While plant-based milk alternatives are advertised as healthy and wholesome, not enough research has been done in understanding the nutritional implications of drinking them in both the short and long term, according to the study, published in the Journal of Food Science and Technology.
Selecting the four most popular plant-based beverages – almond, soy, rice and coconut – they used on-pack nutritional data of several commercially-available brands per ingredient and compared them for average protein, carbohydrate, fat, vitamin and mineral content.
“It is quite clear that nutritionally soy milk is the best alternative for replacing cow’s milk in human diet,” they conclude. However, soy milk sales have been damaged by various issues including the ‘beany flavour’ and presence of perceived anti-nutrients.
“Though almond milk also has a balanced nutrient profile and much better flavour, the nutrient density and the total number of calories are not as rich as that of cow’s milk.”
When drinking almond milk, the scientists said that “care should be taken” to ensure that various essential nutrients are available through other sources in the diet in appropriate quantities.
Meanwhile, rice milk and coconut milk may be ideal for individuals that are allergic to soybeans or almonds but “cannot act as an ideal alternative for cow’s milk because of limited nutrient diversity”.
The review could help the readers in making an informed decision about introduction of plant milks in comparison to the traditional bovine milks, they wrote.
However, they called for additional research to fully understand the effect of various conventional and novel processing methods on the nutrient profile, flavour and texture of alternative milks.
Calcium levels in most of milk alternatives tended to be high – a result of post-processing fortification.
In the seven unsweetened almond milk brands, carbohydrate and protein content ranged from 0.25 to 3 g and 1 to 5 g respectively.
Soy milk performed well for carbohydrates (ranging from 3 to 8 g) and protein, which ranged from 7 to 12 g.
Meanwhile, rice milk, which is generally made by mixing milled brown rice and water, tends to contain more sugar than cow’s milk as the carbohydrates break down into sugars.
The researchers also pointed to some studies which show some commercial rice milks in the US to be 70% above safe World Health Organisation (WHO) levels for arsenic in drinking water, due to the natural presence of arsenic in rice.
“Nutritionally [rice milk] is very rich in carbohydrates ranging between 23 and 27 g with 26 g as the median. Proteins and fats are present in minute amounts.”
Although coconut milk is high in saturated fats, Vanga and Raghavan wrote that past studies have shown evidence that eating or drinking coconut milk can increase the high-density lipoprotein (HDL) levels, which help in reducing the harmful low-density lipoprotein (LDL).
The nutritional profile of coconut milk, as it is consumed in the West, however, may be reduced as storage time increases: past research has shown that lipid oxidation of thermally processed coconut milk can increase certain components such as aldehydes.
They said coconut milk is “completely unique” compared to the other milks as the calorie content was quite low. “But, the majority of these calories come from saturated fats as it contains no proteins and as little as 0.75 g of carbohydrates compared to 4–5 g of fats.”
Cows’ milk also provide minerals such as magnesium (32 mg), phosphorous (230 mg) and potassium (373 mg). Most of the alternative milks contained at least 50 to 70% of minerals with the exception of coconut milk, which had no phosphorous reported and rice milk and coconut milk which had lower amounts of potassium.
“Few brands of soy milk were found to contain even higher amounts of phosphorous and potassium compared to cow’s milk. Cow’s milk is also a very good source of vitamins. But, among alternative milks only soy milk contains comparable amounts of nutrients.”
Source: Journal of Food Science and Technology
“How well do plant based alternatives fare nutritionally compared to cow’s milk?”
Published online ahead of print, January 2018, Vol. 55, Issue 1, pp 10–20
Authors: Sai Kranthi Vanga, Vijaya Raghavan