We get lots of questions about nuts in the clinic. Aren’t nuts going to make me gain weight? Which nuts are best? How many nuts can I eat? Let’s explore nuts in detail and provide some guidelines on incorporating them as a healthy part of your nutrition plan.
Health Benefits of Nuts
Although nuts in the past had been defamed as a fattening snack, there are now multiple large scale studies indicating that regular nut consumption in moderation can lower the risk of heart attack and sudden cardiac death by 30-50 percent. Where do some of these benefits come from?
- Nuts contain heart-healthy facts such as omega-3s and monounsaturated fats
- Nuts contain plant sterols which can help lower cholesterol
- Nuts are a good source of plant-based fiber which is good for heart and digestive health
- Nuts have essential vitamins and micronutrients like magnesium, vitamin E, and folate
- Nuts are a source of L-Arginine, which can improve the health of your arteries
- Nuts are a good source of plant-based protein, especially for vegetarians looking for more protein sources in their diet.
- Nuts can be more filling and satisfying than most other snacks since they combine all of the above (protein, fiber, healthy fats and micronutrients)
Some Concerns About Nuts
Clearly nuts have some great nutritional value, but there can be some downsides which I've listed below.
- Added Oils: Many nuts come in packages and are bathed in highly inflammatory seed-based oils like canola, sunflower seed oil, or the ever mysterious but equally unhealthy “edible vegetable oil” labeled on many Indian snack packages. For example, in Indian and other ethnic grocery stores often nuts are soaked in these low quality oils, packaged and stored and shipped overseas in hot and humid conditions. Such conditions make these oils even more inflammatory, which counteracts all the natural nutritional benefits of nuts and makes them a potential risk to health.
- Packaged Trail Mixes: Many patients consume packaged trail mixes in the name of “healthy” nut consumption. Unfortunately these mixes not only contain the above oils, but have added sugar from dried fruits, chocolate chunks, raisins and even candy like M&Ms! Don’t kid yourself into thinking this is a healthy snack. Despite the name “trail mix,” these snacks nowadays are more commonly consumed in front of a screen or in the car during a long commute, rather than during the rigorous hiking trail they were originally intended for.
- Phytic Acid: Nuts contain phytic acid which in excess can block the absorption of some key nutrients. Read about phytic acid in my post here. This is another reason nuts should be consumed in moderation and ideally as a snack apart from meals to minimize it from binding key vitamins and minerals from the other nutrient dense foods you eat. Also, soaking, dehydrating and roasting nuts can lower phytic acid content.
- Excess Omega-6s: Omega-6 (aka O6) fats are inflammatory compared to the more anti-inflammatory Omega-3s (aka O3). A standard American diet has an O6:O3 ratio of 20:1 or more which promotes inflammation. An ideal ratio is significantly lower and closer to 3:1 or less. Most nuts do contain more O6s, which is another reason to keep amounts limited. However, since nuts are a more complete food with the various nutrients already discussed, O6s from nuts are far less inflammatory than the O6s coming from seed-based vegetable oils (sunflower, safflower, canola, etc.) used in cooking and found in most packaged foods. Remember from the first item on the list that many nut packages have added seed-based oils, so that's an O6 double whammy …O6 that occurs naturally in the nut and O6 from the added oils!
- Peanuts: Although studies have shown heart healthy benefits with peanuts, I tend to avoid them because they are very high in O6s, are frequently contaminated with a carcinogenic mold called aflatoxin, and are also a high-pesticide crop. There are far better nut options out there and if you or your child absolutely loves peanut butter, make sure it’s organic!
- Can be addictive: Nuts can be addictive and although they can be a nutrient-dense snack, they can often trigger overeating of more nuts or other snacks. Read my next section in case you’re a “Nutaholic.”
