A Polarizing Meat High In Protein And Magnesium Is Also High In Cholesterol

Joe Rogan and other fans of the carnivore diet are quick to praise the perks of eating only meat, and there's no denying that this way of eating delivers plenty of protein. For example, just six ounces of cooked chicken breast packs over 54 grams of protein, which is more than most people need in a day. Along with all that protein, you're also getting B vitamins, potassium, zinc, and about 54 milligrams of magnesium.

But hardcore carnivore dieters often go beyond muscle meat and recommend eating organ meats, which are typically even richer in nutrients. If you ever spot "sweetbreads" on an appetizer menu, don't be fooled. They're not sugary or bread-like at all. Sweetbreads are actually organ meats that come from the thymus gland of young lamb, beef, or veal.

Nutritionally, sweetbreads hold their own. Six ounces of cooked lamb sweetbreads provide around 36 grams of protein and 43 milligrams of magnesium. But one thing you might not be looking for in your organ meats? Cholesterol. That same serving comes with a hefty 786 milligrams of it.

If the amount of cholesterol in sweetbreads surprises you, it's important to understand the relationship between dietary cholesterol and blood cholesterol. For many years, scientists believed that cholesterol in food directly raised blood cholesterol levels. But as research progressed, the picture became more complex.

Researchers found that foods like shellfish and eggs — both high in cholesterol but low in saturated fat — had little effect on blood cholesterol. This led to the conclusion that saturated fat, rather than dietary cholesterol, plays a more significant role in raising blood cholesterol, according to a 2019 study in Nutrients. A 3-ounce serving of lamb sweetbreads contains about 2 grams of saturated fat, while the same amount of beef sweetbreads contains 10.6 grams.

Still, not all saturated fats affect cholesterol the same way. According to a 2010 article in Current Atherosclerosis Reports, stearic acid has little to no effect on blood cholesterol, whereas lauric acid has the strongest cholesterol-raising effect. In lamb sweetbreads, about 44% of the saturated fat is stearic acid. In beef sweetbreads, it's about 43%. Lauric acid makes up less than 1% of the total saturated fat in both types.

Palmitic acid, another type of saturated fat, is known to raise LDL ("bad") cholesterol. It accounts for about 43% of the saturated fat in lamb sweetbreads and 46% in beef sweetbreads. Palmitic acid's impact on your blood cholesterol is generally greater when combined with a high-calorie, high-cholesterol diet.

You may have heard that sweetbreads contain more vitamins and minerals than muscle meat, but that's not necessarily the case. Beef roast has more iron, selenium, zinc, and certain B vitamins than both beef and lamb sweetbreads. While sweetbreads do contain some omega-3 and omega-6 fatty acids, they have less than beef roast. One monounsaturated fat found in all three meats is oleic acid, an omega-9 fatty acid also found in olive oil. Oleic acid may help lower LDL ("bad") cholesterol and reduce inflammation (per NetMeds).

People with gout or frequent kidney stones may want to avoid sweetbreads and other organ meats because they're high in purines. When your body breaks down purines, uric acid is produced. Eating purine-rich foods can cause uric acid to build up in the body. Excess uric acid can form crystals in the blood that settle in the joints, leading to painful gout flare-ups (here are foods to eat and avoid for gout). These crystals can also accumulate in the kidneys, forming uric acid kidney stones.