Overall summary: Dr Barnard emphasizes hormone regulation via food choices. In particular, for estrogen regulation, high fiber intake and low fat is important. Where is fiber found? Exclusively in plants (especially unprocessed plant foods)! So on the whole, he presents arguments in favor of a Low-Fat, Whole Food, Plant-Based diet.

(Offset 1:56) Foods for fertility?

Summary of Dr Barnard response: Hormones influence fertility; hormones can be dialed up or down by foods we consume!

(Offset 4:03) What is the relationship between fat cells in body and fertility?

Summary of Dr Barnard response: Fat cells are not bystanders; they are active biological systems — they actually produce estrogen!

Fat cells produce estrogen in men too. Men with extra estrogen tend to develop breasts ("man boobs"). Dr Barnard emphasizes that it's not the soy that results in these developments; it's the fats we're consuming and the fats in our bodies.

(Offset 6:22) Is thinner better for fertility?

Summary of Dr Barnard's reply: If we are really really thin, ovarian function shuts down. Some athletes who work out too much face fertility problems. Explanation: BMI in 18.5 to 25 is healthy. But for fertility, BMI in 19 to 21 is ideal. If BMI is 16 or 17, we're too thin. Dr Barnard emphasizes that it's not the exercise that's bad for fertility; it's very low fat in our body (low BMI) that's not good for fertility.

(Offset 8:16) If excess sex hormones cause fertility problems, how may we get rid of them?

Summary of Dr Barnard's response: Our liver is constantly filtering our blood — it flushes estrogens via bile duct into intestines… but… if our diet is low fiber, these estrogens are re-absorbed via intestinal walls back into the blood stream! This re-absorbed estrogen works its way back into the liver and the cycle repeats. This way, estrogen keeps circulating in our body. Summary: if our diet is low fiber, our estrogen levels rise.

Relieving Yourself of Excess Estrogen (4 mins, 2011) by Dr Greger explains how fiber intake helps our body release estrogen via fecal matter (and when fiber intake is low, this mechanism breaks down).

(Offset 10:07) How much fiber should we consume?

Summary of Dr Barnard's reply: On average, Americans eat 15-16 grams a day. Many people recommend 25-30 grams. Dr Barnard argues 40 or higher.

[Dr Greger has several videos on fiber intake. Here is a sampling: Dr Burkitt's F-Word Diet (4 mins, 2014), How Much Fiber Should You Eat Every Day? (2017; Dr Greger mentions at least 25 grams of soluble fiber and 47 grams of insoluble fiber to really prevent stroke), Were We Wrong About Fiber? (2018), and several videos on microbiome and gut health.]

Which foods contribute most fiber? Dr Barnard explains that fiber is 'plant roughage'. Animal products don't have any fiber! Among plant sources, {bean, peas, lentils} are fiber champions. Starchy root veggies and green leafy veggies come next. Then fruits. Finally, whole grains.

Estrogen needs to be in a "sweet spot" for fertility. Not too low, not too high. Our body eliminates extra estrogen via intestines… but only if we consume sufficient quantities of fiber. If we're consuming a low fiber or very low fiber diet, our system is not able to eliminate the extra estrogen accumulating in our body.

(Offset 12:20) What were the studies at Tufts University, UCLA and American Foundation about about?

Summary of Dr Barnard's response: Historically, estrogen in women was first studied from cancer perspective: high estrogen levels are associated with cancer. Dr Barnard summarizes Tufts University, UCLA and American Foundation studies in this area. He finally emphasizes two points: (a) high fiber, and (b) low fat. If we consume a diet impoverished in fiber or high in fat, our estrogen levels rise. Dr Barnard mentions that experiments have demonstrated these effects: If we introduce beans, peas and lentils (the best sources for dietary fiber) into our diet, estrogen levels decrease. If we introduce fats (from any source) into our diet, our estrogen levels increase.

(Offset 14:35) What is the relationship between dairy products and fertility?

Summary of Dr Barnard's reply: Dairy has no fiber, it's high calories, high fat and has plenty of sugars. Cows make estrogen which gets into their milk. Pregnant cows have much higher levels of estrogen. Now these estrogens in milk are in trace amounts but when dairy is converted into cheese, estrogen levels are higher ("estrogens go with the fats"). Women with breast cancer have much higher rates of mortality if they consume cheese or any other high fat dairy products.

[Dr Greger's videos on the subject: The Effects of Hormones in Milk on Infertility in Women (6 mins, 2020), The Effects of Hormones in Dairy Milk on Cancer (5 mins, 2019)]

(Offset 17:27) What did Daniel Cramer discover?

Summary of Dr Barnard's response: Daniel Cramer studied the relationship between dairy consumption and infertility. Dr Barnard summarizes his work, especially the hypothesis that galactase (a sugar) in milk is the reason for reduced fertility. Women with lower milk intake tend to be fertile longer and have lower risk of ovarian cancer too.

(Offset 21:52) Shouldn't all of us be lactose intolerant?

In general, mammals become lactose intolerant after they stop drinking mother's milk. Starting around age 6, we (humans) become lactose intolerant (because there is no need to digest mother's milk any more). Worldwide, incidence of lactose intolerance is high, especially in African and Asian populations. However, in European (Caucasian / white) populations, lactose intolerance is low incidence due to a genetic mutation.

