By Dr. Mercola
In Traditional Chinese Medicine (TCM), yin and yang refer to opposite elements or forces in nature, which, when balanced, promote harmony. Qi is a type of universal energy, and both yin and yang are manifestations of Qi, each with its own attributes. Where yin tends to manifest cold, moist, cooling, and dark qualities, yang manifests as hot, dry, warming, and bright. The summer months, with their hot temperatures and bright sun, is decidedly yang.
Specifically, TCM describes summer as the season of fire, which is a symbol of the greatest yang. In order to keep harmony, it's important to balance the strong yang energies with those of yin – and this is possible to do via your diet.
The summertime is a perfect opportunity to focus your diet on yin foods, which are by nature cooling or cold. When you eat yin foods in the summer, it helps you avoid "summerheat," which is a condition linked to an overabundance of yang that causes a queasy, fatigued, and "blah" feeling when it's hot outside.1
Top 'Yin' Summer Foods to Enjoy
Cooling foods tend to be in-season with abundance during the summer months. Most "green" foods, including vegetables and fruits, qualify, although some are better than others. To give your body a refreshing break from summer's yang, focus on eating these cooling "yin" foods.
Sprouts may be small, but they are packed with nutrition, including vitamins, minerals, antioxidants, and enzymes that help protect against free radical damage. They're an inherently cooling food and are perfect for adding to salads, either in addition to or in lieu of salad greens, and sandwiches and are especially tasty in combination with fresh avocado. You can also add them to your vegetable juice or smoothies.
Better still, growing your own sprouts is quite easy, and you don't need a whole lot of space either; they can even be grown indoors. Two of my personal favorites are sunflower seed and pea shoots—both of which are typically about 30 times more nutritious than organic vegetables.
They're also among the highest in protein. In addition, sunflower seeds contain healthy fats, essential fatty acids, and fiber—all of which are important for optimal health. Mung beans are another common sprout popular to TCM; they're a good source of protein, fiber, vitamin C, and vitamin A.
I used Ball jars when I first started sprouting seeds about 25 years ago, but I've since switched over to growing them in potting soil. With Ball jars you need to rinse them several times a day to prevent mold growth and it is a hassle to have them draining in the sink, taking up space.
Moreover, you need dozens of jars to produce the same amount of sprouts as just one flat tray. I didn't have the time or patience for that, and you may not either. The choice is yours, though. You can easily grow sprouts and shoots with or without soil. My Sprout Doctor Starter Kit comes with what I consider to be three of the best sprouts to grow – sunflower shoots, broccoli sprouts, and pea shoots.
When grown in soil, you can harvest your sprouts in about a week, and a pound of seeds will probably produce over 10 pounds of sprouts. Sunflower shoots will give you the most volume for your effort and, in my opinion, have the best taste. In one 10x10" tray, you can harvest between one and two pounds of sunflower sprouts, which will last you about three days.
You can store them in the fridge for about a week. Broccoli sprouts look and taste similar to alfalfa sprouts, which most people like. I've partnered with a company in a small town in Vermont that develops, breeds, and grows their own seeds, and are industry leaders in seed safety for sprouts and shoots.
All of my seeds are non-GMO, certified organic, and packed with nutrition. My starter kit makes it easy to grow your own sprouts in the comfort of your home, whenever you want. It provides everything you need, so all you have to do is grow and enjoy your sprouts.
2. Watermelon (and Other Melons)
Watermelon is more than 91 percent water.2 This means that eating watermelon on a hot summer day is a tasty way to help you stay hydrated and avoid dehydration. Watermelon is also an excellent source of lycopene, with upwards of 6,500 micrograms in less than half a cup.
Lycopene's antioxidant activity has long been suggested to be more powerful than that of other carotenoids, such as beta-carotene. In one study, after controlling for other stroke risk factors, such as older age and diabetes, they found that men with the highest blood levels of lycopene were 55 percent less likely to have a stroke than those with the lowest.3
Watermelon also contains citrulline, which in your body is converted into L-arginine, which is a precursor to nitric oxide. Nitric oxide may help your vessels stay relaxed and open for blood flow, which is one reason why it may help lower blood pressure.
What else is watermelon good for? It's rich in anti-inflammatory substances. For instance, watermelon contains the anti-inflammatory antioxidant lycopene as well as cucurbitacin E, or tripterpenoid. This blocks the activity of the pain and inflammation-causing enzyme cyclooxygenase – the same enzyme blocked by COX-2 inhibitors, which include most NSAID drugs like aspirin and ibuprofen.
