Fats, proteins, and carbs are known as macronutrients, and they are the nutrients that provide calories. Each of them has been maligned at different times, but all three are essential, and we consume them in large amounts. But we need to clear up some misconceptions, and even ditch some bad ideas that have been part of the dietary guidelines, so we can choose wisely. Each of these nutrients has an important place in the Med-DASH plan, and we are going to find the balance among them that allows us to be healthy and keep a young body. Since we are focusing on whole foods instead of individual components, we are also going to learn a little about some of the non-caloric, non-macronutrient components that accompany these healthy foods.
The key DASH and Mediterranean diet foods are rich in nutrients and other components that help to make us healthy. We all know that vitamins and minerals are important for good nutrition. But you may not know as much about the other food components, such as fiber, phytochemicals and antioxidants, fats, and protein, that are equally important to our good health. Read on to learn more.
After U.S. dietary guidelines were changed in the mid-1980s, people were encouraged to dramatically cut down on fats. We had fat-free dressings, fat-free cheese, fat-free cookies. All of it designed to reduce calories. Since fat is calorie-dense (containing 9 calories per gram instead of 4 calories like starch, sugar, and protein), it logically seems that this would help lower calories and make it easy to lose weight. Is that how it turned out? No. Since those guidelines appeared, the United States went from having 15 percent of adults being obese to 38 percent.
How could this happen? One of the benefits of fats is that they help you to feel full after a meal or snack; we call this satiety. And it is a very important concept in feeling satisfied with moderate amounts of food. This might seem like a no-brainer, when you consider how we react to food. And yet fat reduction was pushed as a way to avoid excessive intake of calories.
Another benefit of fats is that they help with the absorption of certain key vitamins, the fat-soluble ones, like vitamin A, vitamin D, vitamin E, and vitamin K. The very important antioxidants, carotenoids, are also fat soluble. They include beta-carotene (the orange in carrots and the provitamin converted to vitamin A in the body), lutein (a pale yellow in sweet corn, and found in especially high levels in spinach), lycopene (the red color from tomatoes), and zeathanthin (a red-orange compound found in high amounts in leafy green vegetables, among others). While the names of these phytochemicals are not important to remember, fruits and vegetables are rich in them, and they can have a significant impact on your overall health and well-being. You have long heard about the health benefits of antioxidant-rich foods, and now you know a little more about how they perform their magic. How sad that the old dietary guidelines emphasized low-fat eating, which reduces the absorbability of these key nutrients during digestion.
There are three main categories of fats, monounsaturated (MUFA), polyunsaturated (PUFA), and saturated fatty acids (SFA). (We will use the terms “fats” and “fatty acids” interchangeably, without making you take a chemistry lesson to fully explain it.) Saturated fats can be used by the body to make cholesterol, and are recommended to be consumed in small amounts. On the other hand, they are quite stable to oxidation, which means that they are unlikely to become rancid. Polyunsaturated fats include the heart-healthy omega-3 fats such as those in cold-water fatty fish, and omega-6 fats such as those in soybean or corn oil. The omega-6 fats are quite susceptible to rancidity, both in your kitchen during storage and in your body, and can provoke inflammation. The omega-3 fats are less likely to cause inflammation and are considered to be more heart-healthy. In addition to fish, they are found in canola oil and to a lesser extent in walnuts and other nuts. Monounsaturated fats are considered to be very heart-healthy and are not likely to trigger inflammation. Good sources include olive and canola oils, and nuts. Let’s learn a little more.
Okay, so which fats should we choose? What makes a fat heart-healthy? Let’s discuss some of the most common fats, including important health information about each.
Olive oil: Olive oil is well-known to be good for your heart and is a very important part of the Mediterranean diet. It is rich in monounsaturated fats, especially oleic acid (so named because it comes from olives). DASH diet studies have shown improvements in blood pressure by replacing empty carbs with olive or canola oil. Olive oil consumption is associated with other benefits, including less inflammation and lower rates of some kinds of cancer.
