Sweet potatoes are a healthy and nutritious staple food with a sweet and delicious taste. Research has shown that eating sweet potatoes regularly can help prevent chronic diseases such as diabetes, cardiovascular disease, and cancer. Additionally, sweet potato leaves also offer various health benefits and have anti-cancer and antioxidant properties.
Sweet potatoes are a highly nutritious food. They contain dietary fiber, vitamins A (beta carotene), B, and C, as well as trace elements such as iron, magnesium, and potassium. Sweet potatoes also contain a variety of essential amino acids for the human body, hence, they’re often considered a superfood.
There’s growing evidence that sweet potatoes offer at least four major health benefits, as follows:
1. Prevent and Fight Cancer
In a research report published in the Journal of Epidemiology in August 2005, Japanese researchers conducted a follow-up survey of 47,997 men and 66,520 women aged 40 and over for more than seven years. The results showed that regular consumption of sweet potatoes, potatoes, and taro was associated with a decreased risk of death from kidney cancer.
Premenopausal women who consumed vegetables (such as sweet potato) rich in beta carotene, folic acid, vitamin C, and dietary fiber had a reduced risk of developing breast cancer by about 50 percent, a study published in the Journal of the National Cancer Institute in March 1996 found.
In addition to the aforementioned health benefits, researchers also discovered a unique protein with anti-cancer activity in sweet potatoes as early as 1931.
A study published in the World Journal of Gastroenterology in June 2013 found that protein purified from sweet potatoes demonstrated significant anti-proliferative and anti-metastatic effects on human colorectal cancer cells both in vitro and in vivo. The proteins not only slowed the growth of colorectal cancer cells but also reduced their migration and invasion.
Sweet potato leaves have also been shown to have anti-cancer properties. A study published in the Asia Pacific Journal of Clinical Nutrition in 2007 found that consuming vegetables rich in vitamin A, particularly garland chrysanthemum and sweet potato leaves, may provide protection from lung cancer.
2. Prevent Cardiovascular Disease
Sweet potato leaves also contain phenolic compounds that can scavenge free radicals, thus reducing vascular inflammation. Therefore, regular consumption of sweet potato leaves by hypertensive patients can effectively prevent the occurrence of cerebral arteriosclerosis.
A study published in the journal Life (Basel) in August 2021 found that consuming sweet potato leaves can lower plasma total cholesterol, lower low-density lipoprotein, and reduce oxidative stress. The researchers believe that eating more sweet potato leaves is an effective nutritional strategy for hyperlipidemia and cardiovascular disease prevention. However, the study was conducted with an animal model, so further research is still needed to confirm its effects on the human body.
Dr. Yu Hsiang Fu, former chief physician of the Department of Geriatrics and Gerontology at National Taiwan University Hospital, pointed out in a Facebook post that sweet potatoes are high in dietary fiber, which can lower cholesterol levels. Moreover, sweet potatoes contain mucopolysaccharides that can prevent arteriosclerosis and reduce the risk of heart disease.
Purple sweet potatoes are rich in anthocyanins. A study published in the Journal of Agricultural and Food Chemistry in February 2019 found that dietary intake of anthocyanins may help prevent cardiovascular disease. Although the mechanism by which anthocyanins improve cardiovascular health is still unclear, epidemiological data show that people who consume more anthocyanins have a lower risk of dying from myocardial infarction and cardiovascular diseases.
3. Control Blood Sugar Levels
In a 12-week clinical trial published in the journal Diabetes Care in 2004, researchers at the University of Vienna in Austria measured the efficacy of caiapo, an extract from white sweet potatoes, on metabolic control in 61 patients with Type 2 diabetes. They found that patients taking caiapo had a significant decrease in their glycated hemoglobin levels, from 7.21 percent to 6.68 percent. The results showed that caiapo can help reduce plasma glucose and cholesterol levels in patients with Type 2 diabetes.
Another study, published in Biological and Pharmaceutical Bulletin in January 2000, found that sweet potatoes have remarkable anti-diabetic activity and can improve abnormal glucose and lipid metabolism by reducing insulin resistance.
The researchers fed white-skinned sweet potatoes to mice with diabetes and found that their hyperinsulinemia was significantly improved, with a 60 percent improvement observed after only six weeks of oral administration.
Consuming sweet potatoes in moderation can help control calorie and fat intake, which may benefit individuals with diabetes. However, it’s important to note that after eating sweet potatoes, the intake of other staple foods should be reduced to control total calorie intake.
According to Fu, sweet potatoes have a moderate glycemic index with a value of around 69. They’re also rich in dietary fiber and can create a feeling of fullness, so they’re less likely to cause fluctuations in blood sugar and insulin, which helps to control blood sugar levels. Fu also advised that to achieve the best effect of controlling blood sugar, sweet potatoes should be consumed without any processing or seasoning.
4. Prevent Constipation
Because sweet potatoes are rich in dietary fiber and antioxidants, they can help maintain gut health. They contain both soluble and insoluble dietary fiber, which can’t be digested and absorbed by the body but can provide multiple benefits for the gut.
Soluble fiber, also known as viscous fiber, can absorb water and soften the stool, while nonviscous and insoluble fiber doesn’t absorb water but increases stool volume. Both soluble and insoluble fiber can be fermented by bacteria in the colon, producing short-chain fatty acid compounds that serve as nutrients for intestinal wall cells and help maintain gut health.
According to a study published in the journal Cancer Nursing in June 2016, 57 leukemia patients experienced relief from chemotherapy-induced constipation after eating 200 grams of sweet potatoes per day.
Fu mentioned that sweet potatoes can improve the gut environment. The dietary fiber in sweet potatoes can promote the growth of probiotics while inhibiting harmful bacteria. This, in turn, increases the number of beneficial bacteria in the gut, leading to a healthier gut and reduced risk of gut problems.
