A report in the Globe and Mail says the Canadian federal government is supporting the plan to bury nuclear waste. The most interesting statement comes from Gord Edwards who is the director of the Canadian Coalition for Nuclear Responsibility.

“In the face of a growing nuclear industry or even a static nuclear industry, this is not really a solution to the catastrophe problem at the surface,” Mr. Edwards said. He said any kind of major explosion – such as a terrorist attack – at a surface storage site would release radioactive clouds as deadly as those at the Chernobyl reactor that melted down in the former Soviet Union in 1986.

So how many people died due to the Chernobyl accident? Read the rest of this entry »

In my Vitamin D: Sunshine and Skin Cancer post I mentioned the Greenland Inuit and that they would have acquired all the Vitamin D they need from food. Whenever I hear about an important vitamin/nutrient/macronutrient for health, I ask myself what source contains it for each of the following three well known healthy cultures: Read the rest of this entry »

DasL wants to know how Vitamin D derived from sun exposure can prevent cancer when we have been told to cover up from the sun to prevent skin cancer. Marc answers DasL’s confusion in the comments section (see full exchange here).

So here is my interpretation. There are two types of skin cancer, melanoma and nonmelanoma. Nonmelanoma skin cancers are very common but rarely fatal. Malignant melanoma is very rare but deadly. Over-exposure (i.e. sun burns) can lead to skin cancer in general. Vitamin D protects against cancers that have a very high mortality rate, including malignant melanoma.

Vitamin D is produced in skin exposed to UV-B. The more common and abundant type of UV is UV-A which gives us a tan. UV-B levels are dependent on where the sun is in the sky. Highest levels occur at mid-day in the summer while typical Canadian UV-B levels are insufficient for 4-6 months of the year (winter).

The trick is to get UV-B exposure without getting burned. Short exposures at mid-day are ideal.

So how did the famously healthy Greenland Inuit get their Vitamin D? Food, of course. I’ll take a shot at Vitamin D in food in another post.

New research claims that Vitamin D is key to preventing cancer.

A four-year clinical trial involving 1,200 women found those taking the vitamin had about a 60-per-cent reduction in cancer incidence, compared with those who didn’t take it, a drop so large — twice the impact on cancer attributed to smoking — it almost looks like a typographical error.

We get some Vitamin D from food but we have the ability to produce large amounts in our skin when it is exposed to sunshine (UV rays).

Statistics Canada released some fantastic news about the two biggest killers of Canadians, cancer and cardiovascular disease but you have to dig through the negative spin to find it:

The age-standardized mortality rate for cardiovascular diseases declined 16% from 2000 to 2004, while cancer mortality rates declined 4% over the same period.

That is awesome.

Not only does influenza cause long term heart disease as I pointed out in my 1918 Spanish Flu & Heart Disease post, but it seems the flu can trigger heart attacks within days.

Researchers believe that flu causes an acute and severe inflammation in the body, which, in some patients, can destabilise atherosclerotic plaques [2] in coronary arteries and cause heart attacks.

Prof Madjid said: “Most people develop atherosclerotic lesions in their coronary arteries in early childhood and these lesions grow over time. Inflammation plays a pivotal role in development and growth of these lesions. Most people in Western countries live with different stages of atherosclerosis and many will never show any clinical manifestations of the atherosclerosis. However, in some patients the quiescent, stable atherosclerotic plaques undergo sudden changes, mainly due to exaggerated inflammation, leading to rupture of these vulnerable plaques and subsequent formation of clots resulting in heart attacks.

“This study shows that flu is an important trigger of heart attacks because flu is a severe infection, with high incidence rates and is readily preventable. Therefore, our results give us a new tool for preventing heart attacks.

Tyler Cowen at Marginal Revolution posts about how well various U.S. cities fought Spanish flu in 1918. The New York Times has a longer story about the new research.

I hope someone takes this data and tries to correlate it to the promising hypothesis that the surge in cardiovascular disease that peaked in the 60’s was caused by lingering Spanish flu affects.

It is proposed that an early 20th-century expansion of a coronary heart disease–prone subpopulation, characterized by high serum-cholesterol phenotype and high case-fatality—which contributed to most of the coronary heart disease cases and deaths during the 1960s—may have been a late result of the 1918 influenza pandemic.

