Tag Archives: nuts

Eat Nuts to Improve Your Blood Lipids and Reduce Risk of Cardiovascular Disease

natural cashews, cashew apple

Cashews fresh off the tree. They’re actually fruits, not nuts.

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.

Mediterranean Diet Helps Preserve Brain Function

Well, perhaps that’s a bit of an overstatement. Preserved brain function and the Mediterranean diet were  positively associated in a study involving Americans in Utah. This fits with prior observations that the Mediterranean diet prevents dementia.

Macadamia nuts

In the study at hand, the DASH diet (Dietary Approaches to Stop Hypertension) also protected the brain:

Higher levels of accordance [compliance] with both the DASH and Mediterranean dietary patterns were associated with consistently higher levels of cognitive function in elderly men and women over an 11-year period. Whole grains and nuts and legumes were positively associated with higher cognitive functions and may be core neuroprotective foods common to various healthy plant-centered diets around the globe.

See the American Journal of Clinical Nutrition for details.

Nut Consumption Linked to Longevity

American Journal of Clinical Nutrition has the details.

h/t Ivor Goodbody

Frequent Nuts Consumption Linked to 50% Lower Risk of Fatal Heart Attack

JAMA Internal Medicine has the details. Frequent consumption would be at least four times a week. 

Why Are Nuts So Prominent in My Diet Plans?

Nuts with more omega-3 fatty acids (compared to omega-6) may be the healthiest

Nuts with the lowest omega-6/omega-3 fatty acid ratios may be the healthiest. In other words, increase your omega-3s and decrease omega-6s.

Conner Middelmann-Whitney explains in her recent post at Psychology Today. In a nutshell, they are linked to longer life and better health. For example:

In the largest study of its kind, Harvard scientists found that people who ate a handful of nuts every day were 20% less likely to die from any cause over a 30-year period than those who didn’t consume nuts. The study also found that regular nut-eaters were leaner than those who didn’t eat nuts, a finding that should calm any fears that eating nuts will make you gain weight.

The report also looked at the protective effect on specific causes of death. “The most obvious benefit was a reduction of 29% in deaths from heart disease—the major killer of people in America,” according to Charles S. Fuchs, director of the Gastrointestinal Cancer Treatment Center at Dana-Farber, the senior author of the report and a professor of medicine at Harvard Medical School. “But we also saw a significant reduction—11% —in the risk of dying from cancer,” added Fuchs.

Read the whole enchilada.

Nuts are integral to my Advanced Mediterranean Diet, Low-Carb Mediterranean Diet, Paleobetic Diet, and Ketogenic Mediterranean Diet.

Walnuts seem to have the lowest omega-6/omega-3 fatty acid ratio of all the common nuts. That may make them the healthiest nut. The jury is still out. Paleo dieters focus on cutting out omega-6s and increasing omega-3s. Julianne Taylor has a great post on how to do that with a variety of foods, not just nuts.

Steve Parker, M.D.

Extra Virgin Olive Oil and Mixed Nuts May Be Critical to Healthy Mediterranean Diet

Remember that PREDIMED study published a couple months ago. It showed significant health benefits from a Mediterranean diet supplemented with EVOO and/or nuts. The general press simply focused on the Mediterranean diet angle, which helped with my book sales (thank you!).

Lawrence Appel and Linda Van Horn have an editorial on PREDIMED in New England Journal of Medicine, from which I quote:

Policymakers already recommend consumption of a Mediterranean-style diet on the basis of a persuasive body of evidence from observational studies. Our sense is that the policy implications of the PREDIMED trial relate primarily to the supplemental foods. Specifically, in the context of a Mediterranean-style diet, increased consumption of mixed nuts or substitution of regular olive oil with extra-virgin olive oil has beneficial effects on cardiovascular disease.

Read the rest.

Nuts: What’s Not to Love?

MPj04031620000[1]Nut consumption is strongly linked to reduced coronary heart disease, with less rigorous evidence for several other health benefits, according to the American Journal of Clinical Nutrition.

This is why I’ve included nuts as integral components of the Ketogenic Mediterranean Diet and the Advanced Mediterranean Diet.

Regular nut consumption is associated with health benefits in observational studies of various populations, within which are people eating few nuts and others eating nuts frequently. Health outcomes of the two groups are compared over time. Frequent and long-term nut consumption is linked to:

  • reduced coronary heart disease (heart attacks, for example)
  • reduced risk of diabetes in women (in men, who knows?)
  • less gallstone disease in both sexes
  • lower body weight and lower risk of obesity and weight gain

The heart-protective dose of nuts is three to five 1-ounce servings a week.

Steve Parker, M.D.

Reference: Sabaté, Joan and Ang, Yen. Nuts and health outcomes: New epidemiologic evidence. American Journal of Clinical Nutrition, 89 (2009): 1,643S-1,648S.

Mediterranean Diet + Nuts = Reversal of Metabolic Syndrome

An article published in 2008 by Bloomberg.com presents results of a scientific study in Spain that showed reduction in “metabolic syndrome” by the Mediterranean diet supplemented with nuts. CBSnews.com, Reuters, and others helped spread the news. The Bloomberg article was written by Nicole Ostrow.

