Several studies find further evidence of detrimental effects caused by marijuana smoking

Since this wave of legalization of use of recreational marijuana is spreading gradually but surely to more and more states in the United States, more and more studies funded by medical institutions and organizations are reporting on the very real dangers of frequent marijuana use. I am going to highlight only a few of the studies published on the subject in various medical journals in the past few years.

Journal of Neuroscience (April 16, 2014)

This study conducted by researchers from Harvard University and Chicago's Northwestern Medicine group, using a small sample of 40 individuals between the ages of 18-25 has shown that smoking cannabis ( also known as marijuana) once or twice a week can lead to major changes in brain areas associated with emotions and motivation.

In an article on this study, "Smoking cannabis could change the part of the brain dealing with motivation, according to one new study" published in The Independent ( April 16th 2014), health reporter Charlie Cooper writes;

The researchers used neuroimaging techniques to analyze the brains of cannabis users and non-users.

They found that the nucleus accumbens was unusually large in the cannabis users, while the amygdala also had noticeable abnormalities.
Anne Blood, assistant professor of psychiatry at Harvard Medical School said that the areas affected were "core, fundamental structures of the brain".
"They form the basis for how you assess positive and negative features about things in the environment and make decisions," she said.
The severity of abnormalities in these regions of the brain was directly related to the number of joints a person smoked per week, according to the study, published in the Journal of Neuroscience on Wednesday. The more joints a person smoked, the more abnormal the shape, volume and density of the brain regions, but the effect was noticeable even in those who smoked once or twice a week.
However, experts in the UK said that the study group was small and that more research was needed over a longer timescale to establish whether cannabis smoking caused the unusual brain features, or whether people with such brain features were more likely to smoke cannabis in the first place.
Around one million people aged between 16 and 24 use cannabis in the UK per year, according to the charity DrugScope. Its use has been reported to cause anxiety and paranoia in some users and in rarer cases may be a trigger for underlying mental health problems.
Dr Michael Bloomfield, clinical research fellow at the UK's Medical Research Council (MRC), said that the study added to the MRC's own research which found that heavy cannabis use in adolescence is associated with changes in chemical connections in the brain.

Schizophrenia Bulletin ( December 16, 2013)

Yet another study conducted by Northwestern Medicine and mainly funded by The National Institute of Mental Health and National Institute of Drug Abuse, has shown that heavy use of marijuana (daily for 3 years) in teen years can lead to abnormal changes in the brain structure related to memory. The teens in the study performed poorly on memory tasks.
According to lead study author Matthew Smith, an assistant research professor in psychiatry and behavioral sciences at Northwestern University Feinberg School of Medicine, " The study links the chronic use of marijuana to these concerning brain abnormalities that appear to last for at least a few years after people stop using it, with the movement to decriminalize marijuana, we need more research to understand its effect on the brain."
Chronic use of marijuana may contribute to changes in brain structure that are associated with having schizophrenia, the Northwestern research shows. Of the 15 marijuana smokers who had schizophrenia in the study, 90 percent started heavily using the drug before they developed the mental disorder. Marijuana abuse has been linked to developing schizophrenia in prior research.

As reported in 'Heavy marijuana users have abnormal brain structure and poor memory'

by Eureka Alert online science news service;

"The abuse of popular street drugs, such as marijuana, may have dangerous implications for young people who are developing or have developed mental disorders," said co-senior study author John Csernansky, M.D., chair of psychiatry and behavioral sciences at Northwestern University Feinberg School of Medicine and Northwestern Memorial Hospital. "This paper is among the first to reveal that the use of marijuana may contribute to the changes in brain structure that have been associated with having schizophrenia."
Chronic marijuana use could augment the underlying disease process associated with schizophrenia, Smith noted. "If someone has a family history of schizophrenia, they are increasing their risk of developing schizophrenia if they abuse marijuana," he said.
While chronic marijuana smokers and chronic marijuana smokers with schizophrenia both had brain changes related to the drug, subjects with the mental disorder had greater deterioration in the thalamus. That structure is the communication hub of the brain and is critical for learning, memory and communications between brain regions. The brain regions examined in this study also affect motivation, which is already notably impaired in people with schizophrenia.
"A tremendous amount of addiction research has focused on brain regions traditionally connected with reward/aversion function, and thus motivation," noted co-senior study author Hans Breiter, M.D., professor of psychiatry and behavioral sciences and director of the Warren Wright Adolescent Center at Feinberg and Northwestern Memorial. "This study very nicely extends the set of regions of concern to include those involved with working memory and higher level cognitive functions necessary for how well you organize your life and can work in society."


