When vegan is not enough. Nina and Randa have been vegan all their lives. Listen to their story when they went travelling and began eating a more high-fat, heavily processed vegan diet. Both of them broke out in severe acne. When roaccutane was the only other option, they adopted a very low-fat McDougall starch-based diet and their acne began to improve within days. See Success Stories below for the written story to accompany video.

Although acne is not a life threatening or serious disease in a physical sense, it can still cause considerable personal distress and lead to social isolation and depression. It used to be considered as a condition associated with hormonal changes during teenage years but this may be changing, with many continuing to suffer from acne through their twenties and beyond. Severe acne, if left untreated, can result in permanent scarring.

While medications have their place in the treatment of acne, most acne can be managed by lifestyle changes which treat the cause of the disease – and diet is the most important of these. Many dermatologists and endocrinologists, as well as some sectors of the food industry downplay the link between diet and acne. One study that was often quoted to support the myth that diet has no effect on acne was a study of teenagers which compared the effect of adding a chocolate bar to the usual diet versus a confectionery bar – of course with such minimal change to the overall diet, there was no difference in acne.

The process of acne works something like this: it begins with the excess production of skin oil (sebum) and an overgrowth of the cells that line the ducts that carry this oil to the skin surface. The ducts become blocked and oil collects under the skin and becomes infected with skin bacteria. The mixture of oil and bacteria is highly inflammatory and produces the characteristic red lumps and pustules of acne.

It has often been said that acne is caused by hormones rather than diet. While it is true that acne is the result of excessive levels of androgens (those hormones with testosterone-like effects) and IGF-1 (insulin-like growth factor), it is the rich Western diet that causes these hormones to become elevated to unnatural levels. The effects of diet further accentuate the natural increase in androgens during adolescence and the higher androgen levels of young adults. Elevated androgen levels are also a feature of polycystic ovary syndrome (PCOS), a diet-related condition that many now consider to be a metabolic disease like type 2 diabetes.

The hormone IGF-1 (insulin-like growth factor) plays a key role in acne. There is a complex interaction between IGF-1, insulin and the reproductive hormones that results in increased androgen hormone activity throughout the body. IGF-1 is a growth hormone which stimulates cell proliferation and inhibits the death of cells that are no longer needed. Dietary factors that raise IGF-1 levels are thought to stimulate cancer growth as well as acne. The proteins in cow’s milk are a potent stimulus for the liver to produce more IGF-1. The growth promoting hormonal effects of milk are not unexpected as it is really ‘baby cow growth fluid’. Several large observational studies have found an association between dairy consumption and acne. This is, of course, disputed by the dairy industry. More recently there was a published report of several cases of severe teenage acne associated with whey protein supplements.

Cow’s milk also delivers estrogen hormones directly. Cows are now milked during pregnancy when estrogen levels are high, resulting in significant estrogen levels in the milk which gives consumers an unintended hormone supplement.

Animal protein-rich diets, even without dairy foods, cause elevated IGF-1 levels. And although calorie restricted diets or intermittent fasting have been found to lower IGF-1 levels, a vegan diet is associated with the lowest IGF-1 levels. Plant proteins don’t appear to elevate IGF-1 in the same way that animal proteins do. However high intakes of concentrated soy protein do seem to raise IGF-1 and it is possible that other vegan protein supplements may have a similar effect. Protein supplements are unnecessary and those with acne may benefit by avoiding them.

The hormone insulin also plays a role in acne as well as PCOS and of course, diabetes (type 2). High fat, calorie rich diets, particularly those high in meat, lead to the development of insulin resistance. The resistance to insulin is largely the result of fat-laden muscle cells no longer removing glucose from the blood in response to insulin. The body responds by producing even more insulin and this in turn leads to elevated androgen levels. There is some research suggesting that a low GI (glycaemic index) diet improves acne, presumably through reduced insulin levels.

It may seem intuitive that eating less carbohydrates might reduce insulin levels but this is not the case – a diet based more on fats and/or meat leads to increased insulin resistance. Diabetes research demonstrates that the most effective diet for reducing insulin resistance is a low fat, whole foods plant-based diet (Barnard et al 2009) .

Inflammation plays a role in many diseases including acne. It is the excessive inflammatory response to the trapped oil and bacteria that is responsible for the features of acne. The effectiveness of long term antibiotics for acne is thought to be due, in part, to their anti-inflammatory actions rather than their anti-microbial actions. Animal products, vegetable oils and processed foods promote inflammation throughout the body by multiple mechanisms. Whole plant foods – vegetables, fruits, whole grains and legumes – not only lack these pro-inflammatory effects but contain many phytochemicals that have potent anti-inflammatory effects. While some of these may be due to non-specific free radical scavenging effects, others act directly on some of the key cellular mediators of inflammation such as NFkb. A truly high intake of whole plant foods will alleviate acne and for those with fair skin, replace it with a healthy orange glow.

Sometimes a vegan diet is not enough to control acne. Fat-rich, calorie dense nut products and vegetable oils have become a common feature of modern vegan diets, while whole grains and vegetables have been in retreat. This is particularly true when eating out. The video under Success Stories below is a good illustration of how a rich vegan diet caused severe acne in two young vegan women and how they cured it by adherence to a low fat, whole foods, plant-based diet.



  • Nina and Randa Nelson – Clear Skin Crusaders – Plant Strong Podcast, Season 2 Episode 11 **NEW**
  • Dr. Niyati Sharma on the Connection Between Diet and Skin (1hr 13 min podcast) – Veggie Doctor Radio Episode 27
  • McDougall Message: Acne & Your Diet – In this video, Dr. John McDougall debunks the original study that suggested that diet had no effect on acne and then explains how dairy foods cause acne.
  • Skim Milk and Acne – This video looks at three Harvard studies that found a link between dairy consumption and acne in adolescent boys and girls. As with all videos, you will find links to the original studies under ‘Sources Cited’.
  • National Dairy Council on Acne and Milk  – This video discusses the observed association between milk consumption and acne published in the Journal of the American Academy of Dermatology. It then considers the natural hormones in milk and how these might cause acne. The presenter also raises the issue of drinking milk from pregnant cows.
  • The Acne-Promoting Effects of Milk – This short video discusses a publication on the insulin increasing effects of cow’s milk and the absence of acne in non-milk drinking societies. It is stated that the hormone signalling system of mammalian milk is exclusively designed for early infancy, and that the “chronic abuse” of this signalling system may be the cause of acne and many more serious chronic diseases.

Peer-reviewed articles:

Success stories

Page created 10 January 2013
Last updated 5 April 2017