In a recent study researchers have found a strong link between a common gene and the risk of developing atherosclerosis, which is usually responsible for most heart attacks and strokes. According to researchers, people carrying a variant form of a gene called ALOX5 (5-lipoxygenase) are at increased risk of having cholesterol deposited in their artery walls. In addition to the common form, this gene can be found in a few different variants (polymorphisms) within a population. The new findings suggest that a significant number of people carry a form of ALOX5 that may have a potent effect on cardiovascular disease.
This study was conducted on 470 healthy middle-aged women and men. The DNA sample of each participant was examined for ALOX5 gene. Thereafter, the researchers recorded each participant’s diet over 18 months and used an ultrasound to measure the thickness of carotid artery walls-a determinant of atherosclerosis and heart disease risk.
The scientists observed that the artery walls were 18% thicker in those participants who had the high-risk form of ALOX5. Another interesting finding, which emerged from the study was that, the strong link between the high-risk form of ALOX5 and atherosclerosis was dependent on the type of diet the person (having the ALOX5 gene) was taking. It was found that harmful effects of this gene are accentuated if the person takes certain n-6 polyunsaturated fats whereas they are decreased by intake of fish oils that contain n-3 polyunsaturated fatty acids (or omega-3 fatty acids). Researchers say that this diet-gene interaction can be explained by the fact that ALOX5 protein causes conversion of fatty acids into certain molecules that are involved in the process of inflammation, and atherosclerosis is believed to be an inflammatory process.
For those people who carry the high-risk form of ALOX5 gene two types of n-6 polyunsaturated fatty acids are bad; arachidonic acid (found in some meats) and linoleic acid (found in many vegetable oils). Hence, these people should take less of n-6 polyunsaturated fats and more of n-3 fatty acids (found mainly in oily fish such as salmon, white tuna or albacore, mackerel, herring), as this type of fat is good for them. Moreover, substantial evidence already exists which indicates that eating diet rich in n-3 fatty acids from fish oils prevents arrhythmia.
The researchers suggest that ALOX5 gene may be used as a genetic marker for heart disease and may also lead to an improved diagnosis, prevention and treatment of atherosclerosis.