OTTAWA - Health Canada is warning Canadians and their health-care providers that thermography machines are not approved for use in Canada for breast cancer screening.

The department says it is not aware of any scientific evidence that supports use of the thermal imaging machines as a screening tool for early detection of breast cancer.

Health Canada says there could actually be a potential risk to women if they rely on thermography results.

It's suggested that women who have used thermal imaging for breast screening contact their doctors for appropriate followup and testing.

Health Canada says it is contacting manufacturers of the devices to ensure they know that it is illegal to advertise or sell these types of machines to screen for breast cancer in Canada.

The department is also working with the Canada Border Services Agency to stop any unlicensed devices from entering Canada.

Health Canada says it will be notifying provincial and territorial ministries of health that clinics that fall under their jurisdiction should not be promoting or using thermal imaging machines for breast cancer screening.

Manitoba Health Minister Theresa Oswald has already ordered a thermography clinic in Winnipeg to stop operating.

The Canadian Breast Cancer Foundation is also joining the information effort, telling Canadians that thermography is not recommended by any medical authority or leading cancer organization.

Thermography uses a heat-sensitive infrared camera to take images of the body and detect blood flow pattern. Some breast thermography clinics, which charge consumers for the service, claim the images the machines generate can be used to detect breast cancer.

Here are 6 of the most commonly asked questions and facts about breast cancer:

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• Soy: Good Or Bad?

  One of the possible risk factors that is the most controversial in the world of breast cancer are the findings about soy's source of estrogen — which <a href="http://thechart.blogs.cnn.com/2011/01/19/is-soy-linked-to-breast-cancer/">some say can even cause cancer</a>. One thing is certain, the soybean and its derivatives — tofu, soymilk, tempeh (fermented soybeans) — are all interesting alternatives to meat because of their protein content and unsaturated fat levels. But other studies indicate that soybeans are rich in antioxidants known to prevent several cancers, including breast cancer itself. That being said, some studies indicate that it would be safer to consume soy before menopause and women with breast cancer or in remission should reduce soybean consumption or eat in moderation.

• Should I Avoid Zinc?

  A scientific journal published in <a href="http://advances.nutrition.org/site/misc/pub_dates.xhtml">Advances in Nutrition</a> in 2011, noted the importance of having zinc in your diet to boost the immune system and our DNA make-up. Until more scientific evidence is found, it would still be a good idea to add zinc-related foods to your dish like oysters, clams, butter sesame seeds, pumpkin seeds and legumes.

• Can Vitamin D Prevent Breast Cancer?

  Well known for its role in calcium absorption, vitamin D has also been the subject of studies for cancer prevention. In the case of breast cancer, some studies have s<a href="http://www.google.ca/url?sa=f&rct=j&url=http://www.canadianliving.com/health/prevention/womens_health_vitamin_d_helps_prevent_breast_cancer.php&q=vitamin+d+and+breast+cancer&ei=L3d8UI79NITv0gG0ioGADg&usg=AFQjCNEMnNbMPs-3hZJbv2CP3wiiAq-vyw">hown that vitamin D can even prevent it</a>. On the contrary, other studies have not achieved the same results. That said, we also know that the treatment of breast cancer chemotherapy causes a loss of bone density in women pre-menopause. This is more of a reason to ensure an adequate intake of vitamin D, especially from October to March, when sunlight is rare. Try foods like fish, — especially canned with bones, milk, yogurt, vegetable drinks fortified with vitamin D, eggs and shiitake mushrooms.

• How Much Alcohol Should I Be Drinking?

  Several studies have confirmed that <a href="http://abcnews.go.com/blogs/health/2012/06/03/alcohol-consumption-boosts-breast-cancer-risk/">women who consume alcohol on a regular basis increase their risk of being diagnosed with breast cancer</a>. Even one drink a day raises the risk by four per cent. Those who have the habit of drinking three or more drinks a day saw their risk rise to over 40 per cent. That being said, moderation is key for cancer prevention.

• What's The Risk Of Being Obese And Having Breast Cancer?

  Obesity <a href="http://www.cbc.ca/news/health/story/2012/08/27/breast-cancer-recurrence-obesity.html">significantly increases the risk of developing breast cancer</a>, particularly in post-menopausal women. Being diagnosed with obesity at the time of breast cancer was associated with poorer survival, the study added.

• Can Breastfeeding Prevent Cancer?

  Nursing can possibly help <a href="http://breastcancer.about.com/od/riskfactorsindetail/a/breastfd_prevnt.htm">prevent breast cancer and lower it's risks</a>, according to a report by About.com. On top of this, one 2002 study found that an estimated 25,000 breast cancers would be prevented in developed countries if women had the same number of children but breastfed each child for six months longer, the CBC reports.

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