Evidence Based

How to Increase & Decrease C-Peptide Levels Naturally

Written by Biljana Novkovic, PhD | Reviewed by Ana Aleksic, MSc (Pharmacy) | Last updated:

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C-peptide points to how much insulin you’re making. You want to keep your values balanced, since both high and low levels can negatively impact your health. Read on to discover the best ways to naturally increase or decrease your C-peptide.

What is C-Peptide?

C-peptide is a reliable measure of your insulin production and beta cell (pancreas) function [1, 2].

If you are looking to learn more about C-peptide and what can cause high or low levels, read part 1 of our C-peptide series.

In this article, we’ll first brush up on the basics. Then we’ll jump to the most effective steps you can take to naturally optimize this marker.

Function in the Body

C-peptide was initially considered inactive and scientists didn’t pay much attention to it. Later studies revealed that this peptide can both reduce and worsen inflammation – depending on its levels [3, 4, 5].

C-peptide is tightly linked to the health of your pancreas and its ability to make insulin.

The beta cells in your pancreas don’t create active insulin straight away. They first produce “proinsulin,” which breaks down to equal amounts of insulin and Cpeptide. Put simply, the more proinsulin, the more insulin and C-peptide your body is making [1, 2].

In a nutshell, you want Cpeptide (and insulin production) to be balanced neither too high nor too low.

High levels can signal obesity, insulin resistance, and kidney disease. Overall, high C-peptide worsens inflammation and increases the risk of heart disease, cancer, and even the likelihood of dying from any cause. It can also slightly increase with age in healthy people [6].

In diabetics, the reverse happens: C-peptide tends to decline over time. Its levels in type 1 diabetes are especially important.

In type 1 diabetics, an autoimmune response can eventually destroy the insulin-producing cells of the pancreas. As a result, C-peptide becomes either undetectable or low [2, 7].

Having detectable C-peptide levels in type 1 diabetes is good: it means your pancreas is still producing some insulin. Plus, these detectable (low-normal) levels of C-peptide are anti-inflammatory. They have been linked to fewer health complications and the lower insulin therapy requirements in type 1 diabetics [2, 7].

How to Increase C-Peptide Levels

1) Exercise

If your C-peptide levels are low, exercise can help [8].

In a study of 1,700 elderly people, exercise increased C-peptide levels in those whose levels were initially low [8].

2) Honey

Honey can protect your pancreas. It’s a great substitute for sugar in moderation.

In a study of 80 people, honey increased C-peptide levels much better than glucose or table sugar (sucrose) in both healthy people and those with type 1 diabetes [9].

3) Omega-3 Fatty Acids

Increase the amount of omega-3 fatty acids in your diet. These are abundant in fatty fish and algae.

In 90 pregnant women with type 1 diabetes, DHA and EPA omega-3 supplementation increased C-peptide levels [10].

4) Niacin

Nicotinamide (niacin) can help increase pancreatic beta-cell function.

Niacin supplementation over a year increased C-peptide levels in 36 patients with recent onset type 1 diabetes [11].

5) Whey Protein and Casein

Whey protein and casein can increase C-peptide levels, as revealed by two studies of over 200 people in total [12, 13].

6) Vitamin D

Vitamin D supplementation increased C-peptide levels in a study of 328 people [14].

Researchers pointed out that vitamin D deficiency may be to blame for impaired insulin production and low C-peptide. In line with this, getting more sun could also be a good strategy to naturally increase your vitamin D and C-peptide levels [14].

How to Lower C-Peptide Levels

1) Exercise

Exercise is great because it can balance C-peptide levels. If your levels are low, exercise can increase them, and if your levels are high, exercise helps decrease them [8].

In a study of 1,700 elderly people, those who engaged in vigorous physical activity had lower C-peptide levels than those who engaged in light or no physical activity [8].

Similarly, high physical activity was related to lower C-peptide levels in 199 children [15].

