Please Note: For easy access, resources are directly linked within the blog. To visit a reference simply click on the number and follow the link. You will be taken directly to the appropriate website.
In contemporary society, nearly everyone knows someone or is someone who is avoiding consuming grains in their diet. The reasons of this can vary from the need or desire to avoid gluten to fear of weight gain to minimizing the impact of foods on blood sugar levels. Whatever the reason, there is a strong trend towards minimizing and in some cases even eliminating completely grains from the diet. Many of the popular current dietary trends such as keto, paleo, carnivore, and others exclude grains. However, whole grains have historically made up a significant part of the human diet. world wide whole grains, including important products like maize (corn) in Central America, rice in Asia, and wheat in the Middle East are dietary staples making up over half of the total calories consumed globally.1
The processed food revolution that began over a century ago with the advent of the canning process and the ensuing expansion of processed foods into the homes of nearly all Americans has made refined grains extremely common place. Among US children and adults whole-grain intake averages <1 serving per day and refined grain intake averages 5–6 servings per day.2 An ever expanding body of epidemiological research has routinely supported that ultra-processed and refined foods are detrimental to human health. In high-income countries, ultra-processed foods are now dominating the food supply, and they are rapidly gaining ground in growing economies.3 Conversely, whole grains have been associated with reduced risk of a number of lifestyle diseases including conditions like cancer, heart disease, type 2 diabetes, as well as infectious disease and overall reduction in all cause mortality.4 But what exactly is a whole grain? How is a whole grain different from a refined one? Do they have any value in the modern diet?
What is a whole grain anyway?
As a general rule, grains are in fact members of the grass family. A whole grain is simply the whole seed of the plant (often called a kernel) and is made up of three edible parts wrapped in an inedible protective husk:
- The Bran: This is the grain’s outermost It is high in fiber, omega-3 fats, B- vitamins, and minerals.
- The Germ: The germ is the smallest, innermost portion of the kernel. It has the ability to sprout and become a new plant. It is rich in B vitamins, healthy fats, as well as some protein.
- The Endosperm: If the bran were to sprout, the endosperm would become the largest part of the food supply for the bran and would nourish the new plant in the early stages of its growth. This portion is largely starch and protein with small amounts of vitamins and minerals.
What is the difference between a refined grain and a whole grain?
The industrial revolution led to the advent of several milling processes and techniques that allowed for the widespread availability of refined grains in the food supply. During the refining process, the grain is broken apart into the constituents and the germ and bran portions are removed leaving only the starch-laden endosperm portion. The refining process results in a smoother grain texture as well as increased palatability of grains and grain based products. Additionally, refined grains have a much longer shelf life. In removing the portions of the grains that contain fats, the risk of rancidity is reduced and the grain will be shelf stable for a longer period of time. This improved shelf life also extends to any products that are made from refined grains. The refining process resulted in drawbacks as well, by removing the nutrient dense parts of the grain, the associated fiber, vitamins, minerals, and phytonutrients were also lost. To aid in replacing some of the nutrient value, many refined grain products are “fortified” with synthetic nutrients such as folic acid and minerals like iron.
Can whole grains be included as part of a healthy diet?
The answer is an emphatic yes! Whole grains are actually an extremely important part of a healthy diet. Yet, 93% of Americans fail to consume even the most basic minimum recommendation ½ cup of whole grains per day.5 Only 2–7% of Americans meet the recommendation to consume at least one-half of total grains from whole grains, and <1% of the population consumes ≥3 servings per day (1 serving = 1 oz-equivalent) of whole grains.6,7 with refined grains, whole grains contain higher amounts of dietary fiber, minerals, phytochemicals, and other functional compounds.8 Because they contain all parts of kernel including the nutrient rich germ and bran portions, they provide a number of nutrients such as B-vitamins and fiber as well as important minerals like zinc, magnesium, and iron. They can provide protein components as well. The amino acids found in the protein portions in grains are not considered “complete proteins” in and of themselves, however they serve as “complementary” to the amino acid profile found in other plant-based protein sources such as beans and legumes.
High intake of whole-grain foods has been suggested as a key component of healthy eating for longevity. Assessing the link between whole-grain intake and mortality is important for guiding consumer choices and setting and prioritizing dietary guidelines to reduce the risk.8 Extensive meta-analysis of the existing body of research provides further evidence that whole grain intake is associated with a reduced risk of coronary heart disease, cardiovascular disease, and total cancer, and mortality from all causes, respiratory diseases, infectious diseases, diabetes, and all non-cardiovascular, non-cancer causes.4
Parts of a Grain Graphic: Harvard School of Public Health.9
Andrea Pryce, N.D., received her baccalaureate degree from the University of Alaska-Fairbanks and is a 2006 graduate of Southwest College of Naturopathic Medicine in Tempe, Arizona. Following completion of her N.D. degree she went into private practice in Scottsdale, Arizona. She has a strong background in biomedical research with significant experience in both bench top and field research. She has worked as a bench top research associate performing genetic oncology assays for a major biomedical research foundation. Additionally, she served as a project coordinator for a homeopathy study co-conducted by the Southwest College Research Institute and the University of Arizona’s Arizona Center for Integrative Medicine. She maintains a research interest in the epigenetics and nutrigenomics particularly as they relate to oncology. In 2009, she moved to Florida and began working at Life Extension in Fort Lauderdale where she was Medical Editor for their monthly magazine. Dr. Pryce joined the faculty at Hawthorn University in April of 2014 and also serves on the faculty of Everglades University. She has recently joined the team at the Integrative Health Institute in Boca Raton, Florida.