- Salt: Salt is typically the least of my worries when it comes to consuming nuts. Numerous studies show that excess sodium/salt intake is more of a concern in individuals with conditions like high blood pressure or kidney disease, but is not a major cause of human disease in the absence of such conditions. Read this article for more information.
Help for “Nutaholics”
Nuts are crispy, tasty, and fun to eat and you can go through several handfuls (or bags!) especially if you are passively snacking on them while working or watching your favorite show. The general recommended limit for daily nut consumption is a small handful which is about 1 oz or 30 grams. I give you exact amounts depending on the nut in the next section. Here are some tips to help you control your nut intake:
- Portion control them by putting them in small bags instead of large, easily accessible containers.
- Eat nuts alongside other snacks. When I get the intense snacking urge, often I might have a small plate with a handful of nuts and any combination of a wedge of high quality cheese, maybe a few grapes or berries, a few slices of avocado, and/or a couple squares of dark chocolate. Satiety is about variety not just quantity, so introducing different flavors to your palate instead of a single food like nuts only, will help you feel satisfied sooner.
- Make meals more nutrient dense. People who snack too much on nuts or anything else, often are undereating their preceding meals. Be sure meals are a good combination of protein, healthy fats, and plant based fiber to keep you full. Read my book and other posts in this blog to help you understand the concept of nutrient density.
- Don't make nuts more addictive than they are already. Avoid honey-roasted, excessively seasoned or salted, or the trail mix with dried fruit, candy, etc. that we already mentioned. Adding highly addictive sugar and salt to nuts can make portion control impossible
- Binge eat high quality nuts if you must. If you are just having one of those days and can't control your cravings, please be sure to consume the highest quality nuts possible like the ones I'm about to discuss in the next section. Clean the low quality Indian and ethnic nut mixes that are bathed in the worst quality oils out of your pantry and replace them with healthier nuts and make your own healthy spiced nut mix at home, such as the recipe at the end of this post provided by our dietitian, Prerna Uppal.
Which Nuts Do I Favor?
Diversify your nut intake to take advantage of the various micronutrients found in different nuts. I alternate between pistachios, almonds, walnuts, macadamias and brazil nuts, and add on some others every now and then. I listed a summary of a few of my favorites and end each with a sample serving size. Keep in mind that if you happen to eat a full serving of a particular nut during the day like almonds (~20-25 almonds), then you are done with any other nuts for the rest of the day. You can't pile on more cashews, pistachios, etc.
Great source of heart healthy monounsaturated fats, but are high in O6s and phytic acid. Studies show myriad benefits such as improved lipid profiles, reduced insulin resistance and better blood glucose control in type 2 diabetics. Raw almonds have the most nutrients but keep in mind that it is illegal for stores to sell truly raw almonds due to massive Salmonella outbreaks in the past.
The “raw almonds” labeled from stores like Trader Joe's are actually heat pasteurized which may reduce some of its nutrient content. The only way to get truly raw almonds in the US is to buy them directly from a farm or to purchase raw almonds in the US imported from another country. Dry roasted almonds still do have a respectable nutrition profile and may be easier to digest due to lower phytic acid content.
Daily serving size: Around 20-25 almonds.
The most outstanding benefit of these nuts is the abundant content of a precious nutrient called selenium. The richest, most bioavailable sources of selenium are organ meats and shellfish, but since many of my patients cannot or will not consume these foods, brazil nuts are a good alternative. Selenium is involved in multiple physiological reactions that lower inflammation and oxidative stress to the body, improves immunity, helps the body detoxify, and is especially important for thyroid health.
An example of its detoxification properties is the fact that adequate levels of selenium in the diet can help bind excess mercury from the fish we consume as noted in this study. Mercury is a toxin that can poison multiple systems in our body, especially the nervous system, and is considered by the World Health Organization to be “one of the top 10 chemicals of major public concern.” We are at greater risk from mercury toxicity from fish when our diet is deficient in selenium.
