What milk alternative should you not drink? The expert guide to smart dairy-free choices

November 5, 2025 •

5 min read

The plant-based milk market has surged, yet experts warn that not all alternatives are created equal, with some options containing more sugar and fewer nutrients than traditional dairy. This guide helps you navigate the choices and understand what milk alternative should you not drink for your health goals.

Quick Summary

Several milk alternatives carry risks due to high sugar, low protein, additives like carrageenan, or contaminants like arsenic in rice milk. Choosing an unsweetened variety with minimal ingredients is crucial for a healthy diet.

Key Points

Rice milk is not for children: The high inorganic arsenic content makes rice milk unsuitable for infants and young children and a concern for high-consumption adults.
Avoid excessive added sugars: Flavored and sweetened milk alternatives can contain significant amounts of added sugar, which contributes to poor health outcomes.
Check for unhealthy additives: Look out for thickeners and emulsifiers like carrageenan and various gums, which can cause digestive issues in some individuals.
Soy milk interacts with thyroid medication: Individuals with hypothyroidism should be mindful of soy intake, as its isoflavones can interfere with thyroid medication absorption.
Low-protein nut milks are not a dairy substitute: Unsweetened almond and cashew milks offer very little protein and are nutritionally inferior to dairy for growth and muscle health unless supplemented.
Beware of inflammatory oils: Some brands add inflammatory seed oils like canola or sunflower oil for texture, which is a key ingredient to avoid.
Prioritize reading labels: The best way to identify a healthy milk alternative is by checking the ingredients for simplicity, lack of sugar, and beneficial fortification.

The hidden risks in seemingly healthy alternatives

While many people choose plant-based milk for health, environmental, or ethical reasons, it's crucial to look beyond the marketing and examine the ingredients list. Many commercially produced milk alternatives contain additives that can have adverse health effects, transforming a potentially healthy beverage into one with hidden risks.

The truth about additives

Some of the most concerning additives function as emulsifiers, thickeners, and preservatives. Carrageenan, derived from red seaweed, is a common stabilizer used to create a creamy mouthfeel and prevent separation. However, animal studies have linked it to intestinal inflammation and digestive issues. While the FDA considers it safe in food-grade form, some health experts and consumers still prefer to avoid it, especially if they have sensitive digestion. Gums, such as xanthan, guar, and gellan gum, serve a similar purpose to carrageenan. For some, these additives can lead to gastrointestinal discomfort, including gas, bloating, and diarrhea. Lastly, some brands add inflammatory seed oils, like canola or sunflower oil, to enhance texture. These oils are high in omega-6 fatty acids, and an unbalanced intake can contribute to inflammation. To avoid these ingredients, look for brands with shorter, simpler ingredients lists or consider making your own plant-based milk.

The sugar trap

Many flavored and 'original' milk alternatives are loaded with added sugars to make them more palatable. A single serving can contain significant added sugar, especially in varieties like vanilla or chocolate. This is problematic for those trying to manage their weight or blood sugar, such as people with diabetes. Always opt for unsweetened varieties and check the nutrition facts label carefully. Natural sugars from the base ingredient (e.g., oats) should also be considered, as they can still contribute to blood sugar spikes.

Specific milk alternatives to approach with caution

Certain types of plant-based milks have unique downsides that make them less than ideal for regular consumption, particularly for specific populations.

Rice milk and arsenic contamination

Rice milk is a poor choice for infants and young children due to concerns over inorganic arsenic contamination. Rice plants absorb arsenic from the soil more readily than other crops, and this toxic heavy metal can end up in rice products, including milk. While organic rice isn't guaranteed to have lower levels, the EU and other health bodies advise against giving rice drinks to children under five. Adults who consume rice products daily may also be at risk. Beyond this, rice milk is nutritionally weak, offering minimal protein and high carbohydrates that can cause blood sugar spikes.

Soy milk and thyroid considerations

Soy milk is often praised for its protein content, but it contains compounds called isoflavones, or phytoestrogens. For individuals with a healthy, well-functioning thyroid and adequate iodine intake, moderate soy consumption is generally considered safe. However, in people with pre-existing thyroid conditions, such as hypothyroidism or Hashimoto's, high soy intake could potentially interfere with thyroid function or medication absorption. Soy is also one of the top food allergens and can cause digestive issues in sensitive individuals.

