Harvard lecturer’s new book focuses on nutrition and brain health: Dr. Logan ranks omega-3s as #1 protective factor
by Craig Weatherby
aAlan Logan, N.D. is a naturopathic physician with the human brain on his mind. He is deeply concerned by the rapid decline of Americans' brain health, as evidenced by increasing rates of depression, anxiety, and various forms of dementia, such as Alzheimer’s disease.
And there’s good evidence that his alarm is shared by many health care professionals. Dr. Logan’s 2004 scientific review of the subject—“Omega-3 fatty acids and major depression: A primer for the mental health professional”—is the most frequently accessed article on the Web site of the journal Lipids in Health and Disease.
We noticed an article about his new book—The Brain Diet—which shines a light both on dietary strategies to keep your mind sharp and mood elevated, and on a significant, under-recognized threat to brain health. Intrigued, we read the book, and having found it quite impressive, we then spoke to Dr. Logan.
The Brain Diet is full of useful, novel information gleaned from hundreds of research studies. It offers in-depth coverage of a variety of mental and behavioral disorders in adults and children, and their nutritional connections and therapies. We recommend it highly.
But before we begin our review of the book, we should note Dr. Logan's qualifications to write it.
MDs and preventive health: the nutrition-education gap
Like medical doctors, naturopathic doctors who graduate from accredited institutions are educated in biology, human anatomy and physiology.
Naturopaths—also called NDs—have relatively little training in emergency medicine, because their focus is on prevention
and nutritional intervention. But they receive far more education about diet and health.
The obvious exceptions to this generalization would be nutrition-savvy MDs such as Drs. Andrew Weil, Nicholas Perricone, Christiane Northrup, Fred Pescatore, William Sears and Mark Hyman. But each of these extraordinary physicians had to educate themselves about nutrition and health.
Given the growing, research-based realization that diet is central to the onset, prevention and amelioration of our major degenerative health conditions—heart disease, diabetes, cancer, obesity, and Alzheimer’s—one could argue, credibly, that NDs are very well equipped to help people avoid and deal with them.
And Dr. Logan is an unusually well-trained naturopathic doctor. He is a graduate of the State University of New York and the Canadian College of Naturopathic Medicine, and also received extra training through Harvard's Mind-Body Medical Institute and Georgetown Medical School's Food as Medicine course.
Today, he serves on the faculty of Harvard's School of Continuing Medical Education, where he teaches physicians at its Mind-Body Medical Institute about dietary supplements and nutrition. Dr. Logan also facilitates stress management and anxiety support groups at New York’s White Plains Hospital.
He told us that his Harvard nutrition lectures are well-attended, because physicians are “starving for information”, and because today’s young doctors grasp the importance of emotions, stress, and diet to physical and mental health alike.
While Dr. Logan believes it's possible to enhance brain function by eating right, he counsels patience, since a lifetime of suboptimal eating can’t be reversed overnight, and the turnaround can take up to a year.
We weren’t surprised by his picks as the best dietary brain-protectors: omega-3s and the colorful fruits and vegetables Dr. Nick Perricone calls "rainbow foods". But we weren't as well aware that a leading item on his list of dietary brain-busters—“advanced glycation end-products” or AGEs—presents a specific threat to brain health.
“The Brain Diet” calls omega-3s key players
When we asked Dr. Logan to name the most helpful food factor, he said, “If I had to pick only one dietary factor that could change your psychological condition, omega-3s would be number one.”
He points to data showing that the average person's brain is starved for the omega-3s found in seafood, whole grains, grass-fed beef, flax seeds, walnut oils, and dark leafy greens like kale and spinach.
As he says, “The brain is 60 percent fat and come retirement age or sooner, if you haven't deposited enough of the good kind of fat—omega-3s—there is a greater risk of mental disease.”
Dr. Logan also notes that North Americans consume far too many saturated fats, trans fats and omega-6-rich oils such as corn, soy, cottonseed, and safflower: “These oils are changing our brain chemistry, and not for the better.”
