Pecans are hickories. The pecan tree, Carya illinoinensis, is a large hickory native to the southern United States and northern Mexico. Botanically, the pecan is the seed inside a drupe, a fruit with one stone like a peach, not a true nut.
Genome sequencing of pecan and Chinese hickory found two whole-genome duplications, where the full set of genes was copied. They happened before the line of pecan and Chinese hickory split from walnut.
Most of the fat in a pecan is monounsaturated: 40.8 g per 100 g, the third highest of 123 foods on this site. One ounce (28 g) of raw pecans has 196 calories. It supplies 55% of the Daily Value for manganese, 38% for copper and 16% for thiamin (vitamin B1). Gram for gram, only 5 of 132 foods on this site have more manganese.
Pecans also rank high for antioxidants. In a 2006 analysis of 1,113 US food samples, pecans were among the foods with the most antioxidants per typical serving. Blackberries, walnuts and strawberries were near them.
Whether that matters for health is less clear. In a trial of 16 people, a pecan meal doubled blood gamma-tocopherol (a form of vitamin E) and lowered oxidized LDL by up to 33%. But those are blood markers, not illness. Most pecan trials are small, and several were paid for by pecan industry groups; the cards below say so when the paper does.
Health benefits of pecans
The top findings from 24 studies, strongest evidence first
What the stars mean
- Strong. Several randomized trials, pooled in a meta-analysis, point the same way, or regulators (FDA or EFSA) have approved the claim.
- Moderate. Good randomized trials support it, but there are fewer of them, or their results vary.
- Limited. Small, short or single trials, or mixed results. Promising, but it needs confirmation.
Population and lab studies get no stars: they show a link or a mechanism, not proof.
How we rate evidence →- ★★★Lower “bad” LDL cholesterolAcross 7 trials, pecans lowered it (by 7.42 mg/dL). In a trial of 102 adults, LDL fell by 12.7 mg/dL at 13% of daily calories, but not at 6%.
- ★★No LDL drop in people with heart diseaseIn 204 people with stable heart disease, 30 g of pecans a day for 12 weeks did not change LDL, the trial’s main goal.
- ★★No added effect on inflammation or blood sugarIn heart patients, 30 g of pecans a day for 12 weeks did not differ from diet alone on inflammation or blood sugar markers. Diet quality scored 26 with pecans against 19 on diet alone.
- ★Less weight gain than the calories predictIn 8 weeks, 68 g of pecans a day added 1.1 or 0.9 kg against 3.3 or 3.2 kg predicted, a non-significant trend versus nut-free. In another trial, weight rose 0.4 kg against 2.2 kg expected.
- ★More fullness hormones after pecansAfter a pecan shake, fullness hormone PYY rose, hunger hormone ghrelin fell, and 31 young adults felt fuller. Reported food intake did not differ.
All 24 studies, strongest evidence first
Pecans lowered LDL cholesterol by 7.42 mg/dL across 7 trials
This meta-analysis covered 10 randomized trials in adults (chance decided who ate pecans), with 7 pooled for blood fats. Total cholesterol fell 8.49 mg/dL (milligrams per deciliter of blood) and triglycerides 14.06 mg/dL, and the cholesterol results were consistent between trials. HDL (“good”) cholesterol, fasting glucose, body weight and blood pressure showed little sign of change. The authors call for larger, long-term trials in high-risk groups.
Pecans at 13% or 20% of calories lowered LDL; 6% did not
This single-blind randomized trial compared three pecan doses with a nut-free usual diet in 102 adults with excess weight or abnormal blood fats. LDL fell by 12.7 mg/dL at 13% of daily calories and 11.9 mg/dL at 20%. Total cholesterol, apolipoprotein B and non-HDL cholesterol fell at those doses too, while fasting triglycerides did not differ between groups. The American Pecan Promotion Board and a University of Georgia obesity program funded it.
