Walnuts have long been recognized for their role in heart and blood pressure health and have recently been found to contain nutrients essential to the management of other chronic health conditions such as diabetes, digestive disorders, and age-related brain diseases. Here are 6 reasons to include walnuts in your Keto Diet as well as some insight into the nutrients that make walnuts such an amazing superfood:
1. Weight Management
Although walnuts are calorie-dense due to their high fat content, studies show that nut consumption has either a neutral effect on body weight or can actually decrease body weight. Eating walnuts not only can control your appetite, but it can also increase diet-induced thermogenesis (DIT), which is the energy expenditure associated with digesting and metabolizing food. Using MRI imaging, researchers have also found that eating walnuts may activate a center in the brain known to be associated with hunger and food cravings. Another proposed mechanism explaining the beneficial role of walnuts on obesity is its impact on healthy bacteria in the intestine. The fiber and polyphenols in nuts, including walnuts, are thought to stimulate the growth of good bacteria (probiotics) in the intestine.
Nutrients in Walnuts Linked to Weight Management
The high content of the omega-3 fatty acid ALA in walnuts can be linked to a higher diet-induced fat-burning effect, as well as a lower body fat accumulation. In addition, the skin covering walnuts contains fiber and is rich in plant compounds known as polyphenols, both of which provide fuel for healthy gut bacteria, more commonly known as probiotics. This healthy bacteria has been linked to various metabolic processes that can affect appetite and our body’s energy expenditure.
2. Blood Sugar Management
The role of walnuts in weight management is strongly linked to its ability to prevent and manage type 2 diabetes as well as the risk factors associated with metabolic syndrome. Walnuts may have a more direct effect on blood sugar control due to their high content of the trace mineral manganese, which plays an important role in both the production of insulin and the metabolism of carbohydrates. In addition, walnuts are a good source of magnesium, antioxidant and anti-inflammatory compounds, unsaturated fatty acids, and fiber, all of which have been linked to increased insulin sensitivity. Recent research has shown that even just one ounce of walnuts daily can help reduce other issues related to metabolic syndrome, such as elevated blood pressure and triglyceride levels, and low levels of HDL-cholesterol (“good cholesterol”).
Nutrients in Walnuts Linked to Diabetes and Metabolic Syndrome Management
Walnuts contain several compounds that help manage blood sugar, blood pressure, and abnormal lipid levels associated with diabetes and metabolic syndrome. These include unsaturated fatty acids, fiber, antioxidants, tocopherols (vitamin E), arginine, phytosterols, and minerals like magnesium, and manganese. These healthy nutrients alone, or in combination, help contribute to the improvements in blood sugar control and the management of the various components of the metabolic syndrome. The polyphenols and fiber in walnuts deserve special mention for their potential role in managing the metabolic syndrome by promoting the growth of healthy bacteria in our intestine.
3. Digestive Health
A recent study demonstrated that a daily intake of ~1.5 ounces of walnuts over eight weeks significantly affected the intestinal bacteria profile (microbiome) by promoting the growth of probiotic – and butyric acid – producing bacteria in healthy participants. Research demonstrates that the fiber and polyphenols in walnuts stimulate the production of beneficial bacteria in the intestine which increases butyrate production. This increase in butyrate levels helps promote the production of mucin, a component of the mucous membrane which maintains the integrity of the intestine. As an anti-inflammatory agent, butyrate has also been shown to inhibit a compound in the intestine associated with inflammatory bowel diseases.
Nutrients in Walnuts Linked to Digestive Health
Both fiber and polyphenols in walnuts are linked to gut health and play a potential therapeutic role in the management of inflammatory digestive diseases.
4. Heart Health
A review of 26 clinical trials with over 1,000 participants concluded that incorporating walnuts into the diet improved levels of cholesterol, triglycerides, and apolipoprotein B, a protein in LDL-cholesterol recognized as a risk factor for heart disease. A recent review of literature also revealed that ALA, the omega-3 fat found in walnuts, may be as effective in reducing the risk of cardiovascular disease as fish-and krill-derived omega-3’s. The high phytosterol content of walnuts is another likely contributor to its cholesterol-lowering properties. An analysis of multiple trials on the effect of nuts on blood lipids (cholesterol) revealed that the phytosterols in nuts were associated with LDL-cholesterol reduction.
Nutrients in Walnuts Linked to Heart Health
In addition to their high content of ALA, walnuts contain multiple heart-healthy compounds, such as high levels of arginine, phytosterols, and polyphenols. These nutrients have all been linked to both heart and blood vessel health through their antioxidant and/or anti-inflammatory actions. Walnuts are also unusually high in the gamma-tocopherol form of vitamin E, which has been found to exert a much more potent antioxidant, anti-inflammatory, and heart-protective effect than the more common version of this vitamin, alpha-tocopherol.
5. Blood Pressure Management
Adequate intake of omega-3s, including the alpha-linolenic acid (ALA) present in walnuts, has repeatedly been shown to help improve a wide variety of cardiovascular functions, including blood pressure. In addition, walnuts are a concentrated source of the nitric oxide precursor L-arginine, an amino acid that has been shown to enhance blood vessel dilation and reduce blood pressure. The magnesium in walnuts is linked to a lower risk of major cardiovascular risk factors, including high blood pressure, and is associated with improved blood vessel function.
Nutrients in Walnuts Linked to Blood Pressure Management
The beneficial effects of walnuts on blood pressure may result from their high content of ALA and other healthy fatty acids, as well as from either the isolated and/or combined effects of antioxidant polyphenols, magnesium, and L-arginine—nutrients that are all linked to blood pressure health.
6. Brain Health
It has long been established that the inclusion of walnuts in the diet improves cardiovascular health, which is itself a risk factor for degenerative brain diseases and age-related decline in mental function. A growing body of evidence indicates that omega-3 fatty acids, such as ALA, have a protective effect on the nervous system. These fatty acids influence the levels of neurotrophins, molecules that increase nerve growth and survival. Among neurotrophins, the level of brain-derived neurotrophic factor (BDNF) is known for its effect on promoting nerve cell growth and survival. In addition, the polyphenols and vitamin E tocopherols found in walnuts not only reduce the oxidation and inflammation of brain cells but also improve the signaling between nerve cells, increase cell growth, and enhance the removal of toxic compounds which have been linked to degenerative brain disorders. The compound in walnuts known as phytomelatonin, together with ALA and antioxidants, is also thought to contribute to the beneficial effect on mood which was observed in a trial of walnut supplementation in healthy young men.
Nutrients in Walnuts Linked to Brain Health
Walnuts are rich in numerous plant compounds including healthy fatty acids, polyphenols, tocopherols, and phytomelatonin, all of which offer potential benefits for brain health.