While being very low in calories (about 46 calories in a cup) watermelon also contains an impressive variety of other important nutrients in which many Americans are lacking, including:
- Vitamin C
- Vitamin B6
- Vitamin A
It's not only watermelon that's beneficial to consume in the summer – other melons, like cantaloupe, muskmelon, and honeydew, are also beneficial. Cantaloupes, for instance, provide an excellent source of antioxidants, like vitamin C and vitamin A (in the form of carotenoids). They also contain important nutrients like potassium, folate, copper, B vitamins, vitamin K, magnesium, and fiber.
If you eat the seeds (yes, they're edible), you'll also get beneficial plant-based omega-3 fat in the form of alpha-linolenic acid. With relatively few calories (about 54 per cup) and low fructose (2.8 grams in one-eighth of a medium melon), this is one fruit you can feel good about eating.
Like watermelon, cucumbers are made up of mostly (95 percent) water, making them an ideal hydrating and cooling food. Cucumbers may also help to "cool" the inflammatory response in your body, according to raw-food advocate David Wolfe. Animal studies also suggest that cucumber extract helps reduce unwanted inflammation, in part by inhibiting the activity of pro-inflammatory enzymes (including cyclo-oxygenase 2, or COX-2).4
Cucumbers also contain numerous antioxidants, including the well-known vitamin C and beta-carotene. They also contain antioxidant flavonoids, such as quercetin, apigenin, luteolin, and kaempferol,5 which provide additional benefits. For instance, quercetin is an antioxidant that many believe prevents histamine release—making quercetin-rich foods "natural antihistamines." Kaempferol, meanwhile, may help fight cancer and lower your risk of chronic diseases including heart disease.
Cucumbers also contain multiple B vitamins, including vitamin B1, vitamin B5, and vitamin B7 (biotin). B vitamins are known to help ease feelings of anxiety and buffer some of the damaging effects of stress.
There's good reason to regularly include tomatoes, another cooling food, in your diet, as they are rich in flavonoids and other phytochemicals that have anti-carcinogenic and other healthy properties.
They're also an excellent source of lutein, zeaxanthin, and vitamin C (which is most concentrated in the jelly-like substance that surrounds the seeds) as well as vitamins A, E and B-complex vitamins, potassium, manganese, and phosphorus. Other lesser-known phytonutrients found in tomatoes include:
- Flavonols: rutin, kaempferol, and quercetin
- Flavonones: naringenin and chalconaringenin
- Hydroxycinnamic acids: caffeic acid, ferulic acid, and coumaric acid
- Glycosides: esculeoside A
- Fatty acid derivatives: 9-oxo-octadecadienoic acid
Tomatoes are also a particularly concentrated source of lycopene. In addition to lowering your risk of stroke, lycopene from tomatoes (including unsweetened organic tomato sauce) has also been shown to be helpful in treating prostate cancer. If you eat tomatoes, choose organic varieties. One study found growing tomatoes according to organic standards results in dramatically elevated phenols content compared to tomatoes grown conventionally, using agricultural chemicals.
The organic tomatoes were found to contain 55 percent more vitamin C and 139 percent more total phenolic content at the stage of commercial maturity compared to the conventionally grown tomatoes.6
Rhubarb is high in fiber, which is why it's long been used in TCM for soothing stomach ailments and relieving constipation. A one-cup serving of rhubarb provides high levels of vitamin K, vitamin C, vitamin A, and calcium, along with folate, riboflavin, niacin, B vitamins, and pantothenic acid. Rhubarb also provides important minerals, including manganese, iron, potassium, and phosphorus.
Due to its sour flavor, rhubarb is often found in recipes alongside sugar and other sweeteners. But a healthier (and far more cooling) way to consume it is by juicing raw right into your fresh vegetable juice. Remember, only the stalks can be eaten; rhubarb leaves are poisonous due to high levels of oxalic acid.
6. Dandelion Leaves
Dandelion leaves contain vitamins A, C, and K, along with calcium, iron, manganese, and potassium. They also have antioxidant properties and contain bitter crystalline compounds called taraxacin and taracerin, along with inulin and levulin, compounds thought to explain some of its therapeutic properties. Dandelion leaves can be used in salads, soups, juiced, cooked the same way as spinach, or dried (with flowers) to make dandelion tea (try it iced in the summer!).