Fish oils: The omega-3 fish oils, especially DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid), are known to be very protective for the heart and for the brain. Yes, fish can be considered to be brain food. Studies of the Inuit people in Greenland, who consume high levels of fats, especially from seafood, have shown that they have very low rates of heart attacks. This initially puzzled scientists, until they realized how beneficial these omega-3 fatty acids could be. Especially good plant-food sources of the omega-3 ALA (alpha-linoleic acid), an essential fat, are soy oil, walnuts, peanut oil, flax, and canola oil. Our bodies can turn ALA into the more beneficial DHA but are relatively inefficient at it, so we benefit more from fish oils. In addition to heart and brain health, these omega-3s help reduce inflammation. You probably know someone with rheumatoid arthritis, which is an especially obvious case of inflammation. But there is also low-level inflammation going on throughout your body. Inflammation is associated with initiating and maintaining many diseases, including the formation of plaque in your arteries and the development of type 2 diabetes, Alzheimer’s disease, and many types of cancer. Omega-3s will help reduce your levels of inflammation. One marker that your diet is helping to reduce inflammation is a significant decline in triglyceride levels. C-reactive protein (CRP) is another marker that can identify lower levels of inflammation, but it is not routinely tested.
Flaxseed: Although flaxseed contains high levels of the essential omega-3 ALA, I personally am not a fan because of the high oxidative potential of flax oil. As we discussed, oxidation can be the first step in initiating some kinds of cancer (which is why antioxidants are so very important in your diet). Flax oil (also known as linseed oil) is highly susceptible to oxidation, which, in the realm of oils, means it goes rancid quickly. This is not something you want happening in your foods or in your body. (If you do decide to use flax oil or seeds, keep them refrigerated to avoid rancidity, and don’t grind seeds until just before use.) Fats that oxidize easily will “consume” antioxidants in your body, an undesirable state of affairs. The people who promote it counter that flaxseeds also contain lignans, which have antioxidant potential. However, during digestion, the oil and the lignans are separated and each go their own way. There is no indication that flax oil is protected from oxidation once it is in your body. It isn’t even protected in the seeds.
Furthermore, ALA is very poorly converted to DHA in the body, and DHA and EPA are the omega-3 fats that are truly beneficial for heart health. When evaluating the health benefits of foods, I believe that the most powerful evidence is how it affects health over the long term. There is no long-term evidence of people eating flaxseeds throughout history, although flax was widely grown for making linen. Generally, foods that can be harmful to health are not part of traditional cultural eating habits.
The flax lignans are phytoestrogens (plant estrogens) that have mild estrogenic activity in the human body. Anyone with a history of ER+ breast cancer, or any gynecological cancer, might want to avoid flax.1
Monounsaturated fats (MUFA) are a key part of the Mediterranean diet. Nuts, olives, avocados, olive oil, sesame oil, and canola oil are all great sources of heart-healthy MUFA, and they are less susceptible to oxidation and rancidity than PUFA. Back in the ’70s, people were directed toward corn oil and soy oil for heart health. However, they are high in potentially inflammation-increasing omega-6 PUFA and are more susceptible to oxidation. Olive oil has been shown to benefit heart health, and so is a much better choice than the soy and corn oils that were recommended for decades.
Omega-3 fatty acids: The key fish oils are long-chain PUFA fats with two or more double bonds. Omega-3s have one of these double bonds three carbon atoms in from the end of the chain, which is why it is called omega-3. These fats include ALA and the particularly beneficial DHA and EPA. Omega-3 fats are beneficial for lowering triglycerides, as well as for mental health, brain health, and vision.
Essential fatty acids include the omega-6 fatty acid linoleic acid (LA) and the omega-3 fatty acid ALA. (An essential fat is one that is essential for health but that your body cannot make on its own, so it must be derived from foods. They should not be confused with essential oils, which are the essences of certain plants.) You want to have more of the anti-inflammatory omega-3 fats in your diet and less of the omega-6 fats. Arachidonic acid (AA) is an omega-6 PUFA made in your body from LA, which can be either beneficial or harmful, depending on the level in your system. Although AA helps to control inflammation at low levels, excessive amounts can trigger rampant inflammation, as can LA, although it is an essential fatty acid. Dietary DHA and EPA fish oils are long-chain omega-3 PUFA that are associated with lower total cholesterol, lower triglycerides, and reduced blood clotting risk. In the United States, dietary omega-6 PUFA come primarily from corn oil and soybean oil. These are precisely the oils that were recommended since the early 1970s as replacements for solid fats like butter. They became widely used in our homes and in the preparation of processed foods. They are relatively neutral tasting and inexpensive, so they have been used extensively. If you consume a high ratio of omega-6 to omega-3 fats, you may have more inflammation. Most experts recommend a ratio of 4:1 to 1:1. The typical American diet is in excess of 10:1, which may be a factor in the current epidemics of chronic disease related to inflammation.
