Franziska Spritzler, RD, CDEBrazil nuts are popular among people who follow a ketogenic lifestyle because they’re tasty, convenient, and provide healthy fat with very few carbs. However, there’s something important to be aware of if you consume them on a regular basis.
Brazil Nut Nutrition
From a macronutrient perspective, Brazil nuts fit well with keto. One ounce/28 grams (about 5 to 6 Brazil nuts) provides 19 grams of fat, 4 grams of protein, and only 1 gram of net carbs.
In addition, they’re a good source of vitamin E and several minerals, including magnesium and potassium.
The concern with Brazil nuts is their exceptionally high selenium content. Selenium is a trace mineral that plays several roles in health, including thyroid hormone production, immune function, and reducing inflammation and oxidative stress.(1) Trace minerals are essential nutrients, meaning you need to get them from food because your body can’t make them on its own. However, they are required in much smaller amounts compared to other minerals. As an example, the recommended intake for magnesium in most countries is between 300 and 410 milligrams per day, while the recommended intake for selenium is between 55 and 70 micrograms per day.
Many keto-friendly foods like meat and seafood also provide selenium, but Brazil nuts are by far the richest source. Just one Brazil nut contains about 70 to 100 micrograms of selenium, depending on its size, while 3.5 ounces (100 grams) of meat or seafood typically contains about 30 to 50 micrograms.
Although selenium is an important nutrient, getting too much over an extended period of time can lead to toxicity, known as selenosis, which can cause symptoms like nausea, vomiting, fatigue, hair loss, and neurological problems.(2) The safe upper limit for selenium is 400 micrograms per day—roughly the equivalent of four to five Brazil nuts. And remember, you’ll get small amounts of selenium from other foods as well.
In some trials, cholesterol and triglyceride levels, blood glucose levels, and oxidative stress markers improved in individuals who consumed Brazil nuts, which provided up to 300 micrograms of selenium daily for study periods ranging from 8 weeks to 6 months.(3)
How to Enjoy Brazil Nuts Safely on Keto
Brazil nuts can be a good addition to a ketogenic lifestyle, but it’s important to consume them in moderation if you eat them frequently. Here’s how to enjoy them safely:
- Limit your intake: Stick with 3 or fewer Brazil per day if you include them as part of your daily routine.
- Mix or alternate with other nuts: Go for macadamias, pecans, or other keto-friendly nuts to minimize the chance of overconsuming selenium.
- Consume less frequently: Although selenium can build up in your system over time, going above the recommended amount occasionally is likely OK for most people. So, if you want to eat a large handful of Brazil nuts as a snack, do so only once every few weeks.
When eaten in small servings, Brazil nuts can be a tasty, nutritious addition to your ketogenic lifestyle.
