BEIJING?During a workshop here on Mixed Dyslipidemia (cholesterol problems), I had the privilege to speak in, the issue on whether or not eggs should be restricted for those with heart disease and cholesterol problems was raised.

This has been a raging debate swinging like a pendulum from one end to the other, with even one doctor going on radio regularly advocating intake of three to five eggs a day to ward off many diseases.

Just a brief background on cholesterol, it comes from two sources: from our own body and from the food we eat. Our liver and other cells in our body make about 75 percent of blood cholesterol, while the other 25 percent comes from the foods we eat.

Not all bad

Cholesterol is not all bad. We have the good type (HDL) coming from deep-sea fish and plant sources; and the bad type (LDL-cholesterol) coming mainly from animal meat, dairy products and eggs. When too much of LDL-cholesterol circulates in the blood, it can clog arteries, increasing one?s risk of heart attack and stroke. HDL-cholesterol does the opposite and tries to clean up the system with excess LDL. So we want a higher level of HDL- and a lower level of LDL-cholesterol.

LDL-cholesterol is also produced naturally by the body. Unfortunately, many people inherit genes that cause them to make too much of it. So having cholesterol in excess from the diet can compound the problem for these people.

Good source of nutrition

While it is true that eggs are a good source of nutrition and that some amount of cholesterol is also needed for normal body functioning especially by the brain, an excess of cholesterol intake from the diet can also be bad for cardiovascular health.

Depending on the size of the yolk, one egg contains about 210-250 milligrams (mg) of dietary cholesterol. A slice of cheese (30 grams) or one cup of full-fat milk has about 30 mg of cholesterol; a thin slice or 100 gm of cooked meat has about 100 mg. Plant foods and their products (e.g vegetable oil) do not contain fat.

The daily recommended cholesterol limit is less than 300 mg for people with normal LDL-cholesterol levels. So if one eats two eggs daily for breakfast, one already has a surplus of cholesterol from the diet which can wreak havoc in the network of blood vessels in the body if done for a prolonged period of time. One other problem with eggs is the company it keeps. Those who love eating eggs for breakfast also love eating it with bacon or ham, and that compounds the dietary fat-excess problem even more.

An egg a day can fit within one?s diet provided no other rich sources of fats are taken during the day. I generally recommend an egg a day for my elderly patients, for vegetarians and for other anorexic patients who hardly take anything. The egg-white is rich in proteins and several egg-whites a day can fit into a nutritious heart-healthy diet.

Other healthy egg lovers may have an egg every day provided cholesterol from other sources?such as meats, poultry and dairy products?is limited. They should substitute vegetables for some of the meat, avoid whole milk or full-fat coffee creams. For diabetics and those with elevated cholesterol levels or heart disease, limiting eggs to three to four a week should be acceptable. Beyond this can be courting undue risk.

Significant rise in deaths

A study published in the Journal of Internal Medicine three years ago on over 1,000 people with diabetes reported that a high intake of eggs and saturated fat were associated with a significant increase in deaths. (Trichopoulos et al., J Intern Med. 2006 Jun; 259(6):583-91). Other previous studies had the same findings. In another study, diabetics have an increased risk of developing coronary heart disease (CHD) or stroke if they eat one or more eggs per day. (Hu et el, Jama. 1999 Apr 21;281(15):1387-94) However, in fairness to eggs, those without diabetes did not show this risk.

How about the doctor who regularly broadcasts eating three or more eggs a day as healthy? Is he preaching a correctly founded message? I respect his commitment to his egg advocacy, but I don?t think he?ll hold himself responsible for the many strokes, heart attacks, leg gangrenes and many other cardiovascular complications his believers and followers are likely to develop over time.