Blog

It’s estimated that 29% of Americans experience depression at one time or another. Most people would rather avoid antidepressant medication because of its side effects — so Dr. Terry Shintani, MD, a Harvard-trained physician, nutritionist, and author of The Peace Diet, shares a surprising natural option backed by research.

The research

A study of 13,626 people found that those who consumed the highest amounts of a particular superfood had a 57% lower risk of depression compared to those who consumed the least. The surprise? That superfood is dark chocolate.

A few important caveats

This was an observational study, so it shows an association rather than proof of cause and effect. It’s also worth watching how much added sugar comes along with the chocolate you choose. That said, other research suggests the bioflavonoids found in chocolate have real antidepressant potential.

Beyond chocolate: the bigger picture

Dr. Shintani notes that overall diet quality matters too — avoiding junk food and eating foods rich in bioflavonoids, fiber, and prebiotics helps support the gut microbiome, which plays a role in producing the neurotransmitters that influence mood. Exercise and optimizing hormones such as thyroid, sex hormones, and vitamin D can also help significantly.

The takeaway

A square or two of dark chocolate, as part of an overall healthy lifestyle, may offer a natural mood boost. For more tips on natural health, get Dr. Shintani’s free eBook, Health Secrets, at peacediet.org.

Sources: Chocolate consumption and depressive symptoms in a US adult population — Nguyen et al., Depression and Anxiety, 2019; Gallup — U.S. depression rate data, 2026; NLM Native Voices

Dr. Terry Shintani, MD, a Harvard-trained physician and nutritionist, has been reversing diabetes naturally for over 30 years — using a high-carb diet. The key, he explains, is a nutrient found in some high-carb foods that slows the absorption of sugar: soluble fiber.

How soluble fiber helps control blood sugar

Soluble fiber supports blood sugar control in four important ways:

1. It holds onto sugar and slows its absorption
2. It helps create a mucin layer that protects the intestines and supports proper nutrient sorting
3. It supports a healthy gut microbiome
4. It helps you feel full, so you end up eating fewer calories overall

5 good sources of soluble fiber

1. Oats
2. Chia seeds
3. Flax seeds
4. Beans
5. Lentils

The takeaway

To start getting healthier now, consider eating more of these soluble-fiber-rich foods. For a list of 15 foods and the amount of soluble fiber in each, get Dr. Shintani’s free eBook, Health Secrets, at peacediet.org.

Sources: NLM Native Voices; additional NIH/PubMed citations on soluble fiber and glycemic control available on request.

Most people fear dementia more than they fear death — so prevention of brain decline matters at any age, according to Dr. Terry Shintani, MD, a Harvard-trained physician and nutritionist.

The research

Researchers studying factors that prevent cognitive decline found a surprising result: people who ate mushrooms two or more times a week had 57% less mild cognitive impairment compared to those who ate mushrooms less than once a week.

Why mushrooms may protect the brain

Researchers believe this effect may be due to ergothioneine, a neuroprotective nutrient found in high amounts in mushrooms. Ergothioneine appears to help protect brain and nerve cells against oxidative damage, and may also help promote the growth of new brain cells.

The takeaway

To help cut cognitive impairment and stay sharp, consider eating more mushrooms. For a list of 15 supplements for brain health, get Dr. Shintani’s free eBook, Health Secrets, at peacediet.org.

Sources: Mushroom consumption and cognitive impairment — National University of Singapore study, 2019; Ergothioneine: antioxidative, neuroprotective compound from mushrooms; NLM Native Voices

Alpha-lipoic acid (ALA) is a powerful antioxidant that’s earned a place among Dr. Terry Shintani’s favorite “super nutrients” — and the research behind it backs that up.

Blood sugar and blood pressure

ALA is well known for helping control blood sugar, and clinical research also supports a blood-pressure-lowering effect: a 2023 systematic review and dose-response meta-analysis of randomized controlled trials found that ALA supplementation significantly reduced blood pressure in adults.

Diabetic neuropathy

ALA has one of the strongest evidence bases of any natural compound for diabetic neuropathy. Multiple clinical trials and meta-analyses have found it helps prevent and treat nerve damage in people with diabetes, largely attributed to its ability to reduce oxidative stress and inflammation affecting the nerves.

Cholesterol

Research has also linked ALA supplementation to improvements in cholesterol levels.

Early cancer research

More recent laboratory (in vitro) research suggests ALA may slow the growth of several types of cancer cells, including breast, colon, and other cell lines, and some studies suggest it may work synergistically with chemotherapy drugs. It’s important to note this research is still in early, preclinical stages — these are lab and cell-culture studies, not evidence that ALA treats cancer in humans.

