High levels of HDL may help lower risk of heart disease

Doctor typing on computer

Hello, dear readers, and welcome to a bonus letters column. We're working our way through a bonanza of mail and will continue to respond to as many of your notes and emails as possible.

-- We'll begin with a thank you to the many -- so many! -- of you who wrote in response to a column on time-restricted eating. You pointed out that we misidentified LDL, also known as low-density lipoproteins. This is, as you correctly pointed out, the so-called “bad” cholesterol. LDL contributes to the buildup of fatty debris in the arteries. This causes the vessels to become narrow, which increases the risk of atherosclerosis. The “good” cholesterol is HDL, or high-density lipoprotein. It absorbs cholesterol in the blood and delivers it to the liver for disposal. High levels of HDL can play a role in lowering the risk of heart disease and stroke.

-- The column on time-restricted eating also drew some observations about present-day dietary habits and easy access to abundant food. "Humans, for most of their history, never ate all day long, as we do now. Nor did they have the industrialized/processed foods that have existed only since the 20th century," a reader from California wrote. "The result is that we eat all day, without any meaningful time to burn our stored fat. Like other animals, we evolved to deal well with times of plenty and also times of scarcity. The problem is that (due to the modern diet) there is never any of the latter."

-- We heard from a reader with a rare but severe type of soft tissue injury who wonders if she needs medical attention. "I took a bad fall while camping in 2016, which resulted in a Morel-Lavallee lesion on my left hip," she wrote. "The doctor drained a lot of fluid and said it should heal within a year. Lately, it has begun to be very tender and feels warm to the touch. Should I see an orthopedic doctor again?"

A Morel-Lavallee lesion is what is known as a closed degloving injury. That is a traumatic injury in which sudden and powerful force causes the skin, along with the layers of tissue it sits upon, to separate completely from the underlying muscle, connective tissues, and sometimes the bone. This disrupts the flow of blood, and thus also oxygen and nutrients, to the affected tissues. Due to the extensive trauma in this type of injury, healing can be quite slow. Your instinct is correct. A warm and tender joint needs a formal evaluation by an orthopedist. The concerns here are infection, and perhaps a fracture that previously had not been identified. Please do see your doctor right away.

Thank you, as always, for your letters and emails. We love hearing from you. We read them all, and answer as many as we can. To those who have asked, no, we never publish any names. However, we do enjoy learning where in the nation our readers live, so if you're comfortable doing so, feel free to include the name of your town, city or region.

(Send your questions to [email protected], or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

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