Pea and oat milks: Navigating added ingredients

Pea and oat milks can be good options, but brand variations and added ingredients are key. Pea protein milk is rich in protein, but some manufacturers add vegetable oils for a creamier texture, increasing the omega-6 fatty acid content. Oat milk can be high in carbohydrates and may cause blood sugar spikes. Look for organic, unsweetened versions of both to minimize additives and control sugar intake.

Low-nutrient options: The case of almond and cashew

Nut milks like almond and cashew are generally low in calories and fat, but they are also notably low in protein. A single handful of the nuts themselves contains more nutrients than a diluted cup of the milk. While suitable for calorie-watchers, they are not a nutritionally adequate substitute for dairy, especially for growing children, unless fortified and supplemented with other protein sources. Some people also find cashews to be high in FODMAPs, which can be problematic for those with sensitive digestive systems.

Comparison of common milk alternatives


Feature	Cow's Milk (1%)	Soy Milk (Unsweetened)	Rice Milk (Unsweetened)	Almond Milk (Unsweetened)	Oat Milk (Unsweetened)
Calories (per cup)	100	80-110	120	30	~100
Protein (grams)	8	7-9	<1	<1	2-4
Carbohydrates (grams)	12	7-9	23	1	~16
Added Sugar	No	Watch labels	Watch labels	Watch labels	Watch labels
Key Concerns	Lactose, saturated fat	Thyroid issues (some), allergen	Arsenic, low protein	Low protein, additives	High carbs, additives

Note: Nutritional values can vary significantly by brand and fortification. Always check the label. This table focuses on unsweetened varieties, but many flavored options contain added sugars.

How to choose a better milk alternative

When selecting a plant-based milk, follow these steps to make a more informed choice:

Read the Label: Pay close attention to the ingredients list. Look for unsweetened options with the shortest ingredients list possible to minimize additives.
Opt for Calcium and Vitamin Fortification: Many plant-based milks lack the calcium and vitamin D found in cow's milk. Choose brands that are fortified and shake the carton well, as minerals can settle at the bottom.
Prioritize Protein: If you rely on your milk for protein, choose options like soy or pea milk. If you prefer nut or grain milks, ensure you get protein from other dietary sources.
Assess Personal Needs: Consider any allergies, sensitivities, or pre-existing health conditions (like thyroid issues or blood sugar control) that might make one alternative more or less suitable for you.
Consider Homemade: For complete control over ingredients, you can make your own plant-based milk at home using just the base ingredient and water.

Conclusion: Read your labels, know your needs

When choosing a milk alternative, the answer to what milk alternative should you not drink is often complex and depends on your individual health needs and the specific product. While rice milk carries the most significant red flag due to arsenic concerns, many options pose risks from hidden sugars and synthetic additives like carrageenan. By carefully reading nutrition labels, choosing unsweetened and fortified options, and considering your personal health profile, you can make a choice that truly supports your nutritional diet.

For more guidance on deciphering product labels, the Center for Science in the Public Interest provides useful insights.

Frequently Asked Questions

While the FDA approves food-grade carrageenan, animal studies have linked it to intestinal inflammation. For those with sensitive digestion, it's a common practice to avoid it, though its effects on humans are still debated.

Options like unsweetened soy and oat milk can be beneficial for gut health due to their fiber content. However, sensitivity to additives or high-carb content should be monitored based on individual digestive tolerance.

Yes, 'unsweetened' versions have no added sugar. However, some, like oat or rice milk, are naturally higher in carbohydrates and sugars than others, which can still affect blood sugar levels.

Yes, especially concerning inorganic arsenic levels. Health authorities advise against rice drinks for children under five due to higher risk from smaller body size and proportionally higher milk intake.

For individuals with pre-existing thyroid conditions, especially hypothyroidism, high soy intake might interfere with medication absorption or function. Separating soy consumption from medication timing by several hours is recommended.

Store-bought nut milks like almond and cashew are often diluted with water and the pulp is strained, removing much of the fiber and protein found in whole nuts. Fortification can add back some vitamins and minerals.

Look for organic, unsweetened varieties with minimal ingredients. You can also consider making your own milk alternative at home for complete control over the content.