Many people are in denial about what their arteries look like, but it’s hard to be in denial about what your skin looks like. Americans spend billions of dollars every year on anti-aging skin products. Botox injections and cosmetic surgery account for billions more. However, skin aging is not caused by a deficiency of anti-aging skin creams. Today’s column offers some suggestions for maintaining healthy, young-looking skin.

First of all, don’t smoke. Nicotine and other chemicals in cigarettes damage the blood supply to your skin (as well as other parts of your body). They also damage collagen and elastin in your skin, making it wrinkled and saggy.

Second, according to Dr. Michael Greger’s website nutritionfacts.org, alcohol, especially in large quantities, contributes to skin aging. Breakdown products of alcohol decrease carotenoid antioxidants in the skin, which lowers the threshold for sun damage and increases the risk of skin cancer.

Third, ultraviolet radiation from the sun and tanning booths leads to premature aging, including wrinkling; sagging; and pigmented areas called sun, age, or liver spots. UV exposure also contributes to precancerous rough, red spots called actinic keratoses; basal cell cancer; squamous cell cancer; and life-threatening melanoma. We all like being out in the sun, but it’s best to cover up with long-sleeved, sun-protective clothing and a broad-brimmed hat. Apply a broad-spectrum (protects against both UVA and UVB rays), high SPF sunscreen to the parts of your body you can’t cover up, such as the back of your hands and your lower face. The safest and best sunscreens contain zinc oxide or titanium, which physically block the sun, versus sunscreens with chemicals that can be absorbed and could possibly cause harm. Remember, suntanned skin is sun damaged skin. In Japan, where light, unblotched skin is prized, women wear gloves and use umbrellas when outside in the sun, and as they age, they maintain youthful-looking skin.

Fourth, what you eat affects your skin. Free radicals and oxidation contribute to skin aging and skin cancer. Therefore, it’s important to eat food with lots of antioxidants and other micronutrients, found in unprocessed plant foods. Studies have shown that people who are plant-based are protected from sun damage, compared to people who eat animal products. Their immune system is optimal, skin aging slows, and they are at lower risk for actinic keratoses and skin cancer, including melanoma. Plant-based nutrition has been shown to reverse early skin cancer, including melanoma in some cases.

Acne is a disease associated with a Western diet, according to experts such as Drs. Greger, Fuhrman, and Barnard. Acne is essentially non-existent in Okinawa and other plant-based parts of the world—although this is changing as we export our diet. In the U.S. some 85 percent of teenagers are afflicted with acne, which often persists into their third decade. There’s a clear association between cows’ milk and acne, thought to be due to excessive estrogen (cow’s milk comes from pregnant cows). Skim milk has the highest estrogen content. Antioxidant-rich foods help prevent and treat acne; flavorful (herbs and spices) and colorful plant foods are loaded with antioxidants. The most antioxidant-packed fruit is dried barberries, which can be found in Middle Eastern markets. One teaspoon 3 times a day for a month resulted in a 43 percent decrease in acne in one study.

Many products marketed as anti-aging are of questionable benefit. It’s best to get your skin antioxidants from the inside out. There’s a good plant-based cookbook called “Oh She Glows,” which refers to glowing from the inside out. Healthy, “glowing” skin has a slightly pinkish and yellowish hue, which means it has an abundance of carotenoid antioxidants.