The myth that cholesterol in foods hurts heart health may have been busted for good.
Over the past decade, many expert observers have said that the Emperor has no clothes.
And it's likely that a companion myth – saturated fats cause heart disease – will fall by the wayside as well.
Expert panel concludes that dietary cholesterol is no concern
Every five years, the US government updates its Dietary Guidelines for Americans.
The scientists chosen to advise the USDA on its upcoming Dietary Guidelines for Americans 2015 are recognized experts in nutrition, medicine, and public health.
That panel, called the Dietary Guidelines Advisory Committee (DGAC) held public meetings over the past two years.
Fortunately, the DGAC members heeded the overwhelming evidence that dietary cholesterol is not a significant risk factor for heart disease … except for the very few people who cannot metabolize it properly.
Indeed, rather than being a heart-health threat, cholesterol is essential to a wide variety of body functions, including brain and mental health.
As the DGAC wrote, "Previously, the Dietary Guidelines for Americans recommended that cholesterol intake be limited to no more than 300 mg/day … [but the] … available evidence shows no appreciable relationship between consumption of dietary cholesterol and serum [blood] cholesterol … Cholesterol is not a nutrient of concern for overconsumption.”
The USDA advisory panel's conclusion relied in part on a recent report issued by the American College of Cardiology (ACC) / American Heart Association (AHA) Task Force on Practice Guidelines, which concluded that dietary cholesterol poses no risk (Eckel RH et al. 2013).
Blood cholesterol remains a threat ... sometimes
You will notice that the DGAC did not say that blood cholesterol poses no threat to heart health.
That's because high levels of some kinds of cholesterol and certain "cholesterol profiles” are clearly linked to heart disease.
These cholesterol-related risk factors include high levels of triglyceride-rich VLDL cholesterol, and having high proportions of non-HDL cholesterol.
(Instead of dietary cholesterol, the presence of those risk factors stems from a variety of genetic, diet, and lifestyle factors.)
However, there is less compelling evidence that some traditional risk factors – such as "high” levels of total cholesterol (the definition of which keeps being lowered) – present significant risks to most people.
But that didn't stop another ACC/AHA committee from issuing radical new guidelines for assessing the risk of heart disease ... which would radically raise prescriptions for statin drugs.
Proposal would radically increase statin prescriptions
A different ACC/AHA panel issued new heart-risk assessment guidelines last year (Goff DC Jr et al. 2014).
To avoid confusion, we'll call this second ACC/AHA panel the "risk-assessment” panel.
The risk-assessment guidelines proposed by the second ACC/AHA panel would lead to vastly more Americans taking those cholesterol-lowering drugs.
Worse, its members recently cited new evidence to justify further widening the risk assessment guidelines, which would result in even more Americans taking statins.
Critics take the proposed risk-assessment guidelines to task
Experts have criticized the ACC/AHA risk-assessment panel's radical proposals.
The critics include cardiology heavyweights like Dr. Steven Nissen – former president of the American College of Cardiology – and Dr. Paul Ridker of Harvard Medical School.
As Dr. Nissen noted, the risk-assessment panel's recommendations would have almost all healthy men over 60 taking a statin drug ... even if they're in the lowest-risk group.
And as Dr. Ridker wrote last year, "Selective treatment of those who can anticipate the greatest benefit and the least harm on an individualized basis could reduce the number of unnecessary treatments and healthcare costs …”. (van der Leeuw J et al. 2014)
In other words, radically loosened guidelines for prescription of statins will inevitably undermine doctors' motivation to tailor their advice to patients.
Like Dr. Ridker, Dr. Allan Sniderman of the Mayo Clinic believes that broad-brush recommendations like those issued by the ACC/AHA panel will undermine individualized treatment.
Seemingly in response to the risk-assessment panel's dubious recommendations, he and his colleagues published a paper appropriately titled "The necessity for clinical reasoning in the era of evidence-based medicine” (Sniderman AD et al. 2013)
It's worth quoting some key points made in that paper at length:
- "Although RCTs [randomized controlled trials] provide the best assessment of the overall value of a therapy, high-quality evidence from RCTs is often incomplete, contradictory, or absent even in areas that have been most exhaustively studied.”
