03/29/2019
Looking to Foods of the Past to Prevent Disease
March 20, 2019 - 06:35
The English language is not short on phrases that connote a negative aspect to the past: old-fashioned, out of touch, passé. But just because something is traditional or “old” doesn’t mean it has no place in modern times. In fact, there are just as many phrases emphasizing the importance of lessons from the past: “Everything old is new again.” “Those who don’t learn from history are doomed to repeat it.” The success many patients are experiencing with various dietary approaches shows us this perspective applies well to nutrition.
Some of today’s popular ways of eating celebrate a revival of traditional foods that were once consumed regularly, but which have fallen out of favor in the modern North American palate. Such items include liver and other organ meats, oxtails, bone marrow, chicken feet, beef and lamb shanks, and other meats cooked on the bone. Our great-grandparents and ancestors farther back in time may not have known that these foods are highly nutrient dense. It’s trendy to eat “nose to tail” in the 21st Century, but in the past, the whole animal may have been consumed out of necessity—people didn’t have the luxury of letting anything go to waste. But perhaps it’s not a coincidence that many of these foods make up delicacies in ethnic cuisines around the world. In France, there’s pâté and liver mousse. In Asia, chicken feet are prized, as are animal tendons in soup, and beef or lamb shanks are used for Italian osso bucco.
Collagen powders are a convenient way to increase intake of collagen-specific amino acids, but before these were commercially available, people consumed collagen through bone broth, pork hocks, head cheese, and other dishes prepared with animal bones, skin and connective tissues.
Those who don’t consume animal products can still learn from the culinary and nutritional lessons of the past. Returning to whole foods preferably prepared at home has rekindled people’s courage in the kitchen, leading them to explore techniques such as soaking, sprouting and fermentation for grains, beans, and beverages such as kombucha. Those who consume dairy can experiment with homemade yogurt and kefir. Fermented vegetables and dairy are an obvious source of diverse strains and species of probiotics, and fermenting dairy also reduces its glycemic impact as some of the lactose is consumed during the fermentation process. This reduction in lactose content may mean that fermented dairy could be suitable for some individuals with lactose intolerance. While many popular and effective dietary strategies reduce or eliminate grains, those who choose to consume grains can also learn from the past. Fermenting grains is a way to reduce problematic phytic acid, which limits the bioavailability of minerals such as iron, calcium, magnesium and zinc.
Learning from dietary patterns of the past also suggests a decrease in carbohydrate intake with a concurrent increase in protein and fat as percentages of total caloric intake. In a study of hunter-gatherer populations in geographically diverse areas, it was determined that compared to modern Western dietary intakes, protein consumption was elevated (19-35% of energy) at the expense of carbohydrates (22-40% of energy). (Increased protein may have unique effects on satiety and cravings, with implications for the current obesity and diabetes epidemics.) Even for those who prefer not to consume more protein and less carbohydrate, a shift from grains and refined sugars to vegetables and fruit may ultimately benefit some individuals through a reduction in total glycemic and insulinogenic impact.
It’s no secret now that low-carbohydrate or ketogenic diets are highly effective for type 2 diabetes. But even diets that aren’t very low carb can also be effective for lowering blood sugar and insulin and improving other metabolic parameters. In a study comparing a Mediterranean-style diet (based on whole grains, low-fat dairy, vegetables, fruits, fish, oils and margarines) to a Paleolithic-style diet (lean meat, fish, fruits, vegetables, eggs and nuts) in subjects with ischemic heart disease, subjects on the Paleo-style diet had substantially lower area under the curve (AUC) for glucose. They also had greater decreases in waist circumference and AUC for insulin. Similar results were seen in a study comparing a Paleo-style diet to the American Diabetes Association’s recommended diet for type 2 diabetics: subjects on the Paleo diet saw greater improvements in glucose control, lipid profiles, and insulin sensitivity. A crossover study comparing a Paleo diet to a “diabetes diet” informed by European guidelines on diet and diabetes found that, for type 2 diabetics, the Paleo diet resulted in lower HbA1c, triglycerides, body weight and waist circumference, and higher HDL. It’s often said that exercise is essential for improving diabetes, and while it’s certainly helpful, diet alone can go a long way. With or without exercise, individuals with type 2 diabetes who followed a Paleo diet for 12 weeks saw decreases in body fat and significant improvements in HOMA-IR and HbA1c.
Skyrocketing rates of type 2 diabetes, obesity, metabolic syndrome and related comorbidities are new, but that doesn’t mean we should ignore the past when looking for solutions.
