DEAR DR. BLONZ: What controls how much cholesterol is in the body? Can we manufacture more cholesterol than we get in food? If I were to go vegan and effectively cut out all dietary sources, would that do the job of eliminating cholesterol? -- F.F., Oakland, California
DEAR F.F.: Cholesterol is an essential structural element in just about every cell of the body. In addition, cholesterol is a raw material for a number of hormones, including estrogen and testosterone.
People tend to be surprised when they learn that most of the cholesterol in our body is manufactured in the liver. That means that if you were to go vegan and there was no cholesterol in your diet, your body's liver would continue to crank it out as needed. When cholesterol is present in the foods we eat, the liver will adapt and make less.
There are a number of genetic conditions in which the body makes way more cholesterol than it needs, but these conditions are rare. More common are individuals with unbalanced diets: too much sugar and not enough whole plant foods, including grains, fiber, fresh fruits and vegetables. This way of eating can contribute to blood cholesterol levels that are inconsistent with good health. Fold in weight issues, a bit of stress, smoking, excess alcohol and lack of physical activity, and things get even worse.
The bottom line is that you shouldn't think of cholesterol as the "bad guy."
Levels that are excessive -- too-high levels of LDL cholesterol and too-low levels of HDL cholesterol -- can be indicative of a diet and lifestyle that's chronically off track. To be sure, there are medications that can help adjust your blood cholesterol levels, but equally essential is the effort to bring other aspects of diet and lifestyle into line.
You mention the vegan diet. There are many different takes on a healthful diet, and veganism might not be for everyone, but it does represent an excellent approach as it is entirely focused on plant-based eating. For more on cholesterol, check out: tinyurl.com/zqxrsnb.
Other relevant information, if you do decide to go vegan: Health statistics for vegans and vegetarians include lower rates of heart disease, obesity, obesity-related diabetes, colon cancer, lung cancer, breast cancer, hypertension, osteoporosis, kidney stones, gallstones and diverticular disease. Granted, many people who adopt an entirely new way of eating also adopt other healthy habits, and those habits play a role in these statistics. But the extent of the correlations remains impressive.
Being a successful vegan means learning which foods are required for your complete diet. As long as you eat a varied vegan diet, protein should not be a problem. However, when giving up meat, fish and dairy, these essential nutrients become less available: calcium, iron, zinc, vitamin B12, vitamin D and riboflavin. You can get all of these nutrients in foods, but consider a supplement for added insurance. There is more on vegan/vegetarian eating at tinyurl.com/jd7voh4.
Send questions to: "On Nutrition," Ed Blonz, c/o Universal Uclick, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to firstname.lastname@example.org. Due to the volume of mail, personal replies cannot be provided.