Can Aloe vera and walnuts provide the next novel drugs for diabetes and colon cancer?
A pooled analysis of nine studies that examined the effect of oral Aloe vera in people with diabetes and pre-diabetes suggests the medicinal plant should be further investigated as an anti-diabetic compound.
Aloe vera should be further investigated as a potential anti-diabetic compound, say researchers after analyzing evidence that it lowered blood glucose in patients with diabetes and pre-diabetes.
The analysis is the work of researchers at the David Grant USAF Medical Center at Travis Air Force Base in Fairfield, CA, who report their findings in The Journal of Alternative and Complementary Medicine.
The analysis shows people with diabetes whose fasting blood glucose (FBG) is above 200 mg/dl may benefit the most from treatment with oral Aloe vera.
Also, a team of researchers from UConn Health and The Jackson Laboratory for Genomic Medicine found that eating walnuts can reduce one’s risk of getting colon cancer.
In the study, mice that were fed walnuts (totaling seven percent to 10.5 percent of their total calories) developed fewer instances of colon cancer.
Seven to 10.5 percent of daily total calories coming from walnuts is equivalent to a human eating about an ounce of walnuts every day.
“Our results show for the first time that walnut consumption may reduce colon tumor development,” said Daniel W. Rosenberg of UConn Health, principal investigator on the study.
“There is accumulating evidence that eating walnuts may offer a variety of benefits related to health issues like cancer. This study shows that walnuts may also act as a probiotic to make the colon healthy, which in turn offers protection against colon tumors.”
Walnuts contain more polyunsaturated fatty acids than any of the commonly eaten tree nuts. They also contain significant amounts of vitamin E.
“But walnuts are not merely the sum of their chemical parts, and it may be as a whole food that they pack the most significant anti-cancer punch against colon cancer, the third most common cancer in the world,” says Kim Krieger of UConn Communications.
“Other studies have shown walnuts have promise warding off diseases connected to diet and lifestyle, including heart disease, diabetes, and neurological disorders.”
Meanwhile, diabetes is a lifelong condition where blood sugar is too high, resulting in damage to organs if not treated. There are 382 million people worldwide living with diabetes, with type 2 diabetes accounting for the vast majority of cases.
The authors note that in the United States – where some 21 million people have the disease – the cost of treatment and loss of productivity in 2012 due to diabetes was $245 billion. The global cost is expected to “exceed a staggering $490 billion” by 2030.
People with diabetes are more likely to seek complementary and alternative medicines than people without diabetes. A popular remedy is aloe vera (Aloe barbadensis), a plant used medicinally by the Chinese, Egyptians, Greeks, Indians, Japanese, and Mexicans for thousands of years.
More recently, Aloe vera has been used as a skin application to treat seborrheic dermatitis, psoriasis Vulgaris, and genital herpes, and orally as a laxative.
Aloe vera contains dozens of active compounds
The part of the Aloe vera plant that is used medicinally is the leaves, the major components of which are the green outer rind and the colourless inner gel. Aloe vera products are made from either of these components or both.
The Aloe vera plant contains at least 75 active compounds, “which notably include vitamins, enzymes, minerals, anthraquinones, monosaccharide, polysaccharides, lignin, saponins, salicylic acids, phytosterols, and amino acids,” note the authors, who also cite studies suggesting some of these compounds play a role in improving blood glucose control.
The plant also contains trace elements such as chromium, magnesium, manganese, and zinc, known to be important for glucose metabolism by improving the effectiveness of insulin.
Studies of oral Aloe vera as a remedy for a range of chronic diseases – such as asthma, glaucoma, high blood pressure, inflammatory bowel disease, and diabetes – have produced limited or inconsistent evidence.
However, oral Aloe vera is becoming more popular, and evidence about its effect on lowering blood glucose has been mounting, so the researchers decided to analyse it.
For their analysis, the team looked for studies of the effect of oral aloe vera on fasting blood glucose (FBG), haemoglobin A1c (HbA1c), oral glucose tolerance test (OGTT), and a number of other measures in pre-diabetic and diabetic populations.
They found only nine studies had appropriate data for meta-analyses and covered FBG and HbA1c only. Of these, all nine measured FBG (total of 283 participants), and five measured HbA1c (89 participants).
FBG (sometimes called fasting plasma glucose, FPG) measures the blood glucose level during a period when the patient has not had anything to eat or drink, except water, for at least 8 hours. A level in the range of 100-125 mg/dl is defined as pre-diabetic and 126 mg/dl or higher as diabetic.
HbA1c (glycated haemoglobin, sometimes called haemoglobin A1c or simply A1c) is a measure of average blood glucose over the past two to three months. A level greater than or equal to 6.5 percent is considered diabetic.