‘Good fats’ has become an overused almost meaningless health label.

We advocate a  whole food plant-based diet – a diet built mainly on whole grains, legumes, vegetables, and fruits. This is a low-fat diet because most of the energy these foods provide is in the form of carbohydrates and proteins with only a small contribution from fat. It’s the dietary pattern with evidence for reversal of heart disease and insulin resistance and is of low caloric density, assisting weight loss. The macronutrient ratio (typically >70% carbohydrate, 10-15% protein, 10-15% fat) is a consequence of the composition of our core foods rather than the macro ratio determining our food choices.

“But what about good fats?” is a question or objection often raised when we describe our low-fat dietary approach and the amazing health results we see when people eat this way. People love their fat-rich foods, and the dairy, olive oil and nut industries have successfully dismantled the low-fat diet paradigm during the preceding couple of decades. ‘Good fats’ have gained de facto status as a food group and even many plant-based foodies seem to regard ‘good fats’ as an essential component of every meal. In mainstream nutrition Australians are being encouraged to add hundreds of calories of olive oil to their meals every day in the name of ‘good fats’. Has anyone paused to consider what a ‘good fat’ is? It would seem not when we review the composition of many of these so-called good fats.

Criteria for a ‘good fat’

Whole food: Our first criterion for a ‘good fat’ is that the fat is in the context of a whole food. Vegetable oils and margarine are not ‘good fats’ because they have lost all the fibre and most of the nutrients of their plant of origin (see our No Oil page).

Low in saturated fat: ‘Good fats’ are good because bad fats – i.e. saturated and trans fats – are bad for our health. Any ‘less bad’ fat than these are usually labelled a ‘good fat’ by nutritionists. We can sideline trans fats because they have been largely eliminated from ultra-processed foods, leaving ruminant meats and dairy as the primary dietary source. Saturated fats are widespread in both plant and animal-derived foods. The issue is how much saturated fat does it take to lose the ‘good fats’ tick of approval? The commonly accepted upper healthy limit of saturated fat intake is 10% of total dietary calories. The American Heart Association recommends an even lower target of 5% to 6% of calories from saturated fat. Adding in more calories from foods with a greater percentage of saturated fat than this (e.g. olive oil or avocado) is never going to get us to these targets. How do some common ‘good fats’ compare to these criteria?

Saturated fat as a percentage of total calories:

 

Olive oil, avocado, and many nuts owe their ‘good fats’ label to their high monounsaturated fat content. Monounsaturated fats have a neutral effect on blood cholesterol and metabolic health. We have no requirement for monounsaturated fats other than as a source of calories (energy). Plants with a high monounsaturated content may qualify as ‘good fats’ if they meet our criteria.

Essential fat ratio: The only ‘good fats’ that are essential are two groups of polyunsaturated fats, the omega 6 and omega 3 series. Human requirements for these amounts to only a few percent of daily energy intake and clinical deficiency is extremely rare. What may be more relevant is the ratio (omega-6: omega-3) as the two groups are transformed within the body by the same enzymes, and too much of one may compromise conversion of the other into the long chain form. The modern diet has become skewed towards the omega-6 group, far from the optimal ratio of 4:1 or less. This is thought to contribute to long-term adverse health outcomes. Omega-6 fats are widespread in grains, nuts, seeds, and oils and are more often present in the diet in excess. In contrast, few foods are high in omega-3 fats. The omega-6 to omega-3 ratio of the total dietary pattern is important, rather than that of individual food items. One could eat some high omega-6 meals and counterbalance these with other meals of higher omega-3 content. However, anticipating that something else will compensate for what’s currently on our plate can be a slippery slope in nutrition. Giving the ‘good fats’ tick to foods low in omega 3’s may take people further from an optimal fat ratio. Our final criterion for the ‘good fats’ label is that the item has an omega 6 to omega 3 ratio supporting a total dietary ratio of 4:1 or less. Many foods promoted as ‘good fats’ do not meet this criterion.

Omega 6 to omega 3 ratio in foods of moderate to high fat content:

*Green leafy vegetables are low in fat therefore it takes a lot of them to have a meaningful effect on your omega-3 intake.

The aim of this article was to bring nutrition science into the ‘good fats’ meme to help you make healthier food choices, regardless of where you are on the fats-starches continuum of whole foods, plant-based nutrition. Some individuals and groups may benefit from eating more ‘good fats’ to maintain an adequate calorie (energy) intake. Our personal low-fat, WFPB diet includes ground flaxseed, a few walnuts, a little peanut paste, and tahini as condiments.

