You will be happy to know that the best fats for your cardiovascular health come in a variety of flavors and can be used in so many delicious dishes.
The best fats are literally nutritional powerhouses. Although tree nuts are high in fat, they contain fiber, high-quality protein, potassium, magnesium, anti-inflammatory compounds, and antioxidants. Predominately the fats in nuts are composed of healthy monounsaturated and polyunsaturated fatty acids. Many nuts are also rich in omega-3 fatty acids. Nuts are rich in L-arginine, an amino acid that helps preserve the flexibility of arteries and discourage undesirable clotting.
Which Fats Reduce Risk for Cancer and Cardiovascular Disease?
Spanish researchers examined the effect on the primary prevention of cardiovascular disease of over 7000 older people (ages 55 to 90) randomized to a Mediterranean Diet, supplemented with extra virgin olive oil or nuts, and compared to a control group following a low fat diet. Here are their findings:1
- There were fewer people with type 2 diabetes or people taking medicine for hypertension in the group of people who ate the most nuts.
- Nut eaters had a 39% lower mortality risk and walnut eaters did even better at 45% lower risk.
- People eating more than 3 servings (1 serving — 28 g) a week of tree nuts reduced the risk of death due to cardiovascular disease by 55% and cancer by 40%. A similar effect was demonstrated with walnuts.
Four Ways Nuts Benefit Diabetics
In diabetes the ability of the blood vessels to dilate is significantly compromised. Stress also causes blood vessels to constrict. Two servings of pistachios per day lowered vascular constriction during stress and improved neural control of the heart in diabetic adults. In this study one group of participants ate a standard heart-healthy diet, 27 percent fat and 7 percent saturated fat, while another group consumed a diet containing two servings of pistachios per day, about 3 ounces or 20 percent of calories from pistachio nuts. The typical research participant consumed about 150 pistachio nuts per day. The pistachio diet contained 33 percent fat and 7 percent saturated fat. At the end of each four-week diet period, the researchers measured blood pressure and total resistance to blood flow at rest and during two stress tests: a cold water challenge and a confusing mental arithmetic test. After the pistachio diet, blood vessels remained more relaxed and open during both the stress tests (even though the participants felt angry and frustrated during the math stress test).2
Jenkins and his colleagues found that nuts were useful in replacing some carbohydrate in diabetic individuals. They provided three different diet supplements to subjects with type 2 diabetes. One group was given muffins; the second group was provided with a daily two ounces of assorted nuts including raw almonds, pistachios, walnuts, pecans, hazelnuts, peanuts, cashews, and macadamias; and the third group was given a mixture of muffins and nuts.
The results? Participants receiving the nut-only supplement reported the greatest improvement in blood glucose control using the glycosylated hemoglobin (HbA1c) test. This lab test shows the average level of blood sugar (glucose) over the previous 3 months. Not only did nut diet consumers reduce their HbA1c, they also experienced a reduction in LDL cholesterol (“bad cholesterol”). Participants provided the muffin supplement or the mixed muffin-and-nut supplement experienced no significant improvement in blood sugar control. Those receiving the muffin-nut mixture also significantly lowered their serum LDL levels (“bad cholesterol”). What is also encouraging is that the nut group experienced no weight gain!3
Almonds are particularly helpful for diabetic individuals. Regular, daily almond consumption reduces hemoglobin A(1c) in individuals with well-controlled type 2 diabetes mellitus.4 Inclusion of almonds in the breakfast meal decreased blood glucose concentrations and increased satiety, both acutely, and even after a second meal in adults with glucose intolerance.5
Nuts Help Obese Individuals?
Several cross-sectional analyses have shown an inverse association between higher nut consumption and lower body weight. Other types of studies found that increasing nut consumption was associated with lower weight gain over relatively long periods of time.6
Metabolic syndrome (MetS) is characterized by three of the following: obesity (pot-belly), elevated blood sugar and blood pressure, decreased LDL, and is also accompanied by elevated blood fats, inflammation, increased risk for undesirable blood clots, and increased activation of sympathetic (“fight or flight) nervous system activation. Any of these can increase the risk and contribute to heart and blood vessel diseases.