Two studies with 29 inactive people in total discovered that a single moderate-intensity exercise session can improve blood sugar control and decrease C-peptide and insulin levels. But the effect is modest and short-lived. That’s why it’s important to exercise regularly [16].

2) Lose Weight

Weight loss helps decrease insulin resistance, insulin and C-peptide levels [17, 18].

In 52 obese children, a 10% drop in BMI was associated with 35% lower C-peptide [19].

3) Decrease Carbs

When you eat carbs, your blood sugar increases, and insulin and C-peptide increase in response. Decrease carbs in favor of fats and proteins in your diet.

In 20 healthy volunteers, meals containing less carbs and more protein and fat caused less of an increase in C-peptide levels [20].

In 24 overweight and obese people, a high-fat meal (with unsaturated fats) was more effective in lowering C-peptide levels than a high-protein meal [21].

4) Replace Sugar With Honey

Not all sugars are created equal. Whenever possible, replace sugar with honey. According to a study in 12 healthy people, honey causes less of an insulin and C-peptide spike [22].

5) Fiber

A fiber-rich diet can help decrease urine C-peptide and blood sugar levels. But not all fibers are created equal. Researchers discovered that fibers from beans and lentils are beneficial, whereas cereal fiber isn’t [23].

6) Fasting

Fasting and calorie restriction may be good strategies for lowering C-peptide levels if you have insulin resistance and/or are overweight.

In 12 women with rheumatoid arthritis, calorie restriction and fasting decreased urine C-peptide levels by more than 50% during the fasting periods [24].

Similarly, blood and urine C-peptide levels decreased after fasting and calorie restriction in two studies with 21 obese people in total. It took 5-7 days for C-peptide levels to reach a steady state on the new diet [25, 26].

Diet restriction also decreased urine C-peptide levels in 40 people with type 2 diabetes [27].

Fasting has a stronger effect on urine than on blood C-peptide levels [26].

7) Seafood

Scientists in Norway observed 20 healthy adults on a balanced diet where most (60%) of their protein came from either lean seafood or non-seafood sources. They uncovered that proteins from lean seafood can lower C-peptide levels [28].

8) Coffee

Both caffeinated and decaffeinated coffee help decrease C-peptide levels.

In over 2k healthy women, those who drank more coffee, caffeinated or decaf, had lower C-peptide levels. C-peptide was 16% lower in women who drank >4 cups/day compared with nondrinkers. This effect was even stronger in overweight and obese coffee drinkers, who had 20 – 27% lower C-peptide levels [29].

9) Calcium and Vitamin D

Check your calcium and vitamin D levels.

In a review of 2 studies on almost 900 men and 2,000 women, those with the highest calcium intake and blood vitamin D levels had significantly lower fasting C-peptide levels (35% in men and 12% in women) [30].

However, in another study of 328 people, vitamin D supplementation was linked to higher C-peptide levels [31].

The best way to increase your vitamin D is to get more sun.

10) Avoid Niacin Supplements

Take niacin supplements with due caution.

Niacin increases glucose and insulin levels [32, 33, 34].

In a study of 17 postmenopausal women, niacin supplementation resulted in higher insulin and C-peptide levels [35].

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C-peptide points to how much insulin your body is making and how well your pancreas is working.

Exercise, replacing sugar with honey, and sun exposure can help balance both high and low levels. If you have low levels, you should also get more omega-3s and supplement with niacin, If your levels are high, consider intermittent fasting, weight loss, and reducing your carb intake.

About the Author

Biljana Novkovic

Biljana Novkovic

Biljana received her PhD from Hokkaido University.
Before joining SelfHacked, she was a research scientist with extensive field and laboratory experience. She spent 4 years reviewing the scientific literature on supplements, lab tests and other areas of health sciences. She is passionate about releasing the most accurate science and health information available on topics, and she's meticulous when writing and reviewing articles to make sure the science is sound. She believes that SelfHacked has the best science that is also layperson-friendly on the web.

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