Our ‘good fats’ tips:

1. Source ‘good fats’ from whole foods or minimally processed whole foods.
2. Limit consumption of ‘good fats’ with a higher saturated fat content, particularly if you have heart disease or type 2 diabetes.
3. Choose ‘good fats’ with a lower omega 6:3 ratio.
4. Balance higher intakes of omega 6 predominant ‘good fats’ with increased omega 3 foods.
5. Be mindful that high-fat foods are calorie-dense and good for weight gain.

Related pages:

• Why do we recommend a low-fat diet?
• Omega 3 Essential Fatty Acids
• No oil!
• What’s wrong with saturated fat?
• Energy density
• Low fat diets for weight loss

Resources

• Australian Food Composition Database – Click on ‘Searchable database’ to search for data on the nutrient content of Australian foods.
• FoodData Central – Search for US food data.

 

Page created 30th December 2023
Last updated 5th January 2024

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

• Omega 6:3 ratios
• Resources

A whole foods, plant-based diet provides adequate quantities of omega 3 essential fatty acids. With this dietary pattern, supplements are unnecessary and may be harmful. The alleged health benefits of omega 3 supplements is largely marketing hype and recent research has even questioned the long standing dogma that omega 3 supplements are heart protective. Humans are able to efficiently utilize the type of omega 3’s found in plants. However, excessive dietary omega 6’s inhibits the conversion of these plant omega 3’s into DHA and EPA long chain omega 3’s. Therefore, the ratio of omega 6’s to omega 3’s in the diet may be more important than the total amount of omega 3’s.

Our solution to ensuring optimal omega 3 function is to avoid vegetable oils completely, moderate consumption of most nuts and avocados and consume generous quantities of green leafy and other vegetables. Flaxseed and chia seeds are extremely rich sources of omega 3 fats and the addition of small amounts of these foods to your diet will ensure that your omega 3 intake is more than adequate.

Essential fats

It is often stated that we need fats in our diet and that there is no such thing as a no fat diet. While this is true, adding vegetable oils and high fat foods to the diet is not necessary. All whole plant foods contain small amounts of fats and the diet we advocate provides approximately 10% of calories from the fat, a fair proportion of which are essential fatty acids. This easily meets the human requirement for essential fatty acids (there is no absolute requirement for other fats in the diet).

There are two classes of fatty acids which are essential nutrients – omega 3 and omega 6 fatty acids, and these can only be synthesized by plants. All of the omega 3 oils in the food chain originate from plants. Both plant-based and omnivorous diets provide plenty of omega 6 fats so there is no hype and few supplements for this type of essential fat. While most people equate omega 3’s with fish, they are widely present in plants, with some plants being very rich sources. However the omega 3 fatty acids in plants are present as alpha-linolenic acid (ALA) while the active form in humans and other animals are the longer chain EPA and DHA.

CLASS       PLANT FORM                    ANIMAL FORM
Omega-6    linoleic acid (LA)                 arachidonic acid (AA)
Omega-3    alpha-linolenic acid (ALA)   eicosapentaenoic acid(EPA)
docosahexaenoic acid (DHA)

AA and EPA/DHA are substrates for cell membrane components and a large group of signaling molecules called eicosanoids that have powerful local effects in many different organs. The omega 6’s tend to promote inflammation and blood clotting and over production is associated with chronic disease whereas the omega 3’s tend to have the opposite effect. The AA found in animal products is one of the features that makes these foods pro-inflammatory. The anti-inflammatory, anti-thrombotic effect of omega 3 derived molecules provides a theoretical framework for therapeutic use of EPA/DHA supplements, although clinical trials with these supplements have found limited benefits.

We have an enzyme that can convert the ALA (from plants) into the EPA and DHA (active form) with reasonable efficiency. The problem is that this same enzyme also processes the other class of essential fatty acids, the omega 6 fatty acids, and the two classes of fatty acids are said to “compete” for this enzyme. An overload of omega 6’s will therefore reduce the activation of plant omega 3’s. We actually need more dietary omega-6s than omega-3s but not too much more. It is recommended that the current vegetarian and vegan intake (13:1) be reduced to 4:1 or less. This ratio is more important than the actual quantity of omega 3 fats in the diet.

