Foods That May Harm Your Brain

Health Tips / Foods That May Harm Your Brain

Posted 02/03/2014

This intriguing idea is the lead article in this week’s Medscape Internal Medicine, a newsletter directed to internists like myself. It’s genuinely refreshing to read research that doesn’t extol some new pharmaceutical, but rather encourages simple changes in how we eat to prevent and even treat common emotional problems.

Before I get to the meat (or rather the whole grain) of the article, which contains a lot of info you Health Tip readers already know, the comments section at the end, which unfortunately you can’t access, shows more than 70 physicians expressing appreciation for the information. Some had minor quibbles, others opposed sweeping generalizations, but all things considered I see the positive reception of this article as a good sign.

The article first interviews Drew Ramsey, MD, a psychiatrist from Columbia University College of Physicians and Surgeons in New York and author of The Happiness Diet: A Nutritional Prescription for a Sharp Brain, Balanced Mood, and Lean, Energized Body, published by Rodale Press, home of Prevention Magazine. Movie star-handsome Dr. Ramsey certainly looks like someone who spends the hours away from his analyst couch at a health club or eating scrupulously healthful food. In fact, his second book, Fifty Shades of Kale, is exactly that: 50 recipes for the only food I know that makes me gag. Although I personally feel more at ease when my psychiatrist looks like Paul Giamatti, John Goodman, or Wallace Shawn, The Happiness Diet contains a lot of useful information.

Rather than resort to “in my experience” sort of writing (which immediately alienates physicians, who prefer hard clinical data over anecdotes), Dr. Ramsey in the Medscape piece examines previously published and seriously overlooked large-scale clinical studies linking junk food–chips, soda, fast food, sweets–and mental health. One such study tracked more than 2,500 Australian adolescents over two years and found as eating habits deteriorated, rates of anxiety and depression increased. He quotes a second study that followed 23,000 Norwegian women who ate junk food throughout pregnancy and birthed lots of children with aggressive tendencies, attention deficit disorders, and severe tantrum and other behavioral issues. In other research, the eating habits of 5,731 adults were tracked for several years, with lower rates of both anxiety and depression found in those whose self-reported eating habits were tagged as “very healthy.”

A second psychiatrist interviewed in this Medscape article, Felice Jacka, PhD, is president of the International Society for Nutritional Psychiatry Research, which I never knew existed. She agrees completely that the deleterious effects of junk food on the brain are too often overlooked when starting psychiatric treatment.

According to this informative Medscape slideshow, “a so-called whole diet high in fruits, vegetables, whole grains, and high-quality meats and fish results in a 30% risk reduction for depression and anxiety disorders, compared with consumption of a Western diet high in processed foods and saturated fats, according to a 2010 study. Even unprocessed red meat seems to be protective against depressive and anxiety disorders,in contrast to many studies in which red meat often falls into the category of unhealthy food. In speaking with Medscape News, principal investigator Dr. Felice Jacka specifically addressed the importance of farming practices: Despite the growing locavore movement, much of the livestock in the United States is still raised on industrial feedlots, which ‘…increases saturated fat and decreases very important good fatty acids…pasture-raised animals have a much healthier fatty acid profile.’ A whole dietary pattern may also reduce depression risk, as assessed at 5-year follow-up.”

“A diet high in saturated fats and refined sugars has a very potent negative impact on brain proteins that we know are extremely important in depression ― neurotrophins, which protect the brain against oxidative stress and promote the growth of new brain cells,” Dr. Jacka told Medscape Medical News. “There also seems to be an impact of saturated fat on the stress response system, which is also important in both depression and anxiety.”

In addition, very little research is available on the damaging effects of chemical food additives and preservatives. Most of these are classified as GRAS (Generally Recognized as Safe), but those who classify them often have financial links to the food industry, so no one really knows what we’re dosing ourselves with when we eat them. One very large study from Spain followed 9,000 adults and their nutritional habits and found a direct correlation between fast food intake, development of depression and anxiety, and slow but relentless cognitive decline.

Other studies from around the world are equally chilling. Tracking more than 12,000 university students over a period of 11 years, researchers from Spain found a correlation between the amount of trans fats in the diet and depression, anxiety, and early cardiovascular disease. A recent Women’s Health Study on more than 6,000 people again found correlation between trans fats and early cognitive decline, memory, and verbal IQ. Other studies have identified comparable correlations with sugar intake and depression, anxiety, and mental decline.

Grain and the brain

David Perlmutter, MD, a Florida neurologist I’ve known personally for years, lays much blame on our veritable grain “addiction.” His recent best-selling book Grain Brain proposes a low-carb, low-sugar and good-for-your-brain fats eating program, placing much emphasis on gluten-free, low-glycemic eating (high glycemic foods convert quickly to glucose/sugar in the body).