Where to find it — and typical dosage

ALA is found naturally in foods like carrots, spinach, beets, and broccoli, and is also available as a supplement. A typical dose used in studies is around 600 mg, up to three times per day — but check with your doctor before starting any new supplement, especially if you’re managing diabetes or take blood sugar or blood pressure medication.

For more tips on controlling blood sugar naturally, get Dr. Shintani’s free eBook, Health Secrets, at peacediet.org.

Sources: Alpha-lipoic acid and blood pressure — systematic review/meta-analysis, Frontiers in Cardiovascular Medicine, 2023; Efficacy of alpha-lipoic acid in diabetic neuropathy — PubMed; Lipoic acid synergizes with antineoplastic drugs in colorectal cancer, MDPI Cells, 2019; NLM Native Voices

A striking observation from the animal kingdom may offer clues about preventing Alzheimer’s in humans. According to Dr. Terry Shintani, MD, a Harvard-trained physician and nutritionist, Dr. Rudolph Tanzi — chair of the Alzheimer’s research group at Harvard — has pointed out that meat-eating animals tend to develop Alzheimer’s-related brain pathology if they live long enough, while herbivores largely do not. (This specific observation is being confirmed with Dr. Shintani before a precise citation is added.)

While that observation comes from animal studies, recent human research points in the same direction.

Vegetarian diets and dementia risk

A 2022 study published in the journal Nutrients followed a cohort of Taiwanese adults and found that vegetarians had about a 33% lower risk of developing dementia compared to meat eaters.

Processed meat and dementia risk

A 2024 study presented at the Alzheimer’s Association International Conference found that eating about 1 ounce of processed meat per day was associated with a 14% higher risk of dementia, compared to eating very little processed meat. The same study found that replacing that ounce of processed meat with beans or nuts was associated with a 20% lower risk of dementia.

The takeaway

To help preserve brain function, consider eating less meat — particularly processed meat — and more plant-based foods like beans, nuts, and vegetables.

For more tips on brain health and longevity, get Dr. Shintani’s free eBook, Health Secrets, at peacediet.org.

Sources: Tsai et al., “Taiwanese Vegetarians Are Associated with Lower Dementia Risk,” Nutrients, 2022; 2024 Alzheimer’s Association International Conference — processed meat and dementia risk; NLM Native Voices

What you drink matters for your brain, too. Dr. Terry Shintani, MD, a Harvard-trained physician and nutritionist, shares six beverages worth adding to your routine for memory and cognitive support.

1. Green Tea
Green tea is rich in antioxidants, including catechins and L-theanine, which help protect the brain and support cognitive function.

2. Coffee
Coffee has been linked to a lower risk of Alzheimer’s disease, an effect attributed partly to caffeine and partly to the neuroprotective properties of chlorogenic acid. (Specific risk-reduction figures vary by study — this post will be updated with Dr. Shintani’s preferred source once confirmed.)

3. Beet Juice
Beet juice is known to raise nitric oxide levels in the body, which helps improve blood circulation to the brain.

4. Turmeric Tea with Black Pepper
This combination provides powerful anti-inflammatory protection for the brain — black pepper helps the body absorb turmeric’s active compound, curcumin.

5. Kombucha
As a probiotic beverage, kombucha helps preserve the gut flora responsible for producing neurotransmitters that support brain function.

6. Hibiscus Tea
Recent research has found that hibiscus tea contains gossypetin, a compound shown (in animal studies) to stimulate microglia — the brain’s cleanup cells — to help clear beta-amyloid protein, a hallmark of Alzheimer’s disease. While promising, this research is still in early stages.

The takeaway

From antioxidant-rich teas to circulation-boosting beet juice, these beverages offer simple, daily ways to support brain health. For more tips on health and longevity, get Dr. Shintani’s free eBook, Health Secrets, at peacediet.org.

Sources: Gossypetin and amyloid-beta clearance study; NLM Native Voices; additional coffee/Alzheimer’s citation pending confirmation.

Looking for natural ways to support mental energy and manage stress? According to Dr. Terry Shintani, MD, a Harvard-trained physician and nutritionist, these five herbs are among the most well-studied for brain and stress support.

1. Sage
As its name suggests, sage has long been used to enhance brain power and memory. Research suggests one of its effects is as an acetylcholinesterase inhibitor — meaning it helps preserve acetylcholine, a neurotransmitter important for brain energy and memory.

2. Rhodiola
Rhodiola is thought to help by managing neurotransmitters such as norepinephrine, serotonin, and dopamine — all involved in mood and mental energy.

3. Ashwagandha
This adaptogenic herb helps control cortisol levels and may modestly increase testosterone, supporting the body’s resilience to stress.

4. Holy Basil (Tulsi)
Holy basil also helps regulate cortisol levels, making it another helpful tool for managing stress.

5. Siberian Ginseng (Eleuthero)
Also known as eleuthero, this herb contains compounds called eleutherosides, which appear to boost mental energy by increasing oxygen utilization in the body.

