Ground-breaking research reveals more about the effects of almonds' antioxidants on heart health
MODESTO, Calif., May 20 /PRNewswire-USNewswire/ -- The American Heart Association estimates that one in three American adults have some type of cardiovascular disease, and that cardiovascular disease is the largest major killer of American men and women.(1) So, new research into mechanisms behind fighting heart disease is welcome to many of us -- particularly when it involves a simple behavior change that can make a difference.
The Food and Drug Administration reaffirmed what research has shown for many years: that almonds are a heart smart food(2); but, new, preliminary research published in this month's Journal of Nutrition provides further insight into how the antioxidants in almonds may help maintain a healthy heart.
Almonds aren't typically known for their antioxidants beyond vitamin E, but in previous research, experts determined total antioxidants (phenols, flavonoids, and phenolic acids) in California almonds' skins and kernels using high-performance liquid chromatography (HPLC)/electrochemical detection, UV detection and mass spectometry. They found that almonds contain flavonoids and phenolics in their skins similar to fruits and vegetables.(3)
Antioxidants at Work
In a previous study, 27 men and women with high cholesterol levels consumed three supplements with the same calories each for one month. Supplements consisted of full-dose almonds (73+/-3 g/d), half-dose almonds plus half-dose muffins, and full-dose muffins. Significant reductions from baseline were seen on both half- and full-dose almonds for LDL cholesterol (4.4% and 9.4% respectively).(4) The current study, conducted in collaboration by researchers at the University of Toronto and Tufts University, sought to investigate other factors, beyond lowering cholesterol, that make almonds a heart-smart food, specifically almonds' antioxidants.
The effects of almonds on two markers of oxidative stress, a process which can contribute to clogged arteries, were measured by a team at the Tufts University Antioxidants Research Laboratory led by one of the single-most pioneering researchers in antioxidant research, Dr. Jeffrey Blumberg. The research team found that when men and women with elevated cholesterol ate about two and a half servings of almonds every day for a month, their levels of these two established markers -- blood malondialdehyde (MDA) and urinary isoprostane -- statistically significantly decreased. MDA significantly decreased by 18.75% from baseline in the full-dose almond group and isoprostane decreased by 27% in both almond groups compared to controls.
The researchers hypothesize the antioxidants in almonds are causing this positive effect, and further, that the antioxidants in almonds combined with almonds' favorable effects on blood cholesterol levels may help to explain the overall effects of almonds on maintaining a healthy heart. Although this ground-breaking study provides support for the role of almonds' antioxidants in health, further research is needed to verify these findings.
A Heart-y Boost
Almonds deliver a dose of monounsaturated fats, the good kind found in avocados and olive oil.(5) A recommended serving of almonds (about a handful, or 23 almonds) is an excellent source of vitamin E and magnesium, a good source of fiber, riboflavin and phosphorus, and offers protein (6 grams), calcium (75 mg) and potassium (200 mg). Not only can almonds boost nutrition, but they also add great taste and crunch to any meal or snack.
For More Information
For additional information about almonds, including easy recipes and snack ideas, visit http://www.AlmondsAreIn.com.
Summary of Published Study:
Journal: Journal of Nutrition, May 1, 2008
Research Organization: University of Toronto and Tufts University
Study Title: "Almonds Reduce Biomarkers of Lipid Peroxidation in Older Hyperlipidemic Subjects."
Authors: David J. A. Jenkins, Cyril W. C. Kendall, Augustine Marchie, Andrea R. Josse, Tri H. Nguyen, Dorothea A. Faulkner, Karen G. Lapsley, and Jeffrey Blumberg
Objective: To evaluate the effects of almonds on oxidative stress.
Subjects: 15 men and 12 postmenopausal women from 48 to 86 years old. All subjects had elevated LDL cholesterol upon initial assessment. Body mass indices ranged from normal weight to obese (21.3 to 37 kg/m2).
Study description: The study was a three-phase randomized crossover trial with two week washout periods in between each one month study phase. Subjects were randomized to one of three supplements during the study period: whole natural almonds (73 g/d or about 2.5 ounces), whole natural almonds (37 g/d or about 1 1/3 ounces) and half a whole wheat muffin, and a full whole-wheat muffin. All supplements were matched for calories, protein, saturated fat, polyunsaturated fat and fiber. Subjects were instructed to reduce their calorie intake at other times in the day to accommodate the supplemental almonds and/or muffin. The almonds and/or muffin contributed approximately 20 percent of total calories. During all phases of the study, subjects followed a step II diet (<200 mg/day cholesterol and <7% saturated fat) and had followed this diet for 2 months prior to the start of the study. Subjects received counseling on strategies to maintain their weight and holding exercise constant. No other nuts were consumed during the study period. Body weight, blood samples, and blood pressure were obtained at weeks 0, 2, and 4; seven day weighed diet records were obtained at baseline and at week 4. Blood and urine was analyzed for markers of lipid peroxidation, a process of damaging fat in the blood and causing them to form plagues in the arteries. The markers measured were blood levels of malondialdehyde (MDA) and vitamin E, and urine isoprostane.
Results: Blood levels of MDA decreased significantly during the almond only study phase when compared to the control (whole wheat muffin only). Urinary isoprostane was significantly lowered in the almond only and half almond/half whole wheat muffin phases compared to the control. Contrary to other studies, no increase in blood levels of vitamin E were observed; however, subjects in the study had higher blood vitamin E blood levels at baseline. During the almond only supplementation, subjects achieved a significant decrease in total and LDL cholesterol levels and higher HDL cholesterol levels compared to the control.
(1) Heart Disease & Stroke Statistics: 2008 Update at-a-Glance. American Heart Association, 2008. http://www.americanheart.org/downloadable/heart/1200082005246HS_Stats%202008.final .pdf
(2) The U.S. Food and Drug Administration recognized almonds with a health claim in 2003, stating, "Scientific evidence suggests, but does not prove, that eating 1.5 ounces per day of most nuts, such as almonds, as part of a diet low in saturated fat and cholesterol may reduce the risk of heart disease."
(3) Milbury PE, Chen CY, Dolnikowski GG, Blumberg JB. Determination of flavonoids and phenolics and their distribution in almonds. J Ag Food Chem 2006; 54(14): 5027-33.
(4) Jenkins DJA, Kendall CW, Marchie A, Parker TL, Connolly PW, Qian W, Haight JS, Faulkner D, Vidgen E. Dose response of almonds on coronary heart disease risk factors: blood lipids, oxidized low-density lipoproteins, lipoprotein (a), homocysteine, and pulmonary nitric oxide: a randomized, controlled, crossover trial. Circulation 2002; 106: 1327-32.
(5) Replacing saturated fat with similar amounts of unsaturated fats may reduce the risk of heart disease. To achieve this benefit, total daily calories should not increase.
The Almond Board of California administers a grower-enacted Federal Marketing Order under the supervision of the United States Department of Agriculture. Established in 1950, the Board's charge is to promote the best quality almonds, California's largest tree nut crop. For more information on the Almond Board of California or almonds, visit http://www.AlmondsAreIn.com.
|SOURCE Almond Board of California|
Copyright©2008 PR Newswire.
All rights reserved