(Offset 24:51) Can estrogens in dairy affect men's reproductive abilities?

Summary of Dr Barnard's response: More dairy ⇒ lower sperm counts. More cheese ⇒ worse sperm counts. Estrogen is concentrated in cheese. [Dr Greger's videos on the subject: The Role of Diet in Declining Sperm Counts (4 mins, 2014), Dairy Estrogen & Male Fertility (5 mins, 2014), Male Fertility & Diet (5 mins, 2013), Dairy & Sexual Precocity (4 mins, 2010)]

(Offset 27:08) Does exercise help fertility?

Yes, exercise boosts fertility. But low BMI (16-17) leads to fertility problems; Dr Barnard reminds us that it's the low fat in body, not exercise.

(Offset 27:58) What causes morning sickness?

Summary of Dr Barnard's response: Dr Barnard explains a common intervention for morning sickness called BRAT (bananas, rice, applesauce, tea/toast) — all plant-based foods.

A theory has evolved: a baby is only half a woman's DNA; the other half ('foreign DNA') comes from a man. Progestorone in the woman's body weakens the immune system a little bit so that she doesn't reject the baby. A weakened immune system makes us more vulnuerable to bacterial infections. So instinctually, a pregnant woman avoids unhealthy, potentially contaminated foods which may cause bacterial infections. Now meat has fecal bacteria. And meat is one of the big triggers for morning sickness. [For a detailed explanation of this theory, see Dr Greger's video: Morning Sickness May Protect Mother and Child (5 mins, 2016)]

Vegan pregnancies have fewer complications than other pregnancies [Dr Greger's video on the subject: Why Do Vegan Women Have 5x Fewer Twins? (4 mins, 2014)] Their complications are primarily in addressing family and extended family's concern who are (unnecessarily) worried if we are getting enough proteins, etc.

(Offset 32:42) What role does estrogen play in the menstrual cycle?

Summary of Dr Barnard's response: At the beginning of the month, estrogen levels rise and the lining of the uterus (also known as endometrium) thickens. Towards the end of the month, menstrual flow = endometrial lining discharge.

If estrogen levels are too high in the blood, endometrial lining is thicker than usual. Towards the end of the month, the endometrial layer starts producing maladjusted chemicals called prostaglandins that cause cramping and pain. Okay, so how may we have thinner endometrial lining? Through normal estrogen levels. How? Consume more fiber, cut down on fat.

Dr Barnard explains a study in which women who had moderate to severe cramps (some were on 'fistfuls of ibuprofen') assigned to healthy low fat plant-based diet or assigned to a placebo. PMS symptoms (physical symptoms: bloating, water retention reduced; mood changes and behavioral changes reduced; less pain; shorter duration of pain).

[Dr Greger's video on the subject: Dietary Treatment for Painful Menstrual Periods (3 mins, 2013); Dr Greger's article: Treating Menstrual Pain With Diet (2024)]

(Offset 39:08) Endometriosis

Dr Barnard says that many women are told that pain is their fault (!) The real culprit is likely the foods we are consuming.

Endometriosis is a common cause of pain. What is endometriosis? Cells that are normally found in the endometrium (in the lining of the uterus) start growing outside of it: in ovaries and fallopian tubes, for example. Explanation: it appears that these cells have somehow escaped the uterus, traveled to the fallopian tubes and the abdominal cavity where they swell. These cells can attach to other parts of the body, for example, the intestinal tract.

(Offset 40:55) What about fibroids? Can diet help?

Summary of Dr Barnard's response: Fibroids are lumps of muscular tissue in the wall of the uterus. High levels of estrogen are associated with fibroids.

[Dr Greger's videos on the subject: The Best Diet for Fibroids (8 mins, 2017), The Best Food for Fibroids (7 mins, 2017) — a specific food mentioned by Dr Greger in these videos is green tea.]

(Offset 42:23) Can high fiber diet help with menopause?

Summary of Dr Barnard's response: In Japan, before Westernization, there was no word for hot flashes. After Westernization, hot flashes became commonplace. Working hypothesis: women's bodies get used to high levels of estrogen; at menopause estrogen levels drop (Dr Barnard calls it the "crash and burn" of estrogen levels) resulting in withdrawal symptoms (hot flashes).

(Offset 43:58) Hormone replacement therapy for stabilizing hormones?

Summary of Dr Barnard's response: Hormone Replacement Therapy only defers the onset of hot flashes; it also increases cancer risk. [Dr Greger has a video on the subject: How Did Doctors Not Know About the Risks of Hormone Therapy? (7 mins, 2016)]

[Whales and humans are the only species in which females live beyond menopause] So Dr Barnard and the Jeanne Schumacher engage in a discussion: what's the evolutionary reason for human life beyond menopause: grandmothers helping the younger generations?

(Offset 46:36) Does early morning plant-based protein intake act as a mood stabilizer?

Summary of Dr Barnard's response: Introducing a plant-based protein early in the day and early in every meal helps. For example, grilled tempeh or grilled tofu or beans or legumes in breakfast; similarly, having such foods earlier in any meal is helpful.