Do almonds reduce iron absorption? A definitive guide

According to a study on iron absorption in Indian women, nuts significantly inhibited iron absorption from a meal. Do almonds reduce iron absorption, and if so, how can you minimize this effect while still enjoying their impressive health benefits?

Quick Summary

Almonds contain phytic acid and polyphenols that can bind to non-heme iron, inhibiting its absorption. This effect is generally minimal in a varied diet but can be mitigated with proper food preparation and pairings.

Key Points

• Phytic Acid Is the Inhibitor: Almonds contain phytic acid, which binds to iron and other minerals, hindering their absorption.

• Affects Non-Heme Iron Primarily: The inhibitory effect mainly impacts non-heme iron found in plant-based foods, while heme iron from animal sources is less affected.

• Mitigate with Vitamin C: Pairing almonds with vitamin C-rich foods, such as citrus fruits or bell peppers, can significantly boost non-heme iron absorption and counteract the phytate effect.

• Soaking Offers Modest Reduction: Soaking almonds overnight can help reduce phytic acid levels and improve digestibility, though the reduction may be minimal.

• Balanced Diet is Key: In a varied diet, the inhibitory effect of almonds is less significant than in diets heavily reliant on plant-based foods, especially for those with low iron stores.

• Avoid Other Inhibitors: For optimal absorption, avoid consuming almonds and high-iron foods with other inhibitors like tea, coffee, or calcium-rich dairy.

Understanding Phytic Acid and Iron Absorption

Phytic acid, also known as phytate, is a compound found in many plant-based foods, including whole grains, legumes, seeds, and nuts. In plants, it serves as a storage form for phosphorus. However, when consumed by humans, it can bind to certain minerals, including iron, zinc, magnesium, and calcium, in the digestive tract, forming insoluble complexes. This process is known as chelation and it prevents the body from fully absorbing these essential minerals.

The Impact of Phytic Acid in Almonds

Almonds are known to have a high phytic acid content. This is the primary reason for their inhibitory effect on iron absorption. The impact is primarily on non-heme iron, the type found in plant foods. In contrast, heme iron, found in meat, fish, and poultry, is much less affected by phytates. While phytic acid can reduce the amount of iron your body absorbs from almonds, its overall impact depends on your total diet. For individuals consuming a varied diet that includes meat and other sources of nutrients, the effect is likely to be minimal. However, for those on plant-based diets or with existing iron deficiencies, it becomes more significant.

The Role of Polyphenols and Other Compounds

In addition to phytic acid, almonds and other nuts contain polyphenols, which are antioxidant compounds that can also inhibit non-heme iron absorption. This dual effect from phytic acid and polyphenols contributes to the reduced bioavailability of iron when consuming nuts. Calcium, which is also present in almonds, is another known inhibitor of both heme and non-heme iron absorption, though its effect is less pronounced. Despite these inhibitors, almonds are still a healthy food, containing beneficial fats, protein, and other vitamins. The goal is not to eliminate them but to eat them strategically to maximize nutrient intake.

Strategies to Mitigate Reduced Iron Absorption

Fortunately, several methods can be employed to reduce the phytic acid content in almonds and counter its effects on iron absorption.

• Soaking: Soaking almonds in water overnight can help reduce phytic acid levels, though research suggests the effect on almonds is modest. The process activates enzymes that break down phytates. Soaking also softens the nuts, making them easier to digest.
• Sprouting: Germinating almonds can further decrease phytate levels by activating enzymes.
• Pair with Vitamin C: Consuming a source of vitamin C (ascorbic acid) with a meal containing almonds can significantly enhance the absorption of non-heme iron. A study found that even 50mg of ascorbic acid could overcome the inhibitory effects of nuts. Pair your almonds with citrus fruits, strawberries, or bell peppers.
• Avoid certain pairings: To maximize iron absorption, it is best to avoid consuming large amounts of calcium-rich foods, coffee, or tea at the same time as an iron-rich meal, as these can also inhibit absorption.