- "Moreover, the likelihood of the success or failure of a therapy is not identical in all the individuals treated in any trial because therapy is not the only determinant of outcome.”
- "Therefore, the overall results of a trial cannot be assumed to apply to any particular individual, not even someone who corresponds to all the entry criteria for the trial.”
And they raised a point that applies to the ACC/AHA risk-assessment panel, which included six members with ties to companies that make those drugs: "In addition, the potential for bias due to financial conflicts remains in many guideline groups.” (Sniderman AD et al. 2013)
Finally, although the ACC/AHA risk-assessment panel's study acknowledge that lifestyle changes can substantially reduce the risk of heart disease, it's likely that people given a prescription for statins will be less motivated to make those changes.
Statins for (nearly) all? Potential for harm, missed opportunities, and wasted money
Statins like Lipitor, Crestor, and Zocor lower blood levels of LDL and total cholesterol: two traditional, but largely discredited heart-risk factors.
Considered in isolation, neither of those markers can accurately predict a given person's risk for heart disease.
Instead, a variety of factors combine to raise the risk for heart disease:
- Chronic stress
- Adverse genetics
- Sedentary lifestyle
- Chronic inflammation
- Diabetes or metabolic syndrome
- Diets high in sugars and starches
- High levels and proportions of specific kinds of cholesterol.
While chronic, ‘silent” inflammation is a widespread heart-risk factor, and statins exert significant anti-inflammatory effects, they are not the only or healthiest way to address that problem.
The proposal that most adults – even ones at low risk for heart disease – should take statin drugs seems unjustified, costly, and potentially harmful.
Conversely, exercise and healthy diets – ones low in sugars, refined starches, and omega-6 fatty acids (see Know Your Omega-3/6 Numbers
) – can reduce inflammation, improve blood fat and cholesterol profiles, and improve artery health.
We don't pretend to know or understand the highly complex details of research into risk factors and drug treatments for heart disease.
But we – and some leading cardiologists – recognize a serious lack of common sense when we see it.
- Boekholdt SM et al. Very low levels of atherogenic lipoproteins and the risk for cardiovascular events: a meta-analysis of statin trials. J Am Coll Cardiol. 2014 Aug 5;64(5):485-94. doi: 10.1016/j.jacc.2014.02.615. Review.
- Eckel RH et al. 2013 AHA/ACC guideline on lifestyle management to reduce cardiovascular risk: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. Circulation. 2014 Jun 24;129(25 Suppl 2):S76-99. doi: 10.1161/01.cir.0000437740.48606.d1. Epub 2013 Nov 12.
- Goff DC Jr et al. 2013 ACC/AHA guideline on the assessment of cardiovascular risk: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. Circulation. 2014 Jun 24;129(25 Suppl 2):S49-73. doi: 10.1161/01.cir.0000437741.48606.98. Epub 2013 Nov 12. Erratum in: Circulation. 2014 Jun 24;129(25 Suppl 2):S74-5.
- Ridker PM, Rifai N, Cook NR, Bradwin G, Buring JE. Non-HDL cholesterol, apolipoproteins A-I and B100, standard lipid measures, lipid ratios, and CRP as risk factors for cardiovascular disease in women. JAMA. 2005 Jul 20;294(3):326-33. Ridker PM. LDL cholesterol: controversies and future therapeutic directions. Lancet. 2014 Aug 16;384(9943):607-17. doi: 10.1016/S0140-6736(14)61009-6. Review.
- Sniderman AD, LaChapelle KJ, Rachon NA, Furberg CD. The necessity for clinical reasoning in the era of evidence-based medicine. Mayo Clin Proc. 2013 Oct;88(10):1108-14. doi: 10.1016/j.mayocp.2013.07.012
- van der Leeuw J, Ridker PM, van der Graaf Y, Visseren FL. Personalized cardiovascular disease prevention by applying individualized prediction of treatment effects. Eur Heart J. 2014 Apr;35(13):837-43. doi: 10.1093/eurheartj/ehu004. Epub 2014 Feb 9.