Eating walnuts increases your intake of the nutrients your mind needs to stay healthy, a recent study confirms.
Welcome to Episode 4 of the Food for Mood Series: Walnuts
Go Nuts
Researchers don’t need to convince me that walnuts are good for my health, but it’s always nice to be validated, no?
Most of us know that eating nuts, including walnuts, is good for our health. Many health professionals, including doctors, encourage their patients to eat nuts and the Dietary Guidelines for Americans suggests people include nuts as part of a healthy diet.
However, despite knowing nuts are good for us, only about 7% of the U.S. population regularly consumes them(1). Most Americans choose less nutritious food, or in some cases, ones that are outright harmful to our health.
Those who do eat nuts generally stay in the peanuts or almonds realm. Now, don’t get me wrong, peanuts and almonds are delicious and contain vital nutrients, but consuming a wider variety can offer even greater benefits!
Nuts like walnuts, pecans, pistachios, and cashew nuts all contain additional nutrients that peanuts and almonds may lack. Including them regularly can ensure you get what your body needs.
Our typical western diet lacks many nutrients our bodies and minds need to stay healthy.
Why Walnuts?
Recent evidence suggests daily consumption of walnuts increases our intake of nutrients known to benefit our mental and physical health.
Before we dive deeper into the study methods, the researchers chose walnuts becuase of their unique nutrient profile.
A Closer Look At The Nutrient Composition of Walnuts
A 1-ounce serving (28.35 g) of walnuts provides:
- 4 g of plant protein
- 18 g of total fat
- 2.5 g of monounsaturated fat
- 13 g of polyunsaturated fat (including 2.5 g of omega-3)
- 4 g of carbohydrates
- 2 g of fiber
- 27 mg of calcium
- 45 mg of magnesium
- 98 mg of phosphorus
- 125 mg of potassium
- 28 mcg of folate
- 6 IU of Vitamin A
- 6 mg of Vitamin E
What are the Nutrient Requirements for Women? See how much you should be getting of each of these nutrients in Nutrient Requirements for Women.
Key Nutrients Found In Walnuts Can Affect Our Health
The unique nutrient profile of walnuts is what makes them stand out. The contain, at relatively high concentrations, several nutrients needed for good physical and mental health.
Fiber
Fiber is an important factor invovled in managing our digestive health. It promotes a healthy gut microbiome (good bacteria living in our guts). A healthy gut may play a larger role in mental health than we realize through the gut-brain axis.
Potassium
Potassium is an electrolyte necessary for the intracellular movement of nutrients.
Calcium
Calcium is a mineral famous for its role in bone formation and health. It is also involved in the intracellular flow of nutrients and serotonin production.
Magnesium
Magnesium is another mineral with several vital functions. It is invovled in digestion, bone formation, and vitamin D absorption and utilization. Magnesium is also important for neurotransmitter signaling.
Folate
Folate is famous for its role in neuronal tube formation during pregnancy but is also involved in cell formation and activity.
Vitamin E
Vitamin E plays a significant role in our immune system by acting as a potent antioxidant and savaging for free radials. An overall reduction in inflammation can improve brain function.
Phytosterols
Phytosterols, or plant sterols, protect our hearts by blocking the absorption of cholesterol. Healthy vasculature improves blood flow to and around the brain.
Polyphenols
Polyphenols, compounds found in plant foods, give our foods their color and flavor. When consumed, they act as antioxidants, reducing inflammation.
Polyunsaturated Fats (PUFAs)
PUFAs are a type of fat offering many health benefits. In walnuts, the two main PUFAs are linoleic acid (LA or Omega-6) andalpha-linolenic acid (ALA or Omega-3). If eaten in a 4:1 ratio, respectively, both can positively impact inflammation and protect our cardiovascular system. PUFAs are essential structural features of every cell, including our neurons.
Walnuts and Mental Health
Walnut are a good source of key nutrients that are inovlved in many biological processes, including those of the brain. Because of this, reasearchers are curious to know if eating walnuts can influence health outcomes.
A recent study confirmed that eating walnuts increases your intake of the nutrients your mind needs to stay healthy.