Journal of Chemical Research in Toxicology (May 18, 2009)

The study Dr. Michael Bloomfield mentions was conducted by  Leicester University’s Rajinder Singh, Jatinderpal Sandhu, Balvinder Kaur, Tina Juren, William P. Steward, Dan Segerback and Peter B. Farmer from the Cancer Biomarkers and Prevention Group, Department of Cancer Studies and Molecular Medicine and Karolinska Institute, Sweden. This research was funded by MRC, European Union Network of Excellence (ECNIS) and Cancer Research UK. The findings were published in the Journal of Chemical Research in Toxicology.
In this case researchers found "convincing evidence" that cannabis smoke damages DNA in ways that could potentially increase the risk of cancer development in humans.  

Lead author Dr Singh said:
“There have been many studies on the toxicity of tobacco smoke. It is known that tobacco smoke contains 4000 chemicals of which 60 are classed as carcinogens. Cannabis in contrast has not been so well studied. It is less combustible than tobacco and is often mixed with tobacco in use. Cannabis smoke contains 400 compounds including 60 cannabinoids. However, because of its lower combustibility it contains 50% more carcinogenic polycyclic aromatic hydrocarbons including naphthalene, benzanthracene, and benzopyrene, than tobacco smoke.” 
The authors added: “It is well known that toxic substances in tobacco smoke can damage DNA and increase the risk of lung and other cancers. Scientists were unsure though whether cannabis smoke would have the same effect. Our research has focused on the toxicity of acetaldehyde, which is present in both tobacco and cannabis.”
The researchers add that the ability of cannabis smoke to damage DNA has significant human health implications especially as users tend to inhale more deeply than cigarette smokers, which increases respiratory burden.
"These results provide evidence for the DNA damaging potential of cannabis smoke," the researchers conclude, "implying that the consumption of cannabis cigarettes may be detrimental to human health with the possibility to initiate cancer development."

Although in each case marijuana use supporters will argue the sample sizes are too small or the study was biased, the results of each of these researches were very real. If anything further promotion of the idea that recreational use of marijuana is completely harmless should be discouraged more aggressively.


References:

Cannabis Use is Quantitatively Associated with Nucleus Accumbens and Amygdala Abnormalities in Young Adult

Recreational Users (The Journal of Neuroscience-April 16, 2014)

Smoking cannabis could change the part of the brain dealing with motivation, according to one new study(The Independent April 16, 2014)
Cannabis use increases cancer risk study suggests (MRC News & Publications)
Marijuana May Hurt The Developing Teen Brain(Health News NPR-March 3, 2014)
Heavy Marijuana Use Alters Teenage Brain Structure(Psychology Today-March 30, 2014)

Heavy marijuana users have abnormal brain structure and poor memory (Northwestern University on Eureka Alert-December 16, 2013)

Cannabis-Related Working Memory Deficits and Associated Subcortical Morphological Differences in Healthy Individuals and Schizophrenia Subjects (Schizophrenia Bulletin- Published 12/15/13) 

Evaluation of the DNA Damaging Potential of Cannabis Cigarette Smoke by the Determination of Acetaldehyde Derived N²-Ethyl-2′-deoxyguanosine Adducts(Chemical Research in Toxicology-May 18, 2009)

 

How much benefit do we really get from Organic food?

Most people myself included tend to think of organic foods as healthier and safer. But that may not always be the case, points out Tamar Haspel in her recent article in The Washington Post's Health and food section. To make it simple she simply gives the evidence on the nutrition and contamination of both organic and conventional foods such as milk, meat, eggs, produce and fish. Here is a short excerpt of the article;

Is organic better for your health? A look at milk, meat, eggs, produce and fish.

Organic or conventional? It’s a choice many grocery shoppers are faced with, over and over. The price difference is easy to see; it’s right there on the product. The quality difference is much harder. Is the organic milk better for your kids? Is the conventional lettuce more likely to carry pathogens?

Leave aside for the moment whether organic agriculture is better for the planet and whether organic livestock have better lives, although there’s a strong case for both of those arguments. Leave aside flavor, too, because it’s subjective and variable. What motivates many organic buyers, particularly the parents of small children, is health benefits, and there are two questions: Do organics do us more good (in the form of better nutrition), and do they do us less harm (in the form of fewer contaminants and pathogens)? 

