Category Archives: Heart Disease

Do Nuts Help Or Hurt Cholesterol Levels?

Mixed Nuts Improve Diabetes, Too

Mixed Nuts Improve Diabetes

Most of the diets I recommend to my patients include nuts because they are so often linked to improved cardiovascular health in scientific studies. Walnuts are associated with reduced risk of type 2 diabetes in women, and established type 2 diabetics see improved blood sugar control and lower cholesterols when adding nuts to their diets.

Nut consumption lowers total and LDL cholesterol levels, and if triglycerides are elevated, nuts lower them, too. Those changes would tend to reduce heart disease.

Conner Middelmann-Whitney has a good nutty article at Psychology Today.

Steve Parker, M.D.

Reference: Joan Sabaté, MD, DrPH; Keiji Oda, MA, MPH; Emilio Ros, MD, PhD. Nut Consumption and Blood Lipid Levels: A Pooled Analysis of 25 Intervention Trials. Archives of Internal Medicine, 2010, Vol. 170 No. 9, pp 821-827. Abstract:

Background  Epidemiological studies have consistently associated nut consumption with reduced risk for coronary heart disease. Subsequently, many dietary intervention trials investigated the effects of nut consumption on blood lipid levels. The objectives of this study were to estimate the effects of nut consumption on blood lipid levels and to examine whether different factors modify the effects.

Methods:  We pooled individual primary data from 25 nut consumption trials conducted in 7 countries among 583 men and women with normolipidemia and hypercholesterolemia who were not taking lipid-lowering medications. In a pooled analysis, we used mixed linear models to assess the effects of nut consumption and the potential interactions.

Results:  With a mean daily consumption of 67 g of nuts [about 2 ounces or 2 palms-ful], the following estimated mean reductions were achieved: total cholesterol concentration (10.9 mg/dL [5.1% change]), low-density lipoprotein cholesterol concentration (LDL-C) (10.2 mg/dL [7.4% change]), ratio of LDL-C to high-density lipoprotein cholesterol concentration (HDL-C) (0.22 [8.3% change]), and ratio of total cholesterol concentration to HDL-C (0.24 [5.6% change]) (P < .001 for all) (to convert all cholesterol concentrations to millimoles per liter, multiply by 0.0259). Triglyceride levels were reduced by 20.6 mg/dL (10.2%) in subjects with blood triglyceride levels of at least 150 mg/dL (P < .05) but not in those with lower levels (to convert triglyceride level to millimoles per liter, multiply by 0.0113). The effects of nut consumption were dose related, and different types of nuts had similar effects on blood lipid levels. The effects of nut consumption were significantly modified by LDL-C, body mass index, and diet type: the lipid-lowering effects of nut consumption were greatest among subjects with high baseline LDL-C and with low body mass index and among those consuming Western diets.

Conclusion:  Nut consumption improves blood lipid levels in a dose-related manner, particularly among subjects with higher LDL-C or with lower BMI.

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Filed under Heart Disease, nuts

Worried About Future Heart Attack? Check Your LDL Cholesterol Particle Number (LDL-P)

…according to Drs. Thomas Dayspring and James Underberg. I don’t know if these guys are right or not. I bet it’s more complicated than simple LDL particle number.

Even if you eat lots of eggs, most of your cholesterol is made by your liver. That's where statin drugs work.

Even if you eat lots of eggs, most of your cholesterol is made by your liver. That’s where statin drugs work.

Most heart attacks (aka myocardial infarctions) do indeed seem to be caused by acute rupture of an atherosclerotic plaque that’s been present for years. Two key questions are:

  1. What causes the plaque?
  2. Why causes them to rupture?

Underberg and Dayspring write:

The only absolute requirement for plaque development is the presence of cholesterol in the artery: although there are additional heart risk factors like smoking, hypertension, obesity, family history, diabetes, kidney disease, etc., none of those need to be present. Unfortunately, measuring cholesterol in the blood, where it cannot cause plaque, until recently has been the standard of risk-testing. That belief was erroneous and we now have much better biomarkers to use for CV risk-assessment. The graveyard and coronary care units are filled with individuals whose pre-death cholesterol levels were perfect. We now understand that the major way cholesterol gets into the arteries is as a passenger, in protein-enwrapped particles, called lipoproteins.

