Australia lagged the rest of the world in approving the sale of hemp seeds for human consumption in late 2017. Prior to this, the sale of hemp seeds was legal, provided it was for use in cosmetics or another non-food use. Hemp seeds are produced from non-intoxicating varieties of the hemp plant and do not contain significant cannabinoids.

Hemp seeds will become widely available from 2018 and there will be many new products coming onto the market and many nutrition claims, possibly ‘superfood’ status. As with any other edible seeds, we recommend that if you are going to eat hemp seeds, that you eat whole or ground seeds and not processed food products such as hemp seed protein and hemp seed oil.

We have reviewed the nutrition composition of hemp seeds and compared them to several other nuts and seeds, particularly regarding their omega 3 essential fatty acid content. The USDA data that we used was similar to the nutrient data listed on two different brands of hemp seed in retail outlets.

Protein and other nutrients:

• Hemp seeds are much higher in protein (22% of calories) than flax or chia but lower than legumes.
• Flax and chia are far higher in dietary fibre than hemp and the fibre in flax (lignins) assists the body to excrete excess estrogens.
• The calcium content of the seeds ranged from very high for chia, moderate for flax and low for hemp.

Omega 3’s (alpha linolenic acid):

Many people have sub-optimal intakes of omega 3’s and perhaps more importantly, unfavourably high ratios of dietary omega 6 to omega 3. This is the result of low intakes of omega 3 rich plants combined with high intakes of omega 6 rich plants such as nuts, seeds, avocados as well as vegetable oils. An optimal omega 6 to 3 ratio is 4:1 or less.

For a whole food omega 3 source to bring the dietary omega 6 to 3 ratio into balance, it needs to have a ratio well below the target of 4:1. Flax (ratio 1:4) and chia (ratio 1:3) have more omega 3’s than 6’s and are therefore excellent sources of omega 3 fats. Hemp seeds (3:1) and walnuts (4:1) might be considered good sources on their own, but not good enough to compensate for the omega 6 rich foods in the typical plant-based diet. For more on omega 3’s see our Omega-3 Essential Fatty Acids page.

The following table gives comparative data for four high omega 3 nuts and seeds:

Per 100 g	Flax	Chia	Hemp	Walnut
Calories	534	490	553	765
Fibre (g)	27.3	37.7	4.0	7.8
Protein (g)	18.3	15.6	31.5	17.8
Calcium (mg)	255	631	70	115
Carb: Fat: Protein (% Cal)	22:66:12	36:53:11	6:72:22	9:83:8
Omega 3 (g)	22.8	17.5	9.3	8.7
Omega 6 (g)	5.9	5.7	30.9	27
Omega 6 : 3 ratio	1 : 3.9	1 : 3.1	3.1 : 1	4.1 : 1

The Australian recommended intake range of omega 3 fatty acids is 1-2 grams per day (see Nutrient Reference Values for Australia and New Zealand).
This is met by consuming 10g flax or chia per day.

Hemp seeds have a more favourable fatty acid profile than most other nuts and seeds but fall well behind flax seed and chia seed as a concentrated source of omega 3 fats. They have a mild taste and relatively soft texture which makes them suitable as an ingredient in a variety of dishes. Hemp seeds, like other nuts and seeds, can be a healthy addition to a whole foods, plant-based diet but are best consumed in small amounts.

See also:

• Omega-3 essential fatty acids

Resources

• National Health and Medical Research Council. (2006). Nutrient Reference Values for Australia and New Zealand: Including Recommended Dietary Intakes. Canberra: NHMRC
• USDA Food Data Central

Page created 26 February 2018
Page last updated 2 March 2018

It is generally best to chew your fruit and vegetables. While smoothies and juices can have a role in short term dietary programs and as a minor component of the overall diet, we don’t recommend them as a significant source of calories in the long term.

There are more positives in favour of smoothies rather than juicing. Smoothies are more nutritious than juices because the fibre, and any nutrients attached to the fibre, are retained rather than discarded. Consuming fruit and vegetables as smoothies is better than not consuming them at all and having a smoothie for a meal on the run may be better than skipping a meal. If you are sick or debilitated and unable to eat enough then smoothies may be a means of consuming extra calories and nutrients.

Juice fasting and smoothie detoxing seems to be a useful short term strategy for making a complete break from animal products, processed foods, fat, salt and refined sugar (as seen in Fat, Sick and Nearly Dead). However, a smoothie can become a high calorie sugary drink if a lot of fruit is added to disguise the bitter taste of some raw vegetables. Drinking smoothies and juices displaces starchy whole plant foods from the diet. Because whole grains and legumes are strongly associated with good health, it is of concern when people routinely replace a meal with a smoothie – it means there is at least one meal each day where no grains or legumes are consumed.

The popular concept of supercharging the body with phytonutrients has led to more juicing and smoothies. It based on the belief that more nutrients is always better and that an unhealthy diet can be offset by supplements and super-foods. The research evidence only consistently supports the health benefits of eating more plants. Whole plant foods provide the optimal level of nutrients.

A smoothie is smooth because the blender smashes the structure of food into tiny bits, breaking up the fibre of the cell walls and liberating natural sugars into the emulsion. This freeing up of sugars may cause the body to handle them in a less health supporting way, more like refined sugars, such as fructose, rather than the slow release sugars in whole fruits and vegetables. Digestion is a complex process, only partially understood, and altering one part of the process, such as chewing and the action of saliva, is bound have unexpected repercussions. One example of this complexity is the postulated nitric oxide enhancing effect of chewing nitrate containing vegetables which may improve endothelial function.

So, enjoy a smoothie occasionally as a treat or short-term therapy, but otherwise….. CHEW YOUR FOOD.

Resources

• Blending Up the Smoothie Controversy – Dr Linda Carney
• Dr Esselstyn FAQ on smoothies 
• Are Smoothies Good or Bad? – Thomas Campbell, MD
• To smoothie or not to smoothie? The skinny on blending your fruits and greens – Lani Muelrath
• Why I Stopped Drinking Green Smoothies – Happy Herbivore (Lindsay Nixon)
• The Downside of Green Smoothies – (6 min. video) Dr Michael Greger. See also the other 4 videos of the series.

Jeff Novick, RD answers questions about juicing on the McDougall discussion forum:

• Fruit juice: Just another sugary drink?
• Green smoothies
• Calories, Calorie Density, Fiber, Blending and Juicing
• Cooking vs blending

Page last updated 1 November 2016

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