The Dense Micronutrient Profile of Nuts, Seeds, and Legumes and How Science Reports They Improve Health Status
Almonds, cashews, walnuts, chia seeds, sunflower seeds, pumpkin seeds, flax, hemp, peanuts...the list goes on when considering the variety of nuts and seeds to choose from. Unfortunately, due to our ever ebbing and flowing diet culture, this food group has been demonized because of its high fat content. Ever since the 1980s when low fat diets captured the attention of the public, people have been told to stray away from eating any food that predominates in fat in order to lose weight. However, science and nutrition research has since debunked this claim as it pertains to nuts and seeds in particular. Many studies have demonstrated the vast array of health benefits that this food can offer, ranging from anti-carcinogenic agents to weight loss management factors.
Here is a list of the major health benefits that nuts, seeds, and legumes provide.
A diet that regularly includes nuts and seeds can lead to a lowered risk of obesity, cardiovascular disease, and Type 2 Diabetes
Many of the diseases that place in the top 10 leading causes of death in the United States pertain to metabolic syndromes and illnesses, and they are often related to the diet. Heart disease is the number one killer in the United States, accounting for over 600,000 deaths per year (5). Other leading causes of death include diabetes and cancer, both of which are conditions that are shown to have direct correlations to our daily nutrition. Further, the presence of obesity increases the likelihood of morbidity from these conditions.
The Standard American Diet (the SAD--what an ironic name) contributes greatly to our propensity to metabolic syndromes leading to chronic illness like cardiovascular disease and diabetes. The SAD is one that is high in processed foods, poor-quality protein, fat and sugar, and very low in plant-based nutrients. A large sector of nutrition research has been dedicated to those foods that demonstrate a decreased risk in chronic illness for those who eat them regularly. Nuts and seeds in particular are one of those foods that nutritional scientists have seen to minimize such risks. Researchers suggest that this is because of their macro- and micronutrient profiles. Nuts and seeds are a quality source of "unsaturated" fat, a type of fat that has been shown to lower cholesterol and rates of inflammation (among other things), and therefore should not be avoided. Additionally, research has pointed toward the fact that the type of dietary fat eaten, rather than the amount of total fat eaten, is the true marker of one's risk for chronic illness, especially Type 2 diabetes (7)(9). Other reasons for why nuts and seeds have been shown to lower risk for disease associated with obesity and metabolic syndromes are that this food has been shown to help with satiety (the feeling of being satisfied after eating), and their micronutrient (vitamin and mineral) profiles are shown to help metabolic processes in the body operate more efficiently.
Nuts and seeds help to lower blood lipid profiles
In a meta analysis conducted by researchers at the Friedman School of Nutrition Science and Policy at Tufts University, data was collected from trials that involved consistent nut intake between 3 and 27 weeks. They specifically looked at the biomarkers that appeared in direct relation to this consumption. The result? Consistent nut consumption was seen to have lowered levels of total cholesterol, LDL cholesterol, ApoB apolipoproteins, and triglycerides (1).
Cholesterol is essential to normal cellular function; think of it like glue or caulk that serves a structural and integrity function for the cell membrane. It also plays additional roles as a precursor to some hormones. Though this molecule is vital for cellular processes, most Americans take in too much cholesterol. An abundance of cholesterol (in conjunction with an abundance of Low Density Lipoprotein cholesterol, which is a type of molecule that carries cholesterol to the cells that need it; the bad type of cholesterol) leads to plaque buildup in the blood vessels. Effectively, this is what causes cardiovascular diseases, strokes, and heart attacks. ApoB lipoproteins are the main protein constituents of LDL cholesterol, and therefore measures of ApoB can account for total LDL count in the blood. Finally, triglycerides are the storage form of dietary fat, and elevated levels of triglycerides have many adverse health effects including increased risk for cardiovascular disease as well as increased inflammation.
The full picture: consistent consumption of nuts and seeds was shown to have decreased levels of all of these detrimental blood biomarkers due to the presence of plant sterols. Plant sterols are plant-derived molecules that closely resemble the chemical properties and functions of cholesterol but do not have nearly the number of adverse health risks. Plant sterols can imitate animal-derived cholesterol, they can limit the amount of cholesterol that enters the body, and they can reduce how much cholesterol is made by the body, effectively lowering total count of LDL, ApoB, and total cholesterol levels. This is great news, especially for those who have already been diagnosed as having elevated propensity for cardiovascular disease!
Nuts and seeds are rich in essential micronutrients
Here is a list of vitamins and minerals that are found in various nuts and seeds, accompanied by the health benefits that they provide.
Vitamin E is a fat-soluble vitamin that has a main role of interfering with free radicals, which are a type of damaged molecule that accumulates in response things like eating fatty food, exposure to UV radiation, pollution, smoking, and even excess exercise without proper recovery. Free radicals are incredibly volatile and reactive molecules, and once they are introduced to the body, they compound on each other rapidly. Vitamin E can target free radicals by intercepting and limiting their production. This vitamin also helps to maintain cell membrane integrity by protecting the lipids of the membrane from free radical attack (11).
Folate is a type of B vitamin that has a main role of aiding in the synthesis of DNA and new cells as well as the metabolism of amino acids. Folate also plays a role in red blood cell production (4).