News reports about scientific research rarely distinguish between cause and correlation. Actually many of the studies do no better themselves. I was reminded of this when I heard about the Duke University research that shows that smokers that drink coffee are less likely to get Parkinson’s disease.

In families affected by Parkinson’s disease, the people who smoked cigarettes and drank a lot of coffee were less likely to develop the disease, say researchers at Duke University Medical Center.

They go on to say that:

The biological mechanisms through which smoking and caffeine might work in individuals at risk of Parkinson’s disease are still not clear, said study co-investigator Mark A. Stacy, M.D., associate professor of medicine and director of the Duke Movement Disorders Center.

I’m betting on pure correlation, that is, people with a predisposition to develop Parkinson’s disease are less likely to take up smoking or coffee consumption. I doubt smoking and/or coffee actually protects but, once again, time will tell. There is probably a bias named after this… Causation Bias or maybe Correlation Blindness Bias. Maybe I-Gotta-Make-This-Headline-Interesting Bias.

Israel is considering an organ donation credit for those that sign their donation cards.

The move that I have initiated calls for giving the signatory of a donor card credits concerning his placement on the waiting list of candidates for transplants, if one day he is in need of such an operation. In order to discuss the implications of such a step, which for the first time introduces a non-medical criterion to the list of medical criteria that determine a patient’s place on the list, the National Transplant Center set up a special forum in which several of the best minds in the field of ethics and law in Israel participated. After a penetrating discussion, the following proposal was accepted by a majority: Every list of candidates for an organ transplant will be headed by those candidates who signed a donor card at least a year before being listed (the exact order will be determined according to the currently accepted medical criteria). Candidates who did not sign a donor card in time will be placed further down the list, according to medical criteria. 

According to the article, Israel lags other western countries in organ donation agreements (45% vs. 95%) and organ donation card signatories (8% vs. 30-40%). I wonder what accounts for the difference.

Quirks and Quarks segment Bugs and the Bulge discusses the possibility that gut bacteria (Bacteroidetes) and viruses (AD-36) contribute to obesity. The New York Times has a long (10 page) article named Fat Factors that discusses the same topic. Click on the player to listen to Bugs and the Bulge [22 min].

A statistical correlation between vasectomy surgery and PPA (Primary Progressive Aphasia), a form of dementia, has been discovered by researcher Sandra Weintrau.

Weintraub theorizes a vasectomy may raise the risk of PPA (and possibly FTD) because the surgery breeches the protective barrier between the blood and the testes, called the blood-testis barrier.

Certain organs — including the testes and the brain — exist in what is the equivalent of a gated community in the body. Tiny tubes within the testes (in which sperm are produced) are protected by a physical barrier of Sertoli cells. The tight connections between these cells prevent blood-borne infections and poisonous molecules from entering the semen.

After a vasectomy, however, the protective barrier is broken and semen mixes into the blood. The immune system recognizes the sperm as invading foreign agents and produces anti-sperm antibodies in 60 to 70 percent of men.

Weintraub said these antibodies might cross the blood-brain-barrier and cause damage resulting in dementia. “There are other neurological models of disease which you can use as a parallel,” Weintraub said. Certain malignant tumors produce antibodies that reach the brain and cause an illness similar to encephalitis, she noted.

I didn’t know there was a blood-testis barrier that is similar to the blood-brain barrier. Fascinating.

Birds on My Mind

February 6, 2007

mask_blog.jpgA cull of 159,000 turkeys is now complete in the UK after an outbreak of bird flu was found. Bird flu is certainly weighing on the minds of many people. At the moment, bird flu is not easily transmitted between humans. The fear, however, is that a mutant strain will emerge that is highly contagious and deadly to humans.

This has not happened, thankfully, and I wonder if we are not too focused on bird flu which currently carries low risk compared to other diseases. Before I travelled to Asia in December of 2005 I was shocked to learn that there was an outbreak of Dengue Fever in the region. Singapore had 14,000 cases and 19 deaths. Singapore!!! Sheesh.

Some say that the overdue bird flu pandemic is alarmist. Well if I was a bird I’d certainly be worried and I’m certainly glad public health officials are keeping an eye out for signs of mutation. I hope the health officials do not drop the ball on diseases like TB and Malaria while they focus on bird flu.