The usual Australian diet is low in vegetable sources of omega 3’s and has huge quantities of omega 6s from vegetable oils. The solution is to avoid vegetable oils completely, moderate your intake of most nuts and avocados (which are high in omega 6’s) and to eat generous quantities of green leafy and other vegetables. Flaxseed, chia seeds are extremely rich sources of omega 3 fats and the addition of small amounts of these foods to your diet will ensure that your omega 3 intake is more than adequate. Walnuts and hemp seeds are a moderately rich source of omega 3’s. Eat the whole seed rather than just the oil – flaxseed for example is also rich in other substances known to promote health such as lignans.

Omega 6 : omega 3 ratios of common foods:

Peanut              no omega 3
Sunflower oil     very high
Almonds          2000:1
Cashews           125:1
Avocado             15:1
Olive oil              13:1
Macadamia         6:1
Soybeans            6:1
Walnuts               4:1
Hemp seed         3:1
Canola oil           2:1
Green leafies*    1:1
Chia seed          1:3
Flax seed           1:4

*Green leafy vegetables are low in fat therefore it takes a lot of them to have a meaningful effect on your omega 3 intake.

You may read that our bodies cannot efficiently convert the plant omega 3 (ALA) into the animal (long-chain) omega 3 (EPA and DHA found in fish and lean meats). If this were true then it would make us obligate carnivores like cats who lack the ability to utilize plant forms of the omega 6 fatty acids and therefore must obtain arachidonic acid from meat. There is another viewpoint from which to consider the apparent inefficiency of EPA and DHA production in the human body and that is that we are not cold water fish. Our cell membranes are not meant to contain high levels of EPA and DHA except for a few special cell types. Creating abnormally high levels of any nutrient or substrate within the body always has consequences. High intakes of ALA from plants is safe because the body can choose how much to convert into EPA and DHA.

There is emerging evidence that there are health risks associated with high intakes of long chain omega 3s. There is an increased risk of diabetes associated with both fish oil supplements and high consumption of fish. Clinical trials of fish oil supplements have also found an increased risk of prostate cancer (see Sorongon-Legaspi et al 2013). High doses of fish oils inhibit the function of platelets (involved in blood clotting) and therefore increase the risk of serious haemorrhages.

The long standing belief that fish oil supplements reduce heart risk has been refuted by several recent studies including this one, n–3 Fatty Acids in Patients with Multiple Cardiovascular Risk Factors, published in the New England Journal of Medicine. The evidence for any other significant benefits from taking fish oil supplements is also becoming weaker. Fish oil is a concentrated source of fat soluble persistent organic pollutants such as PCBs. If you do choose to take a DHA/EPA omega 3 supplement you can use microalgae derived DHA. However, when eating a low-fat whole food plant-based diet with no added oils (which is a diet not too high in omega 6s and that provides a healthful omega 6:3 ratio) then we consider it not necessary to take a long chain omega 3 supplement.

See related pages:

• Are hemp seeds a good source of omega-3?
• No Oil
• Vitamins and Minerals
• Why do we recommend a low-fat diet?

Resources

• Do vegans and vegetarians require a DHA supplement? – Dr Tim Radak (1hr video). Conference presentation in 2019.
• DHA: On Further Thought – Dr. Michael Klaper (20 min video)
• Do Vegans Need DHA Supplements? – Jeff Nelson (1hr video) Looks at the research around omega 3 fatty acids, including the body’s ability to convert omega 3 to the long chain form and the risks and benefits of DHA supplementation. 
• Are Omega-3 Supplements Necessary? – Dr Linda Carney
• Increased Omega-3 Fatty Acids Intake Useless for CVD – Pam Popper (12 min video). Pam regularly reviews the science on omega 3 supplements and continues to find there is no benefit in supplementing.
• No benefit of omega-3 supplements for depression or anxiety – Robyn Chuter (2019)
• Do You Need to Supplement With EPA and DHA If You Follow a Whole Food Plant-Based Lifestyle? – Dominic Marro, RD (2016)
• Omega 3 – Discussion by Jeff Novick, RD on the conversion rate of ALA in the McDougall Discussion forum
• NIH study shows no benefit of omega-3 or other nutritional supplements for cognitive decline (2015)