And he agrees that it is ideal to favor the long-chain omega-3s in seafood, known as DHA and EPA. These marine omega-3s—especially DHA—are the forms used in our brain-cell membranes. In addition, the body can only convert five to 15 percent of the short-chain omega-3s in plant foods into DHA and EPA.
Rainbow foods ranked as valuable runners up
Dr. Logan points to intensely colorful—hence, antioxidant-rich—fruits and vegetables as proven protectors of brain health. In particular, he recommends purple produce such as grapes, plums, blueberries, and eggplant, because they are rich in the anthocyanin-class antioxidant pigments shown to protect brain health in test tube and animal studies.
But as Dr. Logan says, the average Americans’ level of vegetable consumption is conspicuously low, and limited in scope: “Recent research shows that only five vegetables—canned tomatoes, fresh and frozen potatoes, iceberg lettuce and onions—account for about half of Americans' vegetable intake. We're talking about the trimmings on a burger and a side of fries.”
He also recommends colorful spices like turmeric, which is turning out to be a superstar brain-protector (see “Curry Spice May Curb Alzheimer’s” in the March 6, 2006 edition of "Vital Choices"). We’d also recommend extra dark chocolate, enjoyed in moderation, as it is very high in anthocyanins and related antioxidant compounds.
“High-and-dry” cooking yields brain-busting AGEs
The most interesting part of our conversation with Dr. Logan centered on a little-known—but possibly primary—threat to brain health. We were aware of the unhealthful sugar-protein compounds in cooked foods called “advanced glycation end-products” or AGEs, thanks to Dr. Nick Perricone’s focus on their pro-inflammatory properties. But until we spoke with Dr. Logan, we’d not realized the dangers that AGEs pose to brain health.
AGEs are harmful in and of themselves, because they promote undesirable “cross-linking” of proteins: a phenomenon that characterizes brains plagued by Alzheimer’s disease.
Worse yet, AGEs generate continuous streams of damaging free radicals, which go on to wreak havoc of their own. In fact, the “oxidative stress” produced by free radicals is now considered a primary engine of the kinds of brain damage seen in Alzheimer’s and other forms of dementia.
Dr. Logan told us that he became aware of research in this area when it began appearing about three years ago. Until then, most of the concern about AGEs focused on their ability to promote and exacerbate cardiovascular disease and diabetes.
But research from the U.S., Japan, and Germany is beginning to raise alarm bells about the devastating effects of these cooking-related compounds.
AGEs are created when the sugars and proteins in foods combine under the influence of high, dry, extended heat. According to the results of a study from New York City’s Mount Sinai School of Medicine, broiled and fried fatty foods are the worst offenders (Goldberg T 2005):
- “Foods of the fat group showed the highest amount of AGE content… High values were also observed for the meat and meat-substitute group. The carbohydrate group contained the lowest values of AGEs…
- “The amount of AGEs present in all food categories was related to cooking temperature, length of cooking time, and presence of moisture. Broiling (225 degrees C) [i.e., 437 degrees F] and frying (177 degrees C) [i.e., 350 degrees F] resulted in the highest levels of AGEs, followed by roasting (177 degrees C) and boiling (100 degrees C) [i.e., 212 degrees F].
However, despite their general statement regarding fatty foods, tests show that when grain-based foods are cooked at high heat for extended periods—biscotti and frozen waffles, for example—they become extremely high in AGEs.
Steam, boil, and cool down to save your brain
Dr. Logan noted that Japanese peoples have had much lower rates of depression, attention deficit disorders, and diseases related to ingestion of AGEs: Alzheimer’s, heart disease, and diabetes. But this is changing along with changes in the Japanese diet. As the Japanese adopt western ways of eating, their rates of mental disease and child behavior problems have risen in tandem.
