Unrefined and Minimally Processed Food – Why It’s Important to Health

By Paul E. Lemanski, MD, MS, FACP

Editor’s Note: This is the 120th in a series on optimal diet and lifestyle to help prevent and treat disease. Any planned change in diet, exercise or treatment should be discussed with and approved by your personal physician before implementation. The help of a registered dietitian in the implementation of dietary changes is strongly recommended.

Medicines are a mainstay of American life and the healthcare system not only because they are perceived to work by the individuals taking them, but also because their benefit may be shown by the objective assessment of scientific study. Clinical research trials have shown that some of the medicines of Western science may reduce the risk of Type 2 diabetes, heart attacks, strokes, cardiovascular death and even some cancers.

In the first 119 installments of the Non-Medicated Life, a healthy diet and lifestyle has been shown to accomplish naturally for the majority of individuals most of the benefits of medications in the prevention of the chronic medical conditions mentioned above. With respect to defining a healthy diet, a whole food, predominantly plant-based diet such as the Mediterranean diet has the most data to support it. Central to the potential benefit of such a “whole food” diet is that food is unrefined and minimally processed. Why this is so?

From a biochemical perspective, a healthy plant-based food is a food which supplies not only needed micronutrients, and some of the fats, proteins, and carbohydrates needed for cellular growth and maintenance, but also fiber to feed our gut bacteria or microbiome. From an evolutionary perspective, our biochemistry has been inherited from our ancestors of 100,000 years ago. That ancestral biochemistry became adapted to the preagricultural food sources of that time and a hunter-gatherer diet – little of which was refined or processed. Animal derived food eaten by humans was wild and naturally lean and may have had a unique amino acid and fatty acid composition determined by the animal’s own food sources. Whole plant-based foods consumed by humans included nuts, seeds, wild berries, vegetables, and fruit and also contained the unique ratios of fiber, carbohydrates, fats and protein inherent to the food.

In this distant preagricultural, hunter-gatherer era, the unique biochemical composition of animal and plant derived food was maintained by the requirement that it be fresh. Animals and to a lesser extent plants needed to be eaten quickly before spoilage. However, as scarcity of food was the rule, humans had to devise methods to ensure the adequacy of the food supply by modifying and reducing the rate of spoilage. Indeed, the first processing and refining of foods was probably done to avoid spoilage. Animals could be cooked; nuts, seeds, beans/legumes and some plants could be dried or cooked. Later, animal flesh could be salted and smoked to preserve it.

Agriculture, which is only about 10,000 years old, introduced more widespread consumption of grains. From an evolutionary perspective, agriculture is probably not old enough to result in genetic changes in human biochemistry. To aid in the preservation of grains and increase time to spoilage, grains such as wheat had the germ (fat) removed, and with it fiber. This processing separated carbohydrate from its naturally accompanying fiber and introduced one of the first modifications resulting in metabolic derangement, as fiber and fat slow the absorption of carbohydrates including glucose. In genetically susceptible individuals (family history of diabetes), a rapid rise in glucose, is followed by a rapid rise in insulin. Such an insulin surge, causes the pancreatic islet cells which produce insulin to overwork, and actually contributes to their loss. When 50-70% of islet cells are lost Type 2 diabetes results – predominantly from a modification of food resulting in a loss of fiber.

The domestication of animals, especially beef, resulted in a change in the amino acid and fatty acid composition of meats. Steers that are not grass fed are generally fed corn to fatten them quickly. Corn contains predominately omega-6 fatty acids, which produce inflammatory cytokines in the body of the animal, and later in the bodies of the humans who consume them. Grass fed steers on the other hand contain predominately omega-3 fatty acids, which produce anti-inflammatory cytokines in the bodies of the animal, and later in the bodies of the humans who consume them. Further, the processing of animal meat to help preserve it includes salting and smoking, the former contributing to hypertension and the latter potentially contributing carcinogens that increase the risk for cancer. Moreover, even the processing of meat in its cooking at high temperature (>300 degrees F) can  contribute to the production of heterocyclic aromatic amines, known carcinogens.

If the consumption of unrefined and unprocessed food is beneficial for the reasons noted above, can you implement this approach without radically altering your diet? I believe it is. First, with regard to grains, keeping to whole grains is best. So, for example, using whole wheat pasta is best. Steel cut oats is best. Adding garbanzo bean pasta to whole wheat pasta will further increase fiber with little change in taste. Additionally adding cooked lentils or garbanzo beans to pasta will naturally increase fiber. Cooling cooked pasta and then reheating will increase resistant starch and slow carbohydrate absorption. When using grain based products, such as bread, look for a ratio of carbohydrate to fiber <5:1.

Increasing the consumption of beans and legumes, such as lentils, can naturally increase carbohydrate and fiber in an acceptable ratio and feed the microbiome. Beans and legumes can actually decrease glucose absorption of the next meal – the so called second meal effect. This can be accomplished very simply by slowly adding beans or legumes to dinner salads, one teaspoon per salad  the first week, increasing by once teaspoon per salad per week to about a quarter cup to half cup per week. By eating beans and legumes at dinner, the microbiome produces butyrate which is absorbed from the gut into the blood stream, and result in an improvement in blood sugar response at the following breakfast.

With regard to meat, fish, and chicken it is best to consume grass fed beef, wild fish (frozen or canned wild is fine), and pasture range raised chicken (and eggs from such chickens). Processed meats should be avoided, whenever possible. Cooking animal protein at lower temperature by the use of slow cookers, and sous-vide will reduce the production of carcinogens. Interestingly, marinating animal protein in a marinade having lemon juice or vinegar as its base will dramatically reduce carcinogens and generally improves taste.

In conclusion, foods that are minimally processed and unrefined improve health in multiple ways. Such foods probably approximate the dietary composition of early humans and as we have inherited their biochemistry, prove to be ideal foods for metabolic health. A predominately whole food, plant-based diet, like the Mediterranean diet, may decrease risk for metabolic disease and cancer and make living the Non-Medicated Life more possible.

Paul E. Lemanski, MD, MS, FACP (plemanski3@gmail.com) is a board-certified internist practicing internal medicine and lifestyle medicine in Albany. Paul has a master’s degree in human nutrition, he’s an assistant clinical professor of medicine at Albany Medical College, and a fellow of the American College of Physicians.