How does cholesterol cause heart disease?
Here’s a question I was recently asked:
How does high cholesterol affect your cardiovascular system?
Let me see if I can explain and keep the process easy to understand!
First the endothelium (thin inner lining of your blood vessels) becomes damaged and inflamed. This damage can be caused by a variety of factors, such as high blood pressure, high stress level, poor diet, toxic chemicals and metals, tobacco smoke, etc.
So, your inflamed endothelium becomes susceptible to attracting fatty particles like cholesterol. The cholesterol particles work their way into the lining. These deposits of cholesterol can then be damaged by free radicals to form oxidized LDL cholesterol.
The immune system responds to the inflamed site by secreting a substance to make the endothelium sticky. The process leads to the formation of macrophages whose goal is to “seek and destroy” foreign objects. However, the oxidized LDL is toxic to macrophages, causing macrophages to be immobilized and unable to return to the blood stream.
The process continues to draw white cells to the area where they too are immobilized by oxidized LDL leading to the formation of a “fatty streak” on the artery wall.
A number of steps now take place involving C-reactive protein, fibrinogen, white blood cells, elastin, and collagen that eventually form a tough, fibrous cap over the fatty steak. Under the fibrous cap, dead cells accumulate, decay, and produce pus. You now have the development of a dangerous plaque within your artery walls. Plaque can continue to grow and instigate the development of additional plaque within the arteries leading to the narrowing of your blood vessels, reduced blood flow, heart attacks, etc.
FYI – Cholesterol does not necessarily need to be elevated for the above steps to take place. It’s becoming more clear that knowing your LDL and HDL particle size gives you a better overview of your heart health than typical cholesterol levels. Particle size can be determined with lab work, such as a Lipoprotein Particle Profile.
All the best,
Lisa Nelson RD
Heart Healthy Tips
Heart Disease – Does green tea lower heart disease risk?
All right, this green tea article has been hanging over my head for at least a month now. I just couldn’t get motivated to wade through all the research to determine if yes, this is an effective way to lower cholesterol and prevent heart disease, or no, it’s just a lot of hype.
Well, I sat down and sorted it all out today and here’s what I found.
Health Claim
The proposed health claim for green tea is that drinking at least 5 fluid ounces as a source of catechins may reduce risk factors associated with cardiovascular disease.
What are catchins?
Green tea contains catechins, which are a type of flavenoid with antioxidant properties. Antioxidants slow the oxidation process. The oxidation of LDL molecules is what results in plaque formation. Therefore, increasing antioxidant intake should slow oxidation of LDL, resulting in less arterial plaque formation.
Also, when molecules are oxidized, free radicals are released that damage cells. These free radicals can increase inflammatory issues associated with cardiovascular disease.
How flavenoids work
The body recognizes flavenoids as foreign particles and works to eliminate them from the body. Flavenoids themselves do not act as an antioxidant and they are poorly absorbed by the body. However, the proposed benefit of extra flavenoids is that as the body eliminates the unwanted flavenoids, damaging free radicals are also eliminated.
Tea production
The various types of tea are produced differently. The leaves of oolong tea and black tea are allowed to oxidize (enzymes in the tea change catechins to larger molecules). Green tea is not oxidized, but produced by steaming fresh-cut leaves whereby enzymes are inactivated and little oxidation occurs. The least processed tea is white tea, which contains the highest levels of catechins. Green tea contains the second highest catechin level, approximately 125 mg catechins per serving (or ~25% dry weight of fresh tea leaves).
Here’s a little breakdown on tea oxidation:
Black tea – Highest oxidation; also, highest caffeine content and strongest flavor; 90% of all tea served in the West is black tea
Oolong tea – 10-70% oxidized
Green tea – Low oxidation
White tea – Minimal oxidation; Uncured, unfermented; Lower caffeine content that other teas
FDA Review
In 2005, the FDA did not approve the health claim for green tea, because the link between green tea and reduced cardiovascular disease risk was too weak and more conclusive evidence was needed.
Recent Research
This past June, 2008, a study was published that links green tea to reduced flow-mediated dilation of brachial arteries (major blood vessels in the upper arms). Flow-mediated dilation is related to coronary endothelial function and is an indicator for cardiovascular disease risk. Increased dilation is good. It means the heart has to do less work to move blood throughout circulation. (The endothelium is the inner layer of an artery, which blood flows against.)
This was a study of 14 healthy individuals that consumed 6 grams of green tea, followed by a measure of flow-mediated dilation. The results showed an increased flow-mediated dilation with tea (peak at 30 minutes post consumption). There was no change to antioxidant status after consumption. It’s proposed that the improved flow-mediated dilation is how green tea reduces cardiovascular disease risk.
The Hype
I came across multiple articles with headlines screaming “Green Tea Protects Against Heart Disease” since this study was published in June. I think there is significant research that still needs to be completed before it can be determined for sure how tea works to prevent heart disease. A study of 14 individuals is a small study.
Drinking 6 grams of green tea, would equal about three – 6 ounce cups of green tea each day. (Based on making 1 six ounce cup of tea with 1 teaspoon or 2.25 grams of green tea.) However, the study results are based on consuming 6 grams of tea in one setting followed by improved flow-mediated dilation at peak levels 30 minutes after consumption. How likely is it for you to drink three cups of tea quickly, back-to-back to reproduce the short-term benefit shown in this study?