All in all, the Med-DASH message is to consume more MUFA, more omega-3s from fish, and fewer fats with omega-6 PUFA to reduce inflammatory activity. We are no longer obsessing about limiting all fats.
If you don’t get enough protein, you will lose muscle and your metabolism will slow. Today people are encouraged to get more protein, especially women, the elderly, and people trying to lose weight. The more muscle you have, the faster your metabolic rate, and the healthier you will be. Loss of muscle is one of the key causes of frailty and disability in the aged.
The best-quality protein for sustaining growth and maintaining muscle is egg albumin, closely followed by milk whey protein, beef, and casein (the chief protein in cow’s milk). The quality is primarily due to the mix of essential amino acids in these animal proteins but is also impacted by digestibility. However, it is possible to be perfectly well nourished from eating a vegetarian or vegan diet. At one time it was thought that vegetarians had to have “complementary” proteins at each meal in order to have the right amino acid mix to allow for rebuilding and repair of muscle and other tissues. For example, some plant-based foods that are complementary are rice and beans, peanut butter and wheat bread, and corn and beans. In each of these combinations, one food fills in some of the amino acid inadequacies of the other. Together, they make foods that behave just the same as the complete proteins. We no longer believe that it is critical for adults to have complementary proteins at the same meal. Adults have a large mix (a “pool”) of free amino acids floating around in the bloodstream, so there are adequate amounts of the right amino acids to fill in for any deficiencies in an individual food to have normal protein metabolism for body maintenance and repair and keeping (or building) strong muscles. Children, however, can benefit from food combining to have the complementary proteins at their meals.
Both vegetarians and omnivores (people who eat meat and plant foods) will get sufficient protein on the Med-DASH plan. You will easily satisfy your protein needs with both plant foods and animal foods. The best sources for animal proteins, in terms of their overall health profile, include eggs, low-fat and nonfat dairy, lean beef and pork, skinless chicken (especially white meat), and fish and other seafood. Lamb is high in cholesterol and saturated fats, so that is an occasional food, if you choose. It is a common part of the Mediterranean diet, so we have included a few recipes for lamb.
In many fad diets, “carbs” is considered a dirty word. Certainly, processed grains and added sugars are not essential to anyone’s diet and are basically empty calories which most of us don’t need.
In the original DASH diet research, carbs were used to provide enough calories so that people did not lose weight during the study period. If the participants had lost weight, it would have made it difficult to evaluate whether the diet pattern or weight loss was the beneficial factor for lowering blood pressure. Subsequent DASH diet research has shown that replacing empty carbs with either protein-rich foods or higher levels of MUFA-rich fats actually gave significantly improved blood-pressure-lowering benefits compared with the higher-carb plan and, as a side benefit, helped to lower triglycerides.
The carbs that break down to simple sugars during digestion are sugar and starch. The primary food sugars (disaccharides) include sucrose (table sugar), lactose (the sugar in milk), and maltose, which break down to glucose and fructose (sucrose), glucose and galactose (lactose), and two glucose molecules (maltose). Honey is a combination of fructose and glucose, a little higher in fructose than glucose. It is not considered to be any healthier than regular table sugar and is actually similar in content to high-fructose corn syrup (HFCS). We don’t need to debate the health aspects of HFCS, because when you are choosing mostly unprocessed foods, it rarely makes its way onto your table. You will be supported here in avoiding most food additives, including artificial sweeteners. This is one of the biggest changes over the past few years. Consumers are demanding foods without these sweeteners. (We are also not going to debate artificial sweeteners here. You will be supported with whatever decision is important for you.) That doesn’t mean that we should jump into beverages with lots of added sugars. Later in the book there are some suggestions for ways to add a little sweetness and flavor to water without artificial sweeteners or teaspoons of sugar.
