David Brown
Feb 22 · 5 min read

Dr. Kassam,

In your Are Dairy-Free Diets A Risk To Bone Health? article you wrote, “ Dairy, including milk and cheese, is one of the top sources of saturated fat in the typical Western diet. Diets high in saturated fat increase the risk of heart disease, stroke and dementia.”

I would point out that T. Colin Campbell, the scientist who coined the phrase plant-based diet, has a different take on saturated fat. In a 2016 article entitled “Plant Oils Are Not a Healthy Alternative to Saturated Fat” he said, “The evidence that saturated fat is a major cause of heart disease, and possibly certain cancers, arises primarily from studies showing a high correlation between saturated fat-laden diets with more heart disease. This is a classic case where correlation does not necessarily mean causation, a serious misinterpretation. Blindly accepting saturated fat as the causation of heart disease was a mistake. It is not biologically plausible, and this relationship should have been questioned.” https://nutritionstudies.org/plant-oils-are-not-a-healthy-alternative-to-saturated-fat/

What, then, is the biologically plausible explanation for heart disease? Excerpt from a 1988 book entitled “The Reverse Effect” by Walter A. Heiby: “It will soon become increasingly clear that, although arachidonic acid plays a useful role in body chemistry and is present in body tissues greatly in excess of any other long-chain polyunsaturated fatty acid, I do not think it’s presence should be encouraged either from dietary sources or via endogenous production. According to A. L. Willis, arachidonic acid is the most common polyunsaturated fatty acid in most meat products, a fact that lends support to vegetarianism.” (I would have said, “…a fact that lends support to limiting meat consumption.”)

Curious about A. I. Willis, I did a web search using A. I. Willis in conjunction with arachidonic acid and found an interesting article entitled Addition of Eicosapentaenoic Acid to γ-Linolenic Acid–Supplemented Diets Prevents Serum Arachidonic Acid Accumulation in Humans The Discussion at the end of the article contained this paragraph.

“A potentially important side effect of GLA supplementation is elongation of GLA to DGLA and further desaturation via Δ-5-desaturase to arachidonic acid (AA) by enzymes in the liver. This causes a marked increase in serum AA levels. In a previous study of AA supplementation in humans, similar increases in serum AA levels were associated with an increase in the in vivo aggregation of platelets (Seyberth et al.1975). This increase in platelet sensitivity raised concerns about potentially harmful cardiovascular side effects and the long-term safety of any dietary strategy that increases serum AA levels, including those current formulations being sold in nutraceutical markets.”

Vegans need not be concerned about consuming too much arachidonic acid. However, it’s precursor, linoleic acid can be problematic for vegan health. Excerpt: “Long term vegetarianism can lead to genetic mutations which raise the risk of heart disease and cancer, scientists have found. Populations who have had a primarily vegetarian diet for generations were found to be far more likely to carry DNA which makes them susceptible to inflammation. Scientists in the US believe that the mutation occurred to make it easier for vegetarians to absorb essential fatty acids from plants. But it has the knock-on effect of boosting the production of arachidonic acid, which is linked to inflammatory disease and cancer. When coupled with a diet high in vegetable oils — such as sunflower oil — the mutated gene quickly turns fatty acids into dangerous arachidonic acid.” https://www.telegraph.co.uk/news/2016/03/29/long-term-vegetarian-diet-changes-human-dna-raising-risk-of-canc/?WT.mc_id=tmg_share_tw

Here in the United States, the American Heart Association promotes excessive linoleic acid consumption. Excerpt from a 2012 article entitled “A controversy over a dietary recommendation for omega-6 fatty acids shows no sign of resolving itself”.

“Is a particular dietary recommendation harming people in the U.S.? For almost 20 years, scientists have been arguing over whether Americans and others on a typical Western diet are eating too much of omega-6s, a class of essential fatty acids. Some experts, notably ones affiliated with the American Heart Association, credit our current intake of omega-6s with lowering the incidence of cardiovascular disease. Others, which include biochemists, say the relatively high intake of omega-6 is a reason for a slew of chronic illnesses in the Western world, including asthma, various cancers, neurological disorders and cardiovascular disease itself.” http://www.asbmb.org/asbmbtoday/asbmbtoday_article.aspx?id=18365

Quote from a 2014 American Heart Association study: “A 5% of energy increment in LA intake replacing energy from saturated fat intake was associated with a 9% lower risk of CHD events and a 13% lower risk of CHD deaths.” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4334131/

Typically, studies of this sort demonstrate, at best, a 30% reduction in heart disease morbidity and mortality. Compare that with the Lyon Diet Heart Study, the only human trial in which linoleic acid was reduced to about half of current average intakes. The result was a 70 percent reduction in heart attack deaths. At a the 2010 ISSFAL Dinner Debate scientists “All agreed that a 5-year randomized controlled trial comparing the effects of historically low (2%) with currently high (7.5%) linoleic acid intakes on cardiac endpoints would address the knowledge gap about the effects of different omega-6 PUFA intakes on the risk of heart disease.”

On a personal note, in my own quest to understand how nourishment works I made mistakes. I’ve been reading nutrition literature for more than 40 years. During the first three decades I ate too much mayonnaise, soybean oil, and peanut butter. I endured months of pain from a leg ulcer and years of pain from varicose veins. (Web search — linoleic acid varicose veins) More recently, excessive arachidonic acid intake from making sandwiches with 99% fat free turkey slices caused shoulder pain, weight gain, and a chronic cough during the cold months. About two years ago I switched to cheese and am now at my summer weight, have normal blood pressure, my chronic cough is gone, and I haven’t had a cold in almost three years.

Clearly, the vegan approach can be therapeutic in terms of correcting metabolic problems. But it isn’t the answer for everyone. Bill Clinton was obliged to add back some animal products to maintain the gains he enjoyed while eating a vegan diet. Excerpt from a 2014 New York Times article:

Nine years ago, on their 30th wedding anniversary, Hillary Rodham Clinton gave her husband a gift she hoped would ensure many more years together: Dr. Mark Hyman. Dr. Hyman was charged with helping the former president after a 2004 quadruple bypass surgery. In the time since, the doctor has become part of the Clintons’ circle of friends and advisers, but one with an important difference. The Clintons, after all, have a small army of aides who offer political and policy advice, but not many who can tell a former and potential president to lay off the ranch dressing. One of the first things Dr. Hyman did was to wean Mr. Clinton off his previously prescribed vegan diet. Despite persistent news media reports that he is vegan, Mr. Clinton does occasionally eat fish and lean protein. “It’s hard being a vegan to eat enough good, quality protein and not have too much starch,” Dr. Hyman said over lunch at the Four Seasons restaurant in New York. “I know a lot of fat vegans.” https://www.nytimes.com/2014/04/13/fashion/dr-mark-hyman-clintons-health.html

I hope you found this information helpful.

Dave Brown