Previously, we discussed about Milk Thistle’s benefits on the liver so we’ll shift our focus on its secondary benefit on glycemic and cardiovascular support.

For a quick recap, Milk Thistle or Silymarin functions as a liver support due to its powerful antioxidant and anti-inflammation properties. The antioxidant nature of Milk Thistle also leverages the effect to lower blood sugar, improve insulin resistance and decrease cholesterol levels.

Mechanism

Type II diabetics experience hyperglycemia caused by various processes one of which is an increase of gluconeogenesis. Gluconeogenesis is the production of glucose from a DHA, pyruvate, lactate and various amino acids in the liver and kidneys. Our body can generate its own glucose from non-carbohydrate agents. Insulin helps regulate gluconeogenesis by controlling the glucose output into the bloodstream. (1)

When insulin is insufficient, gluconeogenesis becomes unregulated which leads to unhealthy blood sugar levels. In vitro studies (test tube experiments), researchers observed silybin to decrease DHA gluconeogenesis by 33% and subsequently decreased glycolysis (which is the process of breaking down glucose for energy). (2)

They concluded by measuring the drop of lactate (helps jump start gluconeogenesis) and pyruvate production (glycolysis output). This finding can potentially help diabetics regulate their glucose production. (3)

In other lab studies, silybin’s effects were tested on adipocytes or fat storage cells. Researchers detected that silybin prevented the development of pre-adipocytes to adipocytes. Silybin’s interruption of maturing adipocytes is also followed by a reduction of triglycerides. (4)

These effects were due to silybin’s actions on lipid gene expressions such as C/EBP, PPARα, aP2, FAS, LPL, and SREBP1c mRNA. This lab finding may potentially help cardiovascular risk by reducing high fat cell deposits on the liver and throughout the body. (5)

A lab study was conducted to study the effects of silybin on pancreatic beta cells. Silybin’s antioxidant effect possessed the capability of extending the viability of beta cells. It was also noted that silybin was able to reduce beta cell toxicity in human islet amyloid polypeptide (which is responsible of inhibiting insulin & glucagon secretion). This suggests silybin’s potential in alleviating insulin resistance and support beta cell vitality for diabetic patients. (6)

A lab study dove into Milk Thistle’s antioxidant function in the pancreas. The study revealed that silymarin was successful in increasing antioxidant enzymes such as Superoxide dismutase (SOD), glutathione peroxidase (GSHPx), and catalase (CAT). This finding suggests Milk Thistle to have a boosting effect on other antioxidant enzymes as well as providing pancreatic protection from alloxan-induced damage (a toxic glucose compound that attacks beta cells). (7)

“Silibin seems to be capable of increasing the viability of pancreatic beta-cells by inhibiting fibrillation, improving oligomerization, and decreasing beta-cell cytotoxicity of human islet amyloid polypeptide (hIAPP) in a dose-dependent manner [9]. Isosylibin A was recently identified as the first PPARγ flavonoglycan agonist.”

These findings were conducted in lab testing which results were observed through test tubes and petri dishes. But so far Milk Thistle’s active compound, silybin, has promising effects on potential diabetic and cardiovascular treatments. Silybin was shown to inhibit gluconeogenesis, interrupt fat storage cell growth, increase beta cell vitality and induce pancreatic protection. Now that we have an idea of Milk Thistle’s effects on diabetic issues let’s explore the clinical applications on human patients.

Clinical Trials

1. A clinical study involved patients with alcoholic liver disease and noninsulin-dependent diabetes. The patients were administered with an isolated compound of Silybin β-cyclodextrin which is Milk Thistle’s active phenol combined with carb molecule for increase solubility and bioavailability.

Researchers administered a low dosage of 135mg and examined insulin section, glucose and triglycerides. At small dosages, researchers discovered reductions in glucose and triglyceride levels, but it did not have an impact on insulin secretion. Even at minimal dosage, we can see a great potential in treating hypoglycemia and cardiovascular issues. (8)

2. A couple of randomized controlled trial studies investigated silybin on diabetic patients. Researchers directed patient’s dosages of 200mg of silybin taken twice a day. After the trial, they monitored the patients’ bodily serums and noted significant decreases in blood glucose, lipids, LDL and triglycerides. (9)

3. Another similar study consisted a randomized double-blind clinical trial. The trial examined 51 type II diabetic patients; one group received silymarin dosed at 200mg taken three times a day with conventional therapy while the other group received a placebo with the same therapy.

