The idea that animal fat consumption causes heart disease is perhaps the most controversial component of the standard preventative advice given to reduce heart disease. This association is based upon the research of Ancel Keyes, who compared heart disease rates in the United States, Canada, Australia, England, Italy, and Japan and found that lower rates of heart disease were manifested in countries with less saturated fat consumption. However, there are many examples of tribes that ate diets high in animal fats and protein yet had low rates of heart disease until exposed to a Western diet: the lifestyle practices of the industrialized world clearly seems more apt to contribute to heart disease but exactly how remains uncertain. There is a complex interplay of genetics and other metabolic factors in the development of atherosclerosis (Teicholz 2007).

Total cholesterol alone has a limited value in predicting the tendency to develop heart disease: the HDL/LDL (good vs. bad cholesterol) ratio and triglycerides "which are a measure of the amount of fat circulating in your blood" must be collectively assessed (Teicholz 2007). Some forms of fat can increase HDL, such as the plant-based fats in olive oil and avocados. And a diet low in carbohydrates, even if high in animal fats, has been shown to be beneficial in some studies: "As your carb intake rises, so does your blood sugar. This causes your body to release the hormone insulin. Insulin's job is to...

As a result, your liver starts converting excess blood sugar to triglycerides, or fat" (Teicholz 2007). To further complicate matters, not all persons seem to be equally affected by diet and lifestyle practices because of genetics, while some are more affected. There is no universal preventative prescription for guaranteeing one will not develop atherosclerosis. But despite these controversies, maintaining a healthy weight, quitting smoking, exercising, and seeing one's physician regularly for checkups are all advised as a way of mitigating the risks.
References

Atherosclerosis. (2012). American Heart Association. Retrieved:

http://www.heart.org/HEARTORG/Conditions/Cholesterol/WhyCholesterolMatters/Atherosclerosis_UCM_305564_Article.jsp

Atherosclerosis disease. (2012). Ultrasound services. Retrieved:

http://prosono.ieasysite.com/patho_chapter_atherosclerotic_disease.pdf

Heart disease. (2013). Women's Health. Retrieved:

http://womenshealth.gov/minority-health/african-americans/heart-disease.cfm

Teicholz, Nina. (2007). What if bad fat is actually good for you? Men's Health.

Retrieved: http://www.menshealth.com/health/saturated-fat

"What is atherosclerosis?" (2013). NIH. Retrieved:

http://www.nhlbi.nih.gov/health/health-topics/topics/atherosclerosis/