Sweet potatoes have been eaten since at least the 15th century, as Christopher Columbus is known to have brought them back to Spain after his first New World voyage in 1492. From there, they travelled to Italy, and then to Austria, France, England, and Germany, where they became a beloved delicacy.
As of 2015, there’s over 400 varieties, and almost all are extremely healthy. The sweet potato was the first food early English settlers in the US ate en masse, as they discovered native Incan races cultivating them and quickly followed suit. Sweet potatoes alone kept many American communities from starving and fizzling out.
There’s one power of sweet potatoes that might be of interest to you…
…and that’s their strong power to clear your acne.
The best energy source for an acne-clearing enthusiast
Firstly, the sweet potato is the most nutritious and least problematic carbohydrate source for acne available.
On this website, we recommend against high-carb diets, as too many cranks up your insulin levels and therefore oily skin. But ultra low-carb diets are also damaging. You need at least 120 grams of carbs daily for blood-pumping exercise, and to manufacture the happiness hormone serotonin, which keeps acne-causing stress at bay.
Read Annihilate Your Acne – get the ultimate diet for clear and glowing skin!
200g of sweet potatoes delivers 40 carbs, but also tons of micronutrients:
566% of the RDI for vitamin A – the greatest acne nutrient for clogged pores. Vitamin A simultaneously reduces oil (sebum) production and controls keratin, a protein that clumps dead skin cells together into acne-causing blobs.
The outstanding vitamin A content is evident in the plant’s intense orange colour. Beta carotene, the form of pro-vitamin A in sweet potatoes, provides yellow, red and orange hues to plants (like pumpkins and carrots), and sweet potatoes are the most orange food in the business.
66% for vitamin C – important for the production of collagen, your skin’s main structural protein, which helps your dying acne to fade away faster. Also useful for clearing excess stress hormones (cortisol).
14% for magnesium – helps the body to manufacture its own antioxidants, like glutathione. Magnesium also reduces stress and can beat sleep deprivation; it’s so effective that the media widely hails magnesium as the “relaxation mineral”. Deficiencies are at epidemic levels.
An ORAC score of 4230 – this means that sweet potatoes are packed with antioxidants, which protect your skin against acne from harsh elements like chlorine and air pollution. Regular potatoes also score well (2600), but are substantially lower nevertheless.
A slice of whole grain bread is a bombshell of highly inflammatory gluten. Even oatmeal contains defensive plant weapons called lectins, which can inflame the gut in sensitive people (some can tolerate them).
Sweet potatoes, meanwhile, are as clean a carb source as one could ever hope to stumble across. They do contain 6 grams of sugar per 100 grams, but the dire consequences of sugar like acne only kick in with large intakes. Sweet potatoes may even trump white ones, since their vitamin A content dwarfs the competition.
Sweet potatoes increase insulin sensitivity
Insulin resistance is a nightmare for acne as it leads to elevated insulin levels, which itself stimulates your sebaceous glands to produce more oil.
One protein which is an important regular of insulin metabolism is adiponectin. Patients with dysfunctional insulin metabolism tend to have low levels of adiponectin, whereas people with healthy insulin levels have more. As for sweet potatoes, they’ve been shown to strongly boost production of adiponectin in patients with type 2 diabetes.
There’s plenty of evidence elsewhere too. In this Japanese study from 2013, scientists took 24 rats who had developed diabetes after being assigned a high-fructose diet, and fed them sweet potato starch for 4 weeks. Another group was fed regular potato starch to make a comparison.
The sweet potato starch significantly boosted the function of insulin receptors, meaning that less insulin was required to shuttle energy into them efficiently.
Less insulin is another way of saying far less oiliness, and that’s great news for acne patients. Sweet potatoes are actually feared by many diabetics, because they are high in starch with a glycaemic index of medium. Sweet potatoes digest into glucose and trigger a rapid spike in blood sugar and insulin.
Important article – the top 7 natural topical treatments for acne
However, while sweet potatoes increase insulin in the short term, their insulin sensitivity-boosting powers should allow long-term insulin to fall. For treating acne, long term levels are far more important than the size of temporary spikes.
Sweet potatoes lower inflammation levels
Chronic inflammation is one of two root causes of acne, as it causes an overly savage immune system response to acne bacteria, which swells up the surrounding pore into a pimple. According to studies on purple sweet potatoes, one of the 400 varieties, they can successfully restrain NFkappaB, a master molecule which controls many smaller pro-inflammatory chemicals behind acne.
Similarly, the many flavanols in sweet potatoes have been shown to inhibit COX-2. This chemical is so potent at inflaming tissues that doctors specifically target it with pharmaceutical painkillers, including aspirin and ibuprofen.
Studies reveal that sweet potatoes can inhibit all manner of inflammatory actors:
ONE – this study found that an extract of purple sweet potatoes fed to rats with liver damage significantly inhibited COX-2. It also inhibited NF-KappaB. Meanwhile, antioxidants such as quinine oxidoreductase-1, heme oxygenase-1, and GSTα increased nicely. Sweet potatoes contain their own acne-clearing antioxidants, and may enhance those made by your body.
TWO – this study applied a trypsin inhibitor extracted from sweet potato to mice paws, which had been badly inflamed. Concentrations of inflammatory chemicals like tumour necrosis factor-alpha (TNF-a) fell, as did thiobarbituric acid reactive substances, a family of free radicals.
THREE – the Japanese study above found that sweet potato starch had stronger anti-inflammatory powers than white potato starch. TNF-a and IL-6 both fell, pro-inflammatory chemicals which acne patients have in higher amounts.
What does this mean in the real world? That sweet potatoes have the power to calm down your red and inflamed acne.