Daily serving size: A daily serving of brazil nuts is 7 nuts which provides you with all the selenium you need to power the processes I just described. You can experience selenium toxicity from overdoing selenium so if you are already consuming organ meats and/or shellfish, there's no need to add brazil nuts. More is definitely not better and can be unsafe when it comes to selenium.
Cashews are a delicious, sweet-tasting nut that I find highly addictive, as do many of my patients. I don't typically snack on cashews since I have trouble with portion control, but they are a wonderful addition to stir-fries. Cashews have a very impressive nutrient profile with multiple micronutrients like copper, magnesium, manganese and many more.
If walnuts are the top nut for cognitive brain function (see later on the list), cashews have an ideal mix of nutrients such as vitamin B6, magnesium, and tryptophan, to help regulate mood. The amino acid tryptophan in particular, which is abundant in cashews, boosts levels of serotonin, which is the brain chemical acted upon by common anti-depressant and anti-anxiety drugs like Prozac.
Despite many reports on the web about cashews potentially being an effective anti-depressant and stress reliever, I didn't find any research studies in humans to support this to date. However, given its wonderful potentially mood-enhancing nutrient profile, I would rather have you add cashews in moderation to a healthy diet and lifestyle (better sleep, stress reduction, and exercise) than take a random supplement tablet that claims to improve mood.
Daily serving size: Your daily serving of cashews is between 16-18 nuts. Interestingly, studies show that roasting cashews produces higher levels of beneficial antioxidants.
The Rolls Royce of nuts. They are decadent, delicious, and expensive. They are not as nutrient dense as many of the other nuts we've discussed, but they are low in phytic acid, inflammatory O6s, phytate and pesticides…pretty much the opposite of peanuts. There is some evidence of improved lipid profiles with macadamia nut consumption. This is not my staple nut for consumption due to price and a relative lack of science compared to other nuts, but it does make a very filling and satisfying snack.
As an aside, if I were told I could only eat one last snack for the rest of my life, Hawaiian chocolate covered macadamia nuts would be a top contender. This should not be your preferred form of nut intake, except maybe once a year!
Daily serving size: These marble-sized nuts are larger than pistachios (discussed next) and almonds, so a serving size is smaller at around 12 nuts a day.
I not only love the flavor of pistachios but also the act of unshelling them which keeps my hands busy. In addition, since I focus on reducing insulin resistance and metabolic syndrome risk in my patients (and myself!), there are studies showing a beneficial impact on glucose control, such as this study which shows improvement in cardiometabolic markers. Pistachios are relatively lower in phytic acid, so they are digested easier and won't rob as many nutrients from other foods eaten in close proximity.
Daily serving size: Since pistachios are smaller nuts than almonds and especially macadamias, you can eat closer to 50 pistachios daily which is far more than even I can handle! Again, shelled versions are preferred because unshelling takes a little more time which may help with satiety, and if you flex your forearms and biceps tightly while unshelling those few stubborn pistachio shells that are sealed nearly airtight, you may burn a few extra calories in the process!
I'm actually not a huge fan of walnuts due to individual flavor preference. However, the fact that they are not as addictively delicious to me means I'm less likely to overindulge. Like pistachios, there's a lot of good heart-healthy science showing walnuts lower oxidative stress and cardiometabolic markers, so I do rotate these into my nut intake every now and then.
Walnuts do have a high amount of polyunsaturated fats compared to most other nuts, consisting of more inflammatory O6s than anti-inflammatory O3s, but the overall package of micronutrients and other nutritious ingredients appear to counteract the extra O6s since there's strong scientific support for their heart health benefit.
In addition, walnuts appear to be the top nut for brain health due to its combination of O3s, vitamin E, folate, antioxidants and even sleep-inducing melatonin. This study even shows walnut consumption may improve cognitive performance in young adults. It's easy to remember walnuts are good for the brain since walnuts actually resemble a brain!
Daily serving size: A daily serving is about 14 shelled walnut halves.
