SECOND OPINION | What's with all the studies on coffee, and why can't we get a straight answer?

Here's this week's round-up of eclectic and under-the-radar health and medical science news. If you haven't subscribed yet, you can do that byclicking here.

Coffee lovers rejoiced this week as media outlets around the world pounced on a news release headline from the BMJ (British Medical Journal) that declared, "Moderate coffee drinking 'more likely to benefit health than to harm it,' say experts."

It's just the latest in a parade of often-contradictory studies over many years about the health effects of that cup of java some claiming coffee is good for you, some claiming it can be harmful. In this case, the study went so far as to suggest that drinking three cups a day was associated with lower risks of heart disease, diabetes and some types of cancers.

It is useless. Prof. Ahmed El-Sohemy, University of Toronto, about the health benefits of coffee

But the researchers themselves acknowledged that the data was mostly observational, and essentially concluded that it was likely safe except for pregnant women and people at risk of fractures to proceed to clinical trials to get more definitive answers.

So what does this widely covered study really add to our understanding about coffee and its health effects?

Nothing, according to two nutritional scientists at the University of Toronto.

"It is useless," Ahmed El-Sohemy, who specializes in research about genetics and metabolism, and has conducted several studies on coffee, said bluntly.

That's because these types of studies rely on analyzing data taken from large populations of people and looking for correlations such as whether or not people who reported drinking coffee also developed heart disease or diabetes or liver disease or whatever it is the researchers are looking for.

But, as anyone who has taken a basic statistics course knows, "correlation is not causation," said Richard Bazinet, an associate professor in U of T's department of nutritional science.

"We look at these population-type studies where we say, 'Ah! People who drink two coffees a day, what's their health like?'" Bazinet said. "These correlations show up, and then when you change the population a bit, they disappear, probably because often they're not real effects."

Although researchers try to account for other lifestyle variables that could explain why someone does or doesn't develop a particular disease including diet, smoking, exercise or other risk factors there's only so much they can do with the data they have.

Also, coffee contains different components. Caffeine, for instance, like any other drug, can have different effects positive, negative, or neutral on different people, El-Sohemy said. The antioxidants contained in coffee, meanwhile, are widely considered to be beneficial for people's health.

If it's so hard to get a definitive answer on coffee's health benefits or harms why are there so many studies about it?

One reason is that coffee is such an ingrained part of our culture and so widely consumed, people have an insatiable desire to know its health effects, said Bazinet. It's a similar story with topics like red wine and chocolate.

That public appetite, in turn, could drive medical journals to accept more studies on the subject.

Or perhaps there aren't actually more studies on coffee than other nutrition topics, but media outlets gravitate to them because they know it's what their audiences want to read about.

In the end, El-Sohemy said, the focus needs to shift away from these large population-based studies and attempts to come up with a one-size-fits-all recommendation toward an approach that acknowledges coffee's health effects can vary by individual.

Stem cells for hair growth?

Last week we reported that stem cell clinics are popping up across Canada offering injections of a patient's own bone marrow or fat tissue to treat arthritic joints and other sports injuries, even though the procedures have not been approved by Health Canada.

But what about stem cells for hair growth?

We received an email from a reader in Halifax who wanted to know if the stem cell therapy he had purchased from a clinic there had been approved by Health Canada.

The reader sent us photos of the bottle with liquid that he is supposed to apply to his scalp, along with the clinic's literature, which states: "Treatment works by unclogging the pores of the hair follicle, and introducing stem cells to restart new hair cell growth."

We asked the clinic, Hair Renewal Specialists, for information about the specific ingredient in their CELLTEC formula, which they describe as an active botanical stem cell ingredient that "enhances the production of human hair stem cells to promote cell renewal."

So far, we have not received a response. We couldn't find the product listed on Health Canada's database oflicensed natural health products.

The reader also sent us his bill, which totalled $516 dollars for the stem cell formula and related conditioners and supplements. He says he's tried it for four weeks with no results, but he was told it can take up to eight weeks.

"Botanical stem cells? Let's see the evidence," said Timothy Caulfield, Canada research chair in health law and policy at the University of Alberta. "This is classic 'scienceploitation' leveraging the pop culture excitement surrounding a legitimate area of science (stem cells) to sell an unproven product."

Even though he's optimistic about the potential of stem cells to one day help treat human disease, Caulfield advises consumers to "doubt everything" until the science around stem cells is more advanced.

Advertising rules don't apply

It's common in the United States to see drug advertisements all over the place. But not in Canada. That's because there are rules that limit drug advertisements aimed directly at consumers.

So what's with all of those red-and-white ads for a new shingles vaccine?

The walls of one downtown Toronto subway station are covered with signs, and there are more bright red billboards greeting arrivals at the Toronto island airport. The ads are also showing up on billboards, bus shelters, train stations and airports in other cities in Ontario, B.C. and Quebec.

The reason the company GSKis allowed to advertise directly to consumers is simple: vaccines are not considered prescription drugs, according to Health Canada.

Greater availability of vaccines is better for public health, especially during an emergency when getting prescriptions for vaccines would be impractical, Health Canada told CBC News in an email.

"Vaccine advertising is allowed as long as it is not false, deceptive or misleading."

But it's a different story for prescription drugs. Health Canada confirmed that ads for prescription drugs are still restricted.