How sweet potatoes actually reduce chronic inflammation is unknown, but the sheer concentration of vitamin A might have something to do with it. Sweet potatoes are a complex food, with proanthocyanins, phenols, and carotenoids galore; any compound could be responsible.
Sweet potatoes improve digestion
One of these phytonutrients is the famous quercetin, a flavonoid antioxidant which is promising for food allergies.
Bad reactions to foods as varied as apples and eggs are often caused by the overactivity of immune system mast cells. These fire too many inflammatory chemicals at random foods, regardless of whether they’re a threat or not.
Actors like histamine then flood your bloodstream, cause aches and pains and making your eyes water. One notorious symptom of these random food sensitivities is acne.
The good news is that quercetin can keep these overeager mast cells on a leash. Quercetin directly combats the acne-triggering effects of histamine and other inflammatory chemicals. According to one study, quercetin is more effective at inhibiting mast cell activity than the pharmaceutical drug cromolyn, which is used as a nasal spray to treat asthma…
…and it so happens that sweet potatoes are packed full of quercetin. They don’t quite match onions (the best quercetin source), but rank very highly among carbohydrate rich foods.
Are sweet potatoes a top-notch food?
For an acne patient, they’re superb. Sweet potatoes are particularly great for oily due to their vitamin A, but any acne patient can benefit from the overflowing carotenoid antioxidants.
Then there’s the delicious caramel-like flavour, and the sheer convenience. I eat 400 grams of sweet potatoes every other day. All I do is slice them into wedges and roast them in the oven for 40 minutes on 190c. This creates a culinary masterpiece with less effort than breathing. I tried roasting sweet potatoes in olive oil once, but all that happened was that they became soggy.
However, it is a smart idea to eat some fat with the meal. According to one widely reported study, eating beta-carotene from tomatoes alongside just 3-5 grams of a fatty food like avocado boosted its absorption in the digestive tract 2.4 fold. Furthermore, the conversion of beta-carotene to vitamin A was enhanced 4.8 fold.
Why vitamin C is the acne nutrient you cannot ignore
Therefore, you should eat sweet potatoes in a meal alongside some full-fat yogurt, a piece of steak, or even some dark chocolate (which doesn’t actually cause acne). Even downing a random tablespoon of coconut oil will make a massive difference.
Only 3-5 grams of fat is required. This study compared beef tallow (a saturated fat) and sunflower oil (a polyunsaturated fat) and found that the beef fat improved beta-carotene absorption in female test subjects far more, so skip the vegetable oils. They’re a nightmare for acne anyway.
Organic vs non-organic
Sweet potatoes are also cheap among acne nutrient bombshells, as you don’t have to spend your hard-earned cash on the organic version. Every year, the Environmental Working Group compiles a list of 15 fruits and vegetables with the lowest agrochemical contamination, known as the “clean fifteen”. The positions fluctuate each year, but sweet potatoes nearly always get a place.
Bugs sometimes eat the leaves of sweet potatoes, but because that hardly affects the underground tubers which people actually eat, farmers rarely bother spraying any pesticides.
However, after harvesting sweet potatoes commonly have a problem with fungal growth. Hence, farmers often give the tubers a quick dunk in a dicloran bath before being packed and shipped, to kill it off. Dicloran is a chemical fungicide which is a “possible carcinogen”, according to the useful “What’s on my food” website. Most carcinogens tend to feed into acne via antioxidant depletion as well.
Luckily, dicloran is the only pesticide that is consistently detected in conventional sweet potatoes. On average, one kilogram of regular sweet potatoes contains 1.69 mg of dicloran. Toxicology studies suggest a dicloran safe upper limit of 0.14 mg per kilogram of bodyweight, so a 60 kilogram human being can consume up to 8.4 mg of dicloran with no extra risk of acne.
Furthermore, sweet potatoes taste far better when peeled. As sweet potatoes are dunked in the dicloran bath after they’re fully grown, most of the inflammatory pesticides are concentrated in the skin, meaning that peeling removes them.
Therefore, sweet potatoes are an excellent source of acne-friendly nutrition if you’re low on cash.
Health benefits of sweet potatoes
By getting your carbs from sweet potatoes, and absorbing the carotenoid antioxidants they contain, your entire body will become healthier:
Cancer prevention – a study by Harvard University on more than 124,000 volunteers found that those who regularly consumed carotenoid-rich foods enjoyed a 32 percent reduction in the risk of lung cancer. A study conducted by Women’s Healthy Eating and Living (WHEL) found an inverse correlation between blood carotenoid levels and breast cancer.
Eye protection – carotenoids also boost your eyesight. Sweet potatoes are packed with lutein, which is famous for protecting cells in the cornea of your eye from oxidative stress. In England in 1939, there was a big campaign by the wartime government to get citizens eating carrots (packed with carotenoids), so that they didn’t start falling into ditches and getting run over when the night-time blackout came into force.
Scientists in one study questioned 4,519 people aged 60 to 80 about their dietary habits over a period of six years. People in the top 20% for lutein consumption had a 35 percent lower risk of developing age-related macular degeneration (AMD) than those ranked in the bottom fifth.
I eat a 400 gram serving of sweet potatoes (roughly 14oz) serving every two days, but you’ll benefit from just 80 grams, one moderate sized potato.
Conclusion
Sweet potatoes are the nutritional equal of any fruit or vegetable for acne, even “superfoods” like broccoli and blueberries.
I’m sure you’ll have heard the whole “5-a-day” strategy that schoolteachers relentlessly insist upon. Well, that’s a very good strategy for acne. You need to feed your body a variety of nutrition to give your skin the best possible chance. Sweet potatoes are a tasty and convenient food for doing that.
Replace a bowl of cereal with sweet potatoes, and you could eliminate a chunk of acne in one fell swoop.
NEXT: learn the root causes of acne, clear your skin permanently
Thanks for reading!