Metabolic syndrome is a constellation of clinical factors that are associated with increased risk of type 2 diabetes and atherosclerotic complications such as heart attack and stroke. (Sometimes metabolic sydrome is called Syndrome X, which I sorta like. Oh, the mystery!) One in six Americans have the syndrome. Diagnosis requires at least three of the following five conditions:

  • High blood pressure (130/85 or higher, or using a high blood pressure medication)
  • Low HDL cholesterol: under 40 mg/dl in a man, under 50 in a women (or either sex taking a cholesterol-lowering drug)
  • Triglycerides over 150 mg/dl (or taking a cholesterol-lowering drug)
  • Abdominal fat: waist circumference 40 inches or greater in a man, 35 inches or greater in a woman
  • Fasting blood glucose over 100 mg/dl

The scientific study at hand is part of the PREDIMED study being conducted in Spain. For this portion of the study, 1,224 participants at high risk for cardiovascular disease were randomized to follow a 1) low-fat diet (considered the control group), 2) Mediterranean diet plus 1 liter virgin olive oil per week, or 3) Mediterranean diet plus 30 gm daily of mixed nuts.

Note that the nuts used in this study were walnuts, almonds, and hazelnuts. Half of all nuts were walnuts; a quarter of the nuts were almonds and a quarter were hazelnuts.

Participants were 55-80 years old, and 61% had metabolic syndrome at baseline. Participants could eat all they wanted, and there was no increase in physical activity for any of the groups. Participants were given instructions at baseline and quarterly.

After one year of intervention, the prevalence of metabolic syndrome was reduced by 14% in the Mediterranean diet plus nuts group compared to the control, low-fat diet group. The Mediterranean diet plus extra olive oil group reduced prevalence of metabolic syndrome by 7%, but this did not reach statistical significance (P=0.18).

New cases of metabolic syndrome continued to develop at about the same rate in all three groups. I.e., incident rates were not significantly different. So, the lower prevalence of metabolic syndrome after one year reflected reversion or clearing of the syndrome in many people who had it at baseline. Compared to the control group, people in the nutty group were 70% more likely to resolve their metabolic syndrome. Individuals in the oily group were 30% more likely than controls to resolve the condition.

(Feel free to consult a dictionary for definitions of “prevalence” and “incidence.”)

The researchers conclude that:

A traditional Mediterranean diet enriched with nuts could be a useful tool in the management of the metabolic syndrome.

My Comments:

Thirty grams (daily) of nuts is a decent-sized snack of about 180 calories. Thirty grams of almonds formed a heap in the palm of my hand, not touching my fingers. This is more than the “two tablespoons” reported by CBSnews.com December 9.

If you have metabolic syndrome, you might want to try reversing it with all the usual methods (e.g., lose excess fat weight, exercise more) along with a traditional Mediterranean diet enriched with 30 gm of mixed nuts daily. As usual, check with your personal healthcare provider first. Be aware that many of them won’t know about this study.

The puzzling thing to me is: If the Mediterranean diet plus extra nuts is so effective in reversing metabolic syndrome, why didn’t that study cohort see fewer new cases of metabolic syndrome?

Steve Parker, M.D.

Additional reference: Salas-Salvado, Jordi, et al. Effect of a Mediterranean Diet Supplemented With Nuts on Metabolic Syndrome Status: One-Year Results of the PREDIMED Randomized Trial. Archives of Internal Medicine, 168 (2008): 2,449-2,458.

Nuts Improve Blood Sugar and Cholesterol in Diabetics

Eating nuts improves blood sugar control and cholesterol levels in type 2 diabetics, according to a research report in Diabetes Care.

Canadian researchers randomized 117 type 2 diabetics to eat their usual types of food, but also to be sure to eat either

  • mixed nuts (about 2 ounces a day)
  • muffins (I figure one a day)
  • or half portions of each.

They did this daily for three months. Compared to the muffin group, the full nut group ate quite a bit more monounsaturated fatty acids. (I don’t have full study details because I have access only to the article abstract.)

Results

Hemoglobin A1c, a reliable measure of blood sugar control, fell by 0.21% in the mixed nut group. That’s a move in the right direction. LDL cholesterol, the “bad cholesterol” linked to heart and vascular disease, also dropped significantly.

So What?

The investigators suggest that replacement of certain carbohydrates with 2 ounces of daily mixed nuts is good for people with type 2 diabetes.

I must mention that nuts are a mandatory component of the Ketogenic Mediterranean Diet and the Low-Carb Mediterranean Diet, and a recommended option on the Advanced Mediterranean Diet.

Steve Parker, M.D.

References: Jenkins, David J.A., et al. Nuts as a replacement for carbohydrates in the diabetic diet. Diabetes Care, June 29, 2011. doi: 10.2337/dc11-0338

PS: The lead author of this study is the same David Jenkins of glycemic index fame.