It must be said that Dr. Perlmutter’s work is not completely accepted by the majority of nutritionally oriented psychiatrists and neurologists, who believe that severe carb restrictions and going practically grain-free have not been shown to be worth the effort.

“The book has gotten a lot of buzz, but the argument seems to me to be an unfortunate oversimplification,” Dr. Ramsey told Medscape Medical News. “It’s good that we want people to focus on the health of their brain and how their dietary choices affect the risk of mental illness, but eliminating whole grains just isn’t supported in the evidence for most people, and I doubt that it will be.” He called the argument on glycemic index “misleading.”

Although following a very low-glycemic diet, which eliminates even whole grains, is helpful for weight loss, there’s little clinical evidence that doing so will dramatically affect rates of mental illness or susceptibility to cognitive decline. Both Dr. Perlmutter and Joseph Mercola, MD, who wrote The No-Grain Diet several years ago, endlessly refer to our collective carbohydrate “addiction.”

Extreme language like this may sell books, but I don’t think inducing anxiety in people when they eat the occasional cookie or slice of pizza serves any useful purpose. Anyway, addicts rob gas stations. When have you ever read of a gas station being robbed for its Krispy Kremes?

Here’s what research has been showing…

What not to eat

  • Foods with a high sugar content. You’ll want to eat mostly foods that don’t have labels, but when they do read labels carefully. Look for grams of sugar per serving. I recently purchased a jar of chili that boasted it was all-natural (a meaningless phrase, by the way), organic, and GMO-free, but on careful reading I discovered it also contained 14 grams of sugar per serving, roughly equivalent to a bowl of Captain Crunch cereal.
  • Foods with trans fats. The other name for trans fats is partially hydrogenated vegetable oil. It’s a product created by the food industry that doesn’t exist in nature and isn’t good for you. To make a trans fat, you take a liquid vegetable oil (like corn or peanut oil), and turn it into a solid by bubbling hydrogen through it. Most fried foods are fried in trans fat and virtually all store-bought baked goods use copious amounts. That neon-yellow glob melted down and poured on your movie popcorn when you ask for extra butter definitely does not come from a cow. Don’t eat trans fats.
  • Foods with a high saturated fat content. These are the solid fats and usually come from animals (that marbleized steak, the white flecks in ground beef). Certain oils, like palm and coconut, and cocoa butter are also saturated fats.

You can remember what not to eat by considering the donut. Refined white flour + sugar + deep fried in trans fats. The only healthful part of a doughnut is the hole. A close second is the deep-fried chicken wing. You probably ate one or the other this past Super Bowl Sunday. How else could you explain the anxiety, depression, and cognitive decline you felt Monday morning (what, you also had six mojitos?)?

What to eat

  • Mediterranean diet. All the nutritionally oriented psychiatrists interviewed were enthusiastic about the Mediterranean diet, high in seafood/omega 3s, plant-based foods, nuts, and whole grains. For desserts and snacks, fresh fruit.

Here’s where we likely worry unnecessarily

  • Gluten. Although many people are sensitive to gluten grains, unless you know you can’t tolerate them there’s no evidence of harm. The best way to find out if your body doesn’t like gluten is to eliminate it completely for a couple of weeks. If you feel better, including improved mental clarity, that’s a sign. Then, establish a single day on which you reintroduce gluten. If within 24 hours you feel poorly (digestive symptoms, fatigue, nasal congestion, brain fog) then you’re likely gluten sensitive. But certainly everyone need not eliminate all gluten grains without good evidence that doing so will make a difference.
  • Organic versus non-organic. Although we might feel emotionally more comfortable knowing our food was raised in an organic setting and we might also recognize it’s better for the soil, there’s actually very little data showing specific health benefits or improved nutritional value. On the other hand, because we don’t know much about the long-term effects of all the fertilizers and pesticides used to grow our produce–or the hundreds of additives mixed into prepared food–if you can afford to go organic, it’s probably a good idea. If your budget can’t handle the likes of Whole Foods, then thoroughly clean conventionally grown fruit and veggies and avoid buying processed foods, especially those containing chemical names you can’t pronounce. Here’s a Mayo Clinic article comparing organic and non organic food.
  • GMOs. Yes, the source of much controversy with all sorts of scary scenarios as Frankenfoods give us offspring of goat-babies. Keep in mind, however, that we’ve been tinkering with plant genetics since the dawn of agriculture. They’re called hybrids. The American Association for the Advancement of Science, the World Health Organization, and the European Union all agree that GMO foods are just as safe as non-GMO foods.

Just from talking with patients, I find people worrying themselves into states of anxiety thinking about GMOs, but, really, there’s no evidence that they’re harmful. (I’m sure to get some angry comments about this.)

Be well,
David Edelberg, MD