There are many nuts that I didn't include on this list, but my intention was to share some of my favorites and to give you a sense of what a diverse nutrient profile nuts have.
Your individual choices may be based on flavor, but I would warn against stocking nuts you find highly addictive. If you wanted to be more prescriptive, consider nuts like almonds, walnuts, and pistachios for heart health and to improve glucose control. If you have thyroid issues or inflammatory disorders or consume lots of fish, add brazil nuts to reduce inflammation and protect yourself against mercury toxicity if you're not getting selenium from other food sources. If your thinking isn't as sharp as it used to be and you've been feeling blue lately, maybe walnuts and cashews might be a good brain booster. You get the picture.
Creative Ways to Add Nuts to Your Diet
Instead of just digging into a bag of nuts, think of how nuts can actually improve the nutrient density and flavor of your meals and snacks. Remember, these still count towards your daily nut consumption so if you added crushed pecans to your yogurt for breakfast, spread almond butter onto your apple wedges for your afternoon snack, and are having almond-crusted halibut for dinner, you don't need additional nuts to snack on. You are more than covered. A few tips on adding nuts to your diet:
- Sprinkle nuts on salads or add to stir-fries and rice dishes like a Chinese fried rice or an Indian biryani. Read our rice post, before you start questioning why I'm permitting the thoughtful intake of rice on the menu.
- Add a handful to your smoothies to boost protein power, but make sure your smoothies are more vegetables like leafy greens and less fruit.
- Spread some nut butter on fruits (apple wedges) or veggies (celery sticks) as a snack
- Use nuts to bread meats and fish
- Top your yogurt with crushed nuts
- Make your own homemade trail mix using a variety of healthy nuts, seeds, unsweetened coconut flakes, etc.
- Make your own homemade Indian spiced nut mix using your favorite nuts, spices (which also have great anti-inflammatory powers), healthier oil replacement, lemon juice, etc. See recipe at the end of this post.
- Nut flours like almond flour can be a good gluten-free, high protein flour substitute to make breads and desserts, but it is a relatively high nut load, so would use in moderation.
How Much is Too Much?
Again, stick to the serving sizes I mentioned. We're all human and there are going to be days when you are stressed out or maybe stuck in an airport with limited snack options and you end up doubling or tripling your daily allowance for nuts. Forgive yourself and move on. At least you still indulged in a snack far more nutritious than most of the packaged crispy or sweet snacks you find on shelves.
Bottom line is that body size and energy expenditure also matter. If you're athletic, muscular and very active, you could get away with eating more nuts than someone who is scrawny with very little muscle mass and is inactive. The latter case unfortunately describes the majority of patients I see. Calorie and protein requirements are dependent on body composition and your daily energy expenditure.
When I see patients who are insulin resistant (prediabetes, diabetes, etc.) and addicted to sugar and carbohydrates, I allow them to be more liberal with healthy nut intake while I gradually wean them off their crispy and sweet snacks. Once we cut those sugar and salt cravings, we can work on reducing their intake of excess nuts to a more reasonable level.
Nuts can be a nutritious part of most diets if they are eaten in their natural form and not adulterated with unhealthy vegetable oils and addictive ingredients. They should be a snack replacement strategy and not just added onto other unhealthy snacks. A diverse portfolio of nuts should be considered that can be tailored to your tastes and underlying health risks. Nuts are calorically dense and amounts should especially be moderated if you are physically inactive.
As I've discussed in past posts, don't oversimplify foods into a single nutrient and make irrational conclusions like “I shouldn't eat nuts because they're too high in calories and cholesterol” or “I'll eat an unlimited amount of nuts since I heard they're good for my heart”…. while I ignore the part about being more physically active and eating more vegetables! Look at the big picture of health and decide how nuts can fit into one aspect of your overall lifestyle plan.
Prerna's Recipe for Namkeen (Indian Spiced) Nuts