In contrast to sweet almonds, bitter almonds are known to harbor glycoside amygdalin. When consumed, this compound is metabolized into hydrogen cyanide, a potent and lethal toxin. Almonds are revered as one of the most widely consumed tree nuts across the globe, celebrated for their nutritional value and widely acknowledged for their positive effects on health. However, it is important to note that certain varieties can elevate the risk of foodborne illnesses, digestive issues, and may even heighten the chances of developing serious conditions like cancer. Some types are indeed toxic and should be strictly avoided for human consumption.

This article delves into the various types of almonds, highlighting which are safe to eat and which should be steered clear of.

Almond Varieties: A Closer Look

Almonds can be classified into two primary species that share striking genetic similarities — bitter almonds and sweet almonds. Sweet almonds, characterized by their mild, nutty flavor, are the varieties you commonly encounter in grocery stores or in products like nougat and marzipan. In contrast, bitter almonds are aptly named for their distinctly bitter taste. They can be found in both wild and cultivated settings, primarily utilized for producing bitter almond pastes or extracts, and are generally not available in standard grocery aisles.

Historically, bitter almonds were the predominant species cultivated until a few thousand years ago, when a genetic mutation occurred that inhibited the almond tree’s capacity to produce amygdalin — the compound responsible for the bitterness. This mutation led to the development of sweet almonds, enabling the domestication of the almond trees that we are familiar with today.

Raw Bitter Almonds: A Dangerous Choice

Raw bitter almonds contain a toxin known as glycoside amygdalin. Upon consumption, this toxin decomposes into several harmful compounds, including hydrogen cyanide — a highly toxic substance that can potentially lead to fatal outcomes. Case studies indicate that ingesting just 6 to 10 raw bitter almonds can result in severe poisoning for an average adult, while consuming 50 or more can be lethal. Even smaller amounts may pose similar risks to children or young adults.

Interestingly, it has been observed that hydrogen cyanide tends to leach out when bitter almonds undergo heat processing. For example, methods such as baking, microwaving, and boiling can lower the cyanide levels in bitter almonds by approximately 79%, 87%, and 98%, respectively. However, further research is essential to validate these findings and to ascertain the safe quantity of heat-processed bitter almonds that can be consumed without risk. Until more conclusive data is available, it is advisable to avoid bitter almonds altogether.

Sweet Almonds: A Safe Delight

Sweet almonds, while still containing some amygdalin, have levels that are up to 1,000 times lower compared to their bitter counterparts. These minimal amounts of amygdalin are not enough to generate dangerous quantities of hydrogen cyanide. Consequently, sweet almonds are widely regarded as safe for consumption.

In summary, almonds can be categorized as either sweet or bitter. While bitter almonds possess toxic compounds that may lead to poisoning and even accidental fatalities, sweet almonds are deemed safe for dietary inclusion. Ongoing research is necessary to determine the safety of heat-processed bitter almonds.

Risks Associated with Sprouted and Moldy Almonds

While sprouting almonds can enhance the absorption of essential nutrients by your body, it is important to be aware of the potential risks involved. Sprouted nuts and seeds, including almonds, are significantly more susceptible to contamination by harmful bacteria such as Salmonella.

Studies indicate that nut butters derived from sprouted nuts, particularly sprouted almonds, may elevate the chances of foodborne illness. This is particularly relevant for pregnant women and individuals with weakened immune systems, who may want to avoid these products to ensure their safety. Additionally, both peanuts and tree nuts—like almonds (badam), walnuts, hazelnuts, cashews, pistachios, and Brazil nuts—can harbor toxic molds.

These molds generate mycotoxins, which are harmful compounds associated with a range of health issues, including digestive disorders and liver tumors. The likelihood of mold contamination is notably higher in raw, unsalted nuts compared to their roasted and salted counterparts. Experts attribute this to the high temperatures used in roasting and the reduced moisture content from added salt, both of which help mitigate mold growth.

Regulatory organizations, such as the Food and Drug Administration (FDA) in the United States and the European Food Safety Authority (EFSA), have established maximum allowable levels of mycotoxins deemed safe for consumption. If you have concerns regarding mold levels in almonds, it is advisable to check if your local regulatory body has set safe thresholds. In the absence of such guidelines, opting for roasted or salted almonds may be a prudent choice to minimize your risk.

The Bottom Line

Almonds can be categorized into two types: sweet and bitter. The sweet variety, commonly available in supermarkets, is generally safe for consumption. However, it is advisable for pregnant women and those with weakened immune systems to steer clear of sprouted sweet almonds to reduce any potential risk of foodborne illnesses.

In contrast, bitter almonds contain a natural toxin, which the body metabolizes into cyanide—a substance that can lead to poisoning and even fatality. Consequently, consuming raw bitter almonds is strongly discouraged. Interestingly, methods such as boiling, roasting, or microwaving bitter almonds might help decrease their toxin levels, potentially rendering them safer for consumption. Nevertheless, further research is essential to substantiate these claims.