Q: Japan's 90-year-old body builder, Toshisuke Kanazawa, looks muscular
but showing signs of aging. How could his diet be improved?
(
Google Gemini) "Toshisuke Kanazawa’s longevity and ability to continue competing as a bodybuilder at 90 years old are extraordinary. His traditional, plant-forward Japanese diet - centring on brown rice, natto (fermented soybeans), miso soup (sometimes with eggs), and supplemental protein - provides excellent gut health, antioxidants, and steady energy.
However, looking muscular while also showing advanced skin aging and structural changes is a natural part of nonagenarian biology. While his diet works remarkably well for his overall health, it has a few nutritional blind spots that could be optimized to better support skin elasticity, tissue repair, and senior muscle maintenance:
1. Increase Micronutrient and Antioxidant Diversity
The Current Habit:
Kanazawa’s meals are heavily repetitive, primarily consisting of brown rice with furikake, natto, and miso soup. While wholesome, it lacks a wide variety of colorful fruits and vegetables.
The Improvement: Incorporating a broader spectrum of colorful produce (such as dark leafy greens, berries, citrus fruits, and orange/red vegetables) would provide higher levels of Vitamin C, carotenoids, and polyphenols.
Vitamin C is especially critical because it is a mandatory cofactor for collagen synthesis, which helps improve skin resilience, joint health, and connective tissue integrity.
2. Introduce Healthy Fats for Skin and Joint Health
The Current Habit:
His diet is very low in dietary fats, as he avoids fish and meat and eats a very lean, grain-and-legume-based menu.
The Improvement: Adding healthy, plant-based fats - such as avocado, extra virgin olive oil, walnuts, chia seeds, or flaxseeds - would supply essential fatty acids (like Omega-3s).
Healthy fats help maintain cell membrane integrity, support joint lubrication, and keep the skin hydrated and plump, reducing the sunken or heavily lined appearance often associated with extreme leanness in older age.
3. Optimize Amino Acid Profiles and Protein Distribution
The Current Habit: He relies on natto, eggs, and three protein supplements a day to meet his muscle-building needs.
The Improvement: As we age, the body becomes resistant to anabolic stimuli (sarcopenia), requiring higher thresholds of leucine and total protein per meal to stimulate muscle protein synthesis. While his supplements help, ensuring that his protein sources are high in the amino acid leucine (such as adding soy isolates, dairy like Greek yogurt or cottage cheese if he consumes dairy, or high-quality pea/rice protein blends) can better combat age-related muscle wasting without overloading his digestive system with large volumes of food.
4. Ensure Adequate Hydration and Electrolyte Balance
The Current Habit: Older adults naturally experience a declining sense of thirst, and consuming heavy powders or dry grain-heavy meals requires meticulous hydration.
The Improvement: Emphasizing hydrating, water-rich foods (like broths, cucumber, melon, and steamed vegetables) alongside consistent water intake supports skin turgor (elasticity) and optimal cellular function during heavy training.
Summary
Kanazawa’s discipline is a masterclass in healthy aging, but
shifting his diet from a strictly minimalist routine to a more colorful, fat-inclusive, and micronutrient-dense plant-based approach could better support skin vitality and reduce the physical markers of rapid aging while maintaining his impressive muscle mass."

Speaking of Vitamin C ...
Q: Does unpeeled citrus, cut into wedges, improve these dietary nutrients
since bites of pith can be included when consumed?
(
GG) "Eating unpeeled citrus wedges can indeed increase your intake of certain nutrients and beneficial plant compounds found primarily in the peel and pith (white, spongy inner layer).
Including bites of pith when consuming citrus wedges can boost several nutritional components:
Citrus pith is exceptionally rich in soluble fiber, particularly pectin. Pectin acts as a prebiotic, supports digestive health, and can help moderate blood sugar and cholesterol levels; the juice and flesh contain the bulk of the Vitamin C.
Using chilled citrus wedges as a post-meal 'dessert' is a fantastic, refreshing habit! It gives you that sweet-tart finish without heavy sugars or processed ingredients:
- Natural Digestion Support: Citrus fruits contain natural acids and enzymes that help stimulate digestive juices, making a few wedges a light, refreshing palate cleanser after a heavier meal.
- Curbing Sugar Cravings: The bright, citrusy burst hits your taste buds and signals to your brain that the meal is officially over, which naturally helps deter cravings for heavy sweets or desserts.
- Iron Absorption Booster: If your meal included plant-based iron sources (like spinach, beans, or lentils), the Vitamin C in these citrus wedges significantly boosts how much of that iron your body can actually absorb."
Rod
