Not everything that lowers HDL is bad for you. If you change from a high-fat, high-cholesterol diet to a healthy low-fat, low-cholesterol diet, your HDL levels may stay the same or even decrease because there is less need for it. When you have less garbage, you need fewer garbage trucks to remove it, so your body may make less HDL.

In this quote, Dean Ornish is challenging the conventional thinking about HDL (high-density lipoprotein) cholesterol, often referred to as "good" cholesterol. Typically, higher levels of HDL are considered beneficial for heart health, but Ornish points out that not everything that lowers HDL is harmful. He explains that if you shift from a high-fat, high-cholesterol diet to a healthier low-fat, low-cholesterol diet, your HDL levels might not increase or could even decrease. This happens because there is simply less need for HDL when there is less cholesterol in the body to be removed.

Ornish uses the metaphor of garbage trucks to simplify the process. If there is less garbage (cholesterol) to be collected, then there’s less need for the garbage trucks (HDL) to transport it. This analogy helps explain how the body may produce less HDL when the dietary intake of fat and cholesterol is reduced, as the body has less waste to clear. The overall takeaway is that HDL levels are not the sole indicator of cardiovascular health, and their decrease may simply reflect a more balanced, cleaner internal environment.

The origin of this quote comes from Ornish's well-established research in preventive medicine, specifically in how diet can influence cholesterol levels and overall heart health. Ornish is known for promoting a plant-based diet and emphasizing the importance of lifestyle changes in preventing and even reversing heart disease. This quote is a reflection of his broader message that heart health is not just about focusing on one marker, like HDL, but on adopting an overall healthy lifestyle.

Ultimately, the quote underscores the idea that dietary choices should be seen in context, and cholesterol levels should not be viewed as static or the only measure of health. Ornish advocates for a more holistic approach to wellness, where reducing unhealthy fats and cholesterol can actually lead to better overall health, even if certain metrics like HDL decrease.