Pecans instead of usual snacks lowered LDL cholesterol by 7.2 mg/dL
This single-blind randomized trial, funded by an American Pecan Council grant, included 138 adults with at least one sign of metabolic syndrome. For 12 weeks, some swapped usual snacks for 57 g of pecans a day, and the rest kept their usual diet. Triglycerides fell 16.4 mg/dL, but blood vessel function and blood pressure did not change. Weight tended to rise by 0.7 kg, which was not significant.
Same trial: pecans cut LDL particles by 75.3 nmol/L
This further analysis of the 138-adult, 12-week trial above, with 57 g of pecans a day, counted lipoprotein particles by nuclear magnetic resonance. Apolipoprotein B fell 4.38 mg/dL and triglyceride-rich particles 20.4 nmol/L, while large HDL particles rose 0.35 µmol/L. An index of early insulin resistance fell 4.42 points. The American Pecan Council funded the work.
Pecans did not lower LDL in heart patients
This randomized trial in 204 people aged 40 to 80 with stable coronary artery disease lasted 12 weeks. It compared a healthy diet alone, with 30 g of pecans a day, or with 30 mL a day of extra-virgin olive oil. Non-HDL cholesterol was 114.9 mg/dL with pecans against 127 mg/dL on diet alone. The ratio of total to HDL cholesterol was 3.7 against 4.0, but LDL, the main outcome, did not differ.
Pecans did not change inflammation markers in heart patients
Same randomized trial of 204 patients with coronary artery disease, who added 30 g of pecans a day. Blood levels of hs-CRP, fibrinogen, interferon-gamma and several interleukins did not differ between groups. IL-6, the main outcome, fell over 12 weeks in all three groups, including the group on a healthy diet alone.
Pecans left blood sugar markers and body fat unchanged, raised diet quality
Same 204-patient trial in coronary artery disease, adding 30 g of pecans a day to a healthy diet for 12 weeks. The main outcome, the triglyceride-glucose index (a blood sugar marker), did not differ between groups, and neither did body-fat measures. Diet quality on the modified Alternate Healthy Eating Index ended at 26 with pecans, against 19 on diet alone and 18.9 with olive oil.
Daily pecans lowered LDL from 143 to 129 mg/dL
This randomized trial gave 68 g of pecans a day for 8 weeks to 56 adults at risk of heart disease (overweight or high cholesterol). One pecan group added the nuts to their usual diet (143 to 129 mg/dL). Another swapped them for foods with the same calories (144 to 135 mg/dL), while the nut-free control group did not change. Fasting triglycerides and apolipoprotein B fell as well.
Older adults: pecans lowered LDL by 15 mg/dL in 4 weeks
This randomized trial gave 44 adults, average age 59, 68 g of pecans a day. In the no-nut group, LDL rose 1.9 mg/dL, and total cholesterol fell 14 mg/dL with pecans against 0.2 mg/dL without. Triglycerides after a high-fat meal were lower with pecans. Fasting blood vessel function did not change, though blood flow in small vessels recovered better after the meal.
Pecans at 20% of calories cut LDL 10.4% beyond a cholesterol-lowering diet
This single-blind randomized crossover study (everyone tried both diets in turn) included 23 men and women with normal to moderately high cholesterol. The pecan diet lasted 4 weeks and was compared with the standard Step I cholesterol-lowering diet. Beyond that diet, total cholesterol fell 6.7%, triglycerides 11.1% and apolipoprotein B 11.6%. Body weight did not rise.
Pecans lowered LDL from 2.61 to 2.46 mmol/L at normal cholesterol
This very small randomized study gave 68 g of pecans a day for 8 weeks; 19 people finished, 10 eating pecans and 9 avoiding nuts. At week 8, total cholesterol was lower with pecans than without (4.22 against 5.02 mmol/L, millimoles per liter). So was HDL (1.37 against 1.47 mmol/L), and body weight did not change.
Pecans did not change blood sugar, cholesterol or inflammation markers
This small preliminary study gave people with overweight or obesity 1.5 oz of pecans a day for 8 weeks. A control group kept its usual diet, and body composition and IL-6 did not differ either. The authors say the sample was too small to rule out an effect, and they call for longer, larger trials. The study had no external funding.
