(HealthCastle.com) You may heard that polyunsaturated fatty acids (PUFAs) are good for your heart. In fact, if you live in Canada, you may even have seen heart-health claims on the packaging of many vegetable oils and products containing these oils. Since 2009, Canadian labels of these oils and the foods that contain them have been allowed to claim they promote “a reduced risk of heart disease by lowering blood cholesterol levels.” But a new analysis performed by researchers in Ontario, Canada, and published on the Canadian Medical Association Journal’s website this week suggests that claim may not be accurate if the oil contains high levels of omega-6 but does not also contain high levels of omega-3…