New Study Supports Daily Almonds as Part of a Heart-Healthy Diet
25 Aug 2014 --- A new study published in the British Journal of Nutrition found that participants who ate almonds as part of a heart-healthy diet significantly improved certain factors associated with heart disease risk.
Researchers estimated that for every 30 grams increase (approximately 1 ounce) of almonds consumed daily during the study, study participants' estimated 10-year coronary heart disease (CHD) risk score was reduced by 3.5%.
The randomized, controlled clinical study, conducted by researchers at the University of Toronto, included 27 adult participants (mean age of 64 years) with elevated LDL cholesterol. Participants followed a diet low in saturated fat and cholesterol that also included each of three dietary interventions for four weeks each in a crossover design.
Each day for four weeks, researchers gave one group 50-100 grams (2-4 ounces) of almonds. A control group received 100-200 grams of muffins, and a third group received 25-50 grams (1-2 ounces) of almonds plus 50-100 grams of muffins. Each participant completed all three dietary treatments, so the total length of the study was 12 weeks.
The quantity of almonds and muffins provided to each participant varied according to estimations to maintain his or her baseline weight. The muffins were formulated to provide the same number of calories and the same amount of saturated fat (SFA), polyunsaturated fat (PUFA), protein and fiber as the almonds. The primary difference between the almond composition and the muffin composition was that the almonds had significantly more monounsaturated fat (50% vs 8% of calories), whereas the muffins had significantly more carbohydrates (53% vs 15% of calories).
In the triglyceride fraction, oleic acid and total MUFAs increased significantly in a dose-dependent manner with almond consumption compared to muffins. Increased oleic acid and MUFA content of the serum triglyceride was inversely associated with CHD lipid risk factors and overall estimated 10-year CHD risk.
Previously published data on this same group of people showed that total cholesterol and LDL, or "bad," cholesterol decreased, and HDL, or "good," cholesterol increased, in the almond group compared to the control group.
"The favorable effect of almonds, particularly the monounsaturated fat component, on heart disease risk in this study is consistent with previous research, including Mediterranean diet research," said Cyrill Kendall, PhD, research associate at University of Toronto and the Clinical Nutrition and Risk Modification Center at St. Michael's Hospital, and the study's principal investigator. "The improvement in serum fatty acid profiles observed with almond consumption provides further support for a diet rich in monounsaturated fats for overall cardiovascular health."
A hallmark of the Mediterranean diet is the consumption of MUFA-rich olive oil. Almonds also contain a high proportion of MUFAs, providing 9 grams per 1 ounce serving (or about 50% of their total calories).
And overall, the nutrient profile of almonds – low on the glycemic index and providing a powerful nutrient package including hunger-fighting protein (6 g/oz), filling dietary fiber (4 g/oz) and important vitamins and minerals such as vitamin E (7.3 mg/oz), magnesium (77 mg/oz) and potassium (200 mg/oz), makes them an ideal fit in a heart-healthy lifestyle.
This study comes on the heels of a large-scale review from researchers at Harvard University encompassing 27 studies (16 from North America, 8 from Europe and 3 from Asia) and more than 500,000 adult participants (mean age 53 years) which showed that eating four servings (1 ounce) of nuts weekly was associated with 24% lower risk of fatal heart attacks, 22% lower risk of non-fatal heart attacks and 13% lower risk of diabetes. Although the study was observational in nature, relied on self-reported dietary intake which did not account for nuts consumed as an ingredient, and included relatively few studies per disease state, it adds to the strong body of evidence supporting the consumption of nuts like almonds as part of a heart-healthy dietary pattern.
Nearly two decades of research shows that almonds can help maintain a healthy heart and cholesterol levels. The Food & Drug Administration has noted, "Scientific evidence suggests but does not prove that eating 1.5 ounces per day of most nuts including almonds as part of a diet low in saturated fat and cholesterol may reduce the risk of heart disease."