Are salads healthy? Here’s what you should add and avoid.
The most important health benefit of lettuce and other greens in a salad is fiber. Salads are usually packed with fiber, which is a nutrient—just not for you! Fiber really is food for the microbiome, trillions of bacteria that live in your gut. Fiber is also key to metabolic health. Bacteria in the gut turn fiber into short-chain fatty acids, which can regulate immune function and keep inflammation in check.
To increase the fiber content of the green salad, add various vegetables, such as broccoli and green peppers, and add beans and lentils.
But the healthiest salads contain many other good ingredients, such as antioxidants. Antioxidants are chemicals essential to your liver that detoxify virtually all environmental toxins that enter your body. To perform this magic trick, your liver needs these antioxidants.
For antioxidants, try chopped colorful vegetables (the darker the better), chopped fresh fruit, herbs (fresh or dried) and spices. Then add proteins, such as free-range eggs, pastured meat, fish, chicken, tofu, beans or lentils.
Add fat and fermented foods to the salad
Now add some whole food fats – including avocados, olives, nuts and seeds. Nuts and seeds (such as chia seeds and walnuts) are full of the anti-inflammatory alpha-linolenic acid (ALA), an omega-3 fatty acid that has been shown to reduce the risk of heart disease.
For other sources of omega-3, try small fish, such as anchovies (commonly found in Caesar salads). You can also include other wild-caught fish (sardines, salmon, mackerel) or chicken (free-range, pasture-raised chicken has fewer antibiotics).
Cheeses are a wonderful addition because they contain odd-chain fatty acids, which are protective against diabetes and heart disease. We’ve all been taught to avoid fats because they have more calories, but dairy fatty acids are unique in that they have a specific phospholipid on the end that prevents inflammation. Just don’t use American cheese, which isn’t actually cheese. Instead, try varieties such as feta, cotija, parmesan and mozzarella.
Bonus points go to kale, cabbage and Brussels sprouts – cruciferous vegetables that can increase the body’s own natural production of antioxidants and stimulate the production of liver enzymes for detoxification. Another bonus: fresh tomatoes contain lycopene, an antioxidant that supports eye function and prevents cataracts.
Adding fermented foods like kimchi and sauerkraut can give you a gut-friendly boost, as can homemade dressings made with natural, unsweetened yogurt. And fermented foods already have short-chain fatty acids in them.
Avoid store-bought salad dressings
Right. Now let’s talk about salad dressings. To make a great homemade dressing, focus on ingredients like extra virgin olive oil, avocado oil, tahini, vinegar, dijon, herbs, spices, and low-sugar citrus juices (lemon, lime, grapefruit).
The oleic acid in olive oil activates the liver to produce a factor that increases metabolism. The acetic acid in vinegar inhibits an enzyme that breaks down starch in the mouth, thereby reducing the rate at which glucose appears in the blood. Some homemade dressings get extra antioxidants from spices and seasonings like ginger, garlic, turmeric, thyme and oregano.
But the same cannot be said about most store-bought dressings. Store-bought versions are often made with canola and soybean oils, which are packed with linoleic acid, an inflammatory omega-6 fatty acid.
They can also sneak in large amounts of fructose (the sugar molecule), in the form of cane sugar, high fructose corn syrup or honey – which damages the mitochondria, the energy-producing factories that power each of your cells. When your mitochondria malfunction, your blood sugar and insulin spike, and your liver has no choice but to turn the fructose into fat—driving fatty liver and insulin resistance, and potentially increasing your risk of developing heart disease, cancer, and diabetes.
You might be surprised how common it is for sugar to sneak into bottled dressings. For example, high fructose corn syrup is the second ingredient in Kraft’s Creamy French dressing, which has five grams of added sugar. And watch out for fat-free dressings – for example, Ken’s sun-dried tomato vinaigrette has 12 grams of added sugar.
Shop-bought dressings can also contain ingredients that are harmful to the gut and the trillions of bacteria that live there. These bacteria send chemical signals to your brain asking to be fed. If you don’t feed your bacteria, they actually start eating away at you – stripping the mucin, a protective layer, right off your gut cells. Over time, this can lead to irritable bowel syndrome, inflammatory bowel disease and altered intestinal permeability, which some call “leaky gut.” It can also cause systemic inflammation.
Shop-bought dressings often contain emulsifiers, such as carboxymethylcellulose, polysorbate-80 or carrageenan, which prevent the fat and water from separating – and can dissolve the protective mucin layer in your gut. These pesky added sugars can also cause bad microbiome bacteria to proliferate, potentially leading to gastrointestinal distress, gas, bloating, diarrhea and inflammation.
Croutons and crisps
But that doesn’t mean you should skip the dressing. Studies have shown that fat – like in avocado – actually helps your body absorb the nutrients from some vegetables. The key is to choose the right ingredients and, ideally, make your own dressing at home.
It is also a good idea to steer clear of “crispy” things (such as fried onions and tortilla strips), which are often fried in seed oils at high temperatures, and risk the formation of trans fats and acrylamide, a known carcinogen. I would also suggest being careful with dried fruit; some varieties and brands cover them in sugar to make them sweeter and more palatable.
And finally, beware of processed bread. A Caesar salad isn’t a Caesar salad without croutons – but commercial croutons are usually packed with preservatives, sodium and vegetable oils. Bake your own croutons, or pair the salad with a slice of sourdough bread. But please, don’t eat the fried tortilla.
Robert H. Funny is professor emeritus of pediatrics at the University of California at San Francisco and author of “Metabolic: The Allure and Lies of Processed Food, Nutrition, and Modern Medicine.”