Particle entry into the artery wall is driven by the amount of particles (particle number) not by how much cholesterol they contain. Coronary heart disease is very often found in those with normal total or LDL-cholesterol (LDL-C) levels in the presence of a high LDL particle number (LDL-P). By far, the most common underlying condition that increases LDL particle concentration is insulin resistance, or prediabetes, a state where the body actually resists the action of the sugar controlling hormone insulin. This is the most common scenario where patients have significant heart attack risk with perfectly normal cholesterol levels. The good news is that we can easily fix this, sometimes without medication. The key to understanding how comes with the knowledge that the driving forces are dietary carbohydrates, especially fructose and high-fructose corn syrup. In the past, we’ve often been told that elimination of saturated fats from the diet would help solve the problem. That was bad advice. The fact is that until those predisposed to insulin resistance drastically reduce their carbohydrate intake, sudden deaths from coronary heart disease and the exploding diabetes epidemic will continue to prematurely kill those so afflicted.

***

And for goodness’ sake, if you want to live longer, start reducing the amount of dietary carbohydrates, including bread, potatoes, rice, soda and sweetened beverages (including fruit juices), cereal, candy – the list is large).

Underberg and Dayspring don’t mention don’t mention LDL particle size, such as small/dense and large/fluffy; the former are thought by many to be much more highly atherogenic. Is that outdated?

Whoever figures out the immediate cause of plaque rupture and how to reliably prevent it will win a Nobel Prize in Medicine.

Read the whole enchilada.

Steve Parker, M.D.

About Dayspring and Underberg:

Thomas Dayspring MD, FACP, FNLA   Director of Cardiovascular Education, The Foundation for Health Improvement and Technology, Richmond, VA. Clinical Assistant Professor of Medicine, University of Medicine and Dentistry of New Jersey, New Jersey Medical School.

James Underberg MD, FACP, FNLA   Clinical Assistant Professor of Medicine in the Division of General Internal Medicine at NYU Medical School and the NYU Center for Cardiovascular Disease Prevention . Director of the Bellevue Hospital Primary Care Lipid Management Clinic.

h/t Dr. Axel Sigurdsson

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Filed under coronary heart disease, Heart Disease, Uncategorized

Heart-Healthy Lifestyle Prevents Cancer, Too

…according to a report in MedPageTodayType 2 diabetes is linked to higher incidence of several cancers: liver, pancreas, uterus, colo-rectal, breast, and bladder.  On a brighter note, diabetics have lower risk of prostate cancer. Diabetes is also associated with higher risk of heart disease.

I'm still not convinced that severe sodium restriction is necessary or even possible for most people

I’m still not convinced that severe sodium restriction is necessary or even possible for most people

The American Heart Association has published guidelines aiming to reduce premature death and illness caused by cardiovascular diseases such as heart attacks, high blood pressure, and strokes.

The guidelines focus on seven factors critical to cardiovascular health:

  • smoking
  • blood sugar
  • blood pressure
  • physical activity
  • total cholesterol
  • body mass index (BMI)
  • ideal diet

Using data from the Atherosclerosis Risk In Communities study (almost two decades’ follow-up), researchers found that those who maintained goals for six or seven of the American Heart Association critical factors had a 51% lower risk of cancer compared with those meeting no goals.

For detailed information about the specific goals, click here.

As you might expect, I was curious about what the American Heart Association considered a heart-healthy diet.  I quote the AHA summary:

The recommendation for the definition of the dietary goals and metric, therefore, is as follows: “In the context of a diet that is appropriate in energy balance, pursuing an overall dietary pattern that is consistent with a DASH [Dietary Approaches to Stop Hypertension]-type eating plan, including but not limited to:

  • Fruits and vegetables: ≥ 4.5 cups per day
  • Fish: ≥ two 3.5-oz servings per week (preferably oily fish)
  • Fiber-rich whole grains (≥ 1.1 g of fiber per 10 g of carbohydrate): ≥ three 1-oz-equivalent servings per day
  • Sodium: < 1500 mg per day
  • Sugar-sweetened beverages: ≤ 450 kcal (36 oz) per week

Intake goals are expressed for a 2000-kcal diet and should be scaled accordingly for other levels of caloric intake. For example, ≤ 450 calories per week represents only up to one quarter of discretionary calories (as recommended) coming from any types of sugar intake for a 2000-kcal diet.

Diet recommendations are more complicated than that; read the full report for details.  Only 5% of study participants ate the “ideal diet.”  The AHA-recommended diet may have too many carbohydrates for some diabetics. The Mediterranean diet easily meets four out of five of those diet goals; you’d have to be extremely careful to reach the sodium goal on most any diet.

Cardiovascular diseases and cancer are among the top causes of death in Western societies.  Adhering to the guidelines above may kill two birds with one stone.

Steve Parker, M.D.

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Filed under cancer, Heart Disease

You May Be Wasting Money On Worthless Heart Drugs

 

Open wide!

