One potential reason that peanut butter might cause your face to fill with pimples lies not in the peanut butter itself, but in the heavy amounts of sugar that some brands contain. While natural peanut butter is low on the GI index with a GI of only 14, the situation changes when sugar is added to the product. According to the American Academy of Dermatology Association, higher GI foods can cause blood sugar spikes. This in turn can lead to systemic inflammation, causing you to produce more sebum, the oily substance that protects and hydrates your skin. Having too much sebum can lead to clogged pores and acne breakouts.
According to Curology, another factor that might contribute to the development of acne is the fact that peanut butter is high in omega-6 fatty acids. While these essential fatty acids play several vital roles in the human body, for example stimulating skin and hair growth, problems can arise when they are not in balance with omega-3 fatty acids or there is too much omega-6. This can lead to inflammation throughout the body. Mount Sinai advises seeking a healthy 1:2 to 1:4 balance of omega-3 and omega-6 by eating a diet like the Mediterranean diet that keeps meat consumption low while emphasizing whole grains, fruits, vegetables, fish, olive oil, garlic, and moderate wine consumption.