A pecan-rich diet lowered insulin and insulin resistance in 4 weeks
This randomized, blinded crossover feeding trial included middle-aged and older adults who were overweight or obese, with fat around the middle. The pecan diet beat a nut-free control diet matched in calories, fat and fiber. A combined score of heart and diabetes risk markers also improved. The USDA and the National Pecan Shellers Association, which supplied the pecans, supported it.
A pecan meal cut oxidized LDL by up to 33% within hours
In random order, one week apart, 16 healthy adults aged 23 to 44 ate whole pecans, blended pecans or a matched refined meal. Whole pecans doubled blood gamma-tocopherol, a form of vitamin E. Blood antioxidant capacity rose 10 to 12% at 2 hours. It measured blood markers after single meals, not disease.
Daily pecans curbed blood-fat oxidation after a high-fat shake
This 8-week randomized trial in adults at risk of heart disease had two pecan groups (15 and 16 people). A nut-free control group of 16 saw no change, and the Georgia Agricultural Commodity Commission for Pecans funded the study. After the shake, total antioxidant capacity rose in both pecan groups. Gamma-tocopherol rose from 1.4 to 1.8 µg/mL in the group that added pecans.
Pecans cut blood-fat oxidation after a high-fat meal, not glucose or insulin
This randomized trial included 41 healthy adults aged 50 to 75. For 4 weeks, 21 ate 68 g of pecans a day and 20 avoided nuts. Antioxidant capacity, glucose and insulin did not change, and fasting oxidation of blood fats showed only a trend. The authors say longer trials, or people with diabetes, may be needed to see effects on blood sugar.
A pecan shake raised fullness hormone PYY and lowered hunger hormone ghrelin
In this double-blind randomized crossover trial, 31 healthy young adults drank both shakes. The pecan shake held 68 g of pecans (795 kcal), and the control shake (794 kcal) matched it in calories and macronutrients. The pecan shake changed PYY and ghrelin more, and fullness was greater after pecans. Appetite stayed lower for the rest of the day, but reported food intake did not differ; the Georgia Pecan Commission funded it.
A pecan snack raised blood sugar and insulin less than tortilla chips
In this randomized crossover trial, 20 people with overweight or obesity ate a 250 kcal snack of pecans or tortilla chips. Appetite ratings and the food eaten at lunch did not differ between snacks. Peptide YY and GLP-1, two gut hormones linked to fullness, were higher after pecans. It tested a single snack.
In older adults, pecans raised fullness hormone peptide YY, not reported appetite
In this randomized trial, 44 healthy adults aged 50 to 75 ate 68 g of pecans a day for 4 weeks. Body weight rose only 0.4 kg, against 2.2 kg expected if the extra calories had simply been added. Peak desire to eat fell, but average appetite ratings and calories eaten at a buffet did not differ significantly.
Daily pecans added 1.1 or 0.9 kg, about a third of predicted
In this randomized trial, two pecan groups ate 68 g of pecans a day for 8 weeks. They either added them to their usual diet (30 people) or swapped them for other foods (31), against a nut-free control group (32). The gain against control was a trend, not significant, while the extra calories predicted 3.3 and 3.2 kg. Body fat rose in the swap group only, and the Georgia Pecan Commission funded it.
Pecan shake: 8 of 23 thinking measures better, 3 worse
In this double-blind randomized crossover trial, 31 healthy adults drank a shake with 68 g of pecans and a control shake. They took thinking tests fasting and for 4 hours after each. Pecan did better on attention, processing speed, memory and learning; the control shake did better on word recognition and working memory. It tested single meals, and the Georgia Pecan Commission funded it.
In mice, pecans or extract cut fat mass 44% and cholesterol 40%
Mice ate a high-fat diet with pecans or a pecan polyphenol (plant compound) extract for 18 weeks; this was not a study in people. Insulin was 74% lower, glucose tolerance improved 37%, and gut bacteria were more varied. Pecans made up 30% of the diet. The authors convert that to 110 to 183 g of pecan kernels a day for a person, far more than the trials above used.