Open wide!

…according to an article at MedPageToday.  Specific brands of extended-release niacin and fibrates are mentioned, among others.  I particularly like this quote of Dr. James Stein:

“So at least $4.5 billion was spent on drugs with uncertain benefit and known risks,” Stein said. “I’d much rather these patients focus on exercising and eating a healthy, Mediterranean-based diet, which has been proved to reduce heart attacks and strokes, than spending money on these agents.”

It’s a good idea to talk to the prescribing physician before stopping any of your drugs.

Steve Parker, M.D.

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Filed under Heart Disease

Low Glycemic Index Diets Reduce LDL and Total Cholesterol

…according to a recent report in Nutrition, Metabolism & Cardiovascular Disease. LDL cholesterol is the type we think contributes to coronary artery disease and other forms of atherosclerosis.

Learn about glycemic index at NutritionData.

My Low-Carb Mediterranean and Ketogenic Mediterranean Diets are undoubtedly “low glycemic index.”  The Advanced Mediterranean Diet would also be significantly lower GI than the standard American diet.

Steve Parker, M.D.

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Filed under Glycemic Index and Load, Heart Disease

Is Sugar the New Fat?

Lumps of Death

Lumps of Death

In the 1950s, John Yudkin wrote a book, Pure, White, and Deadly (amazingly still available at Amazon), blaming sugar as the primary cause of heart disease (coronary heart disease).  The idea didn’t gain sufficient traction and the dietary fat theory of heart disease became the reigning dogma.  Now that the latter theory has been discredited, researchers are looking at sugar again.

The British Medical Journal has a pertinent article you’ll undoubtedly enjoy, if you’re the sort of person who enjoys these things.  I quote:

“In recent years, and slowly, the sugar hypothesis has been making a comeback, driven in part by the emerging perception of heart disease as a consequence of what’s now described as the metabolic syndrome: obesity, dyslipidaemia, raised blood pressure, and insulin resistance. Although there is still no consensus about the causes of the syndrome, an excess of fat in the liver—a response to dietary sugar—is one of the acknowledged possibilities.  Fructose, found in large quantities in nearly all added sugars, is known to increase lipogenesis in the liver and the synthesis of hepatic triglyceride.”

Steve Parker, M.D.

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Filed under Heart Disease

Eggs Are Linked to Heart Attacks in Diabetics?

The general population doesn’t need to worry about eggs causing strokes or heart attacks according to a new meta-analysis reviewed at Forbes. We still have a question about high egg consumption and heart attacks in diabetics.

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Filed under Heart Disease

Which Diseases Do Vegetables and Fruits Prevent?

Potential answers are in the American Journal of Clinical Nutrition (2012).  I quote:

For hypertension, coronary heart disease, and stroke, there is convincing evidence that increasing the consumption of vegetables and fruit reduces the risk of disease. There is probable evidence that the risk of cancer in general is inversely associated with the consumption of vegetables and fruit. In addition, there is possible evidence that an increased consumption of vegetables and fruit may prevent body weight gain. As overweight is the most important risk factor for type 2 diabetes mellitus, an increased consumption of vegetables and fruit therefore might indirectly reduces the incidence of type 2 diabetes mellitus. Independent of overweight, there is probable evidence that there is no influence of increased consumption on the risk of type 2 diabetes mellitus. There is possible evidence that increasing the consumption of vegetables and fruit lowers the risk of certain eye diseases, dementia and the risk of osteoporosis. Likewise, current data on asthma, chronic obstructive pulmonary disease, and rheumatoid arthritis indicate that an increase in vegetable and fruit consumption may contribute to the prevention of these diseases. For inflammatory bowel disease, glaucoma, and diabetic retinopathy, there was insufficient evidence regarding an association with the consumption of vegetables and fruit.

It bothers me that vegetables and fruits are lumped together: they’re not the same.

All of my diets—Advanced MediterraneanLow-Carb Mediterranean, and Ketogenic Mediterranean—provide plenty of fruits and vegetables.

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Filed under cancer, Dementia, Fruits, Heart Disease, Stroke, Vegetables

Is Low-Carb Killing Swedish Women?

MPj04384870000[1]A recent Swedish study suggests that low-carbohydrate/high protein diets increase the risk of cardiovascular disease in women.  I’m not convinced, but will keep an eye on future developments.  This is a critical issue since many women eat low-carb/high protein for weight loss and management.

