Nutrition in a Nutshell
Research conducted over the past decade has confirmed that pecans can be a healthy addition to your diet. Below are summaries of landmark research studies confirming the health benefits associated with eating a diet rich in pecans.
Pecans May Protect the Mind
Eating about a handful of pecans each day may play a role in protecting the nervous system, according to a new animal study published in Current Topics in Nutraceutical Research. The study, conducted at the Center for Cellular Neurobiology at the University of Massachusetts Lowell, suggests adding pecans to your diet may delay the progression of age-related motor neuron degeneration. This may include diseases like amyotropic lateral sclerosis (ALS), also known as Lou Gehrig’s Disease.
Researchers suggest vitamin E – a natural antioxidant found in pecans – may provide a key element to neurological protection shown in the study. Antioxidants are nutrients found in foods that help protect against cell damage, and studies have shown, can help fight diseases like Alzheimer’s, Parkinson’s, cancer and heart disease. Lead researcher Dr. Thomas Shea, Ph.D and his research team carried out a number of laboratory studies on three groups of mice specifically bred to demonstrate severe decline in motor neuron function that are commonly used in studies of ALS. Each of the three groups was fed a control diet or one of two diets containing differing amounts of pecans ground into their food. Standard testing methods were used to determine how well the mice scored relative to motor neuron functions, both before and after they were provided with one of the three diets.
Mice provided a diet supplemented with pecans displayed a significant delay in decline in motor function compared to mice receiving no pecans. Mice eating the diet with the most pecans (0.05%) fared best. Both pecan groups fared significantly better than those whose diets contained no pecans. The result was based on how the mice performed in highly specific tests, each of which compared mice on the control diet with mice consuming pecan-enriched diets.
Natural Antioxidants in Pecans
Naturally-occurring antioxidants in pecans may help contribute to heart health and disease prevention, according to a study at Loma Linda Univesity. The results were published in the January 2011 issue of The Journal of Nutrition.
Pecans contain different forms of the antioxidant vitamin E—known as tocopherols, plus numerous phenolic substances, many of them with antioxidant abilities. The nuts are especially rich in one form of vitamin E called gamma-tocopherols. The findings illustrate that after eating pecans, gamma-tocopherol levels in the body doubled and unhealthy oxidation of LDL (bad) cholesterol in the blood decreased by as much as 33 percent. Oxidized LDLs may further contribute to inflammation in the arteries and place people at greater risk of cardiovascular problems.
These findings are from a research project designed to further evaluate the health benefits of pecans, according to Dr. Haddad. She analyzed biomarkers in blood and urine samples from study participants (a total of 16 men and women between the ages 23 and 44) who ate a sequence of three diets composed of whole pecans, pecans blended with water, or a control meal of equivalent nutrient composition. The pecan meals contained about three ounces of the nut. Samples were taken prior to meals and at intervals up to 24 hours after eating.
Following the test meals composed of whole pecans and blended pecans, researchers found that amounts of gamma-tocopherols (vitamin E) in the body doubled eight hours after both meals, and oxygen radical absorbance capabilities (ORAC—a scientific method for measuring antioxidant power in the blood) increased 12 and 10 percent respectively two hours after the meals. In addition, following the whole-pecan meal, oxidized LDL cholesterol decreased by 30 percent (after 2 hours), 33 percent (after 3 hours), and 26 percent (after 8 hours).
Research from Loma Linda University published in the August 2006 issue of Nutrition Research showed that adding just a handful of pecans to your diet each day may help inhibit unwanted oxidation of blood lipids, thus helping prevent coronary heart disease. The researchers suggest that this positive effect was in part due to the pecans’ significant content of vitamin E. Oxidation of lipids in the body – a process akin to rusting – is detrimental to health.
In the laboratory analysis of blood samples from the research subjects, Dr. Haddad’s team found that the diets enriched with pecans significantly reduced lipid oxidation (by 7.4 percent) versus the Step I diet. Oxidation levels were evaluated using the TBARS test, which measures oxidation products. The researchers also found that blood levels of tocopherols were higher after participants were on the pecan diet. Cholesterol-adjusted plasma gamma-tocopherol in the study participants’ blood samples increased by 10.1 percent (P < .001) after eating the healthy pecan diet. The researchers concluded that these data provide some evidence for potential protective effects of pecan consumption in healthy individuals.
In addition, landmark research published in the Journal of Agriculture and Food Chemistry (June 2004) found that pecans rank highest among all nuts and are among the top category of foods to contain the highest antioxidant capacity, meaning pecans may decrease the risk of cancer, coronary heart disease, and neurological diseases such as Alzheimer’s.
Pecans also play a role in lowering cholesterol. Clinical research published in the Journal of Nutrition (September 2001) compared the Step I diet (28 percent fat), recommended by the American Heart Association for individuals with high cholesterol levels, to a pecan-enriched (40 percent fat) diet. The results showed the pecan-enriched diet lowered total cholesterol by 11.3 percent and LDL “bad” cholesterol levels by 16.5 percent – twice that of the Step I diet, without any associated weight gain.
Research conducted by Dr. Ronald Eitenmiller at the University of Georgia has also confirmed that pecans contain plant sterols, which are known for their cholesterol-lowering ability.
The U.S. Food and Drug Administration (FDA) has acknowledged this and related research and approved the following qualified health claim: “Scientific evidence suggests, but does not prove, that eating 1.5 ounces per day of most nuts, such as pecans, as part of a diet low in saturated fat and cholesterol, may reduce the risk of heart disease.”
Weight Control and Pecans
A review of pecan and other nut research, published in the American Journal of Clinical Nutrition (September 2003), suggests that nuts like pecans may aid in weight loss and maintenance. The review cited studies indicating that nut consumption may increase metabolic rates and enhance satiety. When used in conjunction with a healthy low-fat diet, nuts also offer increased flavor, palatability and texture that can lead to greater dietary compliance, according to the review.
A one-ounce serving of pecans (approximately 20 halves) contains 196 calories, 20.4 grams total fat (1.8 saturated fat), 0 mg cholesterol, 0 grams sodium, 2.7 grams dietary fiber and over 19 vitamins and minerals including vitamin A, vitamin E, calcium, potassium and zinc.
Pecans are also a good source of oleic acid, vitamin B1, thiamin, magnesium and protein.
Nearly 60 percent of the fats in pecans are monounsaturated and another 30 percent are polyunsaturated, leaving very little saturated fat in pecans. The unsaturated fat in pecans is heart-healthy fat meeting the new Dietary Guidelines that recommend Americans keep intake between 20 and 35 percent of calories, with most fats coming from heart-healthy sources like fish, nuts and vegetable oils. In addition, pecans contain no trans fat.
Pecans contain more than 19 vitamins and minerals – including vitamin A, vitamin E, folic acid, calcium, magnesium, phosphorus, potassium, several B vitamins and zinc. One ounce of pecans provides 10 percent of the recommended Daily Value for fiber. Pecans are also a natural, high-quality source of protein that contain very few carbohydrates and no cholesterol. Pecans are also naturally sodium-free, making them an excellent choice for those on a salt- or sodium-restricted diet.
Additional Nutritional Resources
The following links lead to external websites and do not necessarily reflect the opinions of the National Pecan Shellers Association or its members.