10 Dietary Rules of Thumb to Eat for Health with Diabetes
Ryan Bradley, ND, MPH July, 2008
Knowing what to eat when managing diabetes can be a real challenge! Recent studies are generating new interest- and new controversy- surrounding the best elements for a good diet for those with diabetes. As anyone who follows nutrition knows, there are many perspectives to ponder when considering food and food choices. How many carbs? Are they “good” carbs or “bad” carbs? How much protein? What about fiber (See Complementary Corner, April 2007) What is the glycemic index? Does this food contain hormones, antibiotics or pesticides? What about advanced glycemic end products (See Complementary Corner, December 2006)? What about inflammation, is this food a pro-inflammatory food? All of these questions- and more- make food choices seem difficult, especially in an environment like ours in which the “good” food choices are not the easy choices to make because we are surrounded by so many options for “bad” food choices!
In order to simplify these many perspectives, I have created my dietary “top 10” list. I use this list with patients regularly- and those who follow the advice do improve their blood sugar, often improving their cholesterol and blood pressure at the same time! Fortunately, research made possible from the support of Diabetes Action, a colleague, Dr. Erica Oberg, ND, MPH and I will study these dietary guidelines to see if they really are superior to standard recommendations for both blood sugar control as well as changes in antioxidant capacity and several markers of inflammation. In the meantime, I hope you find this list helpful. Rest assured, there are still many, many wonderful foods available to enjoy that are guilt free and healthful!
Rule #1: Follow the rainbow by eating colorful vegetables and fruits
The mysteries of fruits and vegetables are still being discovered. The truth is medical and nutritional science still does not understand why eating fruits - and more so vegetables - is good for human health. The antioxidant content (including vitamin C, polyphenols and carotenoids) is a popular theory because so many diseases, including diabetes, are associated with chronic oxidative stress (See Complementary Corner, September 2007). However these antioxidant compounds may prove to be just marker compounds for other, more active, constituents. Also, it may prove that no matter how researchers slice and dice the science of food (no pun intended) we just learn that fruit and vegetables are perfect the way they are, and dissecting them into smaller chemical bits (and putting these bits into bottles for sale, i.e. supplements) may prove fruitless (again no pun intended).
I recommend 5-7 servings (1 serving= ? cup or one medium sized fruit/veggie) of vegetables per day and 1-2 fruit servings. Although fruit contains many important nutrients as well, people with diabetes should reserve fruit for a treat (it is certainly better for you then most processed “treats”) as it is high in sugars, including fructose which may contribute to weight gain, and therefore should be eaten sparingly. Dark berries including blueberries, blackberries and raspberries as well as high fiber foods like apples and pears make the best fruit options.
Rule #2: Use “good” oils (and cook with oil as little as possible)
“Oil” as we know it is really a complex mixture of different fats (called fatty acids) that are somehow extracted from their original source food; for most oils this source food is a fruit (e.g. olives), nut (e.g. walnut) or seed (e.g. corn). There are major differences in the types of fatty acids within each type of oil, as well as differences in the manner in which the oil has been processed (some oils are pressed while others are cooked). Because oils can be an important source of essential fats- as well as a less desirable source of oxidized fats- choosing good oils is important.
As a rule of thumb, I recommend olive oil for day-to-day use, including cooking. Olive oil is an excellent source of mono-unsaturated fatty acids (MUFAs) and also contains some antioxidant polyphenols from the olive fruit that help protect the oil from oxidation. Because olive oil is so rich in unsaturated fats, and because unsaturated fats oxidized with cooking, ideally olive oil should only be cooked on medium heat. Olive oil should be extra virgin and cold-pressed to avoid extra processing during manufacturing. Olive oil has a strong flavor and therefore is not a good choice for when you need a flavorless oil. Canola oil is the best option for a flavorless oil that resists changes with higher cooking temperatures.
An interesting alternative to olive oil is avocado oil; avocado oil is also high in MUFAs, yet also contains some short-chain saturated fat giving it an almost buttery flavor. Avocado oil has a higher “smoke point” than olive oil suggesting it may make an even better cooking oil (although it is expensive to purchase and so better saved for special occasions).
Other “good” oils include walnut oil (uncooked), pistachio oil (uncooked), flax seed oil (uncooked), and grape seed oil (which can be cooked).
Generally oils should be used sparingly- at least for cooking. Cooking in oil can oxidize the oil itself and fried or stir-fried foods are higher in glycylation end products than their steamed, boiled or poached counterparts. So, when possible, steam your vegetable medley until cooked, and add a little uncooked oil at the end for flavor!
Rule #3: Eliminate “white” foods
“White” foods include refined breads, foods made from white flours, refined sweeteners, rice, potatoes and pasta in moderation. These foods tend to contribute considerably to total carbohydrates throughout the day and tend to be very high on the glycemic index, making the foods somewhat inflammatory in nature. Substituting white foods with “whole grain” foods adds more flavor, more fiber and more nutrition to food- while reducing the high glycemic index carbohydrates considerably. Be careful with the “whole grain” labeling that is happening on foods, as many foods say they are “whole grain” but have been quite refined. In generally “whole grain” foods are darker and denser and often either still in the original hull or the hull is visible in the bread or cereal. Examples of whole grains include quinoa, amaranth, millet, barley, rye, buckwheat, whole-grain rice and whole-grain wheat.