The duration of the trial was 4 months, patients were visited monthly to observe their control measures such as HbA1c, fasting blood glucose, insulin, total cholesterol, HDL/LDL, triglyceride, AST and ALT. The patients’ values for each measure noted significant decreases for HbA1c, fasting blood glucose, total cholesterol, triglyceride, LDL, AST and ALT. No differential effects were discovered for insulin and HDL.

These trials concluded similar results further validating common findings. This suggests silymarin to have significant metabolic and cardiovascular applications. (10)

4. A couple of studies were published on the Diabetes Journal website which presented 2 similar clinical trials evaluating the effects of Milk Thistle on type II diabetics. The first trial conducted with 60 type II diabetic patients with cirrhosis. Half of the group received 600mg of Milk thistle and the other half received a placebo for a duration of 12 months.

At the end of the year researchers observed a decline in fasting glucose in the Milk Thistle group from 190mg/dl to 165mg/dl. Their blood glucose was also reduced by 0.7% from 7.9% to 7.2% as well as insulin intake decreased from 55 to 42units/day. (11)

5. In another study, a smaller trial was conducted which included 25 type II diabetic patients. Dosage was administered a silymarin extract of 300mg taken twice daily for 4 months. The findings revealed blood glucose reduced from 7.8% to 6.8% while the placebo group notice an expected increase in their blood sugar.

The silymarin group also had their fasting blood glucose greatly declined from 156 to 133mg/dl. Lastly, their LDL and triglyceride cholesterol levels also reduced. (12)

6. Continuous clinical trials have resulted in very similar findings regarding Milk Thistle’s hypoglycemic and cholesterol-lowering effect. Another study was conducted with patients from the Medical Trust Hospital. Twenty patients with diabetes and cirrhosis were selected to compare the effects of silymarin and amino acid therapies.

Ten received a treatment consisting of silymarin + insulin while the other half received L-ornithine + L-aspartate + insulin. The duration of the trial was from July to December. To observe the effects of the trial, researchers monitored sugar levels, total bilirubin, serum glutamic oxaloacetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT), alkaline phosphatase (ALP), serum albumin before treatment, and after 3 and 5 months of treatment.

For additional background, serum glutamic oxaloacetic transaminase (SGOT) / serum glutamic pyruvic transaminase (SGPT) / alkaline phosphatase (ALP) are enzymes located in the heart and liver. When these enzymes increase to high levels this is usually an indication of liver damages which is detected in the bloodstream.

After the 5-month trial, researchers recorded reductions of these test measures in both therapy treatments. The group that received silymarin + insulin displayed greater percentage reductions in blood sugar, bilirubin, SGOT, SGPT than L-ornithine + L-aspartate + Insulin. Serum levels of ALP was the only measurement that the amino acid + insulin that presented a greater reduction than silymarin + insulin. (13)

These findings continue to remain consistent with other clinical studies. Milk Thistle may contain a potential duo factor in supporting diabetic treatments and regulating unhealthy levels of liver enzymes.

Published studies of Milk Thistle revealed very similar results for alleviating glycemic and lipid profile. But there are also claims such as an increase in HDL, no differentiation in total cholesterol, and triglycerides concentration were also inconsistent with other findings. (14)

These studies reported inconclusive results that appeared to have no effect on total cholesterol or triglyceride concentrations but still was able to reduce other similar parameters. One study reported a significant increase in high-density lipoprotein (HDL) which is a good thing but wasn’t consistent with other various studies. (15)

It is important to acknowledge studies the contradict other findings to better understand the efficacy of Milk thistle supplementation. Like most supplementation, most results will vary positively, negatively or no effect at all.

Conclusion

Based on the studies, common findings such as decrease in blood glucose, triglycerides, LDL, total cholesterol and liver enzyme levels have been validated to have beneficial of effects for Milk Thistle supplementation. Overall, these findings have been consistent across different studies amongst patients which may hold a positive potential in alleviating glucose and cholesterol control. In conclusion, Milk Thistle is suggested to have significant improvements for diabetic patients and those with cardiovascular issues.