August is upon us and summer is in full swing. The long days, warm weather and plentiful sunshine allow for a variety of outdoor activities like hiking, golfing, and relaxing by the pool. Getting outdoors is excellent for our physical and mental health, but long outings in the heat and sun can set us up for dehydration and sun burns. Beyond traditional precautions, such as drinking plenty of water and wearing sunscreen or protective clothing, what we eat and drink can influence our hydration and how our body responds to the sun’s damaging UV rays.
FOOD AS HYDRATION
Mild dehydration is more common than people think. Drinking enough water is the obvious solution, but did you know that certain fruits and vegetables are roughly 90% water? Eating these water-heavy foods can help us stay hydrated throughout the day, and can lend us a hand in rehydrating after physical activity. Hydrating foods with a water content of around 90% include strawberries, watermelon, tomatoes, bell peppers, zucchini, cantaloupe, raw spinach, iceberg lettuce, peaches and celery. Coincidently, all of these foods tend to be in season during the summer. It’s almost as if Mother Nature wants us to stay hydrated.
FOOD AS SUNSCREEN
There’s a case to be made for sensible sun exposure. Spending short periods of time in the sun produces vitamin D, releases mood-boosting endorphins and helps regulate our sleep/wake cycle. ₁ On the other hand, excessive sun exposure causes DNA damage, which can lead to skin cancer. Is there a way to reap some of the benefits of the sun, while minimizing our skin cancer risk? Limiting overall sun exposure and avoiding sunburns is our best option. But consuming certain foods, and the pigments they contain, may reduce the amount of DNA damage caused by the sun, and may increase the time it takes to get sunburned.
A handful of studies have shown that consuming foods rich in certain pigments can offer some protection from the sun’s UV rays. These pigments accumulate in skin tissue where they serve as natural sunscreen by reducing sun damage and sun burns. Lycopene, the red pigment found in tomatoes, watermelon and pink grapefruit is one example. ₂₋₃ Beta-carotene, the orange pigment found in sweet potatoes, carrots, butternut squash, cantaloupe and other orange produce, can also be protective. ₄ And regular consumption of green tea may help as well. ₅
FOOD AS SUNGLASSES
Like our skin, our eyes can also be damaged by sun exposure. You may have noticed that after a long day in the bright sun – even with sunglasses or protective eyewear – your eyes may feel dry, tired or puffy by the end of the day. This is the eyeball equivalent of getting a sunburn. The light that enters our eyes allows us to see, but too much over time can increase our risk of cataracts, macular degeneration and cancers of the eye. Similar to our skin, certain pigments found in food accumulate in the retina and offer some protection. These pigments include lutein, zeaxanthin and a group of pigments called anthocyanins. ₆₋₁₀
Lutein and zeaxanthin are two closely related pigments found in yellow and green foods. Good sources include yellow corn, yellow squash, yellow/orange bell peppers, spinach, kale, broccoli, collard greens, and most other dark, leafy greens. Anthocyanins are responsible for the blue/purple/red color of many fruits and veggies. Good sources include most berries, red grapes, plums, purple cabbage, purple potatoes, cherries, pomegranates, eggplant, figs, and most other purple, blue or red produce.
THE BOTTOM LINE
We should all take advantage of the warm weather and long days that summer offers by getting outside and being active. But we can also be smart about staying hydrated and limiting our sun exposure. Filling our plates with brightly colored fruits and vegetables is good for our overall health, and can also protect our skin and eyes from the sun while keeping us hydrated. In other words, when you’re walking through the produce section of a grocery store, the more your cart resembles a rainbow, the better.References:
- Mead, M Nathaniel. “Benefits of sunlight: a bright spot for human health.” Environmental health perspectives 116,4 (2008): A160-7. doi:10.1289/ehp.116-a160
- Rizwan, M et al. “Tomato paste rich in lycopene protects against cutaneous photodamage in humans in vivo: a randomized controlled trial.” The British journal of dermatology 164,1 (2011): 154-62. doi:10.1111/j.1365-2133.2010.10057.x
- Stahl, W et al. “Dietary tomato paste protects against ultraviolet light-induced erythema in humans.” The Journal of nutrition 131,5 (2001): 1449-51. doi:10.1093/jn/131.5.1449
- Stahl, Wilhelm, and Helmut Sies. “β-Carotene and other carotenoids in protection from sunlight.” The American journal of clinical nutrition 96,5 (2012): 1179S-84S. doi:10.3945/ajcn.112.034819
- Ulrike Heinrich, Carolyn E. Moore, Silke De Spirt, Hagen Tronnier, Wilhelm Stahl, Green Tea Polyphenols Provide Photoprotection, Increase Microcirculation, and Modulate Skin Properties of Women,The Journal of Nutrition, Volume 141, Issue 6, June 2011, Pages 1202–1208, https://doi.org/10.3945/jn.110.136465
- Liu, Yixiang et al. “Blueberry anthocyanins: protection against ageing and light-induced damage in retinal pigment epithelial cells.” The British journal of nutrition 108,1 (2012): 16-27. doi:10.1017/S000711451100523X
- Huang, Fei-fei, and Xiao-ming Lin. Beijing da xue xue bao. Yi xue ban = Journal of Peking University. Health sciences 46,2 (2014): 237-41.
- Ma, Le et al. “Lutein and zeaxanthin intake and the risk of age-related macular degeneration: a systematic review and meta-analysis.” The British journal of nutrition 107,3 (2012): 350-9. doi:10.1017/S0007114511004260
- Moeller SM, Voland R, Tinker L, et al. Associations Between Age-Related Nuclear Cataract and Lutein and Zeaxanthin in the Diet and Serum in the Carotenoids in the Age-Related Eye Disease Study (CAREDS), an Ancillary Study of the Women's Health Initiative. Arch Ophthalmol.2008;126(3):354–364. doi:10.1001/archopht.126.3.354
- Moeller SM, Parekh N, Tinker L, et al. Associations Between Intermediate Age-Related Macular Degeneration and Lutein and Zeaxanthin in the Carotenoids in Age-Related Eye Disease Study (CAREDS): Ancillary Study of the Women's Health Initiative. Arch Ophthalmol.2006;124(8):1151–1162. doi:10.1001/archopht.124.8.1151