Serotonin is a compound that helps transmit nerve signals, promotes a positive outlook and self-control, and decreases feelings of hunger. Just one ounce of mixed nuts (raw unpeeled walnuts, almonds, and hazelnuts) increased the serotonin level in individuals who had metabolic syndrome.7
Individuals who have either substantial obesity or MetS are at risk for developing type 2 diabetes. Another study found that when approximately 1/4 cup of tree nuts replaced refined carbohydrates, reductions in triglycerides and blood glucose occurred.8
In obesity and MetS, the ability of the blood vessels to dilate is impaired. Daily ingestion of 56 g of walnuts (approximately 1/4 cup) improves endothelial function in overweight adults with visceral adiposity. The addition of walnuts to this diet does not lead to weight gain.9
Because of their high fiber and substantial fat content nuts can act as appetite suppressants. Here, though, Korean pine nuts might be your best bet for now because in one small study pine nuts stimulated two well-known appetite suppressing hormones (cholecystokinin and glucagon-like peptide) in overweight women. These women reported significantly less desire to eat only 30 minutes after ingestion compared with an olive oil placebo. A significant increase in cholecystokinin of 60% and glucagon-like peptide-1 of 25% remained as long as four hours after ingestion.10
Regular Consumption of Nuts Helps Chronic Diseases
Inflammation fuels chronic diseases such as obesity, diabetes, metabolic syndrome and atherosclerosis. Regular consumption of nuts is associated with significant reduction of three pro-inflammatory markers.11 A study of 987 diabetic women showed a direct association between nut consumption and increased plasma levels of adiponectin,12 an important hormone that exerts anti-inflammatory properties. Adiponectin also helps to protect from atherosclerosis.
However, some people are allergic to nuts. What can they do? How about the no-oil diets? What are their benefits or drawbacks? In future articles, we will attempt to answer the questions.
- Guasch-Ferré, M. Frequency of nut consumption and mortality risk in the PREDIMED nutrition intervention trial. BMC Medicine, 2013; 11: 164 DOI: 10.1186/1741-7015-11-164
- Penn State. “Pistachios may lower vascular response to stress in type 2 diabetes.” ScienceDaily. ScienceDaily, 5 August 2014. www.sciencedaily.com/releases/2014/08/140805163347.htm
- Jenkins, D. J. Nuts as a Replacement for Carbohydrates in the Diabetic Diet. Diabetes Care, 2011; DOI: 10.2337/dc11-0338
- Cohen, AE, Almond ingestion at mealtime reduces postprandial glycemia and chronic ingestion reduces hemoglobin A(1c) in individuals with well-controlled type 2 diabetes mellitus. Metabolism. 2011 Sep; 60(9):1312-7
- Mori, AM, Acute and second-meal effects of almond form in impaired glucose tolerant adults: a randomized crossover trial. Nutr Metab (Lond). 2011 Jan 28; 8(1):6
- Jackson CL, Hu FB. Long-term associations of nut consumption with body weight and obesity. Am J Clin Nutr. 2014 Jul;100 Suppl 1:408S-11S
- Tulipani, S. Metabolomics Unveils Urinary Changes in Subjects with Metabolic Syndrome following 12-Week Nut Consumption. Journal of Proteome Research, 2011; 110929134856005 DOI: 10.1021/pr200514h
- Viguiliouk, E. Effect of Tree Nuts on Glycemic Control in Diabetes: A Systematic Review and Meta-Analysis of Randomized Controlled Dietary
- Katz DL. Effects of walnuts on endothelial function in overweight adults with visceral obesity: a randomized, controlled, crossover trial. J Am Coll Nutr. 2012 Dec; 31(6):415-23
- American Physiological Society. “Pine Nut Oil Boosts Appetite Suppressors Up To 60 Percent For 4 Hours.” ScienceDaily. ScienceDaily, 4 April 2006. www.sciencedaily.com/releases/2006/04/060404085953.htm
- Brigham and Women’s Hospital. “Frequent nut consumption associated with less inflammation: Five or more servings of nuts per week or substituting nuts for animal proteins tied to a healthy profile of inflammatory biomarkers..” ScienceDaily. ScienceDaily, 29 July 2016
- Ros, ibid