Joel Fuhrman thinks his Nutritarian diet will increase longevity and prevent or treat most chronic diseases. He claims it is based on science, but his evidence is far from convincing.
Joel Fuhrman, MD is a celebrity doctor, entrepreneur, and best-selling author whose latest book, Eat for Life, advocates his “Nutritarian” or micronutrient-rich diet. He calls the diet “the breakthrough nutrient-rich program for longevity, disease reversal, and sustained weight loss”. He says it is possible to never have a heart attack or stroke, to avoid dementia, to radically reduce your chance of getting cancer, avoid and heal digestive problems, resolve high blood pressure, heal auto-immune diseases, prevent and reverse diabetes and high cholesterol. He says it “amounts to a miracle in our modern world”.
If the diet could really do all that, it would be a miracle indeed! I wish it were true, but the book failed to convince me. He claims it is science-based, and he provides over 40 pages of references. In his mind the evidence is overwhelming and the science is settled, but it isn’t. He tends to assume the “associations” shown in many of his references are clear evidence of causation, but they aren’t. And the diet itself has not been evaluated in controlled scientific studies.
He is one of many who are convinced that the one true cause of disease is poor diet. He claims that if you eat right (i.e., follow his Nutritarian diet), you will be able to attain and maintain perfect health. You will never develop chronic diseases and if you already have those diseases the diet will reverse them.
The cause of aging
His view of what science has accomplished is mostly overly optimistic. Occasionally, one of his statements is more circumspect:
Scientific research suggests that biological aging is a treatable condition.
That’s more accurate, but he operates under the assumption that science has conclusively determined the cause of aging. The science of aging has suggested a large number of possible factors but has not conclusively determined which factors are actual causes and which are concomitants, results, or just correlations. The anti-aging researcher Jay Olshansky once said the secret to aging is that there is no secret.
He thinks science has determined that the four processes that drive aging are:
- chronic inflammation
- damage to DNA and proteins (including oxidative damage)
- cellular senescence (cumulative DNA damage leading to dysfunction and loss of ability to divide)
- reduced capacity for tissue repair (due to stem cell dysfunction)
He thinks science has established that these same processes (especially inflammation and oxidative damage) are also responsible for cancer, diabetes, obesity, dementia, and most other chronic diseases. He claims they are caused by eating excess calories and low-nutrient foods. He claims they can be effectively controlled by phytochemicals, caloric restriction, and exercise. The book doesn’t address exercise, and it assumes that calories will be restricted automatically when the emphasis is on micronutrients. It claims:
Caloric restriction with adequate micronutrient intake is the most consistent intervention that slows or hinders these hallmarks of aging therefore extending lifespan.
Is this true? A lawyer would object “assumes facts not in evidence”.
He says telomere shortening is one indicator of biological aging, in fact “telomere shortening is essentially cellular aging”. Maybe, but that’s still controversial. Correlation is not causation. Telomere shortening might accompany aging but not be the cause of aging. It is far from universal: in some animals, telomeres lengthen with age. And there is a species of bat whose telomeres don’t change with age; they live far longer than other bat species and are more resistant to disease.
Insufficient intake of vitamins and minerals?
He cites a study showing that Americans don’t get sufficient vitamins and minerals. It claims that over 60% of Americans have insufficient intakes of vitamins C, K, A, and calcium. That may not be accurate, since the study was based on self-reported estimates and estimated average requirements. Even if accurate, it did not show that insufficient intake had any significant impact on health. We don’t really know the optimum levels of micronutrients.
He fails to mention that the same study showed that a significant number of Americans exceeded the tolerable upper limits for some micronutrients.
He praises the vegan diet and the diets consumed in the so-called Blue Zones but acknowledges that vegans require supplements for adequate nutrition. His Nutritarian diet is essentially a new and improved vegan diet.
Foods to eat and foods to avoid
The Nutritarian diet requires eating these every day:
- A large salad
- At least a half-cup serving of beans/legumes
- At least three fresh fruits
- At least an ounce of raw nuts and seeds
- At least one large serving of green vegetables, steamed or as an ingredient in a soup or entrée
It prohibits these foods:
- Barbecued meats, processed meats, or red meat
- Fried foods
- Dairy (cheese, ice cream, butter, milk)
- Soft drinks, sugar, other sweetening agents, and artificial sweeteners
- White flour products
He claims that once you get used to the Nutritarian diet your tastes and food preferences will change. You will find it delicious and won’t miss the foods you used to eat. Maybe.
Testimonials, recipes, menus, etc.
The book is larded with enthusiastic testimonials from his patients. He claims no one who followed his diet ever had a heart attack. He offers help in the form of recipes and menus. And of course, he has developed products that he sells in his online store, including foods, supplements, multivitamins, salad dressings, superfood powders, nutrition bars, kale chips, and much more. They aren’t cheap, but he offers a discount for members.
Fuhrman invented the term “G-Bombs” as a mnemonic for the 6 best cancer-fighting foods: greens, beans, onions, mushrooms, berries, and seeds. If you eat these every day, will you avoid cancer? Maybe. But there’s no clear evidence. There’s no “breakthrough” here; these foods are included in most conventional diet advice.
Nutrient IQ scores
I was particularly annoyed by his table of Nutrient IQ Scores based on typical serving sizes. Cooked kale scores 112, tomatoes 60, an orange 19, salmon 5, eggs 4, skim milk 5, coffee 2, meats 0, and so on. This looks very sciencey and precise but that’s deceptive. He compiled these scores himself and they have not been validated. He says they are more reliable than the older ANDI scores that Whole Foods Markets have been using. ANDI stands for Aggregate Nutrient Density Index; it rated 34 nutrients by the amount per calorie. Guess who invented the ANDI scale? Joel Fuhrman himself!
Many foods with lower scores are known to be good for health. Coffee, which gets a score of 2, is known to be the number 1 source of antioxidants in the American diet, and his “G-bombs” score far lower than leafy greens. Giving meats a score of zero merely shows his vegan bias; meats are known to have many micronutrients.
He says the Nutrient IQ scores are for men; women should multiply the scores by 1.2, and children younger than 12 should multiply them by 1.75. How does he know this? In fact, how does he know any of this? There are more than 34 micronutrients, and they have not all been identified or quantified. We don’t know which ones are in which foods, and we certainly don’t know the optimum amounts of each or how they affect health.
At one point, Fuhrman himself admits that it is not enough to just track these scores; a healthy diet should include some items not high on the list or not on the list at all.
Conclusion: Insufficient evidence
Fuhrman makes extraordinary claims for the Nutritarian diet, but extraordinary claims must be supported by extraordinary evidence, and the evidence he presents is far from compelling. When I reviewed Craig Good’s book Relax and Enjoy Your Food I found his advice far more reasonable. After all, food is not just for nutrition. It is one of the great pleasures of life and its social and cultural connotations are important too.
Is Fuhrman’s diet healthier than the standard vegan diet or the Mediterranean diet? We simply don’t know yet. Where are the controlled studies comparing their objective results?
A Nutritarian diet requires a lot of time invested in shopping and chopping and it’s very restrictive. I don’t think most people would find it palatable or would be able follow it long term. I eat kale but don’t particularly enjoy it; I found his recipes and menus unappetizing, and I’m not convinced that it’s in my best interest to give up meat and dairy entirely.
Betty White, who was in pretty good health until her death at age 99, would have disagreed with Fuhrman. When asked about her secret to longevity, she said “I try to avoid anything green”.
This article was originally published in the Science-Based Medicine Blog.