Almond Board of California: Nutritional Benefits of Almonds
Over the past 10 years, the Almond Board of California (ABC) has been involved in extensive research exploring the health benefits of almonds. The primary objective is to add scientific validity to the fact that almonds are a healthy snack alternative, and to recognize that they add nutritional value to any dish. ABC pursues research relevant to the health of today's consumers both in the USA and abroad and provides a foundation for the ABC marketing programs worldwide. The project leaders who are commissioned for the research rank at the top of their respective fields come from more than 20 scientific organizations globally, such as the University of California (UC), Loma Linda University (LLU), University of Toronto (U of T), Tufts University, Michigan State University, Purdue University, City of Hope Medical Center, King's College London, Peking Medical University, and others.
Since the inception of the Almond Board's nutrition research program in 1995 and the establishment of a nutrition subcommittee to review the scientific validity of proposals and recommend studies for funding, the program has expanded its budget by 300 percent with an increase in the number of studies from three to more than a dozen. Current areas of investigation focus on the relationship between consumption of almonds and heart disease, weight control, and cancer. Completed research has been submitted for publication in a variety of prestigious scientific journals.
Nutritional Benefits of Almonds
Almonds have been incorporated in diets of numerous cultures for thousands of years. They are recognized as a food staple not only for their taste, but also for their nutritional qualities and health promotion properties. Almonds are cholesterol free, low in saturated fat, and a great source of fiber. They're also high in monounsaturated fat, which can help lower your "bad" cholesterol and maintain your "good" cholesterol. Almonds are the best source of the antioxidant Vitamin E in the form of alpha-tocopherol and also pack plenty of protein, magnesium, calcium, potassium, copper, and zinc. Last but not least, almonds have phytochemicals, which have health benefits of their own. The health benefits of the nutrients in almonds help maintain healthy hearts, protect against cancer, and contribute to weight control and diabetes management.
Almonds Throughout History
References to almonds as a dietary staple can be traced to Biblical times. Europeans traveling to Asia on the Silk Road often consumed almonds on the long, treacherous journey. Almonds continued to grow in popularity in Europe and the British monarchy, where almonds, almond meal, and almond milk were used extensively in various recipes. By the 1700s, Spanish monks were successful in growing almond trees in valleys of California. Throughout history, almonds have been a part of the cuisine and culture throughout the world. Today, we see that nuts are included in many dishes of the Mediterranean cuisine. The average per capita nut consumption in the Mediterranean is about three times that in the United States. Asian cultures also include nuts in their daily eating plans and have a lower risk of chronic disease than in the United States. The Latin American cuisine also encourages a wide variety of ways to incorporate them into exciting dishes. The Oldways Preservation and Exchange Trust (www.oldwayspt.org) provides food pyramid guides to characterize the eating patterns of these traditional, healthy cuisines. In these pyramids it is noted that nuts are moved into their own food group with seeds, separated from meat, fish, and poultry.
Nutritional Components of Almonds
Almonds are a nutrient-dense source of fiber and protein. Almonds provide 164 calories and six grams of high quality, easily digested protein per ounce. Along with the quality proteins in almonds, there are three grams of dietary fiber (80 percent insoluble and 20 percent soluble). This mixture of fibers benefits both gastrointestinal and cardiovascular health. The fiber may block the digestion and absorption of fats present in almonds (Ren et al, 2001), and the combination of high quality protein and dietary fiber in fiber increases satiety (Turnball et al, 1993).
Approximately 70 percent of the fats in almonds are monounsaturated fats, which have been shown to reduce cholesterol levels when substituted for dietary saturated fat (Almonds: A Nutrition and Health Perspective, 2003). Almonds are low in saturated fats and contain Omega-6 fatty acids, which are related to a decreased risk of heart disease.
Epidemiological evidence suggests that individuals who consume diets rich in Vitamin E foods experience a reduction in the risk of heart disease (Panel on Dietary Antioxidants, 2000). The Vitamin E content of almonds (more than 20 percent of the daily value per ounce) makes this food an excellent dietary choice. Almonds are the best whole food source of Vitamin E in the alpha-tocopherol form, which may help prevent cancer. Individuals who consume a variety of vegetables, nuts, and monounsaturated oils, consistent with the Mediterranean diet, experience a decreased risk of heart disease (Barzi, et al, 2003; Pitzavos et al, 2002). The Vitamin E from almonds is efficiently absorbed and may prevent the oxidation of LDL cholesterol, which results in reduced cardiovascular risk (Milbury et al., 2002).
