Is Dietary Cholesterol No Longer a "Nutrient of Concern?"
Whereas egg yolks were worrisome amongst the health world not long ago, current research cracks open the real truth regarding cholesterol and diet.
While cholesterol is predominately known for its existence in egg yolks, it is also a functional waxy substance produced by the liver and required to carry out for vital processes of the body.
What Is Cholesterol?
Cholesterol is major component of all cell membranes and helps produce essential sex hormones, vitamin D, and bile, which helps the body absorb fats and the fat-soluble vitamins A, D, E, and K.
Furthermore, cholesterol cannot be dissolved in the blood and requires lipoproteins as its mode of transportation throughout the body. Cholesterol is mainly broken down into low-density lipoprotein (LDL) and high-density lipoprotein (HDL) depending on what type of lipoprotein is carrying it.
• Low-Density Lipoprotein
Also known as the "bad" cholesterol, LDL contributes to plaque build-up on the artery walls. Too much plaque can result in atherosclerosis, a condition when the blood arteries become clogged and stiffened, and increases the risk of heart disease.
• High-Density Lipoprotein
HDL, or the "good" cholesterol, acts as a garbage truck by scavenging the LDL cholesterol and taking it back to the recycling center (the liver). The liver is responsible for breaking down the LDL cholesterol and disposing it from the body.
Targeted cholesterol levels include HDL cholesterol greater than 60 milligrams/deciliter (mg/dL), LDL cholesterol lower than 100 mg/dL, and total cholesterol less than 200 mg/dL. Cholesterol levels outside of these ranges increases the risk of heart disease.
Cholesterol and Diet
Aside from the notorious egg yolks, cholesterol is found solely in animal sources, including meat, poultry, fish, and dairy products.
Cholesterol diet guidelines previously limited intake to no more than 300 milligrams daily, as there was much concern it would increase cholesterol in the blood. Fast forward to the new 2015-2020 Dietary Guidelines for Americans, it dismisses a dietary cholesterol recommendation and suggests cholesterol is not a nutrient of concern for overconsumption.
According to the Scientific Report of the 2015 Dietary Guidelines Advisory Committee (DGAC), "Previously, the Dietary Guidelines for Americans recommended that cholesterol intake be limited to no more than 300 mg per day. The 2015 DGAC will not bring forward this recommendation because available evidence shows no appreciable relationship between consumption of dietary cholesterol and serum cholesterol, consistent with the conclusions of the American Heart Association and American College of Cardiology (AHA/ACC) report."
What Does Raise Cholesterol?
"If dietary cholesterol is no longer a nutrient of concern, why is there still such a high prevalence of heart disease?" you may wonder. Although age, family history, and race are risk factors for high blood cholesterol, the most common cause relates to an unhealthy lifestyle such as the following:
Saturated and Trans Fats
A diet rich in saturated and trans fat increases the risk of high cholesterol. In an effort to reduce heart disease risk, new draft guidelines issued by the World Health Organization encourages only 10 percent of saturated fats and 1 percent from trans fats in a person's diet.
The majority of saturated fat sources are from animal products such as beef, lamb, pork, and higher fat dairy products, though plant sources such as coconut oil, palm kernel oil, and cocoa butter are also rich sources of saturated fat.
While trans fats can occur naturally in meat and dairy product, they are mostly supplied by baked and fried foods such as donuts, pies, cookies, chips, crackers and other prepackaged snacks.
Continuous and ongoing evidence is going beyond the fear of dietary cholesterol and fat and expanding concerns related to sugar's effect on heart health.
In fact, researchers noted sugar consumption can disturb several markers for cardiovascular disease, including both HDL cholesterol and triglyceride levels.
Having a body mass index (BMI) of 30 or greater increases the risk of high cholesterol, while men with a waist circumference of at least 40 inches and women with a waist circumference of 35 inches are also at a greater risk.
Unmanaged diabetes has shown to increase LDL (the bad) cholesterol and lower HDL (the good) cholesterol, while consistently high blood sugars can damage the lining of the arteries.
A lack of physical activity and increased sedentary time is linked to lower levels of good high-density lipoprotein cholesterol.
Smoking wreaks havoc on the entire body, including increasing heart disease risk by damaging the walls of blood vessels, this making them likely to accumulate fatty deposits.
Smoking has shown to increase LDL cholesterol and reduce HDL cholesterol, particularly in women.