Milk 
 
Nutrition: Compared with conventional milk, organic milk has higher levels of omega-3 fats, which protect against heart disease and may decrease the risk of depression, stroke, cancer and other diseases, but the quantities are too small to be very meaningful. (It takes 11 quarts of organic milk to equal the omega-3s in four ounces of salmon.) Milk’s omega-3 content is a function of the cow’s diet, and higher levels reflect more grass. (A few other nutritional differences between organic and conventional milk have been studied, but there isn’t enough research to draw conclusions.)
Contamination: Neither organic nor conventional milk contains antibiotics. By law, every truckload of milk, organic and conventional, is tested for veterinary drugs, including antibiotics, by trained dairy workers. Any load that tests positive is pulled out of the food supply.
Hormones: The issue with milk is that many conventionally raised dairy cows, unlike organic ones, are injected with bovine growth hormone (BGH, the synthetic version of which is called either recombinant bovine growth hormone, rBGH, or recombinant bovine somatotropin, rBST) to increase their milk production.Both organic and conventional cows have IGF-I in their milk, but cows that get hormone treatment may have more of it.
The use of rBGH has fueled concerns among some parents about giving milk to children, but the FDA report concluded that “consumption by infants and children of milk and edible products from rBGH-treated cows is safe.”
Bottom line: Organic milk has higher omega-3 fat levels, but probably not enough to make a difference. Exposure to pesticides, contaminants or hormones is not a significant risk in either organic or conventional milk.
 
Produce

Nutrition: Many studies have compared the vitamins, minerals, macronutrients and other compounds in organic and conventional produce, and a 2012 review concluded that the results were all over the map. The one exception was that the phosphorus content of organic produce is higher, although the review, done by Stanford University scientists, calls that finding “not clinically significant.”
Contamination: There are two issues for foods that grow in the ground: pesticides and pathogens. There is widespread agreement that organic produce, while not pesticide-free, has lower residue levels and fewer pesticides.
Carl Winter, a toxicologist at the University of California at Davis, says that the Environmental Protection Agency, working from animal research and factoring in the special sensitivities of human subgroups such as babies and children, has found that lifetime risk of adverse health effects due to low-level exposure to pesticide residue through consumption of produce is “far below even minimal health concerns, even over a lifetime.” 
As for pathogens, the 2012 Stanford review found that E. coli contamination is slightly more likely in organic than conventional produce.
The best strategy to reduce risk from produce isn’t to buy either organic or conventional. Rather, it’s to cook your food.
Bottom line: While there may be no significant nutritional difference between organic and conventional produce, organic does have lower levels of pesticide residue. However, there isn’t universal agreement on the risk those residues pose.
 
Meat
 
Nutrition: As with milk, the main issue here is omega-3 fats. Some organic meat and poultry have more of them than conventional products do. The reason is diet: Animals that eat more grass have lower fat levels overall and higher omega-3 levels than animals fed more grain.
Although measurements of omega-3 fats in beef vary, the numbers are low and substantially below what can be found in a serving of salmon.
Contaminants: The USDA randomly tests carcasses for residues of pesticides, contaminants and veterinary drugs including antibiotics. In 2011, it screened for 128 chemicals, and 99 percent of the tested carcasses were free of all of them.
It found a few with residue violations and a similar small number with residue within legal limits (mostly of arsenic and antibiotics). Although the USDA doesn’t report organic and conventional separately, contaminant risk overall is extremely low.
The bigger concern is pathogens. Studies of bacterial contamination levels of organic and conventional meat show widely varying results. These findings suggest that organic meat may be slightly more likely to be contaminated, possibly because no antibiotics are used. But conventional meat is more likely to be contaminated with antibiotic-resistant bacteria. But the risk in meat overall was essentially the same. And whether meat is conventional or organic, the solution is adequate cooking.
Bottom line: Grass-fed beef has a slight edge over grain-fed because of higher omega-3 levels, but the amounts are probably too small to affect human health.

Eggs
 
Nutrition: As with milk and meat, the omega-3 levels of eggs are affected by the hens’ diet and can be increased by pasturing or diet supplementation for either organic or conventional hens. Eggs high in omega-3s are generally labeled.
Contaminants: There’s very little research on contaminants in eggs. The 2012 Stanford review concluded that there is “no difference” in contamination risk between conventional and organic eggs.
Bottom line: There are no significant differences affecting health between organic and conventional eggs.  

Fish
 
The USDA has not issued any organic standards for farmed fish or shellfish, but several overseas organizations have. (Because there’s no way to control the diet of wild fish, “organic” doesn’t apply.) Canadian standards prohibit antibiotics and hormones, restrict pesticides and set criteria for acceptable feed. There’s not enough research comparing organic and conventional fish to draw any conclusions about their health benefits.


Reference:
Is organic better for your health? A look at milk, meat, eggs, produce and fish.