While he acknowledges that the good things that dominate their diets—fish, veggies, soy (in fairly small amounts), and green tea—play an important part in promoting lower rates of degenerative disease, we may have overlooked two factors on the other side of the scale: the scarcity of red meats in Japanese diets and their tendency to cook foods in steam or water rather than in ovens and fry pans.
The obvious exception is stir-frying, but that is—or was—less common in Japan than you’d think, judging by stereotypes and the western authors of “Japanese” cookbooks. And while stir-frying involves high heat, it is also very brief.
Another cooking method that yields high levels of AGEs—grilling—was not mentioned in the Mt. Sinai study. What’s a lover of grilled foods to do? It seems a cruel irony that one of the most flavorful cooking methods may also be one of the least healthful.
But Dr. Logan doesn't think we need to stop broiling, sautéing, and grilling foods. Instead, he suggests that we do more cooking with steam and water, and sauté foods over medium heat.
And we have a suggestion that should mitigate the drawbacks of grilling: cook your fish on cedar planks. This way, the food is kept moister, and is partially insulated from the dry heat of the coals.
Farmed salmon: bad for your brain?
In his chapter titled “Chewing the Right Fats”, Dr. Logan advises readers to seek out fish high in omega-3s and low in omega-6s and mercury: a description that fits our offerings to a “T”.
But on page 66 of this chapter, he points out a little-known risk associated with frequent consumption of farmed salmon, aside from its high levels of pro-inflammatory omega-6 fatty acids: “My real concern is not a theoretical human cancer risk associated with PCBs in fish; A number of human studies, including one in the New England Journal of Medicine (1996) have made clear associations between high-PCB fish consumption in pregnancy and intellectual impairment in the children when assessed years later.
And he says that the risk isn’t limited to children: “In addition, greater intake of high-PCB fish is associated with impairments of memory and learning in older adults, so this more than a pregnancy concern.”
The Brain Diet™, in brief
We recommend that you get a copy of The Brain Diet, for its in-depth coverage of the factors that influence Brain Health, especially for two things:
- His cogent explanation of the role of omega-3s in brain health.
- The book’s innovative discussion of AGEs and its list of the foods highest in these damaging sugar-protein compounds.
Here’s Dr. Logan’s summary of the important points covered in The Brain Diet, edited slightly for brevity:
- Consume a minimum of 5 servings of fruits and vegetables every day. Choose deeply colored items whenever possible: in general, the deeper the color, the greater the source of antioxidant and anti-inflammatory phytochemicals.
- Include fish at least three times per week and choose oily, low mercury fish or take a fish oil supplement.
- Eliminate, or cut back on red meat to a maximum of once per week.
- Add more omega-3 fatty acids to the diet by including organic canola oil, ground flaxseeds or flaxseed oil, walnuts and walnut oil.
- Choose complex carbohydrates, and avoid simple sugars. Consider brown rice, whole wheat pasta, whole grain cereals, and whole grain breads, vs. the white, refined and bleached counterparts.
- Limit corn, safflower, sunflower and soybean oils: these oils contain high levels of omega-6 fatty acids and none or very little omega-3. The current excess of omega-6-rich oils, relative to omega-3, may be contributing to inflammation and oxidative stress.
- Boil, poach and steam foods whenever possible. Fatty meats cooked on high and dry (oven) heat, full-fat cheeses, highly processed foods, dry baked goods cooked on high heat (e.g. dry cookies) and deep fried foods cause the formation of chemicals aptly called AGEs within the food. These advanced glycation end-products, or AGEs, consumed in the diet can promote oxidative stress, inflammation and ultimately compromise cardiovascular and brain function. The general rule is that AGE formation is limited with lower cooking temperature, less cooking time, and in the presence of moisture i.e. (boiling better then deep fried).
- Include anti-inflammatory and antioxidant culinary spices, herbs, and moderate teas and coffee (decaffeinated if bothered by caffeine).
- Take a daily multivitamin.
- Logan AC. The Brain Diet. Cumberland House Publishing. Nashville, 2006.
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