Almonds are a good source of phosphorus and calcium for bone health as well as magnesium and manganese, which act as co-factors in energy metabolism. Vitamin B6 in almonds reduces levels of the amino acid homocysteine, which has been shown to be detrimental to heart health in high concentrations (Whitney and Rolfes, 2005).
Recent research has been conducted to determine the effect of a daily supplement of almonds on the overall nutrient intake of healthy subjects (Jaceldo-Seigl, 2004). Results suggest that a daily supplement of 52 grams of almonds significantly increases intake of monounsaturated fats, polyunsaturated fats, plant protein, fiber, magnesium, copper, and alpha-tocopherol. Reduction of intake of trans fatty acids, animal protein, cholesterol, sodium, and sugars was also observed. This research suggests that the incorporation of a daily supplement of almonds can result in favorable dietary modifications consistent with recommendations for chronic disease risk reduction.
Relationship of Almonds to Cardiovascular Risk Reduction
There is a growing body of evidence relating consumption of almonds to decreased cardiovascular risk. Researchers have determined that men and women who consumed about one ounce (one handful, 23 kernels) of almonds per day lowered LDL cholesterol levels by 4.4 percent from baseline values. Those subjects who consumed two ounces of almonds each day lowered LDL cholesterol by 9.4 percent. All subjects maintained their weight (Jenkins et al, Circulation, 2002a.). Meta-analysis studies of seven clinical trials determined that eating even one ounce of almonds per day as a part of a healthy lifestyle reduces LDL cholesterol levels and thereby reduced cardiovascular risk (Fulgoni, 2002).
A recent research study compared the National Cholesterol Education Program (NCEP) Step 1 Diet (seven percent of calories from saturated fat; 200 mg cholesterol), to diets in which almonds contributed zero percent, 10 percent, and 20 percent of the total calories. Individuals who consumed 20 percent of the calories from almonds lowered total cholesterol, LDL cholesterol, and LDL:HDL ratios significantly more than subjects on the NCEP Step 1 diet or the 10 percent almond diet (Sabate et al, 2003).
Both almonds and almond oil exhibit similar cholesterol-lowering effects. In a study in which individuals replaced half of their daily fat intake with almonds or almond oil for six weeks, subjects exhibited a four percent reduction in total cholesterol, six percent reduction in LDL cholesterol, and a six percent increase in HDL cholesterol (Hyson et al, 2002). In a study of hypercholesterolemic men and women who were fed low-saturated fat, low-cholesterol, high-fiber diets to which almonds and almond oil were added exhibited reductions in total serum cholesterol and LDL cholesterol, with no reductions in HDL cholesterol levels or increase in body weight (Spiller, 1992).
The Portfolio Eating Plan research project examined, through a series of ongoing studies, the combined effects of a variety of recognized heart-healthy foods. In phase one of the Portfolio Eating Plan, hypercholesterolemic subjects consumed a heart-healthy 2000 calorie diet that included one ounce of almonds, two grams of plant sterols, 35 grams soy protein, and 15 grams viscous fiber (combination diet) for one month. Following Phase one, subjects experienced reductions in LDL cholesterol (29 percent) and LDL:HDL ratio (26 percent), which is comparable to a low-dose drug therapy regimen (Jenkins et al, Metabolism, 2002). Phase two of the Portfolio Eating Plan focused on the duration to achieve an effect. One group of hyperlipidemic subjects followed the combination diet, while another group followed the low saturated fat test diet but included wholegrain cereals and low fat dairy foods (control diet). After only two weeks the combination diet group exhibited a 35 percent reduction in LDL cholesterol, while the control group reduced LDL cholesterol by only 12 percent (Jenkins et al, Metabolism 52, 2003). The third phase of the Portfolio research compared the effect of the combination diet to statin drugs and the control diet. Results revealed that the combination diet and the statins significantly lowered LDL cholesterol and C-reactive protein (CRP), an artery inflammation indicator, significantly more than the control diet (Jenkins et al, 2003).