(The Washington Post- Health, Science and Environment 07/04/14)

Fats are not the enemy

Allison Aubrey presented a case for adding some fat to our diets on  NPR's Morning Edition as few weeks back.

Fats have been the target of most of the popular dietary plans. They are looked upon as the enemy to any healthy lifestyle. But is that justifiable and right?

It is well documented that saturated fats can raise the LDL ( Low-density lipoprotein)in the blood, which is the so-called bad cholesterol. Whereas on the other end, plant-based fats such as those found in nuts and olive oil are actually beneficial to our heart health and can help reduce the risk of heart disease. Yet it seems the risks might be more then the benefits, leading most of us to minimize fats intake whenever trying to eat healthy.

Thus the task of  convincing most of us to bring some ats back into our diets is a tough one.
Here is an excerpts of what experts had to say to Allison Aubrey on the subject;

"Fat was really the villain," says , who is chairman of the department of nutrition at the Harvard School of Public Health. And, by default, people "had to load up on carbohydrates."
But, by the mid-1990s, Willett says, there were already signs that the high-carb, low-fat approach might not lead to fewer heart attacks and strokes. He had a long-term study underway that was aimed at evaluating the effects of diet and lifestyle on health.
"We were finding that if people seemed to replace saturated fat — the kind of fat found in cheese, eggs, meat, butter — with carbohydrate, there was no reduction in heart disease," Willett says.
Willett submitted his data to a top medical journal, but he says the editors would not publish his findings. His paper was turned down.
"There was a lot of resistance to anything that would question the low-fat guidelines," Willett says, especially the guidelines on saturated fat.
Willett's was eventually published by a British medical journal, the BMJ, in 1996.

But here's where it gets interesting: "We've learned that carbohydrates aren't neutral," explains , an epidemiologist at Harvard Medical School.
"[Carbs] were the base of the pyramid," says Mozaffarian. The message was "eat all carbohydrates you want."
Americans took this as a green light to eat more refined grains such as breads, processed snack foods and white pasta.
"But carbohydrates worsen glucose and insulin — they have negative effects on blood cholesterol levels," he says. The thinking that it's OK to swap saturated fats for these refined carbs "has not been useful advice."
He says it's clear that saturated fats can raise LDL cholesterol, the bad cholesterol. But that's only one risk factor for heart disease.
There's now evidence that — compared with carbs — saturated fat can raise HDL cholesterol (the good cholesterol) and lower trigylcerides in the blood, which are both countering effects to heart disease, he says.
"When you put all of this together," says Mozaffarian, what you see is that saturated fat has a relatively neutral effect compared with carbs. He says it's "not a beneficial effect but not a harmful effect. And I think that's what the recent studies show." He points to a of studies published in 2010.
He also points to a highly publicized that concludes there's no convincing evidence to support the dietary recommendations to limit saturated fat.
The in that paper have created quite a bit of controversy. For instance, the American Heart Association it stands by its recommendations to limit saturated fat.


Although these new points of view don't say 'Go ahead and load up on fats' they do make it clear that fats should not be excluded from our diets completely. Maybe moderation is a good way to go with all diets. 

 
References:
Rethinking Fat: The Case For Adding Some Into Your Diet (NPR)

 

No such thing as right-brained or left-brained

Remember all those quizzes meant to figure out whether you are left-brained or right-brained? Well, researchers have just declared them all useless since there is no such thing as left-brained or right-brained.
Although distinct skills have been attributed to whichever hemisphere is dominant for ages and seemed to make sense but sadly they have no scientific basis according to a two year research completed by neuroscientists at University of Utah. The study published in the Plos One Journal is based on a two years long study involving scanning the brains of more then a 1000 individuals between the ages of 7-29 while performing such simple tasks such as lying quietly or reading. These scans were used to measure these individuals' brain functional lateralization meaning the specific mental functions occurring on each side of the brain. For accuracy functional lateralization was measured for each pair of 7266 regions of the grey matter.
Analysis of the data collected as a result lead to the conclusion
" An individual brain is not “left-brained” or “right-brained” as a global property, but that asymmetric lateralization is a property of individual nodes or local subnetworks, and that different aspects of the left-dominant network and right-dominant network may show relatively greater or lesser lateralization within an individual. If a connection involving one of the left hubs is strongly left-lateralized in an individual, then other connections in the left-dominant network also involving this hub may also be more strongly left lateralized, but this did not translate to a significantly generalized lateralization of the left-dominant network or right-dominant network. Similarly, if a left-dominant network connection was strongly left lateralized, this had no significant effect on the degree of lateralization within connections in the right-dominant network, except for those connections where a left-lateralized connection included a hub that was overlapping or close to a homotopic right-lateralized hub."

