Understanding Triglycerides

Image: Kiwis/Getty Images
Image: Kiwis/Getty Images
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Understanding Triglycerides

Image: Kiwis/Getty Images
Image: Kiwis/Getty Images

Q. I just got the results of my lipid profile. My cholesterol is high, but so are my triglycerides. What exactly are triglycerides, and how are they different from cholesterol?

A. Triglycerides are the most common form of fat in the bloodstream. They consist of three fatty acid chains linked by a molecule called glycerol.

When you eat food, enzymes in your gut break down fats into their component fatty acids, which are then reassembled to create triglyceride particles. These fatty particles can't move freely through the watery bloodstream. So they combine with cholesterol and protein to form lipoproteins. Your lipid profile lists two of these lipoproteins: low-density lipoprotein (better known as LDL cholesterol) and high-density lipoprotein (also called HDL cholesterol).

But there are actually several other types of lipoproteins, including some that contain mainly triglycerides. Triglycerides can provide energy to fuel your body, while the extras are deposited in fat tissue. After a very heavy, fatty meal, your bloodstream may contain so many triglyceride particles that a blood sample may have a milky tint. But within a few hours, they're mostly cleared out. When you need energy between meals, hormones release the stored triglycerides into the bloodstream.

Your liver also converts carbohydrates into triglycerides. When you eat extra calories — especially from carbohydrate-rich foods such as sweets and white bread — your liver churns out extra triglycerides. Other things that can raise blood levels of triglycerides include being overweight or obese, smoking, or heavy drinking. Certain medical conditions —including diseases affecting the liver, kidneys, or thyroid, and poorly controlled type 2 diabetes — can also lead to high triglycerides.

For healthy adults, normal triglyceride levels are under 150 milligrams per deciliter (mg/dL). Values of 151 to 200 mg/dL are considered borderline high; those 201 to 499 are high, and those 500 and higher are very high (and increase the risk of inflammation of the pancreas gland, called pancreatitis). Growing evidence suggests that above-normal triglyceride levels can raise the risk of cardiovascular disease independent of cholesterol levels.

To get your triglycerides back into a normal range, start with lifestyle changes. Aim for a healthy weight, get regular exercise, and eat more whole, unprocessed grains. Eat fewer refined carbohydrates, and cut back on saturated fat from meat. If you drink alcohol and aren't willing to stop, do not exceed moderate amounts (no more than a drink a day for women or two daily for men).

— by Deepak L. Bhatt, M.D., M.P.H.
Editor in Chief, Harvard Heart Letter



Marseille Airport Suspends Flights Due to Wildfire as Public Warned to Stay at Home

 Smoke rises over Marseille as a fast-moving wildfire spreads on the outskirts the city, southern France, July 8, 2025. (Reuters)
Smoke rises over Marseille as a fast-moving wildfire spreads on the outskirts the city, southern France, July 8, 2025. (Reuters)
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Marseille Airport Suspends Flights Due to Wildfire as Public Warned to Stay at Home

 Smoke rises over Marseille as a fast-moving wildfire spreads on the outskirts the city, southern France, July 8, 2025. (Reuters)
Smoke rises over Marseille as a fast-moving wildfire spreads on the outskirts the city, southern France, July 8, 2025. (Reuters)

A wildfire spurred by hot summer winds reached France's second-largest city Tuesday, grounding all flights to and from Marseille, injuring at least nine people and forcing many residents to evacuate or barricade themselves indoors as smoke choked the Mediterranean air.

A big city hospital switched to generator power, train traffic was halted in most of the surrounding area, and some roads were closed and others tangled with logjams.

More than 1,000 firefighters were deployed to tackle the fire, which broke out near the town of Les Pennes-Mirabeau before racing toward Marseille. Some 720 hectares (acres) were hit by the blaze, the prefecture said.

Nine firefighters were injured, according to the prefecture, or local administration. No dead have been reported.

The prefecture said in a statement Tuesday evening that “the situation is under control,″ though the fire has not yet been extinguished. It described the fire as “particularly virulent.″

It came on a cloudless, windy day after a lengthy heat wave around Europe left the area parched and at heightened risk for wildfires. Several have broken out in southern France in recent days.

Light gray smoke gave the sky over Marseille’s old port a dusty aspect as water-dropping planes tried to extinguish the fire in the outskirts of the city, which has some 900,000 inhabitants.

Hundreds of homes were evacuated. The prefecture urged people in the affected areas to stay indoors and off the roads. With the fire approaching Marseille, the prefecture also advised residents in the north of the city to keep windows closed to prevent toxic smoke from entering their homes.

One distressed family watched the smoke over their neighborhood in the hills above the port city and showed AP how the roof of their neighbor's house had been damaged in the fire as they worried about their own.

Marseille airport announced that the runway had been closed at around midday. The prefecture said train traffic was halted, notably after a fire neared the tracks in L'Estaque, a picturesque neighborhood of Marseille.

As a safety measure, the city's Hospital Nord switched to generators “due to micro power cuts.”

“The aim is to secure the imaging sector. We are not worried as we have a high level of autonomy,” the University Hospitals of Marseille said, adding that because of the disrupted traffic it asked workers to remain at their posts until the next teams starts its shift.