Researchers followed 43,000 women, 30-49 years of age at enrollment, over the course of 16 years.  In that span, they had 1270 cardiovascular events: ischemic heart disease (heart attacks and blocked heart arteries), strokes, subarachnoid hemorrhages,  and peripheral arterial disease.  Food consumption was estimated from a questionnaire filled out by study participants at the time of enrollment (and never repeated).

In practical terms, … a 20 gram decrease in daily carbohydrate intake and a 5 gram increase in daily protein intake would correspond to a 5% increase in the overall risk of cardiovascular disease.

So What?

To their credit, the researchers note that a similar analysis of the Women’s Health Study in the U.S. found no such linkage between cardiovascular disease and low-carb/high protein eating.

The results are questionably reliable since diet was only assessed once during the entire 16-year span.

I’m certain the investigators had access to overall death rates.  Why didn’t they bother to report those?  Your guess is as good as mine.  Even if low-carb/high protein eating increases the rate of cardiovascular events, it’s entirely possible that overall deaths could be lower, the same, or higher than average.  That’s important information.

I don’t want to get too far into the weeds here, but must point out that the type of carbohydrate consumed is probably important.  For instance, easily digested carbs that raise blood sugar higher than other carbs are associated with increased heart disease in women.  “Bad carbs” in this respect would be simple sugars and refined grains.

In a 2004 study, higher carbohydrate consumption was linked to progression of blocked heart arteries in postmenopausal women.

It’s complicated.

Steve Parker, M.D.

PS: I figure Swedish diet doctor Andreas Eenfeldt would have some great comments on this study, but can’t find them at his blog.

Reference: Lagiou, Pagona, et al.  Low carbohydrate-high protein diet and incidence of cardiovascular diseases in Swedish women: prospective cohort study.  British Medical Journal, June 26, 2012.  doi: 10.1136/bmj.e4026

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Filed under Carbohydrate, coronary heart disease, Heart Disease, Protein

Low-Carb Research Update

“What about that recent study in American Journal of Clinical Nutrition…?”

As much as possible, I base my nutrition and medical recommendations on science-based research published in the medical literature.  Medical textbooks can be very helpful, but they aren’t as up-to-date as the medical journals.

In the early 2000s, a flurry of research reports demonstrated that very-low-carb eating (as in Dr. Atkins New Diet Revolution) was safe and effective for short-term weight management and control of diabetes.  I was still concerned back then about the long-term safety of the high fat content of Atkins.  But 80 hours of literature review in 2009 allowed me to embrace low-carbohydrate eating as a logical and viable option for many of my patients.  The evidence convinced me that the high fat content (saturated or otherwise) of many low-carb diets was little to worry about over the long run.

By the way, have you noticed some of the celebrities jumping on the low-carb weight-management bandwagon lately?  Sharon Osbourne, Drew Carey, and Alec Baldwin, to name a few.

My primary nutrition interests are low-carb eating, the Mediterranean diet, and the paleo diet.  I’m careful to stay up-to-date with the pertinent scientific research.  I’d like to share with you some of the pertinent research findings of the last few years.

Low-Carb Diets

  • Low-carb diets reduce weight, reduce blood pressure, lower triglyceride levels (a healthy move), and raise HDL cholesterol (another good trend).  These improvements should help reduce your risk of heart disease.  (In the journal Obesity Reviews, 2012.)
  • Dietary fat, including saturated fat, is not a cause of vascular disease such as heart attacks and atherosclerosis (hardening of the arteries).  (Multiple research reports.)
  • If you’re overweight and replace two sugary drinks a day with diet soda or water, you’ll lose about four pounds over the next six months.  (American Journal of Clinical Nutrition, 2012.)
  • United States residents obtain 40% of total calories from grains and added sugars.  Most developed countries are similar.  Dr. Stephan Guyenet notes that U.S. sugar consumption increased steadily “…from 6.3 pounds [2.9 kg] per person per year in 1822 to 107.7 pounds [50 kg] per person in 1999.  Wrap your brain around this: in 1822 we ate the amount of added sugar in one 12-ounce can of soda every five days, while today we eat that much sugar every seven hours.”
  • A very-low-carb diet improves the memory of those with age-related mild cognitive impairment. Mild cognitive impairment is a precursor to dementia.  (University of Cincinnati, 2012.)
  • High-carbohydrate and sugar-rich diets greatly raise the risk of mild cognitive impairment in the elderly. (Mayo Clinic study published in the Journal of Alzheimers’ Disease, 2012.)
  • Compared to obese low-fat dieters, low-carb dieters lose twice as much fat weight.  (University of Cincinnati, 2011.)
  • Diets low in sugar and refined starches are linked to lower risk of age-related macular degeneration in women.  Macular degeneration is a major cause of blindness.  (University of Wisconsin, 2011.)
  • A ketogenic (very-low-carb) Mediterranean diet cures metabolic syndrome (Journal of Medicinal Food, 2011.)
  • For type 2 diabetics, replacing a daily muffin (high-carb) with two ounces (60 g) of nuts (low-carb) improves blood sugar control and reduces LDL cholesterol (the “bad” cholesterol). (Diabetes Care, 2011.)
  • For those afflicted with fatty liver, a low-carb diet beats a low-fat diet for management. (American Journal of Clinical Nutrition, 2011.)
  • For weight loss, the American Diabetes Association has endorsed low-carb (under 130 g/day) and Mediterranean diets, for use up to two years. (Diabetes Care, 2011.)
  • High-carbohydrate eating doubles the risk of heart disease (coronary artery disease) in women.  (Archives of Internal Medicine, 2010.)
  • One criticism of low-carb diets is that they may be high in protein, which in turn may cause bone thinning (osteoporosis).  A 2010 study shows this is not a problem, at least in women.  Men were not studied.  (American Journal of Clinical Nutrition.)
  • High-carbohydrate eating increases the risk of developing type 2 diabetes (American Journal of Clinical Nutrition, 2010.)
  • Obesity in U.S. children tripled from 1980 to 2000, rising to 17% of all children.  A low-carb, high-protein diet is safe and effective for obese adolescents.  (American Journal of Clinical Nutrition, 2010.)

