Archive for the ‘Heart Health’ Category

Preventing Heart Disease- Beyond Cholesterol

Heart disease is the number one cause of death in the United States.  There is a growing body of research demonstrating that cholesterol levels are no longer the best indicator of a person’s risk for a heart attack or stroke.  In fact, half of the people who suffer a heart attack have completely normal cholesterol levels.  Recent studies have shown that lowering cholesterol alone had no benefit on preventing a person’s first heart attack or stroke.  Medical research is showing that far better indicators for risk of heart attack or stroke are oxidative stress, size of lipid particles, and inflammation status.

Cholesterol

Cholesterol plays several important roles in the body.  It is the backbone of all steroid hormones including testosterone, estrogen, cortisol, and vitamin D which are responsible for blood sugar regulation, mineral balance, blood pressure regulation, libido, and much more.  Cholesterol is a component of bile salts which help us to properly digest fats and it’s role in the brain makes it vital for learning and memory.  Cholesterol is the major component of the cell wall and is responsible for maintaining the integrity of every cell in the body.  It is so vital for health that every cell in the body has the ability to produce cholesterol and we could not survive without it.

Eighty percent of the cholesterol in your blood was actually produced by your own body,  the other twenty percent comes from the diet.  As more cholesterol is consumed in the diet, the body makes less.  Studies have actually shown very little correlation between the amount of cholesterol consumed in the diet and blood cholesterol levels because of this regulatory system.

That is not to say that eating an unhealthy diet full of greasy burgers and french fries will not lead to heart disease, quite the contrary.  But the cause is not about the amount of cholesterol so much as how these foods effect blood sugar regulation, fat deposition, inflammation, lipid particle size, and oxidization of fats.

Oxidative Stress

When oxygen is processed by the body, reactive oxygen species (free radicals) are formed.  Under healthy conditions, the body neutralizes the majority of these metabolites with circulating antioxidants.  When there is not a sufficient quantity of antioxidants available to limit oxidative damage, reactive oxygen species can cause damage to local tissues.  In the cardiovascular system this is especially important because when vessels are damaged plaques can form leading to atherosclerosis and heart disease.

Methods of reducing oxidative stress include eating a colorful whole foods diet, reducing inflammatory substances like trans-fats, cigarettes, alcohol and sugar and, when necessary, taking antioxidant supplements.

Size of Lipid Particles

Low Density Lipoproteins (LDL) are often referred to as the “bad cholesterol.” Under oxidative or inflammatory conditions, LDL particles can embed into vessel walls and form plaques that lead to heart disease.  Gathering evidence is demonstrating that assessing the size of LDL particles is a far better predictor for heart disease than the shear amount of LDL in the blood.  Smaller denser LDL particles have been strongly correlated with heart disease risk where larger “fluffier” LDL particles are not.  Two people with the same LDL levels can have much different risks of developing atherosclerosis depending if their LDL particles are small and dense or large and fluffy.

Inflammation

Inflammation is the body’s attempt to repair.  Think about what the healing process looks like when you cut yourself.  The skin gets red around the cut and slowly over time lays down new tissue until eventually the wound is closed and healed.  The same process happens when internal organs experience injury from extraneous sources.  A poor diet, chronic stress, smoking, inactivity, and poorly controlled blood sugar are just a few sources of chronic inflammation and repair deficit which greatly increase the chance of developing atherosclerosis and heart disease.

Summary

Anyone still taking a cholesterol lowering drug should discuss with their doctor whether it is still appropriate given the lack of evidence to support the efficacy of these drugs in preventing first time cardiovascular events.

The following tests can help determine individual risk of heart attack or stroke with better predictive value than cholesterol alone:  CRP-hs (inflammation), Homocysteine (detoxification and methylation), Oxidized HDL and LDL, and LDL Subfractions (lipid particle size).

References

1. Austin MA, Breslow JL, Hennekens CH, Buring JE, Willet WC, Krauss RM. Low-density lipoprotein sublass patterns and risk of myocardial infarction. JAMA 1988;260(13):1917-21.

2. Ridker PM et al. N Engl J Med. 2002;347:1557-1565.

3. Libby P. Inflammation and cardiovascular disease mechanisms. Am J Clin Nutr. 2006;83(suppl):456S-60S.

4. J Korean Med Sci 2009; 24 (Suppl 1): S115-S120

5. G Ital Cardiol (Rome). 2007 Jun;8(6):327-34. [High sensitivity of C-reactive protein in primary prevention]. Dipartimento di Medicina Interna, Malattie Cardiovascolari e Nefrourologiche, U.O.C. di Cardiologia, Cattedra di Malattie Cardiovascolari, A.O.U.P. Paolo Giaccone, Palermo.

6. Fernandez ML. Dietary cholesterol provided by eggs and plasma lipoproteins in healthy populations. Curr Opin Clin Nutr Metab Care. 2006; 9(1): 8-12.

7. New York Times, “Drug Has No Benefit in Trial, Makers Say,” January 14, 2008

8. New York Times, “Cardiologists Question Delay of Data on 2 Drugs,” November 21, 2007

9. BusinessWeek.com, “Do Cholesterol Drugs Do Any Good?” January 17, 2008

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