Table: How Cooking and Pairing Affects Almonds and Iron

Preparation/Pairing	Effect on Phytic Acid	Effect on Iron Absorption	Best for Maximizing Iron Absorption
Raw Almonds	High	Reduced non-heme absorption	No, unless consumed with enhancers.
Soaked Almonds	Slightly reduced	Moderately reduced non-heme absorption	Better than raw.
Almonds with Vitamin C	Unchanged	Enhances non-heme absorption	Yes, significantly boosts absorption.
Almonds with Heme Iron (Meat)	Unchanged	Enhances non-heme absorption	Yes, heme iron boosts absorption.
Almonds with Tea/Coffee	Unchanged	Further reduced non-heme absorption	No, these are inhibitors.

Conclusion: Finding the Balance

While it is true that almonds can reduce the absorption of iron due to their phytic acid and polyphenol content, this effect is not a reason to avoid them. Almonds are a nutritious food with numerous health benefits. The degree of inhibition is most significant for non-heme iron and is most relevant for individuals with iron deficiency or those following a strictly plant-based diet. For most people with a varied diet, the issue can be easily managed through simple strategies like strategic meal timing and pairing almonds with iron-enhancing foods like vitamin C. For those concerned about their iron levels, it is always recommended to consult with a healthcare professional or a registered dietitian.

What are anti-nutrients, and are they bad?

Anti-nutrients are compounds found in plants that can interfere with the absorption of nutrients. While they can have an impact on mineral absorption, they are not inherently 'bad.' Many of the foods that contain anti-nutrients are highly nutritious, and the compounds themselves often have health benefits, such as acting as antioxidants. In a balanced diet, their effects are typically negligible.

When is the best time to eat almonds for iron absorption?

It's best to consume almonds separately from high-iron meals or with iron-enhancing foods. For example, enjoy them as a snack in between meals or with a vitamin C-rich food like an orange. Avoid eating them at the same time as an iron supplement.

How many almonds should I eat daily?

A moderate intake is generally recommended, such as a small handful (around 20-23 almonds) per day. This provides nutritional benefits without an excessive intake of phytates or calories.

Can almonds be soaked to remove phytic acid?

Yes, soaking nuts overnight can help reduce phytic acid levels, although the effect on almonds is often minimal compared to other foods like legumes. Soaking does have the added benefit of making them easier to digest.

What are the two types of iron, and which is affected by almonds?

There is heme iron, which comes from animal sources and is easily absorbed, and non-heme iron, which comes from plant sources. Almonds primarily affect the absorption of non-heme iron.

What can I add to almonds to increase iron absorption?

Pairing almonds with a source of vitamin C is one of the most effective ways to increase non-heme iron absorption. Examples include adding almonds to a fruit salad with strawberries or having a glass of orange juice with your almond snack.

Does roasting almonds help reduce phytic acid?

Research indicates that cooking methods like roasting can reduce phytic acid, but the effectiveness can vary. Soaking and sprouting are generally more reliable methods for reducing phytate content.

Frequently Asked Questions

What is phytic acid, and is it harmful?

Phytic acid is a compound in many plant foods like nuts and grains that can bind to minerals like iron and reduce their absorption. It is not harmful in a balanced diet, and soaking can reduce its levels.

How can I reduce the effect of almonds on iron absorption?

You can reduce the effect by soaking the almonds, and more effectively, by pairing them with vitamin C-rich foods or a source of heme iron (meat/fish).

Should I avoid almonds if I have an iron deficiency?

No, you don't need to avoid them entirely. Instead, be mindful of timing and pairing. Consume almonds at a different time than your main iron sources or take them with vitamin C to enhance absorption.

Does roasting almonds destroy phytic acid?

Roasting can reduce some phytic acid, but soaking and sprouting are often considered more effective methods. The overall reduction from roasting may not be substantial.

Do all nuts inhibit iron absorption?

Many nuts and seeds contain phytic acid and can inhibit non-heme iron absorption to some degree. Walnuts and almonds are known to have a significant effect, but soaking and proper meal pairing can mitigate this.

What are the health benefits of almonds?

Almonds are a nutritious food, rich in healthy monounsaturated fats, protein, fiber, vitamin E, and magnesium. They can contribute to heart health, and blood health, and provide sustained energy.

Is the effect of phytic acid from almonds a major concern for everyone?

No. The effect is most significant for people who rely heavily on plant-based diets for their iron or who have existing iron deficiency. For those with a varied diet, the impact is generally minimal.