September 2017 Issue
Diet vs Statins
By Densie Webb, PhD, RD
Vol. 19, No. 9, P. 26
Is one better than the other for the prevention of CVD?
Atherosclerotic CVD (ASCVD) is a leading cause of premature death and disability in the United States.1 Advice on ways to reduce CVD risk abounds. So what's the best method for preventing atherosclerosis and ultimately CVD?
Dietary changes can reduce cholesterol levels in the blood, sometimes significantly. Drugs, such as statins, also have been proven effective. But which is best? Should diet be altered before turning to drugs? Should statins be prescribed more liberally? Should diets and drugs be used together for optimal results?
Today's Dietitian examines the research and speaks with experts to learn more about the diet vs statins debate.
Statins for ASCVD Prevention
Elevated blood cholesterol is well established as a factor in the development of atherosclerosis and eventual CVD.2 Prolonged exposure to elevated cholesterol levels increases risk, so the sooner patients take preventive measures the better.3
Statins are medications that commonly are prescribed to lower LDL cholesterol in an effort to prevent CVD development. In fact, they're the only cholesterol-lowering drugs that have been directly associated with decreasing the risk of heart attack or stroke.4 So not only do statins effectively lower LDL cholesterol, but there's also clear evidence they reduce the risk of having a heart attack and prevent both nonfatal and fatal major vascular events. The degree of benefit, however, depends on the person's risk profile, the magnitude of LDL reduction and length of treatment, and whether low-intensity, moderate-intensity, or high-intensity statin therapy is given.
Intensity is based on dosage of the statin used; the higher the risk, the higher the dose recommended.3,5 Despite some reports that statins may offer other health benefits, such as reduced risk of cancer, infections, respiratory disease, and arrhythmias, there's no conclusive evidence demonstrating that these other benefits occur.5
Statin drugs such as Lipitor, Mevacor, Crestor, and Zocor lower LDL cholesterol between 20% and 50% by slowing down the liver's production of cholesterol.6 They also increase the liver's ability to remove LDL cholesterol that's already in the blood.7 Cost varies widely from a few dollars per month to a few hundred dollars depending on whether the statin is available as a generic (most, but not all, have generic formularies) and whether health insurance policies, including Medicare, will reimburse patients (some do, some don't).
The 2016 guidelines from the American College of Cardiology (ACC) recommend statin therapy for four at-risk population groups: 1) adults aged 21 and older with ASCVD; 2) adults aged 21 and older with LDL cholesterol ≥190 mg/dL; and 3) adults aged 40 to 75 without ASCVD but who have diabetes and LDL cholesterol 70 to 189 mg/dL and an estimated 10-year risk of ASCVD of 7.5% or greater.8 A large portion of the adult population meets these criteria.
A patient's or a client's 10-year risk of heart attack or stroke can be calculated online using the American Heart Association (AHA)/ACC risk calculator at www.cvriskcalculator.com. It's also available as an app in iTunes. The calculator assumes there's no existing heart disease and no history of stroke. It doesn't take weight or physical activity into account. According to Jo Ann Carson, PhD, RDN, a professor of clinical nutrition at the University of Texas Southwestern Medical School in Dallas, when people use the risk factors in the calculator, adding in body weight doesn't make a significant difference in the calculated risk.
The calculation is based on total cholesterol and HDL cholesterol, blood pressure, whether a person has received treatment for high blood pressure, and smoking and diabetes status. Because of a lack of evidence, the calculator can't predict CVD risk for people younger than 40 or older than 79 or for those with total cholesterol greater than 320 mg/dL. Nonetheless, according to a recent Cochrane systematic review, statin treatment can be an effective lipid-lowering therapy in children with familial hypercholesterolemia.9 The review found statin treatment to be safe for children in the short term, but long-term safety hasn't been studied. Children treated with statins should be carefully monitored.
Detecting CVD before a cardiac event can be difficult. The risk calculator is an indirect method for detecting the possibility of developing or having CVD. However, a method for more directly assessing risk in people without symptoms of CVD is the Calcium Scoring screening technique, a noninvasive imaging system that detects coronary artery calcium, which indicates the presence of disease with essentially no false-positive findings.10
While statins work virtual miracles for many, they can cause uncomfortable side effects. About 10% to 20% of people taking statins report experiencing muscle aches and muscle weakness.3 In fact, this side effect is a major reason cited for stopping the medication. Rarely, it can progress to rhabdomyolysis, severe muscle weakness from damaged muscles, which can, in turn, damage the kidneys as they try to rid the body of muscle breakdown products.11
Diet for ASCVD Prevention
"Lifestyle modification, including a heart-healthy diet, should be adopted irrespective of level of cardiovascular risk," says Gregg C. Fonarow, MD, a professor of medicine at UCLA and director of the Ahmanson–UCLA Cardiomyopathy Center. Recent studies show that dietary changes can make a big difference in ASCVD risk, even among people who are genetically predisposed to the condition.
An analysis published in the December 15, 2016, issue of The New England Journal of Medicine found that the relative risk of having a coronary event was 91% higher among people at high genetic risk than among those at low genetic risk. However, a "favorable" lifestyle (defined as having at least three of four healthful lifestyle factors—healthful diet, physical activity, nonsmoking, not overweight—was associated with a substantially lower risk of coronary events than an unfavorable lifestyle (defined as having no or only one healthful lifestyle factor), regardless of genetic makeup. Among study participants at high genetic risk, a favorable lifestyle was associated with a 46% lower relative risk of coronary events.12 That's not the result of diet alone, but a heart-healthy diet was a major factor.