To me, that is not a very effective way to reduce heart disease risk. But, I will say that if you like green tea – drink it. Many studies are showing that green tea is beneficial to heart disease. The what, how, and how much is yet to be determined. Who knows what future studies will find?!
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All the best,
Lisa Nelson RD
Lipoprotein a – How to Lower Lipoprotein a
Lipoprotein(a) levels are not affected by the foods you eat or your activity level. There are no prescription medications, including statin drugs, that have an impact on reducing levels. That doesn’t mean you don’t have options if you live with an elevated lipoprotein(a). Using supplements, such as omega 3’s, niacin, and vitamin C are three options for reducing lipoprotein(a).
Work with your doctor to learn your lipoprotein(a) and the best treatment approach for you.
Testing lipoprotein a
Function of lipoprotein a
Dangers of elevated lipoprotain a
All the best,
Lisa Nelson RD
How to Lower Cholesterol in 8 Simple Steps
Lipoprotein a – What is the function of lipoprotein a?
Lipoprotein(a) is formed when one LDL molecule is attached to a protein called apolipoprotein(a). (FYI: Lipo = fat; hence the name lipoprotein – fat with protein.) A healthy level of lipoprotein(a) is beneficial and will:
Repair damaged cells
Restore structure of blood vessel walls
Enhance blood clotting
Prevent excessive blood loss due to damaged vessels
Promote cell regeneration
Basically, lipoprotein(a) at healthy levels acts as an “artery patch”.
Dangers of elevated lipoprotein a levels.
All the best,
Lisa Nelson RD
How to Lower Cholesterol in 8 Simple Steps
Cholesterol Lipoprotein a – Do you know your levels?
Lipoprotein(a) is a type of cholesterol we all have; however, it’s not a cholesterol routinely monitored by physicians. Typically you receive a standard lipid panel which gives you the following labs:
Total Cholesterol
LDL Cholesterol
HDL Cholesterol
Triglycerides (and maybe VLDL Cholesterol)
If the above labs are within normal, there is usually no reason a physician would order any further tests. For those of you with a strong family history of heart disease, I encourage you to have your physician do routine tests beyond this standard lipid panel. You need to have a comprehensive lipid panel. A comprehensive lipid panel tests you for the following labs:
Total Cholesterol
LDL Cholesterol
HDL Cholesterol
Triglycerides
C-Reactive Protein (measure of inflammation)
Insulin
Homocysteine
VLDL Cholesterol
Remnant Lipoprotein
Dense LDL III
Dense LDL IV
Buoyant HDL 2b
LDL Phenotype/Size
Lipoprotein(a)
The function of Lipoprotein a.
All the best,
Lisa Nelson RD
How to Lower Cholesterol in 8 Simple Steps
Eating red meat may shorten your life
A study from the National Cancer Institute found individuals consuming the most red and processed meats at greater risk of death from cancer and heart disease versus those eating lower levels.
The ten year study began in 1995 and evaluated the dietary intake of over 500,000 men and women between the ages of 50 and 71. The study divided types of meat into three categories – red meat, white meat, and processed meat.
Red meat was defined as beef, pork, ham, bacon, hamburger, hot dogs, liver, pork sausage, and steak. As well as meats found in foods like pizza, stews, and lasagna.
White meat was classified as fish, chicken, and turkey.
Processed meat included white or red meats that were cured, dried, or smoked, such as bacon, chicken sausage, lunch meats, and cold cuts.
Individuals eating red meat at the highest levels consumed ~4.5 ounces per day based on a 2,000 calorie/day diet. This is equal to approximately 2 pounds of beef or pork each week. Compare this to the group with the lowest intake of red meat at 5 ounces per week or ~ 0.5 ounce per day.
Those with the highest intake of processed meat consumed approximately 1.5 ounces per day versus the lowest intake group at 0.11 ounces per day.
Men eating red meat at the higher levels each day had a 31% greater risk of dying and women 50% greater risk of dying due to heart disease. The study found that 11% of all deaths in men and 16% of all deaths in women could’ve been prevented by consuming the lower levels of red meat. Looking at just heart disease, death due to heart disease could have been reduced 11% in men and 21% in women if red meat intake was reduced from the highest level to the lowest.
A high intake of processed was linked to a 16% increased risk of dying for men and 25% increased risk for women.
This doesn’t mean you need to switch to a vegetarian diet. Individuals eating white meat had a slightly lower risk of death.
Possible reasons for the increased risk of death linked to eating red meat and processed meat maybe due to the carcinogens formed during cooking, iron in red meat causing oxidative cell damage, and/or saturated fat in red meat increased cancer risk and elevated cholesterol levels.
Here are some tips for making wise meat selections.
- Select lean cuts of meat, such as your “loins” and “rounds”.
- Choose cuts of meat with the least amount of marbling (visible fat).
- Trim visible fat before cooking.
- Marinate before grilling. May decrease formation of carcinogens if marinated in beer or wine prior to cooking.
- Broil versus frying or roast large cuts and skim off the fat.
- Drain oil and rinse ground beef in hot water to decrease fat.
All the best,
Lisa Nelson RD
How to Lower Cholesterol in 8 Simple Steps