During absorption of your digested foods, glucose can be converted to fructose, and vice versa. Both glucose and fructose end up in your bloodstream, but glucose is the sugar that gets measured when people have diabetes. Insulin is required for glucose to be taken up by muscle tissue, whereas fructose does not need insulin to be metabolized. Fructose is more likely to be used by the liver to make triglycerides either for storage (which can result in fatty liver) or for pumping out into the bloodstream.
Let’s not forget the most important carbohydrate class, and the one most lacking in the typical American diet: fiber. Fiber-rich foods tend to be very filling and tend to be associated with lots of other nutrients. Since fiber only comes from plant foods, fiber-rich foods also tend to be great sources of antioxidants and vitamins and minerals. In my undergraduate classes, we were taught that fiber doesn’t provide any calories. However, they actually provide about 10 percent of our calories as the result of breakdown by bacterial fermentation in the colon. We can absorb the gases formed from this fermentation, and some are quite beneficial for keeping us healthy and lean.
The two main types of fiber are soluble and insoluble, although in many scientific reports, two additional classifications are now being used: viscous (usually soluble fiber) and fermentable. Viscous means the fiber thickens the digested food passing through the intestinal tract, which would be beneficial for slowing absorption of glucose. Good examples of viscous fibers are Metamucil (psyllium fiber), pectin (a thickening agent for jams and jellies), and fructooligosaccharides in fruit. Fermentable fibers would include the fiber in beans (gas formers!), oats and barley (beta-glucan), and fruits and vegetables. On the other hand, wheat bran and cellulose are mostly unfermentable, and help with keeping you regular. Having a diet rich in fruits and vegetables is associated with lowering the undesirable LDL cholesterol, while leaving the protective HDL cholesterol high. High-fiber diets are also associated with lower markers of inflammation (CRP) and improved blood pressure. Diets rich in soluble fiber are associated with a lower risk of developing type 2 diabetes. And most diabetes professionals also recommend lots of soluble fiber to help manage blood sugar levels. Fiber from whole (unprocessed) foods is associated with lower weight and improved satiety from meals.3
Who doesn’t love fresh fruits? They are real treasures in terms of having plenty of beneficial fiber for promoting a healthy gut. My favorites of all are the… Well, okay. Maybe they are all my favorites, depending on the time of year. Tangerines in winter. Berries are available all year round, and I love them on my cereal. But in the summer, I love to make multi-berry pies with strawberries, raspberries, and blueberries. So rich in antioxidants (which give them their blue-purple color), and such a fun treat. If you are limiting processed foods in your diet, you can still have room for these indulgences. In summer I also am addicted to stone fruits, including cherries, plums, nectarines, and peaches. As autumn rolls around, I love to make apple pies or crisps. (I love pies in general; to my friends I am the Queen of Pies.) And almost all year round, we can have melons or bananas at breakfast. Pineapples, papayas, and super-ripe mangoes can make a great dessert or even a salsa for topping mild-flavored fish.
Vegetables of all kinds are other terrific sources of both soluble and insoluble fiber. I personally don’t care for hot cereals, but most people do, and you probably know that oatmeal and barley are rich in soluble fiber that helps lower cholesterol and can be very filling. I do love cold cereals, such as the whole-wheat or bran cereals, which help to keep you regular. When they are topped with milk, you get a dairy serving; adding berries or bananas brings in fruit and additional fiber. If you eat breakfast at work, you can bring a cup of fruit yogurt and mix dry cereal into it. There are so many ways to add delicious fiber-rich foods into your diet.
The very important point of the Med-DASH program is that you are eating mostly unprocessed or minimally processed foods, such as yogurt, cheeses, milk, and frozen vegetables and fruits. You could also add fresh (or frozen) meat, poultry, and seafood to that list of minimally processed foods. If you choose to eat more unprocessed foods, with few or no additives, it is very easy to follow the Med-DASH eating plan.