Rats fed pecans avoided a leptin rise and had lower total cholesterol
This was a study in rats on a high-fat diet, not people, against control rats; leptin is a hormone made by fat tissue. Whole pecans worked better than pecan oil or pecan polyphenols alone. They raised the activity of liver antioxidant enzymes and reduced oxidation of fats.
Raw pecan phenolics cut oxidation in human gut cells 37 to 69%
This lab study used human Caco-2 colon cells, not people, with extracts of 25 to 100 µg/mL. For roasted pecans the drop was 26 to 68%, so the authors conclude that roasting does not remove the effect. The main active compounds were small procyanidins that cells can take up.
Who should be careful with pecans
Most people can eat pecans freely. Take a little care if one of these applies:
- Tree nut allergy. The FDA lists pecans among the tree nuts that US labels must name. Pecan and walnut allergy are closely linked. In a clinic study of 76 people sensitized to walnut, 49 of the 61 who were walnut-allergic were also allergic to pecan. None of the 15 who tolerated walnut were. If you are allergic to walnuts or other tree nuts, ask an allergist before eating pecans.
- Calories. One ounce of raw pecans has 196 calories, so a handful adds up. In the trials above, weight rose less than the extra calories predicted. But they lasted only 4 to 12 weeks, so it helps to swap pecans for another snack instead of adding them on top.
How to choose, store and eat pecans
- Amount: trials used 30 to 68 g a day for 4 to 12 weeks. In one dose trial, 13% of daily calories lowered LDL while 6% did not. The FDA qualified claim for nuts uses 1.5 oz a day.
- In the shell: pecans keep 6 to 12 months stored cool and dry, according to Texas A&M AgriLife Extension.
- Shelled: the oils can turn rancid at room temperature. Keep them airtight in the refrigerator for up to 9 months or in the freezer for up to 2 years.
Double-bag shelled pecans, because their fat soaks up smells from other food. Buy only what you will use within a couple of weeks, unless you can chill or freeze them. The nutrition numbers on this page are for raw pecans.
Sources
- Elizur A, Appel MY, Nachshon L, et al. Clinical and molecular characterization of walnut and pecan allergy (NUT CRACKER study). J Allergy Clin Immunol Pract. 2020.
- Goldberg MR, Appel MY, Nega R, et al. A prospective validation of the NUT CRACKER diagnostic algorithm for walnut and pecan allergy with prediction of severity. J Allergy Clin Immunol Pract. 2021.
- Food allergies. U.S. Food and Drug Administration.
- Qualified health claims: letter of enforcement discretion, nuts and coronary heart disease. U.S. Food and Drug Administration. 2003 (archived copy).
- Nut-ritious and delicious Texas pecans. Texas Farm Bureau, quoting Texas A&M AgriLife Extension. 2020.
- Prabhakar H, Stoner-Harris T, Adhikari K, et al. Changes in chemical characteristics and modeling sensory parameters of stored pecan nutmeats. J Food Sci. 2023.
History of pecans
Pecans are native to North America. The tree is a large hickory that grows wild across the southern United States and northern Mexico, around the Mississippi River region.
The word pecan comes from Algonquian languages, where related words named pecans, walnuts and hickory nuts. Indigenous peoples gathered the nuts, ground them into a flour and made a milky drink from them. Spanish explorers met pecans in the 16th century in what is now Louisiana, Texas and Mexico. They carried them to Europe, Asia and Africa.
Early American leaders grew them too. Thomas Jefferson planted pecans at Monticello and gave trees to George Washington, who grew them at Mount Vernon. Orchards for sale came later, because pecan trees take a long time to mature. Commercial growing in the United States began in the 1880s.
The key step was grafting, which lets a grower copy one good tree. In 1846, an enslaved gardener named Antoine at Oak Alley Plantation in Louisiana grafted sixteen trees from a cutting of a wild pecan. That is the account of the National Park Service.