Dandelions offer you a wealth of nutrition; they contain:
✓ One of the richest sources of beta carotene of all herbs (10,161 IUs per 100g, which is 338 percent of the RDA)
✓ Numerous flavonoids, including FOUR times the beta carotene of broccoli; also lutein, cryptoxanthin, and zeaxanthin
✓ One of the HIGHEST herbal sources of vitamin K1, providing 650 percent of the RDA
✓ Vitamins, including folic acid, riboflavin, pyroxidine, niacin, and vitamins E and C
✓ Great source of minerals, including magnesium, calcium, potassium, manganese, and iron
✓ Leaves rich in dietary fiber, as well as a good laxative
7. Citrus Fruits
Oranges, grapefruits, lemons, and limes are all beneficial to add to your summer diet. They're rich in fiber and vitamin C and also contain additional antioxidants known as flavonoids that may play a beneficial role in fighting heart disease, cancer, and inflammation. As noted in the Journal of Agricultural and Food Chemistry:7
"The anti-oxidant and anti-inflammatory properties of Citrus flavonoids can play a key role in their activity against several degenerative diseases and particularly brain diseases."
Citrus fruits are simple to add to your diet; they can be incorporated into vegetable juice, used in salad dressings, squeezed over veggies, or used to make lemon/lime water, for starters. You can, of course, also peel and eat them (oranges and grapefruits), in moderation.
Bananas contain dopamine, a natural reward chemical that boosts your mood. They're also rich in B vitamins, including vitamin B6, which help soothe your nervous system, and magnesium, another nutrient associated with positive mood. In addition, bananas are a good source of fiber, vitamin A, and antioxidants. They also contain fructooligosaccharides (FOS), which are a type of prebiotics that help nourish beneficial bacteria in your body while enhancing your ability to absorb calcium. Nutritionist Laura Flores told Live Science:8
"Bananas are high in antioxidants, which can provide protection from free radicals, which we come into contact with every day… Bananas are known to reduce swelling, protect against developing type-2 diabetes, aid in weight loss, strengthen the nervous system and help with production of white blood cells, all due to the high level of vitamin B6 that bananas contain."
Last but not least, watercress is another cooling vegetable that's perfect for a hot summer day. It may actually be the most nutrient-dense vegetable out there, scoring higher on nutrient density scores than both broccoli and sunflower sprouts. Based on 17 nutrients— including potassium, fiber, protein, calcium, iron, thiamin, riboflavin, niacin, folate, zinc, and vitamins A, B6, B12, C, D, E, and K— watercress scored a perfect 100 in a study titled, "Defining Powerhouse Fruits and Vegetables: A Nutrient Density Approach."9
Watercress, which is a close cousin to mustard greens cabbage and arugula, can be eaten as a salad green, steamed as a vegetable, added to soups and sandwiches, or, my favorite, sprouted. This plant has such a strong history of healing prowess that Hippocrates is said to have located the first hospital on the island of Kos close to a stream so that fresh watercress could be harvested for patients (watercress grows in water). Greek soldiers also reportedly ate it as a health tonic prior to going into battle.10
In a more recent study, people who ate about 1.5 cups of fresh watercress daily for eight weeks had a 10 percent reduction in triglyceride levels and a significant increase in lutein and beta-carotene, by 100 percent and 33 percent, respectively.11 Further, the watercress diet lead to significant reductions in DNA damage to blood cells, with researchers concluding "consumption of watercress can be linked to a reduced risk of cancer via decreased damage to DNA and possible modulation of antioxidant status by increasing carotenoid concentrations."
Melons Should Be Eaten Alone and Other Tips for Fruit Consumption
While melons are a beneficial cooling fruit for summer, they're best off eaten alone. In 2013, I interviewed Dr. Wayne Pickering, a naturopathic physician, on the principles of food combining, and this is one important tip he taught me. Improper food combining is one of the primary factors that cause gas, flatulence, heartburn, and upset stomach. What's worse, poor digestion can also contribute to malnutrition, even if you think you're eating a decent diet. You can learn the details in our interview, but one of the most basic rules to remember is as follows: "Eat melon alone, or leave it alone, or your stomach will moan."
In short, melon does not digest well with other foods and will frequently cause problems unless you eat it alone. So feel free to enjoy melon, but this is best done on an empty stomach (and resist the urge to combine your cantaloupe with yogurt or prosciutto). In addition, I recommend you consume melon and the other fruits on this list in moderation due to their fructose content. While some of these, like cantaloupe, are relatively low-fructose fruits (less than three grams in one-eighth of a melon), your grams can quickly add up if you consume fructose from other sources as well.
Bananas should certainly be eaten only in moderation, as one banana contains about 7.5 grams of fructose. I recommend keeping your total fructose intake below 25 grams of fructose per day if you're in good health and below 15 grams a day if you're overweight or have high blood pressure or diabetes. Finally, remember that variety is key. There are many more beneficial summer foods that are not listed here. If none on the list strike your fancy, other cooling foods often recommended by TCM for the summer months include:12
✓ Summer squash
✓ Lettuce and most greens
✓ Bok choy