The takeaway

These five herbs work through different pathways — some by supporting key brain neurotransmitters, others by helping regulate the body’s stress hormone, cortisol. For a fuller list of stress-support herbs and more natural health tips, get Dr. Shintani’s free eBook, Health Secrets, at peacediet.org.

Sources: NLM Native Voices; further NIH/PubMed citations on sage, rhodiola, ashwagandha, holy basil, and eleuthero to be added if Dr. Shintani wants specific study references included.

Diabetes prevention may come down to simple, everyday food choices. According to Dr. Terry Shintani, MD, a Harvard-trained physician and nutritionist, the research points to four foods worth eating more of — and two worth cutting back on.

Foods associated with a lower risk of diabetes:

A large pooled study tracking over 194,000 people found that higher whole grain intake was associated with a 29% lower risk of type 2 diabetes. Other research has linked:

• Whole fruit — especially blueberries, grapes, and apples, eaten at least twice a week — to up to 23% less diabetes
• Green vegetables to 14% less diabetes
• Legumes and lentils to 35% less diabetes

Foods associated with a higher risk of diabetes:

Ultra-processed food was associated with a 31% higher risk of diabetes. Separately, a Harvard study found that people who ate the most red meat — whether processed or unprocessed — had a 62% higher risk of diabetes compared to those who ate the least.

The takeaway

To help lower your risk of diabetes, consider eating more whole grains, vegetables, fruit, and legumes, while cutting back on red meat and ultra-processed food.

For more science-backed nutrition guidance, get Dr. Shintani’s free eBook, Health Secrets, at peacediet.org.

Sources: BMJ — whole grain intake and type 2 diabetes; BMJ — fruit/vegetable intake and type 2 diabetes; Harvard Gazette — whole fruit and diabetes risk; FoodNavigator — legumes and diabetes risk; Deseret News — Harvard red meat study; Glycemic Index Foundation — ultra-processed food and diabetes; NLM Native Voices

At the World Congress of Anti-Aging Medicine, one researcher made a striking observation: every single chronic disease is characterized by decreased blood flow. If that circulation can be restored, it may be possible to correct many chronic conditions. Dr. Terry Shintani explains why this matters — and what you can do about it.

One of the biggest trends in health research is the role of macro- and micro-circulation in the chronic diseases of aging. Conditions linked to reduced blood flow include:

1. High blood pressure
2. Vascular dementia
3. Diabetes
4. Kidney disease
5. Erectile dysfunction
6. Peripheral neuropathy
7. Digestive diseases

The compound at the center of this research is nitric oxide, which is known to relax blood vessels, lower blood pressure, and improve circulation. Researchers have documented that nitric oxide production gradually declines as we age — raising the possibility that many, or most, of these diseases are related to a lack of it. This also suggests nitric oxide may play a role in reversing these conditions.

About Dr. Terry Shintani
Dr. Terry Shintani, MD, JD, MPH, is a Harvard-trained physician and nutritionist, and the creator of the Peace Diet and the Waianae Diet. His mission is to help people achieve great health for up to 120 years.

For a list of 20 foods high in nitric oxide, get Dr. Shintani’s free eBook, Health Secrets, at peacediet.org.

Sources:

• NLM Native Voices
• NIH / PubMed: search “nitric oxide circulation chronic disease aging” for current research

Many people are looking for natural ways to support weight loss, blood sugar control, and blood pressure — without turning straight to prescription medication. Dr. Terry Shintani points to one nutrient that keeps coming up in the research: chlorogenic acid. While studies on it are inconsistent, a meta-analysis of several trials suggests it may help with:

1. Weight control
2. Blood sugar control
3. Cholesterol control
4. Blood pressure control

There’s even evidence that chlorogenic acid stimulates the GLP-1 receptor — the same mechanism behind the popular weight-loss and blood-sugar drug Ozempic.

Chlorogenic acid is commonly sold as a green coffee bean extract, but it’s also naturally present in many everyday foods, including:

1. Apples
2. Pears
3. Eggplants
4. Blueberries
5. Tomatoes
6. Strawberries
7. Carrots
8. Potatoes

If weight loss, blood sugar, or blood pressure control are on your goal list, working more of these foods into your week is a simple, natural place to start.

About Dr. Terry Shintani
Dr. Terry Shintani, MD, JD, MPH, is a Harvard-trained physician and nutritionist, and the creator of the Peace Diet and the Waianae Diet. His mission is to help people achieve great health for up to 120 years.

Get Dr. Shintani’s free eBook, Health Secrets, at peacediet.org.

Sources:

• NLM Native Voices
• NIH / PubMed: chlorogenic acid and metabolic health (search “chlorogenic acid GLP-1 weight blood pressure” on PubMed for current meta-analyses)