(Read Complete Article)








References:

An Evaluation of the Left-Brain vs. Right-Brain Hypothesis with Resting State Functional Connectivity Magnetic Resonance Imaging(PLOS ONE Journal-August 2013)

Despite what you've been told, you aren't 'left-brained' or 'right-brained' (The Guardian- Nov 2013) 

Lost sleep = Lost Brain Cells

Yes, you read right.
Insufficient sleep is not only detrimental for our physical health but a recent study says it also leads to brain cell death.

The study conducted at University of Pennsylvania School of Medicine was published in the latest issue of The Journal of Neuroscience. While studying lack of sleep in mice, the researchers noticed prolonged lack of sleep lead to 25% of certain brain cells dying. After further observation and research the team concluded that similar damage is most likely occurs in human too.

As explained in the abstract of the article, "Modern society enables a shortening of sleep times, yet long-term consequences of extended wakefulness on the brain are largely unknown. Essential for optimal alertness, locus ceruleus neurons (LCns) are metabolically active neurons that fire at increased rates across sustained wakefulness. We hypothesized that wakefulness is a metabolic stressor to LCns and that, with extended wakefulness, adaptive mitochondrial metabolic responses fail and injury ensues."

With prolonged sleep deprivation the processes that maintain a health metabolic homeostasis in the brain can not be sustained, hence may lead to significant irreversible injury.  Although much more research and work needs to be done to determine whether loss of sleep can lead to real brain damage.

In the end, for all of us who survive on minimal sleep, it is clearly time to make an extra effort to ensure we get a good prolonged sleep every night.



References:

Extended Wakefulness: Compromised Metabolics in and Degeneration of Locus Ceruleus Neurons (The Journal of Neuroscience -March 19th 2014) 

Lost sleep leads to loss of brain cells, study suggests (BBC World News- Health March 19th 2014)

Reduce all animal proteins in our diet to live longer

It has been well documented that consumption of too much red meat as an adult can lead increased risk for type 2 diabetes, coronary heart disease, stroke and certain cancers.

Now researchers in the US and Italy have gathered enough data, over a period of two decades, to conclude that individuals who have diets high in animal proteins during their middle age are four times more likely to die of cancer then their counterparts who had diets low in animal proteins. A risk some have compared with smoking. An increased risk of developing Diabetes Type 2 was also observed.

Valter Longo, a University of Southern California gerontology professor and director of the school’s Longevity Institute, who co-authored the study pointed out "The great majority of Americans could reduce their protein intake," and added "The best change would be to lower the daily intake of all proteins, but especially animal-derived proteins."

The interesting finding though was the fact that if you started eating more animal proteins after the age of 66 years, it is actually good for your health.


Here are two articles on the subject:

Too much animal-based proteins could lead to early death, study says ( Brady Dennis for The Washington Post)

It's time to kick the high-protein diet habit – before it kills you (Holly Baxter for The Guardian)


Reference:

Low Protein Intake Is Associated with a Major Reduction in IGF-1, Cancer, and Overall Mortality in the 65 and Younger but Not Older Population

Anger really harmful to cardiovascular health

We all lose our temper from time to time, and it never feels good. An angry outburst is almost always leaves on exhausted, unhappy and feeling drained. We've all been told a bad temper and anger are bad for us at some point in our life.
Now a research study conducted at the Harvard School of Public Health, has found that the risk of a heart attack or stroke is much higher for about two hours immediately following an angry outburst. The risk for a heart attack is increased almost five-folds, whereas the risk is increased two-folds for stroke. This finding is more consistent in individuals with preexisting risk factors.
According to the researchers, 'At a population level, the risk with a single outburst of anger is relatively low - one extra heart attack per 10,000 people per year could be expected among people with low cardiovascular risk who were angry only once a month, increasing to an extra four per 10,000 people with a high cardiovascular risk. But the risk is cumulative, meaning temper-prone individuals will be at higher risk still.'

It is not exactly clear how anger causes the increased risk, but a constant rise in stress level might be significant. Chronic stress is known to lead to high blood pressure which itself is a risk factor for heart diseases. Use of alcohol consumption or smoking for relieving the stress might further exacerbate that risk. Yet, further research is required to fully understand how anger could lead to an increased risk of cardiovascular events and what steps might successfully abate that risk.

This study involved the data analysis of nine studies in which anger and cardiovascular events were self-reported over a period of two decades. It was published in the European Heart Journal on March 3rd, 2014.


P.S: 
References:

Angry people 'risking heart attacks' (BBC World- Health 03/03/14)

Angry outbursts may raise heart attack, stroke risk (CNN Health 03/03/14)