"Consumers should have access to a health care professional to help inform decisions about their treatment, rather than being influenced by advertising," Health Canada said.

Shingles is a painful rash caused by exposure to the same virus that causes chickenpox, (varicella-zoster virus). The virus lies dormant in the body and can flare up in people with compromised immune systems or after periods of extreme stress.

There is one vaccine already on the market, which costs about $180 dollars and is covered by Ontario's public health program for people ages 65-70. GSK says it has not announced the price of the new vaccine but says the price will be up to 30 per cent higher.

Health Canada assisting private plasma clinic

A coalition of health advocates held a news conference on Parliament Hill on Monday to warn about potential risks to Canada's voluntary blood and plasma donation system. But nobody came.

"Reporters didn't even know we were there," said Kat Lanteigne of BloodWatch, a group advocating for a voluntary blood donor system in Canada.

Standing at a microphone in the foyer of the House of Commons, they released almost 900 internal government documents that they had obtained under Canada's freedom of information laws.

Lanteigne said the documents reveal Health Canada officials quietly working to change a long-standing policy against paying donors for donating blood products.

The group went public with documents on the 20th anniversary of the Krever Commission that investigated Canada's tainted blood scandal. In the 1980s hundreds of Canadians were infected with HIV and Hepatitis C through blood transfusions.

One of the key Krever recommendations was to "ensure that blood products used in Canada are made from the blood and plasma collected from unpaid donors." The World Health Organization also recommends that donorsnot be paid.

• CBCdigital archives: TheKrevercommission

The internal government emails and minutes of meetings show that as early as 2010, Health Canada bureaucrats began assisting in the launch of a new business to harvest plasma from Canadians who would be paid. The public learned of the plans when CBC News first reported it three years later just as the first two clinics were preparing to open for business.

Health Canada officials knew they were helping to open the Canadian plasma sector to a large multinational company, Biotech AG, which was acting as a partner to the smaller company, Canadian Plasma Resources.

"They were actually trying to create a secondary plasma collector in this country and create an American-style model," Lanteigne said. "That's what was so shocking."

• Paid plasma in Canada: 10 things to know about the business of blood

"They should have said, 'no thank you we have a public blood system here, we're not going to support a secondary operator.'"

When the Ontario government learned that three paid plasma clinics were poised to open in Toronto and Hamilton, the province passed a law banning the clinics.

But internal Health Canada emails reveal bureaucrats continued to work with the plasma company even while the Ontario debate unfolded.

• Canadian Blood Services says paid plasma clinics are harming voluntary donations

At one point Jim Pimblett, the lobbyist for the plasma company, emailed a Health Canada bureaucrat, reporting that media reports were favourable to the company. In another document, Health Canada and the private plasma company agreed on the need to co-ordinate their responses to media questions.

A previous access to informationrequest by BloodWatch turned up documents showing that Canada's national blood agency warned Health Canada that the private clinics might draw donors away from the voluntary system. The agency says it has noticed a drop in voluntary blood donations in Saskatoon where people can be paid for their plasma.

They should have said, no thank you we have a public blood system here.KatLanteigne, executive director of BloodWatch

"I have no comment on the correspondence released under the access to information request," said Canadian Plasma Resources CEO Barzin Bahardoust. He told CBC News in an email that he still plans to open ten paid plasma centres across Canada along with a plasma processing facility. Right now there are two clinics in Saskatoon and Monctonwhere donors are paid up to $50 per donation.

Health Canada said it has appointed a panel of experts to study the sustainability of Canada's plasma supply. Most of the plasma used in Canada is used in a manufactured pharmaceutical products including albumin, clotting factors, and immune globulins (IGIV).

As they read through the documents, the BloodWatch group was surprised at the access the private clinic had to Health Canada officials.

"We have asked for years for meetings with Health Canada and meetings with the health minister and we have been denied every single time," Lanteigne said.

Meanwhile, the news conference that no one attended is available on CPAC, Canada's parliamentary television channel.

Hey, that's the same guy!

How did this pointing man end up on two different websites for completely different services?

We visited the website for private plasma clinics and saw hisface with a quote: "I gave to save lives." But later that day we saw him again, this time at a hair restoration clinic in Halifax.

Our tech-savvy colleague Matthew Braga quickly traced the image to iStock, a stock photo site.

It's not surprising that the smiling faces on websites are not actual clients, although there is no disclosure of that fact on either site.

But how to explain the quote that appears to be attributed to the pointing man? We asked Canadian Plasma Resources if he was an actual donor and had said the words "I gave to save lives."

The company's CEO, Barzin Bahardoust,said in an email that the image was a stock photo for illustration and added that there were other testimonials from real donors on the website.

And he also produced examples where CBC News has used stock photo images on our website. That's true. CBC News and other media organizations do use images to illustrate stories, while crediting the source.

The whole issue raises an interesting question about the proliferation of stock images on news sites and commercial websites all over the internet. Some reporters have tracked down the story behind some of the most popular images.

As for the pointing man, over on the Canadian Plasma Resources site, the quotation marks are now gone. The folks at the hair restoration clinic did not respond to CBC's inquiries.

Thanks for reading! You can email us any time with your thoughts or ideas. And if you like what you read, consider forwarding this to a friend.