Understanding Nickel in Grains
Nickel is a trace element found naturally in the Earth's crust and is present in almost all natural foods. For most people, consuming dietary nickel is not a problem. However, for those with a pre-existing nickel sensitivity, also known as systemic nickel allergy syndrome (NAS), consuming foods with higher nickel content can trigger allergic reactions such as eczema, especially on the hands. The amount of nickel in a particular grain is heavily influenced by the nickel concentration in the soil where it was grown. Additionally, the degree of processing also plays a significant role, as refining can remove some of the nickel-rich outer layers of the grain.
Following a low-nickel diet is a key strategy for managing systemic nickel allergy symptoms. While the diet can be restrictive, understanding which grains to prioritize and which to limit is crucial for maintaining a balanced and healthy eating pattern. A doctor or a registered dietitian should supervise this type of diet to ensure proper nutrition is still met.
What Grains Are High in Nickel?
Certain grains are known to accumulate higher concentrations of nickel, making them a primary dietary concern for sensitive individuals. These include:
- Oats and Oatmeal: Oats are consistently listed among the highest-nickel grains. Oat flakes, in particular, can have very high levels.
- Buckwheat: This grain is frequently identified as high in nickel and should be avoided on a restrictive low-nickel diet.
- Whole Wheat and Whole-Grain Products: Because whole grains retain the bran and germ, where much of the nickel is concentrated, they are typically high in nickel. This includes whole-wheat bread, pasta, and multi-grain cereals.
- Wheat Bran and Wheat Germ: As these are parts of the whole grain, they have very high nickel levels and should be avoided.
- Millet: Some studies have found millet to contain particularly high levels of nickel.
- Rye: This grain can also contain considerable amounts of nickel, though levels can vary.
- Unpolished Brown Rice: Unlike polished white rice, brown rice retains its outer layers and therefore has a higher nickel content.
The impact of processing
The method by which a grain is processed directly influences its final nickel content. Whole grains, by definition, have not had their outer shell (bran) or germ removed. It is in these outer layers that nickel tends to be most concentrated. Refining a grain, such as creating white flour from wheat or polishing brown rice into white rice, involves removing these outer layers. This process inadvertently removes a significant amount of the nickel, leaving behind the lower-nickel core of the grain. This is a key reason why a low-nickel diet often recommends refined grains over their whole-grain counterparts.
Comparison of Grains by Nickel Content
To better illustrate the difference, this table compares common grain types and their products based on typical nickel levels. Please note that actual nickel content can vary based on growing conditions.
| Grain Type | High-Nickel Products (Avoid) | Low-Nickel Alternatives (Allow) |
|---|---|---|
| Wheat | Whole-wheat bread, whole-wheat pasta, wheat bran, wheat germ, multi-grain products | Refined white flour, white bread, most processed whole-wheat cereals (may be lower due to processing) |
| Oats | Oatmeal, oat flakes, oat bran, oat-based cereals | None; oats are generally high in nickel |
| Rice | Unpolished brown rice, wild rice | Polished white rice |
| Buckwheat | Buckwheat, roasted buckwheat | None; buckwheat is high in nickel |
| Corn | Corn/tortilla chips (variable), some corn flour | Cornmeal, corn tortillas, cornflakes, cornstarch |
| Other | Millet, rye | Barley groats (often lower than flakes) |
How to Manage Grains in a Low-Nickel Diet
For individuals with nickel sensitivity, navigating the grain aisle requires careful planning. Here are several strategies for incorporating grains while minimizing nickel exposure:
- Choose Refined Over Whole Grains: Opt for polished white rice, cornmeal, and products made from refined white flour instead of brown rice, whole wheat, and multi-grain products.
- Be Cautious with Processed Foods: Many processed snacks and cereals contain high-nickel ingredients like oats, nuts, or seeds. Always read ingredient labels carefully.
- Utilize Low-Nickel Alternatives: Corn-based products like tortillas, cornmeal, and cornflakes are generally good choices.
- Consider Cooking Methods: Research has shown that cooking rice and quinoa by boiling in a large volume of water and discarding the residual water can significantly reduce nickel content, though some nutrients may also be lost.
- Add Vitamin C to Meals: Some evidence suggests that consuming vitamin C-rich foods or a supplement with meals can inhibit the body's absorption of nickel. Always consult with a healthcare provider before starting any new supplement regimen.
Conclusion
For those with a nickel allergy, a targeted nutrition diet is essential for symptom management, and understanding what grains are high in nickel is a key part of this strategy. Whole grains such as oats, buckwheat, and whole wheat should be limited due to their higher nickel content. Conversely, refined grains like polished white rice and corn-based products are generally safer options. By focusing on low-nickel alternatives and adopting specific cooking techniques, individuals can effectively manage their dietary nickel intake while still maintaining a balanced and varied diet. Consultation with a healthcare professional is always recommended before making significant dietary changes. A low-nickel diet can be a valuable tool in reducing systemic nickel exposure and controlling symptoms of dermatitis.