The variety became known as Centennial. Sources differ on some details, and little is recorded of Antoine’s life.
Texas made the pecan its state tree in 1919. The Texas A&M Forest Service says that on March 2, 1906, former governor James Hogg said he wanted no stone monument. He asked his children to plant a pecan tree at the head of his grave. He died the next morning.
Today the United States and Mexico grow almost all the world’s pecans, together 93% of production in 2017. Scientists have sequenced the pecan genome. A 2024 study of 550 trees from 26 geographic origins found eight distinct subpopulations, with southern collections growing faster than northern ones.
Sources
- Pecan. Wikipedia.
- The pecan tree. National Park Service.
- Famous trees of Texas: our state tree. Texas A&M Forest Service.
- Huang Y, Xiao L, Zhang Z, et al. The genomes of pecan and Chinese hickory provide insights into Carya evolution and nut nutrition. Gigascience. 2019.
- Wang X, Stein L, Black M, et al. Phenotypic diversity and population structure of pecan (Carya illinoinensis) collections reveals geographic patterns. Sci Rep. 2024.
- Halvorsen BL, Carlsen MH, Phillips KM, et al. Content of redox-active compounds (ie, antioxidants) in foods consumed in the United States. Am J Clin Nutr. 2006.
Frequently asked questions about pecans
Are pecans good for you?
For most people, yes: one ounce (28 g) of raw pecans has 196 calories, 2.7 g of fiber and 20.4 g of fat, mostly monounsaturated. It also gives 55% of the Daily Value for manganese. A 2026 meta-analysis of 7 trials found LDL cholesterol 7.42 mg/dL lower, but little change in weight, blood sugar or blood pressure. Most pecan trials are small, and several were paid for by pecan industry groups.
Do pecans lower cholesterol?
Yes, modestly. Pooled results from 7 randomized trials showed LDL 7.42 mg/dL lower. In 102 adults, pecans at 13% and 20% of daily calories lowered LDL by 12.7 and 11.9 mg/dL, while 6% did not. A 30 g a day trial in 204 people with coronary artery disease found no LDL drop, so results vary between studies.
How many pecans should you eat a day?
No study here sets an ideal amount. Trials used 30 g up to 68 g a day. In the dose trial, 13% of daily calories worked while 6% did not. One ounce adds 196 calories, so swapping it for another snack is a safer way to add it than eating it on top.
Do pecans make you gain weight?
Less than their calories suggest, in short trials. Eating 68 g a day for 8 weeks added 1.1 or 0.9 kg, against 3.3 and 3.2 kg predicted. Eating 57 g a day for 12 weeks tended to add 0.7 kg, which was not significant.
A meta-analysis of 4 trials found little sign of an effect on body weight. These trials were short, and an ounce still holds 196 calories.
Is a pecan a nut?
Botanically, no: it is the seed inside a drupe, a fruit with one stone, like a peach. In the kitchen, on food labels and in allergy rules, it counts as a tree nut. The FDA names pecans among the tree nuts that US labels must declare.
Can you eat pecans if you are allergic to walnuts?
Not without checking with an allergist. In a clinic study of 76 people sensitized to walnut, 49 of the 61 who were walnut-allergic were also allergic to pecan. None of the 15 who tolerated walnut were. In a later study of 183 patients with a median age of 8, every pecan-allergic patient was also allergic to walnut.
How should you store pecans?
Airtight and cold, says Texas A&M AgriLife Extension advice reported by the Texas Farm Bureau. Shelled pecans keep up to 9 months in the refrigerator and up to 2 years in the freezer. Double-bag them, because their fat absorbs smells. In the shell, pecans keep 6 to 12 months in a cool, dry place.
Are pecans low in carbs?
Yes. One ounce has 3.93 g of carbohydrate, of which 2.7 g is fiber, leaving 1.2 g of net carbs. In 20 people with overweight or obesity, a 250 kcal pecan snack raised blood sugar and insulin less than tortilla chips.