Cereal


Cereals can be a nutritious way to start your day, but most are made up of refined sugars and refined grains. They lack the fiber that a bowl of granola or oatmeal can provide—and can even negatively affect your skin. If you’re craving a cold, crunchy breakfast, look for cereals that contain more whole grains and nuts instead of sugar.

Bacon


Processed meats like bacon are high in sodium, which can wreak havoc on your skin. Preservatives like sodium nitrate can damage collagen and elastin—the proteins that keep your skin supple and bouncy—and increase your risk of skin cancer. Processed meats have also been linked to atopic dermatitis flare-ups. Bacon is also high in nitrates, which can lead to inflammation and wrinkles if they are consumed in large quantities.

Bananas


You might have heard that bananas are a superfood on account of their high Potassium content – but they’re also high in histamine. Histamine is an amino acid that some people can’t break down. This causes a buildup of histamine in the body, which can lead to allergic reactions such as hives, swelling, and itching.

Margarine


Margarine is free of dairy and therefore a good alternative for vegans, but it is not free of hydrogenated oils that are pro-inflammatory. In fact, margarine’s main ingredients are the hydrogenated oils soybean, canola, and olive. Some brands of margarine have trans fats, which increase inflammation levels in our bodies. The best way to make your skin look younger and healthier is to reduce inflammation in your body. The NYU School of Medicine found that people with low levels of inflammation have smoother, more elastic skin. Smooth, elastic skin is a sign of healthy aging. To reduce inflammation in your body: Reduce your intake of processed foods like margarine.

Peanut Butter


A balanced diet calls for both omega-6 and omega-3 fatty acids, and research shows that Western eaters lean much more on omega-6s than omega-3s. When people consume too many omega-6 fatty acids like those in peanut butter, it’s thought to cause an inflammatory response linked to acne and general skin inflammation.

Cow’s Milk


Research shows that milk and dairy products can contribute to acne flare-ups for some people. Doctors aren’t sure why only certain dairy products seem to affect people’s skin, but skim milk seems to be more problematic than plain yogurt, for example. It’s still up for debate as to what causes it. Some say it’s due to hormones passed from the mother cow into her milk; others point out that skim milk has more sugar than whole milk does. On top of that, many people are mildly allergic to or have food sensitivities to milk and dairy products. These allergies complicate skin conditions like eczema and psoriasis.

Yogurt


Yogurt is not a major cause of acne breakouts. However, flavored yogurts can cause problems if they are loaded with added sugars and sweeteners. When your blood glucose levels rise rapidly, as can happen when you eat a lot of added sugars, your body releases more IGF-1, which stimulates your oil glands.

Soy


Phytoestrogens, which are found in soy products such as tofu and soy milk, are a type of plant-derived chemical that may lower the risk of developing osteoporosis, heart disease, breast cancer or menopausal symptoms. However, some research suggests that the benefits of phytoestrogens have been overestimated. New research suggests that phytoestrogens in the diet can upset the balance of oestrogen and androgens, or male hormones, in the body. This can lead to hormone-related problems such as reduced fertility and cancers of the reproductive systems. Soy can also contribute to acne in some people. According to research, soy has been shown to cause inflammation and inhibit the absorption of vital vitamins and minerals, which may lead to acne breakouts and other skin problems.

Popcorn


Although buttery popcorn is delicious, it can be very bad for your skin. Butter contains saturated fats that cause inflammation, which worsens acne. And many brands of microwave popcorn are made with genetically modified corn, which contains pesticides that can cause your pores to produce more oil. If you love the taste of popcorn, try some organic kernels in a stovetop or hot-air popper. You’ll avoid toxic fumes and unappealing ingredients, and you’ll be helping the environment too.

Bottled water


Bisphenol A is a chemical found in many water bottles. It’s an analog of a natural hormone, which means it might cause similar effects in your body. You probably don’t think about what your plastic bottle could do to your skin, and we don’t know the extent of the effects yet—but there are many good reasons not to use plastic bottles all the time.