In this study, researchers hypothesized that regular consumption of walnuts would increase the participant’s intake of calcium, magnesium, folate, vitamin E, vitamin K, and fiber.
Researchers used data from the 2015-2018 National Health and Nutrition Examination Survey (NHANES) to assess the diets of “no-nut consumers,” which they defined as those who do not regularly eat walnuts.
There were two data collection points, one at the start of the study period and then again anywhere from 3-10 days later. Both sets of data were collected by trained professionals.
From this information, researchers then calculated the participants’ intake of specific nutrients.
The results showed that wealthy, highly educated, white females are more likely to eat walnuts and that eating walnuts regularly, significantly increased the participants’ intake of these nutrients.
Bahahaha.. Wouldn’t you know it! Increasing your intake of food with certain nutrients would increase one’s intake of the nutrients. So. Brilliant!
Critically Appraising the Research
I first came across this study on Medium, an online, self-publishing platform where writers like myself can put their work. It was a well-written article that drew my attention because it aligned with a food I was planning to write about myself. I just had to use this article.
But, as I looked closer at the study, I began to realize just how stupid it was.
There is nothing novel about it. It only confirms what we already know- when you eat more nutrients, you increase your intake of those nutrients.
What would have made this article more useful is assessing the participants’ actual nutrient levels through lab work or assessing another measurable outcome like disease risk or symptomology.
However, I’m choosing to use it here to illustrate two points.
One, walnuts are good for your health.
Two, data can be misunderstood, misinterpreted, and used to support any argument.
Thankfully, this article is harmless, but imagine a different article titled “walnuts contribute to slight weight gain.”
You read the headline and took the findings at face value but because you didn’t read the full article, you didn’t learn that the significant weight gain was in only those who were underweight at the start.
You would have written off walnuts for good and missed out on key nutrients unnecessarily.
Note: this article is made up!
Look for Evidence-Based Practices You Can Trust
The internet is literally full of garbage information.
Random people on tictok, or other social media platforms, use one-off articles that seem novel, or promise you an easy solution, to get you to click on their site. Because, when you do, they get paid.
Here’s the real deal. Being human is not easy, and our problems won’t be fixed by doing “these three things.”
What will solve your problems is hard work and consistency. I know, it’s not what you want to hear.
Evidence-based practices are what doctors, and other trained health professionals, use to treat people. It’s where clinical recommendations are born, and things like the Dietary Guidelines for Americans are constructed.
You can find evidence-based recommendations online at Healthline, Harvard Health, or, you guessed it, here, at The Dietitian’s Cauldron.
Does Eating Walnuts Improve Your Mood?
Now that we know eating more walnuts increased our intake of certain nutrients, lets see if those nutrients can impact our moods.
A 2019 study assessed the impact of dietary changes (increased intake of vegetables , fruits, wholegrain cereals, protein, unsweetened dairy, fish, nuts and seeds, olive oil, turmeric and cinnamon; and decreased intake of refined carbohydrates) on symptoms of depression. They found those who followed through with the diet had reduced symptoms of depression at three weeks and at three months.
Although this study illustrates the profound impact our diet can have on our mental health, there are several limitations. First, researchers used a small sample of college students, making the findings not be transferrable to the general population. Secondly, the study design included a follow-up call and financial reimbursement to the intervention group to encourage diet adherence. Behavioral reinforcers like these are not real-life circumstances and likely influenced the results.
Another 2019 study, using data collected from 26,656 participants enrolled in the National Health and Nutrition Examination Survey (NHANES) between 2005 and 2014, found those who ate walnuts had 26% decrease in depression score. This association was stronger in women (32% lower depression score) then men (21% lower depression score).
Furthermore, a 2022 systematic review focusing on nuts specifically stated that, despite the limitations in many available studies, increasing nut consumption could lower the risk of depression, reduce depressive symptoms, and improve moods in the general population.
Given this information, it appears eating walnuts effectively increases our intakes of certain nutrients which lends to improved depression and mood.
Is There A Downside of Eating Walnuts?
Risk of Weight Gain
Walnuts contain fat, which is both good and bad. Although the fats within walnuts are considered “good,” they still contribute to our overall calorie intake and excess calories results in weight gain.