Peer-reviewed articles

• The Risk and Prevention Study Collaborative Group. (2013). n–3 Fatty Acids in Patients with Multiple Cardiovascular Risk Factors. New England Journal of Medicine, 368(19), 1800-1808 – “…there was no significant benefit of n−3 fatty acids in reducing the risk of death from cardiovascular causes”
• Chew, E. Y., et al. (2015). Effect of Omega-3 Fatty Acids, Lutein/Zeaxanthin, or Other Nutrient Supplementation on Cognitive Function: The AREDS2 Randomized Clinical Trial. JAMA, 314(8), 791-801.
• Hooper, L., et al. (2006). Risks and benefits of omega 3 fats for mortality, cardiovascular disease, and cancer: systematic review. BMJ, 332(7544), 752-760 – “…omega 3 fats do not have a clear effect on total mortality, combined cardiovascular events, or cancer”.
• Kaushik, M., et al. (2009). Long-chain omega-3 fatty acids, fish intake, and the risk of type 2 diabetes mellitus. American Journal of Clinical Nutrition, 90(3), 613-620 – “…higher fish and long-chain omega-3 fatty acid consumption appears to be associated with a modestly but significantly higher incidence of T2DM”
• Simopoulos, A. P. (2008). The importance of the omega-6/omega-3 fatty acid ratio in cardiovascular disease and other chronic diseases. Experimental Biology and Medicine, 233(6), 674-688.
• Sorongon-Legaspi, M. K., Chua, M., Sio, M. C., & Morales, M., Jr. (2013). Blood level omega-3 Fatty acids as risk determinant molecular biomarker for prostate cancer. Prostate Cancer, 2013, 875615.
• Welch, A. A., et al. (2010). Dietary intake and status of n-3 polyunsaturated fatty acids in a population of fish-eating and non-fish-eating meat-eaters, vegetarians, and vegans and the product-precursor ratio [corrected] of alpha-linolenic acid to long-chain n-3 polyunsaturated fatty acids: results from the EPIC-Norfolk cohort. American Journal of Clinical Nutrition, 92(5), 1040-1051.

Return to Vitamins and Minerals page

Page created 22 June 2013
Last updated 1 July 2019

• Resources

Specific vitamins, minerals and other nutrients:

• Vitamin B12
• Vitamin D
• Calcium
• Iron
• Iodine
• Omega-3 essential fatty acids
• Protein

Most vitamin and mineral supplements are of no benefit and some may be harmful. With few exceptions we recommend that you get your vitamins, minerals, fibre and other phytonutrients from minimally processed plant foods. The supplements that may be required are related to modern living conditions rather than any inherent deficiency of a plant based diet. Clean food and water and safe food handling, whilst preventing disease, may remove most of the bacteria-derived vitamin B12 from our food supply. Indoor living can deprive us of the UV rays that are required for vitamin D synthesis. Many people take supplements as an insurance policy against dietary inadequacy or to detoxify the effects of too many rich foods. Unfortunately, supplements neither emulate the benefits of nutrients from plants, nor detoxify the harmful effects of excess animal protein, fats and processed foods.

Whole food is complex (see ‘Whole’ by T Colin Campbell in resources below). Our understanding of it is very basic. We know which nutrients are absolutely essential for life and the approximate amounts required. We have identified only a small number of the thousands of other biologically active substances in plants (known as phytochemicals or phytonutrients). We know little of the interactions between these various nutrients and phytonutrients. Often a high intake of a particular nutrient from food is associated with a health benefit, such as less cancer, but when we give them as supplements rather than as whole foods the benefit may be absent or reversed, increasing cancer risk.

There are some medical conditions in which vitamin supplements can be used as a pharmaceutical. Several of the B group vitamins can assist in reducing high homocysteine levels and this has been shown to reduce the progression of the early stages of dementia (see VITACOG study). The dietary approach would be to remove the cause of the elevated homocysteine levels by reducing animal protein consumption. While on the topic of dementia, Dr Neal Barnard recommends a vitamin B12 supplement and advises against taking supplements that contain minerals such as iron, copper and zinc as high levels of these may damage the brain.

No particular food has exclusive ownership of any particular nutrient. You do not need dairy foods for calcium, red meat for iron or fish for omega 3 oils. You do not even need to know which foods are the “best” sources of any particular nutrient. You just need to eat enough calories of whole grains, legumes, vegetables and fruits to maintain a healthy weight. And if you wish to tweak your plant-based diet to include more omega-3s, iodine, resistant starch or any other nutrient or phytochemical then we suggest that you bypass the supplements and just find some whole plant foods rich in the particular phytonutrient and make them a regular part of your diet.

See video: Dr. John McDougall Medical Message: Vitamin Supplements

Last updated 11 April 2015