Also, we had net investment losses from our normal trading activity in the portfolio, given the rising interest rate environment. In addition, we had net derivative losses due to higher interest rates and strengthening of the US dollar versus multiple currencies, primarily the Chilean peso and yen. That said, net derivative losses were partially offset this quarter by market risk benefit or MRB remeasurement gains due to higher interest rates. Overall, the portfolio remains well positioned. Credit losses continued to be modest and the hedging program performed as expected. The table on page four provides highlights of our Annual Actuarial Assumption Review and other insurance adjustments with a breakdown of the adjusted earnings and net income impact by business.
Overall, the impact to adjusted earnings and net income was negligible. In Group Benefits, we had a favorable impact from assumption changes in individual disability, primarily due to lower incident rates and favorable recoveries. In Retirement and Income Solutions or RIS, we lowered our near-term assumption for mortality improvement which resulted in an economic benefit, given the longevity products in this business. In Asia, the net unfavorable impact was due to lapse rate changes across life and accident & health products in Japan, as well as lowering lapse rates and expected fund returns for variable life products in Korea. On page five, you can see the third quarter year-over-year comparison of adjusted earnings by segment, excluding notable items associated with the Annual Assumption Review and other insurance adjustments in both periods.
Adjusted earnings were $1.5 billion up 35% and 33% on a constant currency basis. The primary drivers were higher variable investment income or VII, strong recurring interest margins and favorable underwriting margins. Adjusted earnings per share were $1.95, up 43% and 40% on a constant currency basis. Moving to the businesses, starting with the US. Group Benefits adjusted earnings were $483 million, up 16% versus the prior year period. The key drivers were favorable underwriting margins and solid volume growth. The Group Life mortality ratio was 83.6% favorable to the prior year quarter of 85.7% and below the bottom end of our annual target range of 85% to 90%. As a reminder, mortality results tend to be more favorable in the third quarter, so we would expect our Group Life ratio to be back within the 85% to 90% range in the fourth quarter and full year of 2023.
Regarding non-medical health, the interest adjusted benefit ratio was 69% in the quarter or 70.4% excluding the favorable impact related to the annual assumption review that I mentioned earlier and at the low end of its annual target range of 70% to 75%. Turning to the top line, Group Benefits adjusted PFOs were up 3% year-over-year. Taking participating contracts into account which dampened growth by roughly 1%, the underlying PFO were up approximately 4% year-over-year, primarily due to solid growth across most products. Including continued strong momentum in voluntary and was within our 2023 target growth range of 4% to 6%. In addition Group Benefit sales were up 11% year-to-date driven by strong growth across most products and markets. RIS adjusted earnings were $409 million, up 60% year-over-year.
The primary driver was favorable investment margins due to higher recurring interest and variable investment income. Solid volume growth year-over-year also contributed to the strong performance. RIS investment spreads were 130 basis points. Spreads excluding VII were 138 basis points, up 26 points versus Q3 of 2022 primarily due to higher interest rates as well as income from in-the-money interest rate caps. RIS adjusted PFOs excluding pension risk transfers were up 75% primarily driven by strong sales of structured settlement products, growth in UK longevity reinsurance, and postretirement benefits. With regards to PRT we added transactions worth approximately $1.5 billion in Q3 of 2023, bringing our year-to-date total to roughly $3.5 billion.
Moving to Asia. Adjusted earnings were $369 million, up 23% and 25% on a constant currency basis, primarily due to higher investment margins. Asia’s key growth metrics were solid as journal on assets under management on an amortized cost basis as well as sales both grew 5% year-over-year on a constant currency basis, driven by growth across most of the region. In Japan, sales on a constant currency basis were up 3% year-over-year, driven by strong life sales due to the ongoing momentum of a single premium FX Life product that was relaunched April 1st of this year. In other Asia sales on a constant currency basis were up 8% year-over-year, primarily driven by strong life sales in Korea in advance of a prospective regulatory change that took place on September 1st, that impacts low cash value whole life products.
Looking ahead, while we anticipate Asia year-over-year sales will decline in the fourth quarter, we expect full year 2023 sales growth to be at the top end or exceed our annual guidance range of mid- to high single-digits. Latin America adjusted earnings were $199 million up 26% and 8% on a constant currency basis primarily due to solid volume growth and favorable underwriting margins. Latin America’s topline continues to perform well as adjusted PFOs were up 32% and 16% on a constant currency basis. And sales were also up 16% on a constant currency basis driven by strong growth in Mexico and Chile and solid persistency across the region. EMEA adjusted earnings were $70 million, up 43% and 40% on a constant currency basis primarily due to higher volume growth recurring interest margins as well as underwriting margins running favorable to expectations.
This was partially offset by less favorable expense margins year-over-year. EMEA adjusted PFOs were up 9% on both a reported and constant currency basis and sales were up 20% on a constant currency basis, reflecting strong growth across the region. MetLife Holdings adjusted earnings were $206 million, up 23%, primarily driven by higher variable investment income. Corporate and other adjusted loss was $262 million compared to an adjusted loss of $258 million in the prior year quarter. Higher expenses, including interest on incremental debt, were partially offset by higher net investment income. The company’s effective tax rate on adjusted earnings in the quarter was approximately 23% and within our 2023 guidance of 22% to 24%. On page 6, this chart reflects our pre-tax variable investment income for the prior five quarters including $179 million in Q3 of 2023.
