Anxiety Diets

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By Mary Carpenter

EATING UNRIPE brie and bananas—as well as a host of fermented foods—can help combat anxiety, according to the recent food-as-medicine movement that involves specific personal recommendations from medical specialists, such as nutritional psychiatrists. Addressing “underlying metabolic pathologies associated with mental illness,” Harvard researchers in a 2021 Frontiers review article focus on the gut “microbiome and inflammation as influencers of anxiety.”

Choosing specific foods for health can depend on individual goals—reducing anxiety, lowering blood pressure, losing weight—while individual physiological differences can cause different foods eaten at different times of the day to have varying effects: for example, some people do better eating protein-rich breakfasts. In addition, personal preferences vary on the degree of specificity desired—with specific foods suggestions issued by nutritionists based everywhere from health care settings to pricey residential programs, such as Pritikin and The Ranch, Malibu—the latter the source of the unripe-foods recommendations.

Nutritional psychiatrists advise “paying attention to how eating different foods makes you feel —not just in the moment, but the next day,” writes Harvard nutrition specialist Eva Selub. “Try eating a ‘clean’ diet for two to three weeks—that means cutting out all processed foods and sugar. See how you feel. Then slowly introduce foods back into your diet, one by one, and see how you feel.”

One reason is that more general and widely accepted recommendations—such as eating fewer ultra-processed foods, less sugar, no gluten—don’t work for everyone: The advice to cut down on salt, for example, depends on personal salt sensitivity. Only about one-third of healthy people are salt-sensitive, according to an American Heart Association report, stating that “the effect of salt intake on blood pressure elevation is exaggerated [with salt sensitivity] higher in women than in men and, in both, increases with age.”

“Over recent years, evidence of the links between anxiety and inflammation has grown stronger,” according to MedicalNewsToday. The association of higher anxiety scores with a range of inflammation and coagulation factors has garnered support from studies showing higher levels of inflammation related to PTSD and depression. In addition, “anxiety disorders…may also be associated with increased risk of heart disease and metabolic disorders [that] involve low grade systemic inflammation.”

Blood sugar spikes can provoke changes in mood—with low blood sugar causing nervousness or anxiety along with irritability or impatience, although anxiety itself can also cause widely varying blood sugar levels. As a result, nutritionists rate different foods based on their glycemic index, the scale that measures how much a food or drink raises blood sugar levels. In addition, the microbiome may play as great a role as blood sugar in creating inflammation and thus increasing anxiety, which makes both targets for intervention by nutritional psychiatrists.

Among inflammatory foods associated with the Standard American Diet (SAD), “the two most metabolically challenging are refined sugars and processed vegetable oils [notably corn and soy oil], both of which can contribute to inflammation through myriad mechanisms,” write the Harvard researchers, who consider “lifestyle interventions for mental illness…a form of metabolic medicine.” High-fructose corn syrup, for example, which accounts for 10% of caloric intake in the U.S. “increases neuroinflammation and contributes to metabolic diseases.”

For anxiety, six nutritional interventions from the Harvard team include: avoiding artificial sweeteners and gluten; adding omega-3 fatty acids, turmeric and vitamin D; and following a ketogenic diet—eating normal protein, more fats and fewer carbs to help the body burn more fat for energy. Similar items appearing on a MedicalNews list of nine anti-anxiety food recommendations include fatty fish to increase omega-3s; and turmeric.

Other specific items on the MedicalNews list include pumpkin seeds (also bananas) for potassium because low potassium can elevate levels of the stress hormone cortisol; dark chocolate (and chamomile tea), rich in flavonoids that “might reduce inflammation and cell death” in the brain; green tea—for the amino acid theanine, recently studied for effects on mood disorders; and Brazil nuts, which can increase selenium to improve mood.

Eggs, good sources of vitamin D and protein as well as tryptophan—which indirectly boosts brain levels of serotonin “that helps regulate mood, sleep, memory and behavior” —are number two on the MedicalNews list. Also high on this list and many others naming specific healthy foods is yogurt, for calcium, potassium, and protein—and “most important,” according to the Consumer Reports column in the Washington Post, “live active-cultures and probiotics [that] tamp down chronic inflammation,” that are related to fermentation.

“Yogurt might be the easiest fermented food for Americans to add to their diets,” explains Harvard nutrition professor David Ludwig. While yogurt choices vary by amounts of calcium and fats, many people care most about protein content, which has higher levels in nonfat yogurt than in whole milk, even higher in Greek yogurt and highest in Icelandic yogurt known as skyr—which also ferments longer. Ludwig also encourages people to try pickled vegetables, such as kimchi; fermented soybeans, such as that in tempeh; and pickles labeled “naturally fermented.”

(To boost microbiome health, vegetable pickling should involve “natural fermentation” —not vinegar—using salty brine. In this process, salt releases beneficial bacteria in the vegetables, such as lactic acid. As opposed to the vinegar method, which often employs hot water to seal the vegetables, lacto-fermented pickles are uncooked and must be stored at low temperatures.)

Both green bananas and unripe brie appear on New York-based climate change advocate R.C.’s food prescription list, created by her nutritionist at The Ranch, Malibu—with the original goal of losing weight and, more recently, of reducing anxiety. Green bananas contain more than 50% starch, which helps control blood sugar and works as dietary fiber to create a feeling of fullness that can help limit calorie intake. (Ripening converts the starch to sugars, with fiber content falling to 1%.)

And while health benefits of unripe brie are harder to track down, dairy products including those high in fat, such as soft cheeses and even ice cream, have earned better reputations in recent years for creating feelings of fullness that help with weight management. For me, though, brie as well as skyr are appealing for their high protein content—and a relief for me to find favorite foods on healthy lists—while in general, I balk at dining from prescriptions and meal plans. Although the proposal of two clean weeks as a way to improve physical and mental health sounds manageable, I’m thinking of that only as a possibility—and not before the New Year.

—Mary Carpenter regularly reports on topical subjects in health and medicine.