Both the U.S. Dietary Guidelines for Americans (USDA Dietary Guidelines, 2000) and the National Heart, Lung and Blood Institute (HNLBI) Adult Treatment Panel III Guidelines (Third Report, 2001) recommend substitution of dietary saturated fats with unsaturated fats, such as the monounsaturated fats found in almonds, to decrease cholesterol levels. Research continues to demonstrate that almonds reduce total cholesterol and LDL cholesterol and that increased almond consumption leads to greater decreases in cholesterol levels. In the Portfolio research, almonds also reduced CRP, an indicator of artery-damaging inflammation.
Relationship of Almonds to Diabetes and Cancer
Almonds have been shown to play a role in diabetic control. A recent research study found the incorporation of almonds into a healthy diet lowered LDL and total cholesterol levels without negatively effecting glycemic control (Lovejoy et al, 2002). Research is also being conducted to investigate the relationship of almonds to cancer risk and prevention. Early indications suggest that almonds may reduce the number of precancerous crypt foci lesions in rats (Davis and Iwahashi, 2001), and may, therefore, have a role in the prevention of colon cancer. In another study using mice, an almond diet activated five anti-proliferative genes compared to only two similar anti-proliferative genes in control diets, which may account for the preventive effect of almonds on colon cancer (Davis et al., 2003).
Nutritional Benefits of Vitamin E in Almonds
Vitamin E acts as a powerful antioxidant that is known to reduce cellular oxidative damage from free radicals. Acting synergistically with other antioxidants, including glutathione and Vitamin C, Vitamin E is regenerated to its active state following reaction with and neutralization of free radicals. The 2004 Recommended Dietary Allowance for alpha-tocopherol Vitamin E is 15 milligrams per day for women and men >14 years of age (Dietary Reference Intake, 2004). One ounce of almonds provides 7.2 milligrams of Vitamin E (96 percent of the Vitamin E in almonds is alpha-tocopherol). Increasing scientific evidence suggests a role for Vitamin E in reduction of risk from heart disease, cancer, cataracts, Alzheimer's disease, and complications from diabetes. Vitamin E also increases immune response and slows the aging process by decreasing cellular oxidative damage.
Vitamin E decreases LDL cholesterol oxidation, and numerous animal studies support the antioxidant role of Vitamin E in reduction of atherosclerotic risk (Panel on Dietary Antioxidants). Recent research has examined the relationship of almond skins on LDL oxidation. Results suggest that the polyphenolic compounds in almonds are easily absorbed, powerful in preventing LDL cholesterol oxidation, and that Vitamin E in almonds works synergistically with the polyphenols to reduce oxidation reactions (Millbury et al, 2002).
Role of Almonds in Weight Maintenance
Weight maintenance and weight loss regimens traditionally recommend avoidance of high fat foods. Nuts, however, are recognized as being heart-healthy foods, and almonds have been identified as a nutrient-dense food that can be a component of a healthy diet. A recent research study found that the addition of 320 calories from almonds to a daily diet consumed by free-living subjects did not result in weight gain over a six-month period (Fraser et al, 2002). Results from this research suggest that almonds provide satiation, and not weight gain, when consumed along with a mixed diet. Other research also has provided evidence that addition of almonds in place of calories from other food sources does not result in an increase in body weight (Wein, in press).
The cell walls of almonds have been found to act as a barrier to fat absorption in the intestines, which results in fat excretion and a reduction in total calories absorbed (Ren et al, 2000). Almond cell walls can be detected in the stool of almond eaters, which suggests that the cell walls are not completely broken down in digestion and may limit dietary fat available for absorption.
Based on evidence available from current research, almonds can be incorporated into a variety of weight loss and weight maintenance programs. The fat, protein, and dietary fiber in almonds exert a satiating effect after the meal is consumed, and current research suggests that the addition of almonds to the diet in place of other foods does not result in weight gain (Wein, in press). Individuals should be encouraged to include almonds as a part of a balanced eating plan designed to achieve and maintain a healthy body weight.
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