want to use herbal medicines like these."

The plants can become contaminated at each stage of production: during growth, handling, collection, transportation and storage. Those that are exported for sale may be contaminated before they reach their destination. In Pakistan and many other countries, these plants are primarily sold on markets where hygiene is not top priority.

"By setting limits to fungal contamination of these plants, Pakistan and other countries would be better able to export to places that do have controls in place. Hygienic processing and sale of medicinal plants is essential to protect people, and also if the economy is to benefit from the booming herbal medicine industry," added Ms. Ashiq.