In this episode of Longevity by Design, our hosts, Dr. Gil Blander and Ashley Reaver, MS, RD, CSSD, are joined by Dr. Ronald Krauss, Professor of Medicine at UCSF, and Adjunct Professor of Nutritional Sciences at UC Berkeley. Tune in as Dr. Ronald Krauss discusses the contributing factors to atherosclerosis, the biomarkers most associated with heart disease, and components of a heart-healthy diet.
Meet Longevity by Design’s podcast guest, Dr. Ronald Krauss
Dr. Ronald Krauss is a Senior Scientist at Children’s Hospital Oakland Research Institute, Professor of Medicine at UCSF, and Adjunct Professor of Nutritional Sciences at UC Berkeley. Dr. Krauss’s research aims to understand how to best prevent cardiovascular disease through early detection and management of its major risk factors: most notably, elevated levels of blood cholesterol and lipoproteins.
He has published over 450 research articles and reviews on metabolic, genetic, dietary, and drug effects on plasma lipoproteins and the risk of coronary artery disease, with over 100,000 citations of this work.
What is atherosclerosis?
To begin, Dr. Krauss describes the background of atherosclerosis. He explains that atherosclerosis is a condition that involves the formation of plaques that deposit on the inner walls of arteries. Atherosclerosis can start to impact health when it occurs in the heart or brain, as this plaque build-up can cause heart attacks and strokes when built over time. “Much of the field of cardiovascular prevention is trying to prevent the progression of plaques because when they become more advanced, they can acquire inflammatory properties and lead to clots in both the heart and the brain,” says Dr. Krauss.
Dr. Krauss further discusses the many factors that influence atherosclerosis risk. First is age. Over time, almost everyone has a degree of plaque build-up. Lifestyle factors that contribute to more advanced plaque are high levels of cholesterol, particularly low-density lipoprotein (LDL). Other risk factors include smoking, diabetes, diet quality, high blood pressure, and family history. Dr. Krauss says there is much individual variability in these risk factors, so a preventative approach to care is taken as such.
Plaque metabolism and formation
Dr. Krauss gives us a deeper look into the metabolism of cholesterol and plaque formation. First, the liver synthesizes lipids, cholesterol, and triglycerides. The liver packages the lipids into particles, which usually start as very-low-density lipoprotein (VLDL) and contain triglyceride, cholesterol, and a protein called Apoprotein B (ApoB). VLDL will then undergo many changes, including lipolysis or breakdown of the triglyceride. The body can then use the fatty acid component for energy, muscle tissue, and brain, while excess triglyceride is stored in fat tissue. Atherosclerosis occurs when there is excess lipid metabolism in the liver over time, as the remnant VLDL particles are broken down into LDL and build up plaque in arteries.
There is an important aspect to this process that Dr. Krauss says many people don’t fully understand yet. The form of an LDL particle can differ in size and composition depending on the amount of triglyceride being secreted. “Larger LDL particles spread in healthy individuals who have relatively low triglyceride levels, and they do not appear to be particularly hazardous to the artery,” he explains. However, smaller, more damaging LDL particles form when triglyceride levels increase. Dr. Krauss explains that body weight can be a predictor—people with excess body fat or prediabetes experience elevated triglyceride levels and smaller LDL particles. He explains that LDL particle size is a more precise measurement of heart disease risk than just measuring LDL concentration.
Two markers of heart health: ApoB and LP(a)
Apoprotein B (ApoB) is the major structural component of VLDL, VLDL remnants, LDL particles, and Lipoprotein A. There is one molecule of ApoB for each of these lipoprotein particles. Dr. Krauss believes that measuring ApoB in the blood provides insight into heart disease risk. "The standard measurement of LDL cholesterol is not necessarily reflective of other particles. Since all of these particles can contribute to atherosclerosis and plaque formation in various degrees, there's a strong argument for measuring ApoB in a standardized way." Interestingly, ApoB is not commonly included in standard bloodwork from physicians.
Another type of blood LDL particle that Dr. Krauss discusses is Apolipoprotein A or Lp(a). Lp(a) carries an additional protein that renders it more susceptible to oxidation, damaging the arteries. "Having elevated levels of Lp(a) has a strong genetic influence and is associated with increased risk for heart disease. About one-third of the population has high levels of Lp(a)," he explains. Therefore, Dr. Krauss strongly advocates for including Lp(a) in standardized testing in the population to assess the risk of heart disease and provide early disease prevention.
Components of a heart-healthy dietary pattern
Following the conversation about lipoprotein particles, Dr. Krauss pivots to discussing nutritious dietary patterns that promote heart health. He says diets rich in plant-based foods–specifically fruits, vegetables, and whole grains are associated with low heart disease risk. He also promotes fish as a heart-healthy option.
Interestingly, he discusses his research on dietary saturated fat and clarifies the impact of this dietary component. “We have shown that high levels of saturated fat raise LDL cholesterol, but primarily the larger LDL particles, which are not as strongly associated with heart disease risk as smaller LDL particles,” says Dr. Krauss. He points out that harmful VLDL levels are more influenced by processed foods—specifically those high in sugar. Dr. Krauss emphasizes the benefits of eating a whole food diet that maximizes fruits, vegetables, fermented dairy, and fish while limiting processed foods.
Advice on living a healthier longer life
When asked for his top tip to promote heart health, Dr. Krauss says that nutrition is the most impactful component. “I really think the most important single arena for prevention is a healthful dietary pattern. Nutrition really transcends everything and is the basis for what we do in my practice to decrease heart disease risk.”