Rule #4: "Whole foods" come in husks, hulls, pods, peels, shells, skins & leaves (not boxes wrappers, cans or tubes)
This is a long-winded way of saying: try to avoid processed foods. Granted, boxed foods can meet the needs of a family in a hurry or of someone still learning to cook, but these foods are rarely quality (some higher quality-even whole grain-boxed foods are becoming available for a price) and often contain added preservatives and added salt. Once you begin to experiment cooking with more whole foods, you’ll find these foods taste better, are easy to cook and don’t always take more time than their boxed alternatives. Digging the crock pot or pressure cooker out from way back in the kitchen cupboards can really speed up cooking whole foods, and especially whole grains.
Rule #5: Eliminate corn syrup and reduce salt & all sweeteners. Use natural sweeteners and herbs & spices instead
Our culture tends to rely on the three most universally appealing (but not the more healthful) flavors of sweetness, saltiness and fattiness (technically science still debates whether our fondness for a fatty “mouth feel” is a taste or a touch). Our fondness for these flavors was helpful in the survival of our ancient ancestors, as foods with these flavors provided dense nutrition: they are high in calories, and provide critical electrolytes during exposure to harsh elements. Climbing a tree to secure the last ripe mango was rewarded with dense sweetness that provided necessary energy in times of need! Well, times have changed. Many of us are exposed to environments no harsher than our offices or living rooms and have access to all types of foods with relative ease. Once a survival benefit to have salty, sweet and fatty foods, today over consumption of these foods leads to disease including diabetes and high blood pressure.
The good news is there are many ways to prepare delicious foods and still reduce the sugar and salt in the foods we eat- namely by using more herbs and spices. Not only does experimenting with new spices help to refine the palate and broaden our appreciation of the natural flavors of foods, but herbs and spices also appear to have health benefits for those with diabetes (See Complementary Corner, July 2006). Paprika, for example, is an extremely potent source of plant pigments called carotenoids which may be anti-inflammatory in the body, while basil and rosemary have very high antioxidant capacities.
Unfortunately the herbs and spice section of the grocery store is not the ideal place to start your experimentation with new flavors as many spice blends are loaded with sodium or flavor enhancers and the individual herbs are often over priced. The best option is to find a local spice shop; they often have a variety of blends and the staff will be thrilled to talk with you about your preferences in food and make a recommendation. Alternatively many health food stores, and now even some grocers, have a bulk spice section that will allow you to try small amounts of new flavors and experiment for less cost. Good luck!
Rule #6: Limit consumption of fried, broiled and roasted foods
For those of you who have read past Complementary Corner articles you know I am interested in the health hazards of the advanced glycosylation end (AGE) products in the foods we consume (See Complementary Corner, December 2006). Although, admittedly, it may be too early to place a lot of emphasis on AGE products in food, I believe this is one area of nutrition that deserves additional attention and we may look back someday and shake our heads in disbelief that we did not understand the importance of AGE products in food earlier.
For me, looking at nutrition through this lens helps me make sense of some of the inconsistencies in the nutritional literature. The health effects of eggs may be a prime example! Eggs consist of quality protein, are high in carotenoids and high in helpful sulphur-containing amino acids- they are a “whole food” and yet are often discouraged because of concerns about the cholesterol they contain. From a glycosylation perspective, a boiled or poached egg is much healthier than a fried or scrambled egg! Future studies should consider AGE contents as an important factor when describing the effects of different foods. (I also speculate than low AGE content may be responsible for some of the protective effects of a traditional Asian diet which includes a lot more poached, steamed and boiled foods, including fish).
The good news is the AGE contents in your diet can be greatly limited by reducing the fried, broiled and roasted foods you consume- especially fried, broiled or roasted meats and other animal products!
Rule #7: Eat some protein with every meal
A colleague of mine here in Seattle says, “There are no essential carbohydrates, just essential fats and essential proteins.” I think the carbohydrates are assumed to be essential since carbs provide the most basic unit of energy for the body, but I think he has a good point. The human body is amazingly skilled at converting food into the energy it needs to function, including turning many proteins (technically amino acids- the building blocks of protein) into sugar! Because the body can convert amino acids into glucose, dietary protein provides a good blood sugar balancing effect. Additionally adding protein to meals tends to lower the glycemic index of meals, slowing the rate of absorption. Protein also helps with satisfaction from meals, therefore we tend to eat less than we would otherwise.
Good sources of protein to have include lean meats (white meat turkey & chicken, fish, buffalo, lamb, venison) in small portions (4 oz. servings or the size of the palm of your hand), beans, peas, soy-based foods like tempeh and tofu, garbanzo bean hummus dips, low-fat cheese, nuts and seeds.