Niacin is another B vitamin that primarily functions to aid the digestive system by helping to facilitate the conversion of carbohydrates to glucose as well as metabolizing fat and protein (2). Niacin also plays a role in the protection and repair of photo-damaged skin (skin that has been aged and wrinkled by the sun) (3). Topical application of versions of the vitamin have been shown to visibly smoothen aged skin. Finally, niacin helps in the growth and maintenance of central nervous system tissue (the part of the nervous system that includes the brain and the spinal cord) (3). We'll discuss in later posts the connectivity between niacin compounds and their effects on our propensity towards cognitive disorders and neural degenerative diseases such as depression and dementia, respectively.
Vitamin B6 is involved in a multitude of different processes in the body, including hundreds of enzymatic reactions--most of which are involved in breaking down protein into amino acids and using such to synthesize other proteins in the body (4).
Magnesium is a major mineral that is both present in the food we eat (highest in almonds, cashews and Brazil nuts when thinking about nuts and seeds!) and also synthesized in the body. It's main function is to help with bone formation by way of increasing bone mineral density. The mineral also plays a role in nerve and heart function because of its ability to mobilize calcium and potassium across cell membranes, a process imperative to the proper function of nerve pulses and muscle contraction. Studies have also shown the mineral's effectiveness in aiding in muscle relaxation, which is why it is often supplemented in athletes who require more recovery after training. We can explore this supplementation in later posts (13)!
Potassium is another major mineral and has its hand in a majority of physiological processes. For those of you who are trained in anatomy and physiology, you know how important this mineral is (recall: Sodium-Potassium Pump!). To put it shortly, this mineral plays major roles in aiding nerve transmission and impulses, muscle contraction associated with some of these nerve impulses, and it also aids in the movement of nutrients into the cell and waste, out.
Calcium is a mineral that is widely known by much of the population. It is known to have effects on promoting bone density and health, and it is often fortified in different foods as a way to market such products as a food that is "good for bone growth". This is because bone tissue is largely comprised of calcium, so consuming more of it, in essence, promotes stronger bones. Calcium also plays a role in helping with the blood clotting process in the body. When damage to blood vessels or other tissues occurs, a cascade of enzymes and other molecules flock to the region and are triggered in a specific sequence to help to repair the damage. Calcium helps to activate some of these molecules into their "on" function so that they can work properly to repair damage (8).
Iron is a trace mineral (meaning that only very small amounts of this mineral are required for proper cellular and bodily function) and it's main role is to aid in the transportation of oxygen throughout the body. Iron is a tiny component of hemoglobin, a protein inside of red blood cells that is responsible for housing the necessary oxygen. Without iron, oxygen would not be able to chemically bind to hemoglobin and therefore would become undeliverable to bodily tissues. Iron deficiency often comes in the form of anemia, and fatigue and chronic low body temperature are common symptoms of this.
Zinc is a trace mineral that has varying roles in the body, the first of which is bone regeneration and growth. Unfortunately, the exact mechanism behind how zinc specifically acts to aid in bone regeneration is not well understood. Zinc also plays a part in DNA and RNA synthesis by aiding the enzymes that perform and regulate cell proliferation (cell division and growth). An overall deficiency in zinc has been linked to DNA damage and a possible onset of cancer. Finally, zinc is shown to help our immune system function by aiding the process by which immune cells fight off invaders (10).
Nuts and seeds are a great source of dietary fiber
To keep it short and sweet, nuts and seeds are a good source of fiber, offering 4-11g per serving, which is between 5 and 10% of total daily needs (12)! There are two types of fiber, soluble and insoluble fiber. Insoluble fiber is the type that is not digestible by the human body, and therefore it functions to help with proper digestion and bowel movement. Soluble fiber, the type of fiber found in nuts and seeds, has the primary job of delaying the digestion process of the food it is found in, and therefore allowing you to feel fuller longer.
A diet that frequently incorporates nuts and seeds has been shown to take years* off your life!
Studies have shown that those who adopt certain lifestyles have a statistically higher propensity of not only living longer than the rest of the population, but also being disease-free for longer. Such lifestyles include regular physical activity, adopting a plant-based diet, and incorporating nuts and seeds into the diet on a regular basis. Those who practiced all three of these lifestyles lived on average eight years longer than the rest of the population (6)! That's not to say that eating this food group will ensure you to live to 105, but it certainly plays a role in promoting lasting health due to the factors listed above!
Nuts and seeds are an excellent addition to any meal. They could be incorporated into a salad, a crust for a protein of choice, a vegetable dish--you name it! One of my favorite side dishes is honey-almond green beans! You can also enjoy this food as a snack; the presence of fiber and its high fat content allows for a lasting feeling of satiety after eating. Overall, nuts and seeds are an incredible food source and they should be incorporated into the diet daily!
I hope you're as NUTS about this food group as I am!
Del Gobbo, L. C., Falk, M. C., Feldman, R., Lewis, K., & Mozaffarian, D. (2015). Effects of tree nuts on blood lipids, apolipoproteins, and blood pressure: systematic review, meta-analysis, and dose-response of 61 controlled intervention trials. The American journal of clinical nutrition, 102(6), 1347–1356. https://doi.org/10.3945/ajcn.115.110965
Gasperi, V., Sibilano, M., Savini, I., & Catani, M. V. (2019). Niacin in the Central Nervous System: An Update of Biological Aspects and Clinical Applications. International journal of molecular sciences, 20(4), 974. https://doi.org/10.3390/ijms20040974
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