Gluten Content and Associated Disorders
Perhaps the most significant problem with barley is its gluten content, which makes it unsuitable for individuals with specific health conditions. Unlike wheat, which contains glutenins and gliadins, barley's gluten is primarily composed of hordeins. These hordein proteins trigger adverse reactions in people with celiac disease (CeD) and non-celiac gluten sensitivity (NCGS).
Celiac Disease
For those with celiac disease, a serious autoimmune disorder, consuming barley triggers an immune response that damages the small intestine lining. This damage can prevent proper nutrient absorption and lead to a host of symptoms, including bloating, diarrhea, weight loss, and anemia. The only current treatment for celiac disease is a strict, lifelong gluten-free diet, which necessitates the complete avoidance of barley and all its derivatives, such as malt.
Non-Celiac Gluten Sensitivity (NCGS)
Even without a celiac diagnosis, many people experience symptoms like bloating, gas, and pain after consuming gluten-containing grains like barley. NCGS is a poorly understood condition, but its symptoms often improve significantly on a gluten-free diet. The presence of hordeins in barley means it is a definite trigger for those with NCGS.
Digestive Issues from High Fiber and Fructans
While barley's high fiber content is a benefit for most people, it can be a problem for others. The grain is rich in fermentable fibers known as fructans, which are short-chain carbohydrates.
For individuals with Irritable Bowel Syndrome (IBS) or sensitive digestive systems, these fructans can lead to significant digestive discomfort, including:
- Gas and Bloating: As gut bacteria ferment the fructans, they produce gas, leading to a distended feeling.
- Stomach Cramps: Excess gas and fermentation can cause painful abdominal cramps.
- Constipation or Diarrhea: The fermentable fiber can alter bowel movements, exacerbating existing symptoms in some people.
To avoid these issues, those with sensitive guts must either limit their barley intake or avoid it altogether, especially when consuming it in large amounts.
Antinutrients Affecting Mineral Absorption
Barley, like other whole grains, contains antinutrients, which are natural compounds that interfere with nutrient absorption. The most prominent antinutrient in barley is phytic acid (phytate), which binds to essential minerals.
Impact of Phytic Acid
Phytic acid forms insoluble complexes with minerals such as zinc, iron, calcium, and magnesium, making it difficult for the body to absorb them. For individuals with a diet already low in these minerals, or for growing children, a high intake of un-treated grains could pose a problem. Some researchers have even suggested that high-phytate diets can lead to long-term mineral deficiencies.
Ways to Reduce Phytic Acid
There are traditional food preparation methods that can significantly reduce the antinutrient content in barley, making its nutrients more bioavailable. These include:
- Soaking: Soaking grains for several hours before cooking can reduce phytic acid levels.
- Sprouting: Germinating the grains activates enzymes that break down phytic acid and other antinutrients.
- Fermentation: Using barley in fermented products can help neutralize phytic acid.
Potential for Contaminants
Beyond its intrinsic biological makeup, barley can also be susceptible to external contaminants from its growing environment and processing. Concerns have been raised regarding mycotoxins and heavy metal accumulation.
Mycotoxins
These toxic compounds are produced by certain fungi that can infect barley crops, particularly under specific weather conditions like rainy growing seasons. While regulations exist to limit exposure, elevated levels of mycotoxins such as zearalenone and nivalenol have been detected in some barley samples. Consumption of mycotoxin-contaminated grain can lead to various health issues in humans and animals.
Heavy Metals
Studies have shown that barley grown in areas with contaminated irrigation water can accumulate heavy metals like cadmium (Cd), lead (Pb), and chromium (Cr) in concentrations above permissible levels for human consumption. This is a serious concern, as heavy metal exposure can pose significant health risks, especially chronic exposure to carcinogenic metals like arsenic.
Comparison: Barley vs. Wheat
While both grains contain gluten and have potential issues, their specific nutritional profiles differ. It is important to note that the degree of processing (e.g., hulled vs. pearled barley, or refined vs. whole wheat) significantly impacts their final nutrient content.
| Feature | Hulled Barley | Whole Wheat |
|---|---|---|
| Gluten | Hordeins, triggers celiac disease. | Gliadins and Glutenins, triggers celiac disease. |
| Dietary Fiber | Very high, especially beta-glucan; can cause digestive upset in some. | High; generally more digestible for most people. |
| Processing Loss | Pearling removes bran and nutrients, but less impact than refining wheat. | Refining removes significant fiber, minerals, and vitamins. |
| Antinutrients | Contains phytic acid; mitigated by soaking and sprouting. | Contains phytic acid; also mitigated by preparation methods. |
| Beta-Glucan | Significantly higher content; linked to lower cholesterol and improved blood sugar. | Present, but in lower amounts than barley. |
Conclusion
While barley offers impressive nutritional benefits like high fiber and minerals, particularly for heart health and blood sugar control, it is not without problems. For those with celiac disease or gluten sensitivity, the presence of hordein proteins is an absolute contraindication. Individuals with IBS or a sensitive gut may experience significant digestive discomfort due to its fermentable fructans. Furthermore, the presence of antinutrients like phytic acid can reduce mineral absorption, although this can be addressed through proper preparation techniques. Finally, environmental contamination with mycotoxins and heavy metals remains a concern, particularly with certain farming and storage conditions. Ultimately, a person's individual health status and dietary needs should determine if barley is a suitable and safe part of their diet. NIH study on barley's gluten challenge.
