There is a lot of conflicting messaging about nuts—eat them, don’t eat them, they’ll make you fat, they’ll help you lose weight, they’ll give you heart disease, they’ll cure your heart disease, and so on.
Unfortunately this is nothing new when it comes to the consumer world of nutrition media messaging. Because nutrition science is constantly evolving and new studies are being published every day, it’s easy to cherry pick studies to prove a point. And the number of studies saying one thing versus another isn’t necessarily something to rely on—depending on many factors including study design, sample size and statistical analysis, a single study may be more reliable than 5 others combined.
That’s why it’s important to look at the body of evidence as a whole and focus on strong trials, systematic reviews and meta-analyses. A meta-analysis is the best way to get a broad view because it combines data from many studies and analyzes it to look at things as a whole and detect patterns and relationships. Enough about assessing nutrition science…
Nuts are one of the most nutrient-dense foods out there. They pack a punch of protein, fiber and fat and provide many essential =nutrients. I hate to leave peanuts out of this, because they are technically a legume, but they also deserve plenty of love and attention too—they’re rich in the amino acid lysine and are an affordable, versatile protein source. In fact, they were the first meat analog! Here are five health outcomes regular nut consumption can help you achieve.
- Reduce heart disease risk
A 2014 meta-analysis of over 300,000 people found that those consuming the most nuts (at least 2 servings per week) had the lowest risk of coronary artery disease. Researchers found a dose-response relationship (read: the more you eat, the lower your risk) between nut consumption and heart disease risk—the risk of developing heart disease decreased 5% with every serving of nuts per week consumed.
A 2010 pooled analysis of 25 studies found that consuming nuts was associated with lower total and LDL cholesterol (the “bad” cholesterol) and lower triglycerides in those who had higher triglycerides to start with. Again, a dose-response relationship between amount of nuts consumed and lipid outcomes was observed.
A 2015 meta-analysis of randomized controlled trials (the strongest type of intervention study) found that nut consumption significantly reduced systolic blood pressure in those with type 2 diabetes. People with diabetes are already at an increased risk for heart disease, so this is important. Evidence showing an inverse relationship between nut consumption and the risk of type 2 diabetes is limited and thus doesn’t make this list.
- Maintain a Healthy Weight
This may be counter-intuitive, since nuts are calorie-dense and portions must be controlled to prevent overeating. Nuts have a positive effect on satiety—they help you feel full and satisfied after you eat them. Interestingly, in studies that allowed participants to eat whatever they wanted, people didn’t tend to gain weight when they added nuts to their diets, even if they were consuming more calories as a result.
A 2013 meta-analysis of 33 clinical trials found that those who consumes nuts were not at an increased risk of weight gain. A 2008 review found that people on weight-loss diets who consumed nuts stuck to their diets longer and lost more weight than those who did not include nuts.
- Lower Mortality Risk
Another 2015 meta-analysis of over 350,000 people found a significant inverse relationship between nut consumption and mortality from all causes and specifically from cardiovascular disease and cancer. A single serving of nuts per week was associated with a 27% lower risk of cardiovascular disease mortality (the likelihood of dying from heart disease). This study also showed those who consumed nuts had lower body mass indices, providing further evidence for the healthy weight benefit.
A third 2015 meta-analysis including people of low socioeconomic status also found a significant inverse relationship between nut consumption and mortality, especially from heart disease, across genders and races. A 2015 analysis of data from the Physician’s Health Study (of over 20,000 male physicians) found that those who consumed at least 5 servings of nuts per week had the lowest mortality risk.
- Obtain Essential Nutrients
Finally, a good reason to eat nuts is they provide us, especially vegans, with the nutrients we need (see the table below). Other than seeds, walnuts are one of the few plant-based foods that are rich in the omega-3 essential fatty acid ALA and Brazil nuts are exceedingly rich in selenium.
Nuts are tasty and nutritious morsels that can be eaten alone or added to a variety of foods. Try topping your oatmeal or cereal with chopped walnuts, adding sliced almonds to your salad or mixing some cashews into your stir-fry. Always exercise portion control when consuming nuts as they are quite energy-dense—a serving of nuts is one ounce.
Percent of Daily Value for Various Nutrients in 1 oz of Nuts
|Nut||Nuts/1 oz||Protein||Fiber||Iron||Potassium||Vitamin E||Magnesium||Zinc|
|Walnuts||7||4 g||2 g||5%||4%||1%||11%||6%|
|Almonds||24||6 g||4 g||6%||6%||24%||19%||6%|
|Cashews||18||5 g||1 g||11%||5%||1%||21%||11%|
|Pistachios||49||6 g||3 g||6%||8%||2%||9%||4%|
|Macadamia Nuts||12||2 g||2 g||6%||3%||1%||9%||2%|
|Pecans||8||3 g||3 g||4%||3%||1%||9%||9%|
Nutrition information from the USDA National Nutrient Database for Standard Reference. As defined by the FDA, a food that contains 10-19% DV of a nutrient is considered a “good source” of that nutrient. A food with 20% DV or more is considered an “excellent source” of that nutrient.
Note: Because it’s always a good idea to read about the funding sources of studies, I want to acknowledge that two authors on the 2010 pooled analysis received research funding from various nut entities, one of the authors on the 2013 meta-analysis received research support from the Almond Board of California, and the primary author of the 2008 review received honorarium from the International Nut Council Nutrition Research & Education Foundation and Peanut Institute. I am confident in the methodology of these studies and that the results of would remain unchanged without their involvement.