Mediterranean Diet

The traditional Mediterranean diet is well established as a healthy way of eating despite being relatively high in carbohydrate: 50 to 60% of total calories.  It’s known to prolong life span while reducing rates of heart disease, cancer, strokes, diabetes, and dementia.  The Mediterranean diet is rich in fresh fruits, vegetables, nuts and seeds, olive oil, whole grain bread, fish, and judicious amounts of wine, while incorporating relatively little meat.  It deserves your serious consideration.  I keep abreast of the latest scientific literature on this diet.

  • Olive oil is linked to longer life span and reduced heart disease.  (American Journal of Clinical Nutrition, 2012.)
  • Olive oil is associated with reduced stroke risk.  (Neurology, 2012).
  • The Mediterranean diet reduces risk of sudden cardiac death in women.  (Journal of the American Medical Association, 2011.)
  • The Mediterranean diet is linked to fewer strokes visible by MRI scanning.  (Annals of Neurology, 2011.)
  • It reduces the symptoms of asthma in children.  (Journal of the American Dietetic Association, 2011.)
  • Compared to low-fat eating, it reduces the incidence of type 2 diabetes by 50% in middle-aged and older folks.  (Diabetes Care, 2010.)
  •  A review of all available well-designed studies on the Mediterranean diet confirms that it reduces risk of death, decreases heart disease, and reduces rates of cancer, dementia, Parkinson’s disease, stroke, and mild cognitive impairment.  (American Journal of Clinical Nutrition, 2010.)
  • It reduces the risk of breast cancer.  (American Journal of Clinical Nutrition, 2010.)
  • The Mediterranean diet reduces Alzheimer’s disease.   (New York residents, Archives of Neurology, 2010).
  • It slows the rate of age-related mental decline.  (Chicago residents, American Journal of Clinical Nutrition, 2010.)
  • In patients already diagnosed with heart disease, the Mediterranean diet prevents future heart-related events and preserves heart function.  (American Journal of Clinical Nutrition, 2010.)

Clearly, low-carb and Mediterranean-style eating have much to recommend them.  Low-carb eating is particularly useful for weight loss and management, and control of diabetes, prediabetes, and metabolic syndrome.  Long-term health effects of low-carb eating are less well established.  That’s where the Mediterranean diet shines.  That’s why I ask many of my patients to combine both approaches: low-carb and Mediterranean.  Note that several components of the Mediterranean diet are inherently low-carb: olive oil, nuts and seeds, fish, some wines, and many fruits and vegetables.  These items easily fit into a low-carb lifestyle and may yield the long-term health benefits of the Mediterranean diet.  If you’re interested, I’ve posted on the Internet a Low-Carb Mediterranean Diet that will get you started.

Steve Parker, M.D.

Disclaimer:  All matters regarding your health require supervision by a personal physician or other appropriate health professional familiar with your current health status.  Always consult your personal physician before making any dietary or exercise changes.

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Filed under Carbohydrate, Fat in Diet, Health Benefits, Heart Disease, ketogenic diet, Mediterranean Diet, nuts, olive oil, Stroke, Vegetables, Weight Loss