So, does increasing consumption of walnuts lead to weight gain?
An somehwhat older study from 2005 looked at walnut consumption over a 12-month period. Researchers were pleasantly surprised to find that while there was weight gain amount regular nut eater, it was less than expected.
Furthermore, a longitudinal study completed in 2019 assessed the long-term effect of nut consumption on weight over a period of two decades. They found those who consumed walnuts regularly had lower rates of weight gain, especially when substituted for less healthy foods, like chips or processed meats.
Depending on several factors, like sedetary lifestyle or poor dietary choices overall, consuming more than a handful of nuts each day could contribute to weight gain, but not quite as much as you might expect.
The benefits you reap certainly outweigh (ha, pun) the low risk of weight gain, which can absolutely be avoided if you make a few simple adjustments to your lifestyle.
Keeping portions to a handful, incorporating regular exercise, and filling your diet with other anti-inflammatory foods, will give you the all benefits of walnuts without the risk of weight gain.
So, you can have your walnuts and eat them, too!
Tree Nut Allergy
Then there are nut allergies. Because walnuts are a type of tree nut, they can trigger an allergic reaction in some people. For those allergic to tree nuts, sorry. You’re missing out but can eat a variety of other foods that contain these healthy fats and promote good moods.
Cost
Some might worry about the costs associated with eating walnuts, and it’s true. Adding walnuts will increase your grocery bill, but not by much.
Think about this. Investing in your health is the most important thing you can do in your time here on earth. No one is going to take care of you except you.
Plus, you ought to buy them in place of another less healthy snack. So, forgo those Doritos and you’ll save enough to offset the cost of the walnuts. And remember, a little goes a long way.
My Recommendations
- Eat more walnuts!
- Keep your portions small (one handful each day).
- Always question what you read, especially regarding something that seems too good to be true.
- Invest in your health. Nobody will but you.
Try These Products
Ways To Eat Walnuts
Walnuts pair well with sweet and tart flavors.
- Throw in a salad and eat them for lunch
- Put them in trail mix and eat them as a snack
- Use them in desserts
- Bake into cookies or brownies
- Candied walnuts and mashed bananas
- Dip them in melted dark chocolate
- Make cranberry walnut chicken salad or this …
Walnut Kale Pesto
Bon Appetit, Witch!
Reference
- Spence LA, Henschel B, Li R, Tekwe CD, Thiagarajah K. Adding Walnuts to the Usual Diet Can Improve Diet Quality in the United States: Diet Modeling Study Based on NHANES 2015–2018. Nutrients. 2023; 15(2):258. https://doi.org/10.3390/nu15020258
- Francis, Heather & Stevenson, Richard & Chambers, Jaime & Gupta, Dolly & Newey, Brooklyn & Lim, Chai. (2019). A brief diet intervention can reduce symptoms of depression in young adults – A randomised controlled trial. PLOS ONE. 14. e0222768. 10.1371/journal.pone.0222768.
- Arab L, Guo R, Elashoff D. Lower Depression Scores among Walnut Consumers in NHANES. Nutrients. 2019 Jan 26;11(2):275. doi: 10.3390/nu11020275.
- Rubén Fernández-Rodríguez, Estela Jiménez-López, Miriam Garrido-Miguel, Isabel A Martínez-Ortega, Vicente Martínez-Vizcaíno, Arthur Eumann Mesas, Does the evidence support a relationship between higher levels of nut consumption, lower risk of depression, and better mood state in the general population? A systematic review, Nutrition Reviews, Volume 80, Issue 10, October 2022, Pages 2076–2088, https://doi.org/10.1093/nutrit/nuac022
- Sabaté J, Cordero-Macintyre Z, Siapco G, Torabian S, Haddad E. Does regular walnut consumption lead to weight gain? Br J Nutr. 2005 Nov;94(5):859-64. doi: 10.1079/bjn20051567. PMID: 16277792.
- Liu X, Li Y, Guasch-Ferré M, et al Changes in nut consumption influence long-term weight change in US men and women. BMJ Nutrition, Prevention & Health 2019;2 doi.org/10.1136/bmjnph-2019-000034