Mediterranean-style diets have been found to reduce LDL cholesterol anywhere from 10% to 29%.13,14 Another study published in the April 4, 2013, issue of The New England Journal of Medicine found that the Mediterranean diet was associated with primary CVD prevention in people at high risk.15 As part of the PREDIMED study (Prevención con Dieta Mediterranea), a Mediterranean diet supplemented with extra-virgin olive oil or nuts substantially reduced the incidence of major cardiovascular events in a Spanish population. But the problem with broadly applying the findings, according to the AHA, is that while the Mediterranean diet is widely recommended, it's inconsistently defined.16
For all patients, the current recommendations from the AHA and the ACC for ASCVD prevention emphasize that lifestyle modification (a heart-healthy diet, regular exercise, avoidance of tobacco products, and maintenance of a healthy weight) remains a critical component of any prevention plan, both before and together with the use of any cholesterol-lowering drug therapies. The ACC also states that "referral to a registered dietitian nutritionist may be considered to improve understanding of heart-healthy dietary principles and individualize nutrition recommendations." The recommendations also state that adherence to lifestyle modifications should be regularly assessed both before and during statin therapy monitoring.
Achieving adherence to the AHA-recommended dietary pattern for risk reduction can be accomplished by helping clients and patients choose preferred foods they enjoy, with consideration of cultural, economic, and social factors. The AHA statement says that by considering nutrient-dense choices that meet but don't exceed calorie needs, individuals can achieve further weight-control goals. Emphasizing patient/client-tailored intervention that encourages self-monitoring of diet and physical activity levels is an effective strategy for promoting greater acceptance and sustained adherence to the recommended heart-healthy AHA dietary pattern.16
Angel Planells, MS, RDN, CD, a spokesperson for the Academy of Nutrition and Dietetics and lead dietitian in the home-based primary care program at the VA in Puget Sound, Washington, says, "Encouraging citizens to get their annual health checkups and see a dietitian can be a great way to get folks to make a change before adding statins to a regimen to reduce risk."
The 2016 joint recommendations of the AHA and the ACC for lowering blood cholesterol and reducing ASCVD risk include the following for a 2,000-kcal diet*:
• Fruits: 2 cups/day
• Vegetables: 21/2 cups/day
• Beans and peas: 11/2 cups/week
• Whole grains: 3 servings/day
• Nuts, seeds, legumes: 5 oz/week
• Fat-free or low-fat dairy: 3 cups/day
• Fiber: 31 g/day
• Sodium: 1,787 mg/day
• Oils, unsaturated: 3 T/day
• Added sugars: 61/2 tsp/day
• Fish: 8 oz/week
• Meat, poultry, eggs: 26 oz eq/week**
* For other calorie levels, visit http://circ.ahajournals.org/content/134/22/e505.long.
** 1 oz equivalent is 1 oz lean meat, poultry, or seafood; 2 egg whites or 1 egg; 1/4 cup cooked beans; 1 T peanut butter; 0.5 oz unsalted nuts/seeds.
So, Diet or Statins?
The answer to this question isn't so simple. That's because there's no single answer. Whether diet or statins is best depends on individual patients, their risk profile, and which approach they're likely to adhere to over the long term. Carson says that while some populations may be motivated to follow a risk-reducing Mediterranean-style diet, others have no desire to even attempt such a change from their usual dietary patterns.
"For individuals with 5% or more risk over 10 years (using the risk calculator), statin therapy is recommended and statins should be applied together with lifestyle modifications," Fonarow says. But how much an individual's lifestyle will be changed is impossible to predict.
Statin therapy and dietary modifications can be thought of as two legs of a three-legged stool—the third being other lifestyle factors, such as physical activity and not smoking. "There's a whole stack of studies showing statins are effective at reducing risk, but most incorporated a heart-healthy diet as part of the treatment," Carson says.
And while statins generally reduce blood cholesterol, regardless of diet, Carson says that fact can present a perception problem, noting that attitudes sometimes shift in patients taking statins. "They might say, 'I can eat hot dogs now. I don't have to worry, because I'm taking a statin,'" she says.
Another issue that can affect adherence to statins is that patients feel the same whether they take them or not. A similar situation exists with blood pressure medications: The patient doesn't feel any improvement, so there's no tangible reward, no incentive for continuing.
Patients may be much more aware of the side effects than of the benefits. The potential side effect of muscle pain can be a deterrent to sticking with statin therapy. However, "The side effect of not taking statins is a 25% to 45% higher risk of heart attack, stroke, and premature cardiovascular death," Fonarow says, adding that "it's generally difficult to get individuals to adhere to things that help lower their risk safely and effectively. This is true whether it involves dietary changes or taking a prescription medication."
In addition, there's considerable hype and misinformation on the internet from fad diet groups pushing the idea that cholesterol is good, ie, it's OK to have high cholesterol. Add to that consumer mistrust of large pharmaceutical companies and people often are willing to avoid statins and rely on diet and exercise alone to lower cholesterol no matter the health consequences.
The current health care climate of high health insurance deductibles, increased out-of-pocket expenses, and changing availability and unaffordability of many insurance policies can present even greater obstacles to continued adherence to statins and obtaining diet counseling.
It's a given that everyone, regardless of risk profile, should make lifestyle modifications, including a heart-healthy diet, to reduce the likelihood of ASCVD developing or worsening. Whether statins should be added to the mix is something a client's health care provider must determine. But it's important for individuals to understand that while statins are effective at lowering cholesterol and reducing the risk of a cardiac event, a statin prescription doesn't mean that a heart-healthy diet is no longer needed to reduce risk.
— Densie Webb, PhD, RD, is a freelance writer, editor, and consultant based in Austin, Texas.
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