Rule #8: Eat breakfast every day
In research investigating diet and behavior for weight loss, eating breakfast seems to come out on top as an important contributor to maintaining normal body weight. It isn’t clear why this is, however one possibility involves helping to regulate a stress hormone called cortisol. Cortisol is produced by our adrenal glands (small glands on the tops of our kidneys) and is released in a regular rhythm to peak in the early hours of the morning , usually between 7-9 am.
Cortisol is considered a stress hormone because it is released in times of trauma and low blood sugar (which could accompany starvation which would be a real stressor). One of cortisol’s actions is to reduce our sensitivity to insulin, the hormone that lowers our blood sugar, thus raising blood sugar. In the morning, following an overnight fast, we need a little extra push to get up and going in the morning- and we need enough blood sugar to be awake enough to function! So ideally, we get up, move around a little and within a short period of time,break our overnight fast with breakfast to provide our body with the energy it needs to start the day and our cortisol levels drop back down to a nice low level thus returning our sensitivity to insulin back to normal.
However, if we do not break our fast, our cortisol level continues to be elevated into the late morning hours (or until lunch for some) . All this time our cortisol remains elevated and thus we remain less sensitive to insulin. Skipping breakfast every now and then and this is unlikely to be very important in the development of diabetes or in the course of diabetes, however day after day and this effect may accumulate and slowly, progressively lead to resistance to insulin.
Unfortunately, good choices for breakfast are not well modeled by our culture.. Standard breakfast foods are either fried dough (AKA pancakes), fried fat (AKA bacon and sausage) or fried cholesterol (AKA fried eggs) and no matter which nutritional lens you look through (fat content, AGE content, inflammatory effect), they tend to be bad. So eating breakfast also means redefining breakfast for many. Breakfast can be leftovers from dinner the night before, a whole grain muesli that you make yourself (soak rolled oats, sunflower seeds, walnuts and unsweetened coconut flakes in soy or rice milk overnight until soft, add fresh berries in the morning), poached eggs with a side of veggies, a whole grain piece of bread with smoked salmon and avocado, steel-cut oatmeal with blueberries and walnuts, etc. These are just some examples of how breakfast can be full of good nutrition, low on the AGE, glycemic and inflammatory index, and taste great!
Rule #9: Eat carbohydrate foods earlier in the day and eat light late
Let’s face the facts; few of us are as active as we probably should be throughout our days. Whether it’s because our jobs keep us chained to a desk, we are limited due to pain, or we just can’t get to the gym, few of us exercise as much as we should. Therefore, it is important to consider how we time our food choices based on how active we are throughout the day. Because our body can “decide” how it uses protein - for repair, for detox, for energy, etc. - and because vegetables seem universally healthful ( I do not know of exceptions), these foods are better choices later in the day when we have less time for activity before sleep. Said differently, it is better to consume carbs earlier in the day because you have the whole day before you to be active and burn off the calories (and glucose load) from the carbohydrate foods.
As a rule of thumb, try to eliminate or greatly reduce the carbs from your dinner time meal, focus instead on proteins and vegetables. If you are going to have carbs for dinner, be sure it is a whole grain dish, rather than a “white” carbohydrate load like potatoes or white rice. Save the carbs for the following morning.
Rule #10: Follow a Mediterranean diet (& lifestyle when possible!)
After giving you so many rules of thumb it seems unlikely to be able to distill it all down into one recommendation, but if there is one diet pattern than seems to do the best job of incorporating these many rules, it would be to follow the Mediterranean diet. The Mediterranean diet is a dietary pattern that includes lots of fresh vegetables, fresh lean meats including regular fish, whole grains eaten in moderation, olive oil as the principle oil, legumes eaten several times per week and moderate consumption of alcohol (specifically red wine).
A recent clinical trial comparing a low fat diet, a low carbohydrate diet and the Mediterranean diet found that the low carb diet and the Mediterranean diet did similarly well for weight loss and cholesterol lowering after two years, but for those with diabetes the Mediterranean diet was better at lowering fasting blood sugar and improved measures of insulin sensitivity more than the other diets (Shai et al, DIRECT, New Eng J Med. 2008).
I believe there is more to the protective nature of the Mediterranean diet than just the foods that are consumed- namely the lifestyle. While it is not feasible for many of us to bask under the Tuscan sun sipping a glass of Burgundy all afternoon (though wouldn’t it be nice!), it is possible for us to incorporate more relaxation, laughter and mindfulness into our eating behaviors. Simple pleasures like sitting down to eat, sharing meals with friends and family, taking a moment to breathe between bites of food, and savoring the flavors of our meal as we eat will improve digestion through relaxation and may lead to being more satisfied with our meal more quickly leading to eating less!
Remember food is all about nourishment and this nourishment is far more involved than just fat and carbs- or AGE products for that matter! I hope these rules of thumb help guide you to some new ways your diet can be improved for your health and the health of your family.
In health- Ryan Bradley, ND, MPH